* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
[not found] <4CD538CA.8010901@xs4all.nl>
@ 2010-11-07 22:07 ` Andi Kleen
2010-11-07 23:03 ` Andreas Schwab
0 siblings, 1 reply; 52+ messages in thread
From: Andi Kleen @ 2010-11-07 22:07 UTC (permalink / raw)
To: Jim; +Cc: Linux Kernel Mailing List, gcc
Jim <jim876@xs4all.nl> writes:
> After upgrading my Dell laptop, both OS+kernel the i8k interface was giving
> nonsensical output. As it turned out it's not the kernel but compiler
> upgrade which broke this.
>
> Guys at Archlinux have found the underlying cause (but don't seem to have
> submitted a patch yet):
> https://bbs.archlinux.org/viewtopic.php?pid=780692#p780692
> gcc seems to optimize the assembly statements away.
>
> And indeed, applying this patch makes the i8k interface work again,
> i.e. replacing the asm(..) construct by asm volatile(..)
The compiler really should not optimize the asm away, because
it has both input and output arguments which are later used.
"asm volatile" normally just means "don't move significantly"
I tested it with gcc version 4.5.0 20100604 [gcc-4_5-branch revision
160292] (SUSE Linux)
and the asm statement is there for both 32bit and 64bit
(with an allmodconfig, with both -O2 and -Os)
If gcc 4.5.1 broke that over 4.5.0 you should really file a bug report
for the compiler, it seems like a serious regression in 4.5.1
-Andi
--
ak@linux.intel.com -- Speaking for myself only.
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-07 22:07 ` gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ? Andi Kleen
@ 2010-11-07 23:03 ` Andreas Schwab
2010-11-08 0:36 ` Andi Kleen
2010-11-15 18:57 ` Jeff Law
0 siblings, 2 replies; 52+ messages in thread
From: Andreas Schwab @ 2010-11-07 23:03 UTC (permalink / raw)
To: Andi Kleen; +Cc: Jim, Linux Kernel Mailing List, gcc
Andi Kleen <andi@firstfloor.org> writes:
> Jim <jim876@xs4all.nl> writes:
>
>> After upgrading my Dell laptop, both OS+kernel the i8k interface was giving
>> nonsensical output. As it turned out it's not the kernel but compiler
>> upgrade which broke this.
>>
>> Guys at Archlinux have found the underlying cause (but don't seem to have
>> submitted a patch yet):
>> https://bbs.archlinux.org/viewtopic.php?pid=780692#p780692
>> gcc seems to optimize the assembly statements away.
>>
>> And indeed, applying this patch makes the i8k interface work again,
>> i.e. replacing the asm(..) construct by asm volatile(..)
>
> The compiler really should not optimize the asm away, because
> it has both input and output arguments which are later used.
> "asm volatile" normally just means "don't move significantly"
The asm fails to mention that it modifies *regs.
Andreas.
--
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756 01D3 44D5 214B 8276 4ED5
"And now for something completely different."
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-07 23:03 ` Andreas Schwab
@ 2010-11-08 0:36 ` Andi Kleen
2010-11-08 10:54 ` Richard Guenther
2010-11-15 18:57 ` Jeff Law
1 sibling, 1 reply; 52+ messages in thread
From: Andi Kleen @ 2010-11-08 0:36 UTC (permalink / raw)
To: Andreas Schwab; +Cc: Jim, Linux Kernel Mailing List, gcc
Andreas Schwab <schwab@linux-m68k.org> writes:
>
> The asm fails to mention that it modifies *regs.
It has a memory clobber, that should be enough, no?
Besides in any case it cannot be eliminated because it has
valid non dead inputs and outputs.
-Andi
--
ak@linux.intel.com -- Speaking for myself only.
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-08 0:36 ` Andi Kleen
@ 2010-11-08 10:54 ` Richard Guenther
2010-11-08 11:20 ` Andi Kleen
2010-11-15 19:11 ` Jeff Law
0 siblings, 2 replies; 52+ messages in thread
From: Richard Guenther @ 2010-11-08 10:54 UTC (permalink / raw)
To: Andi Kleen; +Cc: Andreas Schwab, Jim, Linux Kernel Mailing List, gcc
On Mon, Nov 8, 2010 at 12:03 AM, Andi Kleen <andi@firstfloor.org> wrote:
> Andreas Schwab <schwab@linux-m68k.org> writes:
>>
>> The asm fails to mention that it modifies *regs.
>
> It has a memory clobber, that should be enough, no?
No. A memory clobber does not cover automatic storage.
Btw, I can't see a testcase anywhere so I just assume Andreas got
it right as usual.
Richard.
> Besides in any case it cannot be eliminated because it has
> valid non dead inputs and outputs.
>
> -Andi
> --
> ak@linux.intel.com -- Speaking for myself only.
>
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-08 10:54 ` Richard Guenther
@ 2010-11-08 11:20 ` Andi Kleen
2010-11-08 11:48 ` Richard Guenther
` (2 more replies)
2010-11-15 19:11 ` Jeff Law
1 sibling, 3 replies; 52+ messages in thread
From: Andi Kleen @ 2010-11-08 11:20 UTC (permalink / raw)
To: Richard Guenther; +Cc: Andreas Schwab, Jim, Linux Kernel Mailing List, gcc
Richard Guenther <richard.guenther@gmail.com> writes:
> On Mon, Nov 8, 2010 at 12:03 AM, Andi Kleen <andi@firstfloor.org> wrote:
>> Andreas Schwab <schwab@linux-m68k.org> writes:
>>>
>>> The asm fails to mention that it modifies *regs.
>>
>> It has a memory clobber, that should be enough, no?
>
> No. A memory clobber does not cover automatic storage.
That's a separate problem.
> Btw, I can't see a testcase anywhere so I just assume Andreas got
> it right as usual.
An asm with live inputs and outputs should never be optimized
way. If 4.5.1 started doing that it's seriously broken.
-Andi
--
ak@linux.intel.com -- Speaking for myself only.
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-08 11:20 ` Andi Kleen
@ 2010-11-08 11:48 ` Richard Guenther
2010-11-08 11:54 ` Paul Koning
2010-11-08 12:36 ` Michael Matz
2010-11-08 20:20 ` Dave Korn
2 siblings, 1 reply; 52+ messages in thread
From: Richard Guenther @ 2010-11-08 11:48 UTC (permalink / raw)
To: Andi Kleen; +Cc: Andreas Schwab, Jim, Linux Kernel Mailing List, gcc
On Mon, Nov 8, 2010 at 12:20 PM, Andi Kleen <andi@firstfloor.org> wrote:
> Richard Guenther <richard.guenther@gmail.com> writes:
>
>> On Mon, Nov 8, 2010 at 12:03 AM, Andi Kleen <andi@firstfloor.org> wrote:
>>> Andreas Schwab <schwab@linux-m68k.org> writes:
>>>>
>>>> The asm fails to mention that it modifies *regs.
>>>
>>> It has a memory clobber, that should be enough, no?
>>
>> No. A memory clobber does not cover automatic storage.
>
> That's a separate problem.
>
>> Btw, I can't see a testcase anywhere so I just assume Andreas got
>> it right as usual.
>
> An asm with live inputs and outputs should never be optimized
> way. If 4.5.1 started doing that it's seriously broken.
Please provide a testcase, such asms can be optimized if the
outputs are dead.
Richard.
> -Andi
>
> --
> ak@linux.intel.com -- Speaking for myself only.
>
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-08 11:48 ` Richard Guenther
@ 2010-11-08 11:54 ` Paul Koning
2010-11-08 12:20 ` Jakub Jelinek
0 siblings, 1 reply; 52+ messages in thread
From: Paul Koning @ 2010-11-08 11:54 UTC (permalink / raw)
To: Richard Guenther
Cc: Andi Kleen, Andreas Schwab, Jim, Linux Kernel Mailing List, gcc
On Nov 8, 2010, at 6:20 AM, Richard Guenther wrote:
> On Mon, Nov 8, 2010 at 12:20 PM, Andi Kleen <andi@firstfloor.org> wrote:
>> Richard Guenther <richard.guenther@gmail.com> writes:
>>
>>> On Mon, Nov 8, 2010 at 12:03 AM, Andi Kleen <andi@firstfloor.org> wrote:
>>>> Andreas Schwab <schwab@linux-m68k.org> writes:
>>>>>
>>>>> The asm fails to mention that it modifies *regs.
>>>>
>>>> It has a memory clobber, that should be enough, no?
>>>
>>> No. A memory clobber does not cover automatic storage.
>>
>> That's a separate problem.
>>
>>> Btw, I can't see a testcase anywhere so I just assume Andreas got
>>> it right as usual.
>>
>> An asm with live inputs and outputs should never be optimized
>> way. If 4.5.1 started doing that it's seriously broken.
>
> Please provide a testcase, such asms can be optimized if the
> outputs are dead.
I don't know about 4.5, but I noticed that with 4.6 (trunk), testcasese like gcc.c-torture/compile/20000804-1.c optimize away the asm and all the operand generation except for -O0.
paul
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-08 11:54 ` Paul Koning
@ 2010-11-08 12:20 ` Jakub Jelinek
0 siblings, 0 replies; 52+ messages in thread
From: Jakub Jelinek @ 2010-11-08 12:20 UTC (permalink / raw)
To: Paul Koning
Cc: Richard Guenther, Andi Kleen, Andreas Schwab, Jim,
Linux Kernel Mailing List, gcc
On Mon, Nov 08, 2010 at 06:47:59AM -0500, Paul Koning wrote:
> I don't know about 4.5, but I noticed that with 4.6 (trunk), testcasese
> like gcc.c-torture/compile/20000804-1.c optimize away the asm and all the
> operand generation except for -O0.
That's fine, the asm isn't volatile and the output is not used.
Jakub
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-08 11:20 ` Andi Kleen
2010-11-08 11:48 ` Richard Guenther
@ 2010-11-08 12:36 ` Michael Matz
2010-11-08 20:20 ` Dave Korn
2 siblings, 0 replies; 52+ messages in thread
From: Michael Matz @ 2010-11-08 12:36 UTC (permalink / raw)
To: Andi Kleen
Cc: Richard Guenther, Andreas Schwab, Jim, Linux Kernel Mailing List, gcc
Hi,
On Mon, 8 Nov 2010, Andi Kleen wrote:
> Richard Guenther <richard.guenther@gmail.com> writes:
>
> > On Mon, Nov 8, 2010 at 12:03 AM, Andi Kleen <andi@firstfloor.org> wrote:
> >> Andreas Schwab <schwab@linux-m68k.org> writes:
> >>>
> >>> The asm fails to mention that it modifies *regs.
> >>
> >> It has a memory clobber, that should be enough, no?
> >
> > No. A memory clobber does not cover automatic storage.
>
> That's a separate problem.
>
> > Btw, I can't see a testcase anywhere so I just assume Andreas got
> > it right as usual.
>
> An asm with live inputs and outputs should never be optimized
> way. If 4.5.1 started doing that it's seriously broken.
You know the drill: testcase -> gcc.gnu.org/bugzilla/
(In particular up to now it's only speculation in some forum that the asm
really is optimized away, which I agree would be a bug, or if it isn't
merely that regs->eax isn't reloaded after the asm(), which would be
caused by the problem Andreas mentioned)
Ciao,
Michael.
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-08 11:20 ` Andi Kleen
2010-11-08 11:48 ` Richard Guenther
2010-11-08 12:36 ` Michael Matz
@ 2010-11-08 20:20 ` Dave Korn
2010-11-09 13:48 ` Michael Matz
2 siblings, 1 reply; 52+ messages in thread
From: Dave Korn @ 2010-11-08 20:20 UTC (permalink / raw)
To: Andi Kleen
Cc: Richard Guenther, Andreas Schwab, Jim, Linux Kernel Mailing List, gcc
On 08/11/2010 11:20, Andi Kleen wrote:
> An asm with live inputs and outputs should never be optimized
> way. If 4.5.1 started doing that it's seriously broken.
I don't see that. Consider:
void foo (void)
{
int x, y, z;
x = 23;
y = x + 1;
z = y + 1;
}
So far, you'd agree the compiler may optimise the entire function away? So
why not this:
void foo (void)
{
int x, y, z;
x = 23;
asm ("do something" : "=r" (y) : "r" (x) );
z = y + 1;
}
?
cheers,
DaveK
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-08 20:20 ` Dave Korn
@ 2010-11-09 13:48 ` Michael Matz
2010-11-09 14:19 ` Andi Kleen
0 siblings, 1 reply; 52+ messages in thread
From: Michael Matz @ 2010-11-09 13:48 UTC (permalink / raw)
To: Dave Korn
Cc: Andi Kleen, Richard Guenther, Andreas Schwab, Jim,
Linux Kernel Mailing List, gcc
Hi,
On Mon, 8 Nov 2010, Dave Korn wrote:
> void foo (void)
> {
> int x, y, z;
> x = 23;
> asm ("do something" : "=r" (y) : "r" (x) );
> z = y + 1;
> }
The case in i8k.c really is different. It does use the value by
influencing the return value and the callers use the returned value in
conditionals and the like. It really, really _is_ used :-) and if GCC
removes the asm (which up to now is only speculation) then it's a GCC bug.
The code outlines like so:
int i8k_smm (regs) {
int rc;
asm (... : "=r"(rc) ...);
if (rc != 0 || ...)
return -EINVAL;
return 0;
}
...
struct regs regs = {.eax = ...}
return i8k_smm(regs) ?: regs.eax;
...
My speculation is, that the asm is not removed but rather that regs.eax
isn't reloaded after the asm because the memory clobber doesn't clobber
automatic variables.
Ciao,
Michael.
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-09 13:48 ` Michael Matz
@ 2010-11-09 14:19 ` Andi Kleen
2010-11-09 15:54 ` Andreas Schwab
0 siblings, 1 reply; 52+ messages in thread
From: Andi Kleen @ 2010-11-09 14:19 UTC (permalink / raw)
To: Michael Matz
Cc: Dave Korn, Andi Kleen, Richard Guenther, Andreas Schwab, Jim,
Linux Kernel Mailing List, gcc
> My speculation is, that the asm is not removed but rather that regs.eax
> isn't reloaded after the asm because the memory clobber doesn't clobber
> automatic variables.
Yes that makes sense. I wasn't able to verify it so far though.
Maybe the original poster could try the obvious patch
instead of the volatile change.
i8k: tell gcc that regs gets clobbered
Signed-off-by: Andi Kleen <ak@linux.intel.com>
diff --git a/drivers/char/i8k.c b/drivers/char/i8k.c
index 3bc0eef..f3bbf73 100644
--- a/drivers/char/i8k.c
+++ b/drivers/char/i8k.c
@@ -142,7 +142,7 @@ static int i8k_smm(struct smm_regs *regs)
"lahf\n\t"
"shrl $8,%%eax\n\t"
"andl $1,%%eax\n"
- :"=a"(rc)
+ :"=a"(rc), "=m" (*regs)
: "a"(regs)
: "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
#else
@@ -167,7 +167,7 @@ static int i8k_smm(struct smm_regs *regs)
"movl %%edx,0(%%eax)\n\t"
"lahf\n\t"
"shrl $8,%%eax\n\t"
- "andl $1,%%eax\n":"=a"(rc)
+ "andl $1,%%eax\n":"=a"(rc), "=m" (*regs)
: "a"(regs)
: "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
#endif
-Andi
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-09 14:19 ` Andi Kleen
@ 2010-11-09 15:54 ` Andreas Schwab
2010-11-09 17:45 ` Jim
0 siblings, 1 reply; 52+ messages in thread
From: Andreas Schwab @ 2010-11-09 15:54 UTC (permalink / raw)
To: Andi Kleen
Cc: Michael Matz, Dave Korn, Richard Guenther, Jim,
Linux Kernel Mailing List, gcc
Andi Kleen <andi@firstfloor.org> writes:
> @@ -142,7 +142,7 @@ static int i8k_smm(struct smm_regs *regs)
> "lahf\n\t"
> "shrl $8,%%eax\n\t"
> "andl $1,%%eax\n"
> - :"=a"(rc)
> + :"=a"(rc), "=m" (*regs)
I think this should be "+m".
Andreas.
--
Andreas Schwab, schwab@redhat.com
GPG Key fingerprint = D4E8 DBE3 3813 BB5D FA84 5EC7 45C6 250E 6F00 984E
"And now for something completely different."
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-09 15:54 ` Andreas Schwab
@ 2010-11-09 17:45 ` Jim
2010-11-13 16:01 ` [PATCH] i8k: Tell gcc that *regs gets clobbered Jim Bos
2010-11-15 8:56 ` gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ? James Cloos
0 siblings, 2 replies; 52+ messages in thread
From: Jim @ 2010-11-09 17:45 UTC (permalink / raw)
To: Andreas Schwab
Cc: Andi Kleen, Michael Matz, Dave Korn, Richard Guenther,
Linux Kernel Mailing List, gcc
[-- Attachment #1: Type: text/plain, Size: 470 bytes --]
On 11/09/2010 02:57 PM, Andreas Schwab wrote:
> Andi Kleen <andi@firstfloor.org> writes:
>
>> @@ -142,7 +142,7 @@ static int i8k_smm(struct smm_regs *regs)
>> "lahf\n\t"
>> "shrl $8,%%eax\n\t"
>> "andl $1,%%eax\n"
>> - :"=a"(rc)
>> + :"=a"(rc), "=m" (*regs)
>
> I think this should be "+m".
>
> Andreas.
>
Just tested Andi's patch with Andreas' suggestion to make it +m,
i.e. like attached and can confirm it solves the issue.
Thanks guys,
Jim Bos
[-- Attachment #2: PATCH.i8k.c --]
[-- Type: text/plain, Size: 565 bytes --]
--- i8k.c.ORIG 2010-08-02 17:20:46.000000000 +0200
+++ i8k.c 2010-11-09 17:31:29.000000000 +0100
@@ -141,7 +141,7 @@
"lahf\n\t"
"shrl $8,%%eax\n\t"
"andl $1,%%eax\n"
- :"=a"(rc)
+ :"=a"(rc), "+m" (*regs)
: "a"(regs)
: "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
#else
@@ -166,7 +166,7 @@
"movl %%edx,0(%%eax)\n\t"
"lahf\n\t"
"shrl $8,%%eax\n\t"
- "andl $1,%%eax\n":"=a"(rc)
+ "andl $1,%%eax\n":"=a"(rc), "+m" (*regs)
: "a"(regs)
: "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
#endif
^ permalink raw reply [flat|nested] 52+ messages in thread
* [PATCH] i8k: Tell gcc that *regs gets clobbered
2010-11-09 17:45 ` Jim
@ 2010-11-13 16:01 ` Jim Bos
2010-11-15 8:56 ` gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ? James Cloos
1 sibling, 0 replies; 52+ messages in thread
From: Jim Bos @ 2010-11-13 16:01 UTC (permalink / raw)
To: Linus Torvalds
Cc: Andreas Schwab, Andi Kleen, Michael Matz, Dave Korn,
Richard Guenther, Linux Kernel Mailing List, gcc
[-- Attachment #1: Type: text/plain, Size: 464 bytes --]
More recent GCC caused the i8k driver to stop working, on Slackware
compiler was upgraded from gcc-4.4.4 to gcc-4.5.1 after which it
didn't work anymore, meaning the driver didn't load or gave total
nonsensical output.
As it turned out the asm(..) statement forgot to mention it modifies
the *regs variable.
Credits to Andi Kleen <andi@firstfloor.org> and Andreas Schwab
<schwab@linux-m68k.org> for providing the fix.
Signed-off-by: Jim Bos <jim876@xs4all.nl>
[-- Attachment #2: PATCH.i8k.c --]
[-- Type: text/plain, Size: 624 bytes --]
--- linux-2.6.36/drivers/char/i8k.c.ORIG 2010-08-02 17:20:46.000000000 +0200
+++ linux-2.6.36/drivers/char/i8k.c 2010-11-13 11:35:11.000000000 +0100
@@ -141,7 +141,7 @@
"lahf\n\t"
"shrl $8,%%eax\n\t"
"andl $1,%%eax\n"
- :"=a"(rc)
+ :"=a"(rc), "+m" (*regs)
: "a"(regs)
: "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
#else
@@ -166,7 +166,8 @@
"movl %%edx,0(%%eax)\n\t"
"lahf\n\t"
"shrl $8,%%eax\n\t"
- "andl $1,%%eax\n":"=a"(rc)
+ "andl $1,%%eax\n"
+ :"=a"(rc), "+m" (*regs)
: "a"(regs)
: "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
#endif
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-09 17:45 ` Jim
2010-11-13 16:01 ` [PATCH] i8k: Tell gcc that *regs gets clobbered Jim Bos
@ 2010-11-15 8:56 ` James Cloos
2010-11-15 9:13 ` Linus Torvalds
1 sibling, 1 reply; 52+ messages in thread
From: James Cloos @ 2010-11-15 8:56 UTC (permalink / raw)
To: Linux Kernel Mailing List
Cc: Andreas Schwab, Andi Kleen, Michael Matz, Dave Korn,
Richard Guenther, Jim, gcc, Jim Bos, Linus Torvalds
Gcc 4.5.1 running on an amd64 box "cross"-compiling for a P3 i8k fails
to compile the module since commit 6b4e81db2552bad04100e7d5ddeed7e848f53b48
with:
CC drivers/char/i8k.o
drivers/char/i8k.c: In function ‘i8k_smm’:
drivers/char/i8k.c:149:2: error: can't find a register in class ‘GENERAL_REGS’ while reloading ‘asm’
drivers/char/i8k.c:149:2: error: ‘asm’ operand has impossible constraints
-JimC
--
James Cloos <cloos@jhcloos.com> OpenPGP: 1024D/ED7DAEA6
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 8:56 ` gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ? James Cloos
@ 2010-11-15 9:13 ` Linus Torvalds
2010-11-15 10:03 ` Jakub Jelinek
0 siblings, 1 reply; 52+ messages in thread
From: Linus Torvalds @ 2010-11-15 9:13 UTC (permalink / raw)
To: James Cloos
Cc: Linux Kernel Mailing List, Andreas Schwab, Andi Kleen,
Michael Matz, Dave Korn, Richard Guenther, gcc, Jim Bos
On Sun, Nov 14, 2010 at 4:52 PM, James Cloos <cloos@jhcloos.com> wrote:
> Gcc 4.5.1 running on an amd64 box "cross"-compiling for a P3 i8k fails
> to compile the module since commit 6b4e81db2552bad04100e7d5ddeed7e848f53b48
> with:
>
> CC drivers/char/i8k.o
> drivers/char/i8k.c: In function ‘i8k_smm’:
> drivers/char/i8k.c:149:2: error: can't find a register in class ‘GENERAL_REGS’ while reloading ‘asm’
> drivers/char/i8k.c:149:2: error: ‘asm’ operand has impossible constraints
At this point, I think this falls clearly under "unresolvable gcc bug".
Quite frankly, I think gcc was buggy to begin with: since we had a
memory clobber, the "+m" (*regs) should not have mattered. The fact
that "*regs" may be some local variable doesn't make any difference
what-so-ever, since we took the address of the variable. So the memory
clobber _clearly_ can change that variable.
So when Richard Gunther says "a memory clobber doesn't cover automatic
storage", to me that very clearly spells "gcc is buggy as hell".
Because automatic storage with its address taken _very_ much gets
clobbered by things like memset etc. If the compiler doesn't
understand that, the compiler is just broken.
And now, if even the (superfluous) "+m" isn't working, it sounds like
we have no sane options left. Except to say that gcc-4.5.1 is totally
broken wrt asms.
Can we just get gcc to realize that when you pass the address of
automatic storage to an asm, that means that "memory" really does
clobber it? Because clearly that is the case.
Linus
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 9:13 ` Linus Torvalds
@ 2010-11-15 10:03 ` Jakub Jelinek
2010-11-15 10:24 ` Andi Kleen
` (3 more replies)
0 siblings, 4 replies; 52+ messages in thread
From: Jakub Jelinek @ 2010-11-15 10:03 UTC (permalink / raw)
To: Linus Torvalds
Cc: James Cloos, Linux Kernel Mailing List, Andreas Schwab,
Andi Kleen, Michael Matz, Dave Korn, Richard Guenther, gcc,
Jim Bos
On Sun, Nov 14, 2010 at 07:21:50PM -0800, Linus Torvalds wrote:
> So when Richard Gunther says "a memory clobber doesn't cover automatic
> storage", to me that very clearly spells "gcc is buggy as hell".
> Because automatic storage with its address taken _very_ much gets
> clobbered by things like memset etc. If the compiler doesn't
> understand that, the compiler is just broken.
I'll leave the discussion about meaning of "memory" clobber aside to
Richard,
> And now, if even the (superfluous) "+m" isn't working, it sounds like
> we have no sane options left. Except to say that gcc-4.5.1 is totally
just to say that of course there are sane options left.
:"=a"(rc), "+m" (*regs)
: "a"(regs)
: "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
is simply too high register pressure for i386 if you force also
-fno-omit-frame-pointer, there is not a single register left.
Yes, reload should figure out it has address of regs already tied to %eax,
unfortunately starting with IRA it doesn't (I'll file a GCC bug about that;
so that leaves 4.4/4.5/4.6 currently not being able to compile it).
That said, changing the inline asm to just clobber one less register
would be completely sufficient to make it work well with all gccs out there,
just push/pop one of the register around the whole body. I doubt calling
out SMM BIOS is actually so performance critical that one push and one pop
would ruin it. Of course x86_64 version can stay as is, there are enough
registers left...
Jakub
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 10:03 ` Jakub Jelinek
@ 2010-11-15 10:24 ` Andi Kleen
2010-11-15 10:55 ` Jakub Jelinek
` (2 subsequent siblings)
3 siblings, 0 replies; 52+ messages in thread
From: Andi Kleen @ 2010-11-15 10:24 UTC (permalink / raw)
To: Jakub Jelinek
Cc: Linus Torvalds, James Cloos, Linux Kernel Mailing List,
Andreas Schwab, Andi Kleen, Michael Matz, Dave Korn,
Richard Guenther, gcc, Jim Bos
> That said, changing the inline asm to just clobber one less register
> would be completely sufficient to make it work well with all gccs out there,
> just push/pop one of the register around the whole body. I doubt calling
> out SMM BIOS is actually so performance critical that one push and one pop
> would ruin it. Of course x86_64 version can stay as is, there are enough
> registers left...
Yes traditionally clobbering all registers has been dangerous
and it clearly can be done inside the asm too.
Here's a untested patch to do some manual push/pops too. Could someone with
the hardware please test it? (running a 32bit kernel)
-Andi
---
i8k: Clobber less registers
gcc doesn't like inline assembler statements that clobber nearly
all registers. Save a few registers manually on i386 to avoid this
problem.
Fix suggested by Jakub Jelinek
Signed-off-by: Andi Kleen <ak@linux.intel.com>
diff --git a/drivers/char/i8k.c b/drivers/char/i8k.c
index f0863be..a2da38b 100644
--- a/drivers/char/i8k.c
+++ b/drivers/char/i8k.c
@@ -146,7 +146,10 @@ static int i8k_smm(struct smm_regs *regs)
: "a"(regs)
: "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
#else
- asm("pushl %%eax\n\t"
+ asm("pushl %%ebx\n\t"
+ "pushl %%ecx\n\t"
+ "pushl %%edx\n\t"
+ "pushl %%eax\n\t"
"movl 0(%%eax),%%edx\n\t"
"push %%edx\n\t"
"movl 4(%%eax),%%ebx\n\t"
@@ -167,10 +170,13 @@ static int i8k_smm(struct smm_regs *regs)
"movl %%edx,0(%%eax)\n\t"
"lahf\n\t"
"shrl $8,%%eax\n\t"
- "andl $1,%%eax\n"
+ "andl $1,%%eax\n\t"
+ "popl %%edx\n\t"
+ "popl %%ecx\n\t"
+ "popl %%ebx\n"
:"=a"(rc), "+m" (*regs)
: "a"(regs)
- : "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
+ : "%esi", "%edi", "memory");
#endif
if (rc != 0 || (regs->eax & 0xffff) == 0xffff || regs->eax == eax)
return -EINVAL;
--
ak@linux.intel.com -- Speaking for myself only.
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 10:03 ` Jakub Jelinek
2010-11-15 10:24 ` Andi Kleen
@ 2010-11-15 10:55 ` Jakub Jelinek
2010-11-15 11:38 ` Jakub Jelinek
2010-11-15 12:04 ` Richard Guenther
3 siblings, 0 replies; 52+ messages in thread
From: Jakub Jelinek @ 2010-11-15 10:55 UTC (permalink / raw)
To: Linus Torvalds
Cc: James Cloos, Linux Kernel Mailing List, Andreas Schwab,
Andi Kleen, Michael Matz, Dave Korn, Richard Guenther, gcc,
Jim Bos
On Mon, Nov 15, 2010 at 09:56:05AM +0100, Jakub Jelinek wrote:
> Yes, reload should figure out it has address of regs already tied to %eax,
> unfortunately starting with IRA it doesn't (I'll file a GCC bug about that;
http://gcc.gnu.org/PR46479
Jakub
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 10:03 ` Jakub Jelinek
2010-11-15 10:24 ` Andi Kleen
2010-11-15 10:55 ` Jakub Jelinek
@ 2010-11-15 11:38 ` Jakub Jelinek
2010-11-15 12:29 ` Andi Kleen
2010-11-15 12:04 ` Richard Guenther
3 siblings, 1 reply; 52+ messages in thread
From: Jakub Jelinek @ 2010-11-15 11:38 UTC (permalink / raw)
To: Linus Torvalds
Cc: James Cloos, Linux Kernel Mailing List, Andreas Schwab,
Andi Kleen, Michael Matz, Dave Korn, Richard Guenther, gcc,
Jim Bos
On Mon, Nov 15, 2010 at 09:56:05AM +0100, Jakub Jelinek wrote:
> On Sun, Nov 14, 2010 at 07:21:50PM -0800, Linus Torvalds wrote:
> > So when Richard Gunther says "a memory clobber doesn't cover automatic
> > storage", to me that very clearly spells "gcc is buggy as hell".
> > Because automatic storage with its address taken _very_ much gets
> > clobbered by things like memset etc. If the compiler doesn't
> > understand that, the compiler is just broken.
>
> I'll leave the discussion about meaning of "memory" clobber aside to
> Richard,
And for this the starting point should be what has been requested,
i.e. preprocessed source + gcc options + gcc version and some hints what
actually misbehaves (with the , "+m" (*regs) change reverted)
in gcc bugzilla. Only with that we can actually look at what has been
happening, see whether it is the tree optimizations or RTL and which one
makes a difference.
If I've missed a PR about this I apologize.
Jakub
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 10:03 ` Jakub Jelinek
` (2 preceding siblings ...)
2010-11-15 11:38 ` Jakub Jelinek
@ 2010-11-15 12:04 ` Richard Guenther
3 siblings, 0 replies; 52+ messages in thread
From: Richard Guenther @ 2010-11-15 12:04 UTC (permalink / raw)
To: Jakub Jelinek
Cc: Linus Torvalds, James Cloos, Linux Kernel Mailing List,
Andreas Schwab, Andi Kleen, Michael Matz, Dave Korn, gcc,
Jim Bos
On Mon, Nov 15, 2010 at 9:56 AM, Jakub Jelinek <jakub@redhat.com> wrote:
> On Sun, Nov 14, 2010 at 07:21:50PM -0800, Linus Torvalds wrote:
>> So when Richard Gunther says "a memory clobber doesn't cover automatic
>> storage", to me that very clearly spells "gcc is buggy as hell".
>> Because automatic storage with its address taken _very_ much gets
>> clobbered by things like memset etc. If the compiler doesn't
>> understand that, the compiler is just broken.
>
> I'll leave the discussion about meaning of "memory" clobber aside to
> Richard,
Of course GCC handles memset just fine. Note that I was refering
to non-address taken automatic storage for "memory" (even though
when double-checking the current implementation GCC even thinks
that all address-taken memory is clobbered by asms as soon as
they have at least one memory operand or a "memory" clobber).
It's just that in future we might want to improve this and I think
not covering non-address taken automatic storage for "memory"
is sensible. And I see that you don't see address-taken automatic
storage as a sensible choice to exclude from "memory", and I
have noted that.
Btw, I still haven't seen an testcase for the actual problem we are
talking about.
Richard.
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 11:38 ` Jakub Jelinek
@ 2010-11-15 12:29 ` Andi Kleen
2010-11-15 14:40 ` Jakub Jelinek
0 siblings, 1 reply; 52+ messages in thread
From: Andi Kleen @ 2010-11-15 12:29 UTC (permalink / raw)
To: Jakub Jelinek
Cc: Linus Torvalds, James Cloos, Linux Kernel Mailing List,
Andreas Schwab, Andi Kleen, Michael Matz, Dave Korn,
Richard Guenther, gcc, Jim Bos
> And for this the starting point should be what has been requested,
> i.e. preprocessed source + gcc options + gcc version and some hints what
> actually misbehaves (with the , "+m" (*regs) change reverted)
> in gcc bugzilla. Only with that we can actually look at what has been
> happening, see whether it is the tree optimizations or RTL and which one
> makes a difference.
> If I've missed a PR about this I apologize.
I tried to file one, but I can't reproduce it currently
(I don't have hardware, so have to rely on code reading and the 32bit
code looks correct to me even without the additional +m)
The preprocessed source is at
http://halobates.de/tmp/i8k.i
Options I used:
-D__KERNEL__ -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -Werror-implicit-function-declaration -Wno-format-security -fno-delete-null-pointer-checks -O2 -m32 -msoft-float -mregparm=3 -freg-struct-return -mpreferred-stack-boundary=2 -march=i686 -mtune=pentium3 -mtune=generic -maccumulate-outgoing-args -Wa,-mtune=generic32 -ffreestanding -DCONFIG_AS_CFI=1 -DCONFIG_AS_CFI_SIGNAL_FRAME=1 -DCONFIG_AS_CFI_SECTIONS=1 -pipe -Wno-sign-compare -fno-asynchronous-unwind-tables -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -Wframe-larger-than=2048 -fno-stack-protector -fno-omit-frame-pointer -fno-optimize-sibling-calls -pg -Wdeclaration-after-statement -Wno-pointer-sign -fno-strict-overflow -fconserve-stack
-Andi
--
ak@linux.intel.com -- Speaking for myself only.
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 12:29 ` Andi Kleen
@ 2010-11-15 14:40 ` Jakub Jelinek
2010-11-15 14:56 ` Andi Kleen
2010-11-15 17:06 ` Linus Torvalds
0 siblings, 2 replies; 52+ messages in thread
From: Jakub Jelinek @ 2010-11-15 14:40 UTC (permalink / raw)
To: Andi Kleen
Cc: Linus Torvalds, James Cloos, Linux Kernel Mailing List,
Andreas Schwab, Michael Matz, Dave Korn, Richard Guenther, gcc,
Jim Bos
On Mon, Nov 15, 2010 at 11:54:46AM +0100, Andi Kleen wrote:
> > And for this the starting point should be what has been requested,
> > i.e. preprocessed source + gcc options + gcc version and some hints what
> > actually misbehaves (with the , "+m" (*regs) change reverted)
> > in gcc bugzilla. Only with that we can actually look at what has been
> > happening, see whether it is the tree optimizations or RTL and which one
> > makes a difference.
> > If I've missed a PR about this I apologize.
>
> I tried to file one, but I can't reproduce it currently
> (I don't have hardware, so have to rely on code reading and the 32bit
> code looks correct to me even without the additional +m)
>
> The preprocessed source is at
> http://halobates.de/tmp/i8k.i
>
> Options I used:
>
> -D__KERNEL__ -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -Werror-implicit-function-declaration -Wno-format-security -fno-delete-null-pointer-checks -O2 -m32 -msoft-float -mregparm=3 -freg-struct-return -mpreferred-stack-boundary=2 -march=i686 -mtune=pentium3 -mtune=generic -maccumulate-outgoing-args -Wa,-mtune=generic32 -ffreestanding -DCONFIG_AS_CFI=1 -DCONFIG_AS_CFI_SIGNAL_FRAME=1 -DCONFIG_AS_CFI_SECTIONS=1 -pipe -Wno-sign-compare -fno-asynchronous-unwind-tables -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -Wframe-larger-than=2048 -fno-stack-protector -fno-omit-frame-pointer -fno-optimize-sibling-calls -pg -Wdeclaration-after-statement -Wno-pointer-sign -fno-strict-overflow -fconserve-stack
Indeed, with this and 4.5.2 20101111 (prerelease) from SVN as well as
gcc-4.5.1-5.fc14:
...
movl %eax, -16(%ebp) # regs, %sfp
movl (%eax), %eax # regs_2(D)->eax,
movl %eax, -20(%ebp) #, %sfp
movl -16(%ebp), %eax # %sfp,
#APP
# 149 "/home/lsrc/git/linux-work2/drivers/char/i8k.c" 1
...
#NO_APP
testl %eax, %eax #
movl $-22, %edx #, D.18378
movl %eax, -24(%ebp) #, %sfp
je .L7 #,
.L2:
movl -12(%ebp), %ebx #,
movl %edx, %eax # D.18378,
movl -8(%ebp), %esi #,
movl -4(%ebp), %edi #,
movl %ebp, %esp #,
popl %ebp #
ret
.p2align 4,,7
.p2align 3
.L7:
movl -16(%ebp), %eax # %sfp,
movl (%eax), %ecx # regs_2(D)->eax, D.18371
cmpw $-1, %cx #, D.18371
je .L2 #,
cmpl %ecx, -20(%ebp) # D.18371, %sfp
cmovne -24(%ebp), %edx # %sfp,, D.18378
jmp .L2 #
.size i8k_smm, .-i8k_smm
I don't see any problems on the assembly level. i8k_smm is
not inlined in this case and checks all 3 conditions.
Guess we need somebody who actually reported the problem, state what
gcc was actually used and post preprocessed source, gcc options
from his case.
Jakub
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 14:40 ` Jakub Jelinek
@ 2010-11-15 14:56 ` Andi Kleen
2010-11-15 18:10 ` Jim Bos
2010-11-15 17:06 ` Linus Torvalds
1 sibling, 1 reply; 52+ messages in thread
From: Andi Kleen @ 2010-11-15 14:56 UTC (permalink / raw)
To: Jakub Jelinek
Cc: Andi Kleen, Linus Torvalds, James Cloos,
Linux Kernel Mailing List, Andreas Schwab, Michael Matz,
Dave Korn, Richard Guenther, gcc, Jim Bos
> Guess we need somebody who actually reported the problem, state what
> gcc was actually used and post preprocessed source, gcc options
> from his case.
Jim Bos,
Can you please supply that?
Please use
rm drivers/char/i8k.o
make V=1 drivers/char/i8k.o
make drivers/char/i8k.i
and supply the .i file and the output of the first make line
Thanks,
-Andi
--
ak@linux.intel.com -- Speaking for myself only.
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 14:40 ` Jakub Jelinek
2010-11-15 14:56 ` Andi Kleen
@ 2010-11-15 17:06 ` Linus Torvalds
2010-11-15 18:18 ` Jim Bos
1 sibling, 1 reply; 52+ messages in thread
From: Linus Torvalds @ 2010-11-15 17:06 UTC (permalink / raw)
To: Jakub Jelinek
Cc: Andi Kleen, James Cloos, Linux Kernel Mailing List,
Andreas Schwab, Michael Matz, Dave Korn, Richard Guenther, gcc,
Jim Bos
[-- Attachment #1: Type: text/plain, Size: 1341 bytes --]
On Mon, Nov 15, 2010 at 3:16 AM, Jakub Jelinek <jakub@redhat.com> wrote:
>
> I don't see any problems on the assembly level. i8k_smm is
> not inlined in this case and checks all 3 conditions.
If it really is related to gcc not understanding that "*regs" has
changed due to the memory being an automatic variable, and passing in
"regs" itself as a pointer to that automatic variable together with
the "memory" clobber not being sufficient, than I think it's the lack
of inlining that will automatically hide the bug.
(Side note: and I think this does show how much of a gcc bug it is not
to consider "memory" together with passing in a pointer to an asm to
always be a clobber).
Because if it isn't inlined, then "regs" will be seen a a real pointer
to some external memory (the caller) rather than being optimized to
just be the auto structure on the stack. Because *mem is auto only
within the context of the caller.
Which actually points to a possible simpler:
- remove the "+m" since it adds too much register pressure
- mark the i8k_smm() as "noinline" instead.
Quite frankly, I'd hate to add even more crud to that inline asm (to
save/restore the registers manually). It's already not the prettiest
thing around.
So does the attached patch work for everybody?
Linus
[-- Attachment #2: patch.diff --]
[-- Type: text/x-patch, Size: 1019 bytes --]
drivers/char/i8k.c | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/char/i8k.c b/drivers/char/i8k.c
index f0863be..101011e 100644
--- a/drivers/char/i8k.c
+++ b/drivers/char/i8k.c
@@ -114,7 +114,7 @@ static inline const char *i8k_get_dmi_data(int field)
/*
* Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
*/
-static int i8k_smm(struct smm_regs *regs)
+static noinline int i8k_smm(struct smm_regs *regs)
{
int rc;
int eax = regs->eax;
@@ -142,7 +142,7 @@ static int i8k_smm(struct smm_regs *regs)
"lahf\n\t"
"shrl $8,%%eax\n\t"
"andl $1,%%eax\n"
- :"=a"(rc), "+m" (*regs)
+ :"=a"(rc)
: "a"(regs)
: "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
#else
@@ -168,7 +168,7 @@ static int i8k_smm(struct smm_regs *regs)
"lahf\n\t"
"shrl $8,%%eax\n\t"
"andl $1,%%eax\n"
- :"=a"(rc), "+m" (*regs)
+ :"=a"(rc)
: "a"(regs)
: "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
#endif
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 14:56 ` Andi Kleen
@ 2010-11-15 18:10 ` Jim Bos
2010-11-15 18:26 ` Jakub Jelinek
0 siblings, 1 reply; 52+ messages in thread
From: Jim Bos @ 2010-11-15 18:10 UTC (permalink / raw)
To: Andi Kleen
Cc: Jakub Jelinek, Linus Torvalds, James Cloos,
Linux Kernel Mailing List, Andreas Schwab, Michael Matz,
Dave Korn, Richard Guenther, gcc
[-- Attachment #1: Type: text/plain, Size: 677 bytes --]
On 11/15/2010 12:37 PM, Andi Kleen wrote:
>> Guess we need somebody who actually reported the problem, state what
>> gcc was actually used and post preprocessed source, gcc options
>> from his case.
>
> Jim Bos,
> Can you please supply that?
>
> Please use
>
> rm drivers/char/i8k.o
> make V=1 drivers/char/i8k.o
> make drivers/char/i8k.i
>
> and supply the .i file and the output of the first make line
>
> Thanks,
> -Andi
>
Andi,
See attached, note this is the vanilla 2.6.36 i8k.c (without any patch).
And to be 100% sure, if I build this (make drivers/char/i8k.ko) it won't
work.
[ The i8k.i is rather big, even gzipped 80k, not sure if it'll bounce ]
_
Jim
[-- Attachment #2: outp.txt --]
[-- Type: text/plain, Size: 3690 bytes --]
rm -f include/config/kernel.release
echo "2.6.36$(/bin/sh /usr/src/linux-2.6.36/scripts/setlocalversion /usr/src/linux-2.6.36)" > include/config/kernel.release
set -e; : ' CHK include/linux/version.h'; mkdir -p include/linux/; (echo \#define LINUX_VERSION_CODE 132644; echo '#define KERNEL_VERSION(a,b,c) (((a) << 16) + ((b) << 8) + (c))';) < /usr/src/linux-2.6.36/Makefile > include/linux/version.h.tmp; if [ -r include/linux/version.h ] && cmp -s include/linux/version.h include/linux/version.h.tmp; then rm -f include/linux/version.h.tmp; else : ' UPD include/linux/version.h'; mv -f include/linux/version.h.tmp include/linux/version.h; fi
set -e; : ' CHK include/generated/utsrelease.h'; mkdir -p include/generated/; if [ `echo -n "2.6.36" | wc -c ` -gt 64 ]; then echo '"2.6.36" exceeds 64 characters' >&2; exit 1; fi; (echo \#define UTS_RELEASE \"2.6.36\";) < include/config/kernel.release > include/generated/utsrelease.h.tmp; if [ -r include/generated/utsrelease.h ] && cmp -s include/generated/utsrelease.h include/generated/utsrelease.h.tmp; then rm -f include/generated/utsrelease.h.tmp; else : ' UPD include/generated/utsrelease.h'; mv -f include/generated/utsrelease.h.tmp include/generated/utsrelease.h; fi
mkdir -p .tmp_versions
make -f scripts/Makefile.build obj=scripts/basic
rm -f .tmp_quiet_recordmcount
make -f scripts/Makefile.build obj=.
mkdir -p kernel/
mkdir -p arch/x86/kernel/
make -f scripts/Makefile.build obj=. missing-syscalls
/bin/sh scripts/checksyscalls.sh gcc -Wp,-MD,./.missing-syscalls.d -nostdinc -isystem /usr/lib/gcc/i486-slackware-linux/4.5.1/include -I/usr/src/linux-2.6.36/arch/x86/include -Iinclude -include include/generated/autoconf.h -D__KERNEL__ -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -Werror-implicit-function-declaration -Wno-format-security -fno-delete-null-pointer-checks -Os -m32 -msoft-float -mregparm=3 -freg-struct-return -mpreferred-stack-boundary=2 -march=i686 -mtune=pentium3 -mtune=generic -Wa,-mtune=generic32 -ffreestanding -DCONFIG_AS_CFI=1 -DCONFIG_AS_CFI_SIGNAL_FRAME=1 -DCONFIG_AS_CFI_SECTIONS=1 -pipe -Wno-sign-compare -fno-asynchronous-unwind-tables -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -Wframe-larger-than=1024 -fno-stack-protector -fomit-frame-pointer -Wdeclaration-after-statement -Wno-pointer-sign -fno-strict-overflow -fconserve-stack -D"KBUILD_STR(s)=#s" -D"KBUILD_BASENAME=KBUILD_STR(missing_syscalls)" -D"KBUILD_MODNAME=KBUILD_STR(missing_syscalls)"
make -f scripts/Makefile.build obj=scripts
make -f scripts/Makefile.build obj=scripts/mod
make -f scripts/Makefile.build obj=drivers/char drivers/char/i8k.o
gcc -Wp,-MD,drivers/char/.i8k.o.d -nostdinc -isystem /usr/lib/gcc/i486-slackware-linux/4.5.1/include -I/usr/src/linux-2.6.36/arch/x86/include -Iinclude -include include/generated/autoconf.h -D__KERNEL__ -Wall -Wundef -Wstrict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -Werror-implicit-function-declaration -Wno-format-security -fno-delete-null-pointer-checks -Os -m32 -msoft-float -mregparm=3 -freg-struct-return -mpreferred-stack-boundary=2 -march=i686 -mtune=pentium3 -mtune=generic -Wa,-mtune=generic32 -ffreestanding -DCONFIG_AS_CFI=1 -DCONFIG_AS_CFI_SIGNAL_FRAME=1 -DCONFIG_AS_CFI_SECTIONS=1 -pipe -Wno-sign-compare -fno-asynchronous-unwind-tables -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -Wframe-larger-than=1024 -fno-stack-protector -fomit-frame-pointer -Wdeclaration-after-statement -Wno-pointer-sign -fno-strict-overflow -fconserve-stack -DMODULE -D"KBUILD_STR(s)=#s" -D"KBUILD_BASENAME=KBUILD_STR(i8k)" -D"KBUILD_MODNAME=KBUILD_STR(i8k)" -c -o drivers/char/i8k.o drivers/char/i8k.c
[-- Attachment #3: i8k.i.gz --]
[-- Type: application/gzip, Size: 79922 bytes --]
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 17:06 ` Linus Torvalds
@ 2010-11-15 18:18 ` Jim Bos
2010-11-15 18:38 ` Linus Torvalds
0 siblings, 1 reply; 52+ messages in thread
From: Jim Bos @ 2010-11-15 18:18 UTC (permalink / raw)
To: Linus Torvalds
Cc: Jakub Jelinek, Andi Kleen, James Cloos,
Linux Kernel Mailing List, Andreas Schwab, Michael Matz,
Dave Korn, Richard Guenther, gcc
On 11/15/2010 05:04 PM, Linus Torvalds wrote:
> On Mon, Nov 15, 2010 at 3:16 AM, Jakub Jelinek <jakub@redhat.com> wrote:
>>
>> I don't see any problems on the assembly level. i8k_smm is
>> not inlined in this case and checks all 3 conditions.
>
> If it really is related to gcc not understanding that "*regs" has
> changed due to the memory being an automatic variable, and passing in
> "regs" itself as a pointer to that automatic variable together with
> the "memory" clobber not being sufficient, than I think it's the lack
> of inlining that will automatically hide the bug.
>
> (Side note: and I think this does show how much of a gcc bug it is not
> to consider "memory" together with passing in a pointer to an asm to
> always be a clobber).
>
> Because if it isn't inlined, then "regs" will be seen a a real pointer
> to some external memory (the caller) rather than being optimized to
> just be the auto structure on the stack. Because *mem is auto only
> within the context of the caller.
>
> Which actually points to a possible simpler:
> - remove the "+m" since it adds too much register pressure
> - mark the i8k_smm() as "noinline" instead.
>
> Quite frankly, I'd hate to add even more crud to that inline asm (to
> save/restore the registers manually). It's already not the prettiest
> thing around.
>
> So does the attached patch work for everybody?
>
> Linus
Hmm, that doesn't work.
[ Not sure if you read to whole thread but initial workaround was to
change the asm(..) to asm volatile(..) which did work. ]
Jim.
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 18:10 ` Jim Bos
@ 2010-11-15 18:26 ` Jakub Jelinek
2010-11-15 18:43 ` Jim Bos
0 siblings, 1 reply; 52+ messages in thread
From: Jakub Jelinek @ 2010-11-15 18:26 UTC (permalink / raw)
To: Jim Bos
Cc: Andi Kleen, Linus Torvalds, James Cloos,
Linux Kernel Mailing List, Andreas Schwab, Michael Matz,
Dave Korn, Richard Guenther, gcc
On Mon, Nov 15, 2010 at 06:36:06PM +0100, Jim Bos wrote:
> On 11/15/2010 12:37 PM, Andi Kleen wrote:
> See attached, note this is the vanilla 2.6.36 i8k.c (without any patch).
> And to be 100% sure, if I build this (make drivers/char/i8k.ko) it won't
> work.
>
> [ The i8k.i is rather big, even gzipped 80k, not sure if it'll bounce ]
Please also say which exact gcc you are using.
Note, I've compiled it with current 4.5 branch and made the function
always_inline and still didn't see any issues in the *.optimized dump,
regs.eax after the inline asm has always been compared to the constant
that has been stored into regs.eax before the inline asm.
Jakub
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 18:18 ` Jim Bos
@ 2010-11-15 18:38 ` Linus Torvalds
2010-11-15 18:47 ` Jim Bos
0 siblings, 1 reply; 52+ messages in thread
From: Linus Torvalds @ 2010-11-15 18:38 UTC (permalink / raw)
To: Jim Bos
Cc: Jakub Jelinek, Andi Kleen, James Cloos,
Linux Kernel Mailing List, Andreas Schwab, Michael Matz,
Dave Korn, Richard Guenther, gcc
On Mon, Nov 15, 2010 at 9:40 AM, Jim Bos <jim876@xs4all.nl> wrote:
>
> Hmm, that doesn't work.
>
> [ Not sure if you read to whole thread but initial workaround was to
> change the asm(..) to asm volatile(..) which did work. ]
Since I have a different gcc than yours (and I'm not going to compile
my own), have you posted your broken .s file anywhere? In fact, with
the noinline (and the removal of the "+m" thing - iow just the patch
you tried), what does just the "i8k_smm" function assembly look like
for you after you've done a "make drivers/char/i8k.s"?
If the asm just doesn't exist AT ALL, that's just odd. Because every
single call-site of i8k_smm() clearly looks at the return value. So
the volatile really shouldn't make any difference from that
standpoint. Odd.
Linus
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 18:26 ` Jakub Jelinek
@ 2010-11-15 18:43 ` Jim Bos
2010-11-15 18:45 ` Jakub Jelinek
0 siblings, 1 reply; 52+ messages in thread
From: Jim Bos @ 2010-11-15 18:43 UTC (permalink / raw)
To: Jakub Jelinek
Cc: Andi Kleen, Linus Torvalds, James Cloos,
Linux Kernel Mailing List, Andreas Schwab, Michael Matz,
Dave Korn, Richard Guenther, gcc
On 11/15/2010 06:44 PM, Jakub Jelinek wrote:
> On Mon, Nov 15, 2010 at 06:36:06PM +0100, Jim Bos wrote:
>> On 11/15/2010 12:37 PM, Andi Kleen wrote:
>> See attached, note this is the vanilla 2.6.36 i8k.c (without any patch).
>> And to be 100% sure, if I build this (make drivers/char/i8k.ko) it won't
>> work.
>>
>> [ The i8k.i is rather big, even gzipped 80k, not sure if it'll bounce ]
>
> Please also say which exact gcc you are using.
>
> Note, I've compiled it with current 4.5 branch and made the function
> always_inline and still didn't see any issues in the *.optimized dump,
> regs.eax after the inline asm has always been compared to the constant
> that has been stored into regs.eax before the inline asm.
>
> Jakub
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
# gcc -v
Reading specs from /usr/lib/gcc/i486-slackware-linux/4.5.1/specs
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/i486-slackware-linux/4.5.1/lto-wrapper
Target: i486-slackware-linux
Configured with: ../gcc-4.5.1/configure --prefix=/usr --libdir=/usr/lib
--mandir=/usr/man --infodir=/usr/info --enable-shared --enable-bootstrap
--enable-languages=ada,c,c++,fortran,java,objc --enable-threads=posix
--enable-checking=release --with-system-zlib
--with-python-dir=/lib/python2.6/site-packages
--disable-libunwind-exceptions --enable-__cxa_atexit --enable-libssp
--with-gnu-ld --verbose --with-arch=i486 --target=i486-slackware-linux
--build=i486-slackware-linux --host=i486-slackware-linux
Thread model: posix
gcc version 4.5.1 (GCC)
I'm re-reading this thread where I found the asm-> asm volatine suggestion:
https://bbs.archlinux.org/viewtopic.php?pid=752099#p752099
but nobody there reported their gcc version (but apparently first
people started complaining May 1st).
_
Jim
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 18:43 ` Jim Bos
@ 2010-11-15 18:45 ` Jakub Jelinek
2010-11-15 19:53 ` Jim Bos
0 siblings, 1 reply; 52+ messages in thread
From: Jakub Jelinek @ 2010-11-15 18:45 UTC (permalink / raw)
To: Jim Bos
Cc: Andi Kleen, Linus Torvalds, James Cloos,
Linux Kernel Mailing List, Andreas Schwab, Michael Matz,
Dave Korn, Richard Guenther, gcc
On Mon, Nov 15, 2010 at 07:17:31PM +0100, Jim Bos wrote:
> # gcc -v
> Reading specs from /usr/lib/gcc/i486-slackware-linux/4.5.1/specs
> COLLECT_GCC=gcc
> COLLECT_LTO_WRAPPER=/usr/libexec/gcc/i486-slackware-linux/4.5.1/lto-wrapper
> Target: i486-slackware-linux
> Configured with: ../gcc-4.5.1/configure --prefix=/usr --libdir=/usr/lib
> --mandir=/usr/man --infodir=/usr/info --enable-shared --enable-bootstrap
> --enable-languages=ada,c,c++,fortran,java,objc --enable-threads=posix
> --enable-checking=release --with-system-zlib
> --with-python-dir=/lib/python2.6/site-packages
> --disable-libunwind-exceptions --enable-__cxa_atexit --enable-libssp
> --with-gnu-ld --verbose --with-arch=i486 --target=i486-slackware-linux
> --build=i486-slackware-linux --host=i486-slackware-linux
> Thread model: posix
> gcc version 4.5.1 (GCC)
Does it have any patches applied? The gcc options look the same as what
I've been already trying earlier.
Thus, can you run gcc with those options on i8k.i and add -fverbose-asm
to make it easier to read and post i8k.s you get?
Jakub
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 18:38 ` Linus Torvalds
@ 2010-11-15 18:47 ` Jim Bos
2010-11-15 18:52 ` Jim Bos
` (2 more replies)
0 siblings, 3 replies; 52+ messages in thread
From: Jim Bos @ 2010-11-15 18:47 UTC (permalink / raw)
To: Linus Torvalds
Cc: Jakub Jelinek, Andi Kleen, James Cloos,
Linux Kernel Mailing List, Andreas Schwab, Michael Matz,
Dave Korn, Richard Guenther, gcc
[-- Attachment #1: Type: text/plain, Size: 1006 bytes --]
On 11/15/2010 07:08 PM, Linus Torvalds wrote:
> On Mon, Nov 15, 2010 at 9:40 AM, Jim Bos <jim876@xs4all.nl> wrote:
>>
>> Hmm, that doesn't work.
>>
>> [ Not sure if you read to whole thread but initial workaround was to
>> change the asm(..) to asm volatile(..) which did work. ]
>
> Since I have a different gcc than yours (and I'm not going to compile
> my own), have you posted your broken .s file anywhere? In fact, with
> the noinline (and the removal of the "+m" thing - iow just the patch
> you tried), what does just the "i8k_smm" function assembly look like
> for you after you've done a "make drivers/char/i8k.s"?
>
> If the asm just doesn't exist AT ALL, that's just odd. Because every
> single call-site of i8k_smm() clearly looks at the return value. So
> the volatile really shouldn't make any difference from that
> standpoint. Odd.
>
> Linus
>
Attached version with plain 2.6.36 source and version with the committed
patch, i.e with the '"+m" (*regs)'
_
Jim
[-- Attachment #2: i8k.s-2.6.36 --]
[-- Type: text/plain, Size: 22373 bytes --]
.file "i8k.c"
# GNU C (GCC) version 4.5.1 (i486-slackware-linux)
# compiled by GNU C version 4.5.1, GMP version 5.0.1, MPFR version 2.4.2-p3, MPC version 0.8.2
# GGC heuristics: --param ggc-min-expand=81 --param ggc-min-heapsize=96817
# options passed: -nostdinc -I/usr/src/linux-2.6.36/arch/x86/include
# -Iinclude -D__KERNEL__ -DCONFIG_AS_CFI=1 -DCONFIG_AS_CFI_SIGNAL_FRAME=1
# -DCONFIG_AS_CFI_SECTIONS=1 -DMODULE -DKBUILD_STR(s)=#s
# -DKBUILD_BASENAME=KBUILD_STR(i8k) -DKBUILD_MODNAME=KBUILD_STR(i8k)
# -isystem /usr/lib/gcc/i486-slackware-linux/4.5.1/include -include
# include/generated/autoconf.h -MD drivers/char/.i8k.s.d drivers/char/i8k.c
# -m32 -msoft-float -mregparm=3 -mpreferred-stack-boundary=2 -march=i686
# -mtune=pentium3 -mtune=generic -mno-sse -mno-mmx -mno-sse2 -mno-3dnow
# -auxbase-strip drivers/char/i8k.s -Os -Wall -Wundef -Wstrict-prototypes
# -Wno-trigraphs -Werror-implicit-function-declaration -Wno-format-security
# -Wno-sign-compare -Wframe-larger-than=1024 -Wdeclaration-after-statement
# -Wno-pointer-sign -fno-strict-aliasing -fno-common
# -fno-delete-null-pointer-checks -freg-struct-return -ffreestanding
# -fno-asynchronous-unwind-tables -fno-stack-protector -fomit-frame-pointer
# -fno-strict-overflow -fconserve-stack -fverbose-asm
# options enabled: -falign-loops -fargument-alias -fauto-inc-dec
# -fbranch-count-reg -fcaller-saves -fcprop-registers -fcrossjumping
# -fcse-follow-jumps -fdefer-pop -fdwarf2-cfi-asm -fearly-inlining
# -feliminate-unused-debug-types -fexpensive-optimizations
# -fforward-propagate -ffunction-cse -fgcse -fgcse-lm
# -fguess-branch-probability -fident -fif-conversion -fif-conversion2
# -findirect-inlining -finline -finline-functions
# -finline-functions-called-once -finline-small-functions -fipa-cp
# -fipa-pure-const -fipa-reference -fipa-sra -fira-share-save-slots
# -fira-share-spill-slots -fivopts -fkeep-static-consts
# -fleading-underscore -fmath-errno -fmerge-constants -fmerge-debug-strings
# -fmove-loop-invariants -fomit-frame-pointer -foptimize-register-move
# -foptimize-sibling-calls -fpeephole -fpeephole2 -freg-struct-return
# -fregmove -freorder-blocks -freorder-functions -frerun-cse-after-loop
# -fsched-critical-path-heuristic -fsched-dep-count-heuristic
# -fsched-group-heuristic -fsched-interblock -fsched-last-insn-heuristic
# -fsched-rank-heuristic -fsched-spec -fsched-spec-insn-heuristic
# -fsched-stalled-insns-dep -fschedule-insns2 -fshow-column -fsigned-zeros
# -fsplit-ivs-in-unroller -fsplit-wide-types -fthread-jumps
# -ftoplevel-reorder -ftrapping-math -ftree-builtin-call-dce -ftree-ccp
# -ftree-ch -ftree-copy-prop -ftree-copyrename -ftree-cselim -ftree-dce
# -ftree-dominator-opts -ftree-dse -ftree-forwprop -ftree-fre
# -ftree-loop-im -ftree-loop-ivcanon -ftree-loop-optimize
# -ftree-parallelize-loops= -ftree-phiprop -ftree-pre -ftree-pta
# -ftree-reassoc -ftree-scev-cprop -ftree-sink -ftree-slp-vectorize
# -ftree-sra -ftree-switch-conversion -ftree-ter -ftree-vect-loop-version
# -ftree-vrp -funit-at-a-time -fvect-cost-model -fverbose-asm
# -fzero-initialized-in-bss -m32 -m96bit-long-double -malign-stringops
# -mfused-madd -mglibc -mieee-fp -mno-fancy-math-387 -mno-red-zone
# -mno-sse4 -mpush-args -msahf -mtls-direct-seg-refs
# Compiler executable checksum: 7ba2dc3c015559b9d16b297ee7f8d354
.text
.type i8k_smm, @function
i8k_smm:
pushl %ebp #
movl %eax, %ebp # regs, regs
pushl %edi #
pushl %esi #
pushl %ebx #
subl $8, %esp #,
movl (%eax), %eax # regs_2(D)->eax,
movl %eax, 4(%esp) #, %sfp
movl %ebp, %eax # regs,
#APP
# 148 "drivers/char/i8k.c" 1
pushl %eax
movl 0(%eax),%edx
push %edx
movl 4(%eax),%ebx
movl 8(%eax),%ecx
movl 12(%eax),%edx
movl 16(%eax),%esi
movl 20(%eax),%edi
popl %eax
out %al,$0xb2
out %al,$0x84
xchgl %eax,(%esp)
movl %ebx,4(%eax)
movl %ecx,8(%eax)
movl %edx,12(%eax)
movl %esi,16(%eax)
movl %edi,20(%eax)
popl %edx
movl %edx,0(%eax)
lahf
shrl $8,%eax
andl $1,%eax
# 0 "" 2
#NO_APP
testl %eax, %eax #
movl $-22, %edx #, D.15130
movl %eax, (%esp) #, %sfp
jne .L2 #,
movl 0(%ebp), %ecx # regs_2(D)->eax, D.15123
cmpw $-1, %cx #, D.15123
je .L2 #,
cmpl 4(%esp), %ecx # %sfp, D.15123
cmovne %eax, %edx #,, D.15130
.L2:
addl $8, %esp #,
movl %edx, %eax # D.15130,
popl %ebx #
popl %esi #
popl %edi #
popl %ebp #
ret
.size i8k_smm, .-i8k_smm
.type i8k_get_bios_version, @function
i8k_get_bios_version:
pushl %edi #
xorl %eax, %eax # tmp61
subl $24, %esp #,
movl $6, %ecx #, tmp62
movl %esp, %edi #, tmp60
rep stosl
movl %esp, %eax #, tmp63
movl $166, (%esp) #, regs.eax
call i8k_smm #
movl $166, %edx #, tmp65
testl %eax, %eax # D.15225
cmove %edx, %eax # D.15225,, tmp65, D.15225
addl $24, %esp #,
popl %edi #
ret
.size i8k_get_bios_version, .-i8k_get_bios_version
.type i8k_get_fn_status, @function
i8k_get_fn_status:
pushl %edi #
movl $6, %ecx #, tmp63
pushl %ebx #
xorl %ebx, %ebx # tmp62
subl $24, %esp #,
movl %ebx, %eax # tmp62,
movl %esp, %edi #, tmp61
rep stosl
movl %esp, %eax #, tmp64
movl $37, (%esp) #, regs.eax
call i8k_smm #
testl %eax, %eax # rc
cmovg %ebx, %eax # rc,, tmp62, tmp65
addl $24, %esp #,
popl %ebx #
popl %edi #
ret
.size i8k_get_fn_status, .-i8k_get_fn_status
.type i8k_get_power_status, @function
i8k_get_power_status:
pushl %edi #
movl $6, %ecx #, tmp63
pushl %ebx #
xorl %ebx, %ebx # tmp62
subl $24, %esp #,
movl %ebx, %eax # tmp62,
movl %esp, %edi #, tmp61
rep stosl
movl %esp, %eax #, tmp64
movl $105, (%esp) #, regs.eax
call i8k_smm #
testl %eax, %eax # rc
cmovg %ebx, %eax # rc,, tmp62, tmp65
addl $24, %esp #,
popl %ebx #
popl %edi #
ret
.size i8k_get_power_status, .-i8k_get_power_status
.type i8k_get_fan_status, @function
i8k_get_fan_status:
pushl %edi #
movl %eax, %edx # fan, fan
subl $24, %esp #,
xorl %eax, %eax # tmp64
movl %esp, %edi #, tmp63
movl $6, %ecx #, tmp65
rep stosl
andl $255, %edx #, tmp66
movl %esp, %eax #, tmp67
movl %edx, 4(%esp) # tmp66, regs.ebx
movl $163, (%esp) #, regs.eax
call i8k_smm #
movl $163, %edx #, tmp69
testl %eax, %eax # D.15134
cmove %edx, %eax # D.15134,, tmp69, D.15134
addl $24, %esp #,
popl %edi #
ret
.size i8k_get_fan_status, .-i8k_get_fan_status
.type i8k_get_fan_speed, @function
i8k_get_fan_speed:
pushl %edi #
movl %eax, %edx # fan, fan
subl $24, %esp #,
xorl %eax, %eax # tmp67
movl %esp, %edi #, tmp66
movl $6, %ecx #, tmp68
rep stosl
andl $255, %edx #, tmp69
movl %esp, %eax #, tmp70
movl $675, (%esp) #, regs.eax
movl %edx, 4(%esp) # tmp69, regs.ebx
call i8k_smm #
testl %eax, %eax # D.15145
jne .L13 #,
imull $675, fan_mult, %eax #, fan_mult, D.15145
.L13:
addl $24, %esp #,
popl %edi #
ret
.size i8k_get_fan_speed, .-i8k_get_fan_speed
.type i8k_get_dell_signature, @function
i8k_get_dell_signature:
pushl %edi #
movl %eax, %edx # req_fn, req_fn
subl $24, %esp #,
xorl %eax, %eax # tmp63
movl %esp, %edi #, tmp62
movl $6, %ecx #, tmp64
rep stosl
movl %esp, %eax #, tmp65
movl %edx, (%esp) # req_fn, regs.eax
call i8k_smm #
movl $-1, %edx #, tmp67
testl %eax, %eax # rc
cmovns %edx, %eax # rc,, tmp67, rc
addl $24, %esp #,
popl %edi #
ret
.size i8k_get_dell_signature, .-i8k_get_dell_signature
.type i8k_open_fs, @function
i8k_open_fs:
movl %edx, %eax # file, file
xorl %ecx, %ecx #
movl $i8k_proc_show, %edx #,
jmp single_open #
.size i8k_open_fs, .-i8k_open_fs
.section .rodata.str1.1,"aMS",@progbits,1
.LC0:
.string "?"
.text
.type i8k_get_dmi_data, @function
i8k_get_dmi_data:
call dmi_get_system_info #
testl %eax, %eax # dmi_data
je .L20 #,
cmpb $0, (%eax) #,* dmi_data
movl $.LC0, %edx #, tmp63
cmove %edx, %eax # dmi_data,, tmp63, dmi_data
ret
.L20:
movl $.LC0, %eax #, dmi_data
ret
.size i8k_get_dmi_data, .-i8k_get_dmi_data
.type i8k_get_temp.clone.1, @function
i8k_get_temp.clone.1:
pushl %edi #
xorl %eax, %eax # tmp61
subl $24, %esp #,
movl $6, %ecx #, tmp62
movl %esp, %edi #, tmp60
rep stosl
movl %esp, %eax #, tmp63
movl $4259, (%esp) #, regs.eax
call i8k_smm #
testl %eax, %eax # rc
js .L22 #,
movl prev.12857, %eax # prev, rc
movl $127, prev.12857 #, prev
.L22:
addl $24, %esp #,
popl %edi #
ret
.size i8k_get_temp.clone.1, .-i8k_get_temp.clone.1
.section .rodata.str1.1
.LC1:
.string "1.0"
.LC2:
.string "%s %s %s %d %d %d %d %d %d %d\n"
.text
.type i8k_proc_show, @function
i8k_proc_show:
pushl %ebp #
pushl %edi #
pushl %esi #
pushl %ebx #
orl $-1, %ebx #, ac_power
subl $16, %esp #,
movl %eax, 12(%esp) # seq, %sfp
call i8k_get_temp.clone.1 #
movl %eax, (%esp) #, %sfp
movl $1, %eax #,
call i8k_get_fan_status #
movl %eax, 4(%esp) #, %sfp
xorl %eax, %eax #
call i8k_get_fan_status #
movl %eax, %esi #, right_fan
movl $1, %eax #,
call i8k_get_fan_speed #
movl %eax, %edi #, left_speed
xorl %eax, %eax #
call i8k_get_fan_speed #
movl %eax, %ebp #, right_speed
call i8k_get_fn_status #
cmpl $0, power_status #, power_status
movl %eax, 8(%esp) #, %sfp
je .L24 #,
call i8k_get_power_status #
movl %eax, %ebx #, ac_power
.L24:
movl $7, %eax #,
call i8k_get_dmi_data #
pushl 8(%esp) # %sfp
pushl %ebx # ac_power
pushl %ebp # right_speed
pushl %edi # left_speed
pushl %esi # right_fan
pushl 24(%esp) # %sfp
pushl 24(%esp) # %sfp
pushl %eax # D.15110
pushl $bios_version #
pushl $.LC1 #
pushl $.LC2 #
pushl 56(%esp) # %sfp
call seq_printf #
addl $64, %esp #,
popl %ebx #
popl %esi #
popl %edi #
popl %ebp #
ret
.size i8k_proc_show, .-i8k_proc_show
.type copy_from_user.clone.2, @function
copy_from_user.clone.2:
movl $4, %ecx #,
jmp _copy_from_user #
.size copy_from_user.clone.2, .-copy_from_user.clone.2
.type i8k_ioctl, @function
i8k_ioctl:
pushl %ebp #
movl %edx, %ebp # cmd, cmd
pushl %edi #
pushl %esi #
movl $-22, %esi #, ret
pushl %ebx #
movl %ecx, %ebx # arg, arg
subl $48, %esp #,
testl %ecx, %ecx # arg
movl $0, 44(%esp) #, val
je .L28 #,
cmpl $-2147194493, %edx #, cmd
je .L32 #,
ja .L37 #,
cmpl $-2147194495, %edx #, cmd
je .L30 #,
ja .L31 #,
cmpl $-2147194496, %edx #, cmd
jne .L46 #,
jmp .L58 #
.L37:
cmpl $-1073452667, %edx #, cmd
je .L34 #,
ja .L38 #,
cmpl $-2147194492, %edx #, cmd
jne .L46 #,
jmp .L59 #
.L38:
cmpl $-1073452666, %edx #, cmd
je .L35 #,
cmpl $-1073452665, %edx #, cmd
jne .L46 #,
jmp .L60 #
.L58:
call i8k_get_bios_version #
jmp .L41 #
.L30:
leal 24(%esp), %esi #, tmp93
xorl %eax, %eax # tmp95
movl %esi, %edi # tmp93, tmp94
movl $4, %ecx #, tmp96
rep stosl
movb $7, %al #,
call i8k_get_dmi_data #
movl $16, %ecx #,
movl %eax, %edx # D.15468,
movl %esi, %eax # tmp93,
call strlcpy #
jmp .L39 #
.L32:
call i8k_get_fn_status #
jmp .L41 #
.L31:
call i8k_get_power_status #
jmp .L41 #
.L59:
call i8k_get_temp.clone.1 #
jmp .L41 #
.L34:
leal 44(%esp), %eax #, tmp98
movl %ecx, %edx # arg,
call copy_from_user.clone.2 #
movl $-14, %esi #, ret
testl %eax, %eax # D.15473
jne .L28 #,
movl 44(%esp), %eax # val,
call i8k_get_fan_speed #
jmp .L41 #
.L35:
leal 44(%esp), %eax #, tmp100
movl %ecx, %edx # arg,
call copy_from_user.clone.2 #
movl $-14, %esi #, ret
testl %eax, %eax # D.15476
jne .L28 #,
movl 44(%esp), %eax # val,
jmp .L57 #
.L60:
cmpl $0, restricted #, restricted
je .L40 #,
movl $21, %eax #,
orl $-1, %esi #, ret
call capable #
testl %eax, %eax # D.15479
je .L28 #,
.L40:
leal 44(%esp), %eax #, tmp102
movl %ebx, %edx # arg,
call copy_from_user.clone.2 #
movl $-14, %esi #, ret
testl %eax, %eax # D.15480
jne .L28 #,
leal 4(%ebx), %edx #, tmp103
leal 40(%esp), %eax #, tmp104
call copy_from_user.clone.2 #
testl %eax, %eax # D.15482
jne .L28 #,
movl %esp, %edi #, tmp105
movl $6, %ecx #, tmp107
movl 40(%esp), %edx # speed, speed.19
rep stosl
movl 44(%esp), %esi # val, val.15
movl $419, (%esp) #, regs.eax
cmpl $2, %edx #, speed.19
movb $2, %cl #,
cmovle %edx, %ecx # speed.19,, speed
movl %esi, %edx # val.15, tmp112
testl %ecx, %ecx # speed
cmovns %ecx, %eax # speed,, tmp113
andl $255, %edx #, tmp112
sall $8, %eax #, tmp113
orl %edx, %eax # tmp112, tmp113
movl %eax, 4(%esp) # tmp113, regs.ebx
movl %esp, %eax #, tmp114
call i8k_smm #
testl %eax, %eax # D.15487
jne .L41 #,
movl %esi, %eax # val.15,
.L57:
call i8k_get_fan_status #
.L41:
movl %eax, 44(%esp) # D.15487, val
.L39:
movl 44(%esp), %esi # val, ret
testl %esi, %esi # ret
js .L28 #,
cmpl $-2147194496, %ebp #, cmd
je .L55 #,
cmpl $-2147194495, %ebp #, cmd
jne .L55 #,
leal 24(%esp), %edx #, tmp116
movl $16, %ecx #,
.L56:
movl %ebx, %eax # arg,
call copy_to_user #
cmpl $1, %eax #, D.15485
sbbl %esi, %esi # ret
notl %esi # ret
andl $-14, %esi #, ret
jmp .L28 #
.L55:
leal 44(%esp), %edx #, tmp117
movl $4, %ecx #,
jmp .L56 #
.L46:
movl $-22, %esi #, ret
.L28:
addl $48, %esp #,
movl %esi, %eax # ret,
popl %ebx #
popl %esi #
popl %edi #
popl %ebp #
ret
.size i8k_ioctl, .-i8k_ioctl
.section .rodata.str1.1
.LC3:
.string "<6>i8k: not running on a supported Dell system.\n"
.LC4:
.string "<6>i8k: vendor=%s, model=%s, version=%s\n"
.LC5:
.string "<3>i8k: unable to get SMM Dell signature\n"
.LC6:
.string "<4>i8k: unable to get SMM BIOS version\n"
.LC7:
.string "<4>i8k: BIOS version mismatch: %s != %s\n"
.LC8:
.string "1.14 21/02/2005"
.LC9:
.string "<6>Dell laptop SMM driver v%s Massimo Dal Zotto (dz@debian.org)\n"
.LC10:
.string "i8k"
.section .init.text,"ax",@progbits
.type i8k_init, @function
i8k_init:
pushl %esi #
movl $i8k_dmi_table, %eax #,
pushl %ebx #
subl $4, %esp #,
call dmi_check_system #
testl %eax, %eax # D.15529
jne .L62 #,
cmpl $0, ignore_dmi #, ignore_dmi
jne .L63 #,
cmpl $0, force #, force
movl $-19, %eax #, D.15099
je .L64 #,
.L63:
pushl $.LC3 #
call printk #
movl $2, %eax #,
call i8k_get_dmi_data #
movl %eax, %esi #, D.15525
movl $5, %eax #,
call i8k_get_dmi_data #
movl %eax, %ebx #, D.15524
movl $4, %eax #,
call i8k_get_dmi_data #
pushl %esi # D.15525
pushl %ebx # D.15524
pushl %eax # D.15523
pushl $.LC4 #
call printk #
addl $20, %esp #,
.L62:
movl $2, %eax #,
call i8k_get_dmi_data #
movl $4, %ecx #,
movl %eax, %edx # D.15522,
movl $bios_version, %eax #,
call strlcpy #
movl $65187, %eax #,
call i8k_get_dell_signature #
testl %eax, %eax # D.15521
je .L65 #,
movl $65443, %eax #,
call i8k_get_dell_signature #
testl %eax, %eax # D.15520
je .L65 #,
pushl $.LC5 #
call printk #
movl $-19, %eax #, D.15099
cmpl $0, force #, force
popl %edx #
je .L64 #,
.L65:
call i8k_get_bios_version #
testl %eax, %eax # version
jg .L66 #,
pushl $.LC6 #
call printk #
popl %eax #
jmp .L67 #
.L66:
movl %eax, %edx # version, tmp79
sarl $16, %edx #, tmp79
movb %dl, (%esp) # tmp79, buff
movl %eax, %edx # version, tmp80
sarl $8, %edx #, tmp80
movb %al, 2(%esp) # version, buff
movl $2, %eax #,
movb %dl, 1(%esp) # tmp80, buff
movb $0, 3(%esp) #, buff
call dmi_get_system_info #
testl %eax, %eax # D.15514
jne .L68 #,
movl %esp, %edx #, tmp81
movl $4, %ecx #,
movl $bios_version, %eax #,
call strlcpy #
.L68:
movl $4, %ecx #,
movl $bios_version, %edx #,
movl %esp, %eax #,
movl %esp, %ebx #, tmp82
call strncmp #
testl %eax, %eax # D.15513
je .L67 #,
pushl $bios_version #
pushl %ebx # tmp82
pushl $.LC7 #
call printk #
addl $12, %esp #,
jmp .L67 #
.L74:
pushl $.LC8 #
pushl $.LC9 #
call printk #
xorl %eax, %eax # D.15099
popl %ebx #
popl %esi #
.L64:
addl $4, %esp #,
popl %ebx #
popl %esi #
ret
.L67:
pushl $0 #
xorl %ecx, %ecx #
xorl %edx, %edx #
movl $.LC10, %eax #,
pushl $i8k_fops #
call proc_create_data #
movl %eax, %edx #, proc_i8k
testl %edx, %edx # proc_i8k
popl %eax #
movl $-2, %eax #, D.15099
popl %ecx #
je .L64 #,
jmp .L74 #
.size i8k_init, .-i8k_init
.section .exit.text,"ax",@progbits
.type i8k_exit, @function
i8k_exit:
xorl %edx, %edx #
movl $.LC10, %eax #,
jmp remove_proc_entry #
.size i8k_exit, .-i8k_exit
.section .modinfo,"a",@progbits
.align 4
.type __mod_fan_mult83, @object
.size __mod_fan_mult83, 48
__mod_fan_mult83:
.string "parm=fan_mult:Factor to multiply fan speed with"
.align 4
.type __mod_fan_multtype82, @object
.size __mod_fan_multtype82, 22
__mod_fan_multtype82:
.string "parmtype=fan_mult:int"
.section __param,"a",@progbits
.align 4
.type __param_fan_mult, @object
.size __param_fan_mult, 16
__param_fan_mult:
# name:
.long __param_str_fan_mult
# ops:
.long param_ops_int
# perm:
.value 0
# flags:
.value 0
# <anonymous>:
# arg:
.long fan_mult
.section .modinfo
.align 4
.type __mod_power_status79, @object
.size __mod_power_status79, 51
__mod_power_status79:
.string "parm=power_status:Report power status in /proc/i8k"
.align 4
.type __mod_power_statustype78, @object
.size __mod_power_statustype78, 27
__mod_power_statustype78:
.string "parmtype=power_status:bool"
.section __param
.align 4
.type __param_power_status, @object
.size __param_power_status, 16
__param_power_status:
# name:
.long __param_str_power_status
# ops:
.long param_ops_bool
# perm:
.value 384
# flags:
.value 0
# <anonymous>:
# arg:
.long power_status
.section .modinfo
.align 4
.type __mod_restricted75, @object
.size __mod_restricted75, 62
__mod_restricted75:
.string "parm=restricted:Allow fan control if SYS_ADMIN capability set"
.align 4
.type __mod_restrictedtype74, @object
.size __mod_restrictedtype74, 25
__mod_restrictedtype74:
.string "parmtype=restricted:bool"
.section __param
.align 4
.type __param_restricted, @object
.size __param_restricted, 16
__param_restricted:
# name:
.long __param_str_restricted
# ops:
.long param_ops_bool
# perm:
.value 0
# flags:
.value 0
# <anonymous>:
# arg:
.long restricted
.section .modinfo
.align 4
.type __mod_ignore_dmi71, @object
.size __mod_ignore_dmi71, 74
__mod_ignore_dmi71:
.string "parm=ignore_dmi:Continue probing hardware even if DMI data does not match"
.align 4
.type __mod_ignore_dmitype70, @object
.size __mod_ignore_dmitype70, 25
__mod_ignore_dmitype70:
.string "parmtype=ignore_dmi:bool"
.section __param
.align 4
.type __param_ignore_dmi, @object
.size __param_ignore_dmi, 16
__param_ignore_dmi:
# name:
.long __param_str_ignore_dmi
# ops:
.long param_ops_bool
# perm:
.value 0
# flags:
.value 0
# <anonymous>:
# arg:
.long ignore_dmi
.section .modinfo
.align 4
.type __mod_force67, @object
.size __mod_force67, 63
__mod_force67:
.string "parm=force:Force loading without checking for supported models"
.align 4
.type __mod_forcetype66, @object
.size __mod_forcetype66, 20
__mod_forcetype66:
.string "parmtype=force:bool"
.section __param
.align 4
.type __param_force, @object
.size __param_force, 16
__param_force:
# name:
.long __param_str_force
# ops:
.long param_ops_bool
# perm:
.value 0
# flags:
.value 0
# <anonymous>:
# arg:
.long force
.section .modinfo
.align 4
.type __mod_license63, @object
.size __mod_license63, 12
__mod_license63:
.string "license=GPL"
.align 4
.type __mod_description62, @object
.size __mod_description62, 58
__mod_description62:
.string "description=Driver for accessing SMM BIOS on Dell laptops"
.align 4
.type __mod_author61, @object
.size __mod_author61, 41
__mod_author61:
.string "author=Massimo Dal Zotto (dz@debian.org)"
.data
.align 4
.type fan_mult, @object
.size fan_mult, 4
fan_mult:
.long 30
.local power_status
.comm power_status,4,4
.local restricted
.comm restricted,4,4
.local ignore_dmi
.comm ignore_dmi,4,4
.local force
.comm force,4,4
.section .rodata
.align 4
.type i8k_fops, @object
.size i8k_fops, 100
i8k_fops:
# owner:
.long __this_module
# llseek:
.long seq_lseek
# read:
.long seq_read
# unlocked_ioctl:
.zero 20
.long i8k_ioctl
# open:
.zero 8
.long i8k_open_fs
# release:
.zero 4
.long single_release
.zero 44
.local bios_version
.comm bios_version,4,4
.local prev.12857
.comm prev.12857,4,4
.section .rodata.str1.1
.LC11:
.string "Dell Inspiron"
.LC12:
.string "Dell Latitude"
.LC13:
.string "Dell Inspiron 2"
.LC14:
.string "Dell Latitude 2"
.LC15:
.string "Dell Inspiron 3"
.LC16:
.string "Dell Precision"
.LC17:
.string "Dell Vostro"
.section .init.data,"aw",@progbits
.align 4
.type i8k_dmi_table, @object
.size i8k_dmi_table, 2988
i8k_dmi_table:
# ident:
.zero 4
.long .LC11
# matches:
# slot:
.byte 4
# substr:
.string "Dell Computer"
.zero 65
# slot:
.byte 5
# substr:
.string "Inspiron"
.zero 70
.zero 160
.zero 4
# ident:
.zero 4
.long .LC12
# matches:
# slot:
.byte 4
# substr:
.string "Dell Computer"
.zero 65
# slot:
.byte 5
# substr:
.string "Latitude"
.zero 70
.zero 160
.zero 4
# ident:
.zero 4
.long .LC13
# matches:
# slot:
.byte 4
# substr:
.string "Dell Inc."
.zero 69
# slot:
.byte 5
# substr:
.string "Inspiron"
.zero 70
.zero 160
.zero 4
# ident:
.zero 4
.long .LC14
# matches:
# slot:
.byte 4
# substr:
.string "Dell Inc."
.zero 69
# slot:
.byte 5
# substr:
.string "Latitude"
.zero 70
.zero 160
.zero 4
# ident:
.zero 4
.long .LC15
# matches:
# slot:
.byte 4
# substr:
.string "Dell Inc."
.zero 69
# slot:
.byte 5
# substr:
.string "MM061"
.zero 73
.zero 160
.zero 4
# ident:
.zero 4
.long .LC15
# matches:
# slot:
.byte 4
# substr:
.string "Dell Inc."
.zero 69
# slot:
.byte 5
# substr:
.string "MP061"
.zero 73
.zero 160
.zero 4
# ident:
.zero 4
.long .LC16
# matches:
# slot:
.byte 4
# substr:
.string "Dell Inc."
.zero 69
# slot:
.byte 5
# substr:
.string "Precision"
.zero 69
.zero 160
.zero 4
# ident:
.zero 4
.long .LC17
# matches:
# slot:
.byte 4
# substr:
.string "Dell Inc."
.zero 69
# slot:
.byte 5
# substr:
.string "Vostro"
.zero 72
.zero 160
.zero 4
.zero 332
.section .rodata
.align 4
.type __param_str_fan_mult, @object
.size __param_str_fan_mult, 9
__param_str_fan_mult:
.string "fan_mult"
.align 4
.type __param_str_power_status, @object
.size __param_str_power_status, 13
__param_str_power_status:
.string "power_status"
.align 4
.type __param_str_restricted, @object
.size __param_str_restricted, 11
__param_str_restricted:
.string "restricted"
.align 4
.type __param_str_ignore_dmi, @object
.size __param_str_ignore_dmi, 11
__param_str_ignore_dmi:
.string "ignore_dmi"
.align 4
.type __param_str_force, @object
.size __param_str_force, 6
__param_str_force:
.string "force"
.globl init_module
.set init_module,i8k_init
.globl cleanup_module
.set cleanup_module,i8k_exit
.ident "GCC: (GNU) 4.5.1"
.section .note.GNU-stack,"",@progbits
[-- Attachment #3: i8k.s-2.6.36+patch --]
[-- Type: text/plain, Size: 22948 bytes --]
.file "i8k.c"
# GNU C (GCC) version 4.5.1 (i486-slackware-linux)
# compiled by GNU C version 4.5.1, GMP version 5.0.1, MPFR version 2.4.2-p3, MPC version 0.8.2
# GGC heuristics: --param ggc-min-expand=81 --param ggc-min-heapsize=96817
# options passed: -nostdinc -I/usr/src/linux-2.6.36/arch/x86/include
# -Iinclude -D__KERNEL__ -DCONFIG_AS_CFI=1 -DCONFIG_AS_CFI_SIGNAL_FRAME=1
# -DCONFIG_AS_CFI_SECTIONS=1 -DMODULE -DKBUILD_STR(s)=#s
# -DKBUILD_BASENAME=KBUILD_STR(i8k) -DKBUILD_MODNAME=KBUILD_STR(i8k)
# -isystem /usr/lib/gcc/i486-slackware-linux/4.5.1/include -include
# include/generated/autoconf.h -MD drivers/char/.i8k.s.d drivers/char/i8k.c
# -m32 -msoft-float -mregparm=3 -mpreferred-stack-boundary=2 -march=i686
# -mtune=pentium3 -mtune=generic -mno-sse -mno-mmx -mno-sse2 -mno-3dnow
# -auxbase-strip drivers/char/i8k.s -Os -Wall -Wundef -Wstrict-prototypes
# -Wno-trigraphs -Werror-implicit-function-declaration -Wno-format-security
# -Wno-sign-compare -Wframe-larger-than=1024 -Wdeclaration-after-statement
# -Wno-pointer-sign -fno-strict-aliasing -fno-common
# -fno-delete-null-pointer-checks -freg-struct-return -ffreestanding
# -fno-asynchronous-unwind-tables -fno-stack-protector -fomit-frame-pointer
# -fno-strict-overflow -fconserve-stack -fverbose-asm
# options enabled: -falign-loops -fargument-alias -fauto-inc-dec
# -fbranch-count-reg -fcaller-saves -fcprop-registers -fcrossjumping
# -fcse-follow-jumps -fdefer-pop -fdwarf2-cfi-asm -fearly-inlining
# -feliminate-unused-debug-types -fexpensive-optimizations
# -fforward-propagate -ffunction-cse -fgcse -fgcse-lm
# -fguess-branch-probability -fident -fif-conversion -fif-conversion2
# -findirect-inlining -finline -finline-functions
# -finline-functions-called-once -finline-small-functions -fipa-cp
# -fipa-pure-const -fipa-reference -fipa-sra -fira-share-save-slots
# -fira-share-spill-slots -fivopts -fkeep-static-consts
# -fleading-underscore -fmath-errno -fmerge-constants -fmerge-debug-strings
# -fmove-loop-invariants -fomit-frame-pointer -foptimize-register-move
# -foptimize-sibling-calls -fpeephole -fpeephole2 -freg-struct-return
# -fregmove -freorder-blocks -freorder-functions -frerun-cse-after-loop
# -fsched-critical-path-heuristic -fsched-dep-count-heuristic
# -fsched-group-heuristic -fsched-interblock -fsched-last-insn-heuristic
# -fsched-rank-heuristic -fsched-spec -fsched-spec-insn-heuristic
# -fsched-stalled-insns-dep -fschedule-insns2 -fshow-column -fsigned-zeros
# -fsplit-ivs-in-unroller -fsplit-wide-types -fthread-jumps
# -ftoplevel-reorder -ftrapping-math -ftree-builtin-call-dce -ftree-ccp
# -ftree-ch -ftree-copy-prop -ftree-copyrename -ftree-cselim -ftree-dce
# -ftree-dominator-opts -ftree-dse -ftree-forwprop -ftree-fre
# -ftree-loop-im -ftree-loop-ivcanon -ftree-loop-optimize
# -ftree-parallelize-loops= -ftree-phiprop -ftree-pre -ftree-pta
# -ftree-reassoc -ftree-scev-cprop -ftree-sink -ftree-slp-vectorize
# -ftree-sra -ftree-switch-conversion -ftree-ter -ftree-vect-loop-version
# -ftree-vrp -funit-at-a-time -fvect-cost-model -fverbose-asm
# -fzero-initialized-in-bss -m32 -m96bit-long-double -malign-stringops
# -mfused-madd -mglibc -mieee-fp -mno-fancy-math-387 -mno-red-zone
# -mno-sse4 -mpush-args -msahf -mtls-direct-seg-refs
# Compiler executable checksum: 7ba2dc3c015559b9d16b297ee7f8d354
.text
.type i8k_smm, @function
i8k_smm:
pushl %ebp #
movl %eax, %ebp # regs, regs
pushl %edi #
pushl %esi #
pushl %ebx #
subl $8, %esp #,
movl (%eax), %eax # regs_2(D)->eax,
movl %eax, 4(%esp) #, %sfp
movl %ebp, %eax # regs,
#APP
# 148 "drivers/char/i8k.c" 1
pushl %eax
movl 0(%eax),%edx
push %edx
movl 4(%eax),%ebx
movl 8(%eax),%ecx
movl 12(%eax),%edx
movl 16(%eax),%esi
movl 20(%eax),%edi
popl %eax
out %al,$0xb2
out %al,$0x84
xchgl %eax,(%esp)
movl %ebx,4(%eax)
movl %ecx,8(%eax)
movl %edx,12(%eax)
movl %esi,16(%eax)
movl %edi,20(%eax)
popl %edx
movl %edx,0(%eax)
lahf
shrl $8,%eax
andl $1,%eax
# 0 "" 2
#NO_APP
testl %eax, %eax #
movl $-22, %edx #, D.15130
movl %eax, (%esp) #, %sfp
jne .L2 #,
movl 0(%ebp), %ecx # regs_2(D)->eax, D.15123
cmpw $-1, %cx #, D.15123
je .L2 #,
cmpl 4(%esp), %ecx # %sfp, D.15123
cmovne %eax, %edx #,, D.15130
.L2:
addl $8, %esp #,
movl %edx, %eax # D.15130,
popl %ebx #
popl %esi #
popl %edi #
popl %ebp #
ret
.size i8k_smm, .-i8k_smm
.type i8k_get_bios_version, @function
i8k_get_bios_version:
pushl %edi #
xorl %eax, %eax # tmp62
subl $24, %esp #,
movl $6, %ecx #, tmp63
movl %esp, %edi #, tmp61
rep stosl
movl %esp, %eax #, tmp64
movl $166, (%esp) #, regs.eax
call i8k_smm #
testl %eax, %eax # D.15225
cmove (%esp), %eax # regs.eax,, D.15225
addl $24, %esp #,
popl %edi #
ret
.size i8k_get_bios_version, .-i8k_get_bios_version
.type i8k_get_fn_status, @function
i8k_get_fn_status:
pushl %edi #
xorl %eax, %eax # tmp65
subl $24, %esp #,
movl $6, %ecx #, tmp66
movl %esp, %edi #, tmp64
rep stosl
movl %esp, %eax #, tmp67
movl $37, (%esp) #, regs.eax
call i8k_smm #
testl %eax, %eax # rc
js .L9 #,
movl (%esp), %eax # regs.eax, csui.31
shrl $8, %eax #, csui.31
andl $7, %eax #, csui.31
leal -1(%eax), %edx #, csui.31
xorl %eax, %eax # rc
cmpl $3, %edx #, csui.31
ja .L9 #,
movl CSWTCH.30(,%edx,4), %eax # CSWTCH.30, rc
.L9:
addl $24, %esp #,
popl %edi #
ret
.size i8k_get_fn_status, .-i8k_get_fn_status
.type i8k_get_power_status, @function
i8k_get_power_status:
pushl %edi #
xorl %eax, %eax # tmp63
subl $24, %esp #,
movl $6, %ecx #, tmp64
movl %esp, %edi #, tmp62
rep stosl
movl %esp, %eax #, tmp65
movl $105, (%esp) #, regs.eax
call i8k_smm #
testl %eax, %eax # rc
js .L12 #,
xorl %eax, %eax # rc
cmpb $5, (%esp) #, regs.eax
sete %al #, rc
.L12:
addl $24, %esp #,
popl %edi #
ret
.size i8k_get_power_status, .-i8k_get_power_status
.type i8k_get_fan_status, @function
i8k_get_fan_status:
pushl %edi #
movl %eax, %edx # fan, fan
subl $24, %esp #,
xorl %eax, %eax # tmp66
movl %esp, %edi #, tmp65
movl $6, %ecx #, tmp67
rep stosl
andl $255, %edx #, tmp68
movl %esp, %eax #, tmp69
movl $163, (%esp) #, regs.eax
movl %edx, 4(%esp) # tmp68, regs.ebx
call i8k_smm #
testl %eax, %eax # D.15134
jne .L14 #,
movl (%esp), %eax # regs.eax, regs.eax
andl $255, %eax #, D.15134
.L14:
addl $24, %esp #,
popl %edi #
ret
.size i8k_get_fan_status, .-i8k_get_fan_status
.type i8k_get_fan_speed, @function
i8k_get_fan_speed:
pushl %edi #
movl %eax, %edx # fan, fan
subl $24, %esp #,
xorl %eax, %eax # tmp69
movl %esp, %edi #, tmp68
movl $6, %ecx #, tmp70
rep stosl
andl $255, %edx #, tmp71
movl %esp, %eax #, tmp72
movl $675, (%esp) #, regs.eax
movl %edx, 4(%esp) # tmp71, regs.ebx
call i8k_smm #
testl %eax, %eax # D.15145
jne .L16 #,
movl (%esp), %eax # regs.eax, regs.eax
andl $65535, %eax #, D.15145
imull fan_mult, %eax # fan_mult, D.15145
.L16:
addl $24, %esp #,
popl %edi #
ret
.size i8k_get_fan_speed, .-i8k_get_fan_speed
.type i8k_get_dell_signature, @function
i8k_get_dell_signature:
pushl %edi #
movl %eax, %edx # req_fn, req_fn
subl $24, %esp #,
xorl %eax, %eax # tmp65
movl %esp, %edi #, tmp64
movl $6, %ecx #, tmp66
rep stosl
movl %esp, %eax #, tmp67
movl %edx, (%esp) # req_fn, regs.eax
call i8k_smm #
testl %eax, %eax # rc
js .L18 #,
orl $-1, %eax #, rc
cmpl $1145651527, (%esp) #, regs.eax
jne .L18 #,
xorl %eax, %eax # rc
cmpl $1145392204, 12(%esp) #, regs.edx
sete %al #, rc
decl %eax # rc
.L18:
addl $24, %esp #,
popl %edi #
ret
.size i8k_get_dell_signature, .-i8k_get_dell_signature
.type i8k_open_fs, @function
i8k_open_fs:
movl %edx, %eax # file, file
xorl %ecx, %ecx #
movl $i8k_proc_show, %edx #,
jmp single_open #
.size i8k_open_fs, .-i8k_open_fs
.section .rodata.str1.1,"aMS",@progbits,1
.LC0:
.string "?"
.text
.type i8k_get_dmi_data, @function
i8k_get_dmi_data:
call dmi_get_system_info #
testl %eax, %eax # dmi_data
je .L24 #,
cmpb $0, (%eax) #,* dmi_data
movl $.LC0, %edx #, tmp63
cmove %edx, %eax # dmi_data,, tmp63, dmi_data
ret
.L24:
movl $.LC0, %eax #, dmi_data
ret
.size i8k_get_dmi_data, .-i8k_get_dmi_data
.type i8k_get_temp.clone.1, @function
i8k_get_temp.clone.1:
pushl %edi #
xorl %eax, %eax # tmp63
subl $24, %esp #,
movl $6, %ecx #, tmp64
movl %esp, %edi #, tmp62
rep stosl
movl %esp, %eax #, tmp65
movl $4259, (%esp) #, regs.eax
call i8k_smm #
testl %eax, %eax # rc
js .L26 #,
movl (%esp), %eax # regs.eax, regs.eax
andl $255, %eax #, rc
cmpl $127, %eax #, rc
jle .L27 #,
movl prev.12857, %eax # prev, rc
movl $127, prev.12857 #, prev
jmp .L26 #
.L27:
movl %eax, prev.12857 # rc, prev
.L26:
addl $24, %esp #,
popl %edi #
ret
.size i8k_get_temp.clone.1, .-i8k_get_temp.clone.1
.section .rodata.str1.1
.LC1:
.string "1.0"
.LC2:
.string "%s %s %s %d %d %d %d %d %d %d\n"
.text
.type i8k_proc_show, @function
i8k_proc_show:
pushl %ebp #
pushl %edi #
pushl %esi #
pushl %ebx #
orl $-1, %ebx #, ac_power
subl $16, %esp #,
movl %eax, 12(%esp) # seq, %sfp
call i8k_get_temp.clone.1 #
movl %eax, (%esp) #, %sfp
movl $1, %eax #,
call i8k_get_fan_status #
movl %eax, 4(%esp) #, %sfp
xorl %eax, %eax #
call i8k_get_fan_status #
movl %eax, %esi #, right_fan
movl $1, %eax #,
call i8k_get_fan_speed #
movl %eax, %edi #, left_speed
xorl %eax, %eax #
call i8k_get_fan_speed #
movl %eax, %ebp #, right_speed
call i8k_get_fn_status #
cmpl $0, power_status #, power_status
movl %eax, 8(%esp) #, %sfp
je .L29 #,
call i8k_get_power_status #
movl %eax, %ebx #, ac_power
.L29:
movl $7, %eax #,
call i8k_get_dmi_data #
pushl 8(%esp) # %sfp
pushl %ebx # ac_power
pushl %ebp # right_speed
pushl %edi # left_speed
pushl %esi # right_fan
pushl 24(%esp) # %sfp
pushl 24(%esp) # %sfp
pushl %eax # D.15110
pushl $bios_version #
pushl $.LC1 #
pushl $.LC2 #
pushl 56(%esp) # %sfp
call seq_printf #
addl $64, %esp #,
popl %ebx #
popl %esi #
popl %edi #
popl %ebp #
ret
.size i8k_proc_show, .-i8k_proc_show
.type copy_from_user.clone.2, @function
copy_from_user.clone.2:
movl $4, %ecx #,
jmp _copy_from_user #
.size copy_from_user.clone.2, .-copy_from_user.clone.2
.type i8k_ioctl, @function
i8k_ioctl:
pushl %ebp #
movl %edx, %ebp # cmd, cmd
pushl %edi #
pushl %esi #
movl $-22, %esi #, ret
pushl %ebx #
movl %ecx, %ebx # arg, arg
subl $48, %esp #,
testl %ecx, %ecx # arg
movl $0, 44(%esp) #, val
je .L33 #,
cmpl $-2147194493, %edx #, cmd
je .L37 #,
ja .L42 #,
cmpl $-2147194495, %edx #, cmd
je .L35 #,
ja .L36 #,
cmpl $-2147194496, %edx #, cmd
jne .L51 #,
jmp .L63 #
.L42:
cmpl $-1073452667, %edx #, cmd
je .L39 #,
ja .L43 #,
cmpl $-2147194492, %edx #, cmd
jne .L51 #,
jmp .L64 #
.L43:
cmpl $-1073452666, %edx #, cmd
je .L40 #,
cmpl $-1073452665, %edx #, cmd
jne .L51 #,
jmp .L65 #
.L63:
call i8k_get_bios_version #
jmp .L46 #
.L35:
leal 24(%esp), %esi #, tmp93
xorl %eax, %eax # tmp95
movl %esi, %edi # tmp93, tmp94
movl $4, %ecx #, tmp96
rep stosl
movb $7, %al #,
call i8k_get_dmi_data #
movl $16, %ecx #,
movl %eax, %edx # D.15467,
movl %esi, %eax # tmp93,
call strlcpy #
jmp .L44 #
.L37:
call i8k_get_fn_status #
jmp .L46 #
.L36:
call i8k_get_power_status #
jmp .L46 #
.L64:
call i8k_get_temp.clone.1 #
jmp .L46 #
.L39:
leal 44(%esp), %eax #, tmp98
movl %ecx, %edx # arg,
call copy_from_user.clone.2 #
movl $-14, %esi #, ret
testl %eax, %eax # D.15472
jne .L33 #,
movl 44(%esp), %eax # val,
call i8k_get_fan_speed #
jmp .L46 #
.L40:
leal 44(%esp), %eax #, tmp100
movl %ecx, %edx # arg,
call copy_from_user.clone.2 #
movl $-14, %esi #, ret
testl %eax, %eax # D.15475
jne .L33 #,
movl 44(%esp), %eax # val,
jmp .L62 #
.L65:
cmpl $0, restricted #, restricted
je .L45 #,
movl $21, %eax #,
orl $-1, %esi #, ret
call capable #
testl %eax, %eax # D.15478
je .L33 #,
.L45:
leal 44(%esp), %eax #, tmp102
movl %ebx, %edx # arg,
call copy_from_user.clone.2 #
movl $-14, %esi #, ret
testl %eax, %eax # D.15479
jne .L33 #,
leal 4(%ebx), %edx #, tmp103
leal 40(%esp), %eax #, tmp104
call copy_from_user.clone.2 #
testl %eax, %eax # D.15481
jne .L33 #,
movl %esp, %edi #, tmp105
movl $6, %ecx #, tmp107
movl 40(%esp), %edx # speed, speed.19
rep stosl
movl 44(%esp), %esi # val, val.15
movl $419, (%esp) #, regs.eax
cmpl $2, %edx #, speed.19
movb $2, %cl #,
cmovle %edx, %ecx # speed.19,, speed
movl %esi, %edx # val.15, tmp112
testl %ecx, %ecx # speed
cmovns %ecx, %eax # speed,, tmp113
andl $255, %edx #, tmp112
sall $8, %eax #, tmp113
orl %edx, %eax # tmp112, tmp113
movl %eax, 4(%esp) # tmp113, regs.ebx
movl %esp, %eax #, tmp114
call i8k_smm #
testl %eax, %eax # D.15486
jne .L46 #,
movl %esi, %eax # val.15,
.L62:
call i8k_get_fan_status #
.L46:
movl %eax, 44(%esp) # D.15486, val
.L44:
movl 44(%esp), %esi # val, ret
testl %esi, %esi # ret
js .L33 #,
cmpl $-2147194496, %ebp #, cmd
je .L60 #,
cmpl $-2147194495, %ebp #, cmd
jne .L60 #,
leal 24(%esp), %edx #, tmp116
movl $16, %ecx #,
.L61:
movl %ebx, %eax # arg,
call copy_to_user #
cmpl $1, %eax #, D.15484
sbbl %esi, %esi # ret
notl %esi # ret
andl $-14, %esi #, ret
jmp .L33 #
.L60:
leal 44(%esp), %edx #, tmp117
movl $4, %ecx #,
jmp .L61 #
.L51:
movl $-22, %esi #, ret
.L33:
addl $48, %esp #,
movl %esi, %eax # ret,
popl %ebx #
popl %esi #
popl %edi #
popl %ebp #
ret
.size i8k_ioctl, .-i8k_ioctl
.section .rodata.str1.1
.LC3:
.string "<6>i8k: not running on a supported Dell system.\n"
.LC4:
.string "<6>i8k: vendor=%s, model=%s, version=%s\n"
.LC5:
.string "<3>i8k: unable to get SMM Dell signature\n"
.LC6:
.string "<4>i8k: unable to get SMM BIOS version\n"
.LC7:
.string "<4>i8k: BIOS version mismatch: %s != %s\n"
.LC8:
.string "1.14 21/02/2005"
.LC9:
.string "<6>Dell laptop SMM driver v%s Massimo Dal Zotto (dz@debian.org)\n"
.LC10:
.string "i8k"
.section .init.text,"ax",@progbits
.type i8k_init, @function
i8k_init:
pushl %esi #
movl $i8k_dmi_table, %eax #,
pushl %ebx #
subl $4, %esp #,
call dmi_check_system #
testl %eax, %eax # D.15529
jne .L67 #,
cmpl $0, ignore_dmi #, ignore_dmi
jne .L68 #,
cmpl $0, force #, force
movl $-19, %eax #, D.15099
je .L69 #,
.L68:
pushl $.LC3 #
call printk #
movl $2, %eax #,
call i8k_get_dmi_data #
movl %eax, %esi #, D.15525
movl $5, %eax #,
call i8k_get_dmi_data #
movl %eax, %ebx #, D.15524
movl $4, %eax #,
call i8k_get_dmi_data #
pushl %esi # D.15525
pushl %ebx # D.15524
pushl %eax # D.15523
pushl $.LC4 #
call printk #
addl $20, %esp #,
.L67:
movl $2, %eax #,
call i8k_get_dmi_data #
movl $4, %ecx #,
movl %eax, %edx # D.15522,
movl $bios_version, %eax #,
call strlcpy #
movl $65187, %eax #,
call i8k_get_dell_signature #
testl %eax, %eax # D.15521
je .L70 #,
movl $65443, %eax #,
call i8k_get_dell_signature #
testl %eax, %eax # D.15520
je .L70 #,
pushl $.LC5 #
call printk #
movl $-19, %eax #, D.15099
cmpl $0, force #, force
popl %edx #
je .L69 #,
.L70:
call i8k_get_bios_version #
testl %eax, %eax # version
jg .L71 #,
pushl $.LC6 #
call printk #
popl %eax #
jmp .L72 #
.L71:
movl %eax, %edx # version, tmp79
sarl $16, %edx #, tmp79
movb %dl, (%esp) # tmp79, buff
movl %eax, %edx # version, tmp80
sarl $8, %edx #, tmp80
movb %al, 2(%esp) # version, buff
movl $2, %eax #,
movb %dl, 1(%esp) # tmp80, buff
movb $0, 3(%esp) #, buff
call dmi_get_system_info #
testl %eax, %eax # D.15514
jne .L73 #,
movl %esp, %edx #, tmp81
movl $4, %ecx #,
movl $bios_version, %eax #,
call strlcpy #
.L73:
movl $4, %ecx #,
movl $bios_version, %edx #,
movl %esp, %eax #,
movl %esp, %ebx #, tmp82
call strncmp #
testl %eax, %eax # D.15513
je .L72 #,
pushl $bios_version #
pushl %ebx # tmp82
pushl $.LC7 #
call printk #
addl $12, %esp #,
jmp .L72 #
.L79:
pushl $.LC8 #
pushl $.LC9 #
call printk #
xorl %eax, %eax # D.15099
popl %ebx #
popl %esi #
.L69:
addl $4, %esp #,
popl %ebx #
popl %esi #
ret
.L72:
pushl $0 #
xorl %ecx, %ecx #
xorl %edx, %edx #
movl $.LC10, %eax #,
pushl $i8k_fops #
call proc_create_data #
movl %eax, %edx #, proc_i8k
testl %edx, %edx # proc_i8k
popl %eax #
movl $-2, %eax #, D.15099
popl %ecx #
je .L69 #,
jmp .L79 #
.size i8k_init, .-i8k_init
.section .exit.text,"ax",@progbits
.type i8k_exit, @function
i8k_exit:
xorl %edx, %edx #
movl $.LC10, %eax #,
jmp remove_proc_entry #
.size i8k_exit, .-i8k_exit
.section .modinfo,"a",@progbits
.align 4
.type __mod_fan_mult83, @object
.size __mod_fan_mult83, 48
__mod_fan_mult83:
.string "parm=fan_mult:Factor to multiply fan speed with"
.align 4
.type __mod_fan_multtype82, @object
.size __mod_fan_multtype82, 22
__mod_fan_multtype82:
.string "parmtype=fan_mult:int"
.section __param,"a",@progbits
.align 4
.type __param_fan_mult, @object
.size __param_fan_mult, 16
__param_fan_mult:
# name:
.long __param_str_fan_mult
# ops:
.long param_ops_int
# perm:
.value 0
# flags:
.value 0
# <anonymous>:
# arg:
.long fan_mult
.section .modinfo
.align 4
.type __mod_power_status79, @object
.size __mod_power_status79, 51
__mod_power_status79:
.string "parm=power_status:Report power status in /proc/i8k"
.align 4
.type __mod_power_statustype78, @object
.size __mod_power_statustype78, 27
__mod_power_statustype78:
.string "parmtype=power_status:bool"
.section __param
.align 4
.type __param_power_status, @object
.size __param_power_status, 16
__param_power_status:
# name:
.long __param_str_power_status
# ops:
.long param_ops_bool
# perm:
.value 384
# flags:
.value 0
# <anonymous>:
# arg:
.long power_status
.section .modinfo
.align 4
.type __mod_restricted75, @object
.size __mod_restricted75, 62
__mod_restricted75:
.string "parm=restricted:Allow fan control if SYS_ADMIN capability set"
.align 4
.type __mod_restrictedtype74, @object
.size __mod_restrictedtype74, 25
__mod_restrictedtype74:
.string "parmtype=restricted:bool"
.section __param
.align 4
.type __param_restricted, @object
.size __param_restricted, 16
__param_restricted:
# name:
.long __param_str_restricted
# ops:
.long param_ops_bool
# perm:
.value 0
# flags:
.value 0
# <anonymous>:
# arg:
.long restricted
.section .modinfo
.align 4
.type __mod_ignore_dmi71, @object
.size __mod_ignore_dmi71, 74
__mod_ignore_dmi71:
.string "parm=ignore_dmi:Continue probing hardware even if DMI data does not match"
.align 4
.type __mod_ignore_dmitype70, @object
.size __mod_ignore_dmitype70, 25
__mod_ignore_dmitype70:
.string "parmtype=ignore_dmi:bool"
.section __param
.align 4
.type __param_ignore_dmi, @object
.size __param_ignore_dmi, 16
__param_ignore_dmi:
# name:
.long __param_str_ignore_dmi
# ops:
.long param_ops_bool
# perm:
.value 0
# flags:
.value 0
# <anonymous>:
# arg:
.long ignore_dmi
.section .modinfo
.align 4
.type __mod_force67, @object
.size __mod_force67, 63
__mod_force67:
.string "parm=force:Force loading without checking for supported models"
.align 4
.type __mod_forcetype66, @object
.size __mod_forcetype66, 20
__mod_forcetype66:
.string "parmtype=force:bool"
.section __param
.align 4
.type __param_force, @object
.size __param_force, 16
__param_force:
# name:
.long __param_str_force
# ops:
.long param_ops_bool
# perm:
.value 0
# flags:
.value 0
# <anonymous>:
# arg:
.long force
.section .modinfo
.align 4
.type __mod_license63, @object
.size __mod_license63, 12
__mod_license63:
.string "license=GPL"
.align 4
.type __mod_description62, @object
.size __mod_description62, 58
__mod_description62:
.string "description=Driver for accessing SMM BIOS on Dell laptops"
.align 4
.type __mod_author61, @object
.size __mod_author61, 41
__mod_author61:
.string "author=Massimo Dal Zotto (dz@debian.org)"
.data
.align 4
.type fan_mult, @object
.size fan_mult, 4
fan_mult:
.long 30
.local power_status
.comm power_status,4,4
.local restricted
.comm restricted,4,4
.local ignore_dmi
.comm ignore_dmi,4,4
.local force
.comm force,4,4
.section .rodata
.align 4
.type i8k_fops, @object
.size i8k_fops, 100
i8k_fops:
# owner:
.long __this_module
# llseek:
.long seq_lseek
# read:
.long seq_read
# unlocked_ioctl:
.zero 20
.long i8k_ioctl
# open:
.zero 8
.long i8k_open_fs
# release:
.zero 4
.long single_release
.zero 44
.local bios_version
.comm bios_version,4,4
.local prev.12857
.comm prev.12857,4,4
.section .rodata.str1.1
.LC11:
.string "Dell Inspiron"
.LC12:
.string "Dell Latitude"
.LC13:
.string "Dell Inspiron 2"
.LC14:
.string "Dell Latitude 2"
.LC15:
.string "Dell Inspiron 3"
.LC16:
.string "Dell Precision"
.LC17:
.string "Dell Vostro"
.section .init.data,"aw",@progbits
.align 4
.type i8k_dmi_table, @object
.size i8k_dmi_table, 2988
i8k_dmi_table:
# ident:
.zero 4
.long .LC11
# matches:
# slot:
.byte 4
# substr:
.string "Dell Computer"
.zero 65
# slot:
.byte 5
# substr:
.string "Inspiron"
.zero 70
.zero 160
.zero 4
# ident:
.zero 4
.long .LC12
# matches:
# slot:
.byte 4
# substr:
.string "Dell Computer"
.zero 65
# slot:
.byte 5
# substr:
.string "Latitude"
.zero 70
.zero 160
.zero 4
# ident:
.zero 4
.long .LC13
# matches:
# slot:
.byte 4
# substr:
.string "Dell Inc."
.zero 69
# slot:
.byte 5
# substr:
.string "Inspiron"
.zero 70
.zero 160
.zero 4
# ident:
.zero 4
.long .LC14
# matches:
# slot:
.byte 4
# substr:
.string "Dell Inc."
.zero 69
# slot:
.byte 5
# substr:
.string "Latitude"
.zero 70
.zero 160
.zero 4
# ident:
.zero 4
.long .LC15
# matches:
# slot:
.byte 4
# substr:
.string "Dell Inc."
.zero 69
# slot:
.byte 5
# substr:
.string "MM061"
.zero 73
.zero 160
.zero 4
# ident:
.zero 4
.long .LC15
# matches:
# slot:
.byte 4
# substr:
.string "Dell Inc."
.zero 69
# slot:
.byte 5
# substr:
.string "MP061"
.zero 73
.zero 160
.zero 4
# ident:
.zero 4
.long .LC16
# matches:
# slot:
.byte 4
# substr:
.string "Dell Inc."
.zero 69
# slot:
.byte 5
# substr:
.string "Precision"
.zero 69
.zero 160
.zero 4
# ident:
.zero 4
.long .LC17
# matches:
# slot:
.byte 4
# substr:
.string "Dell Inc."
.zero 69
# slot:
.byte 5
# substr:
.string "Vostro"
.zero 72
.zero 160
.zero 4
.zero 332
.section .rodata
.align 4
.type CSWTCH.30, @object
.size CSWTCH.30, 16
CSWTCH.30:
.long 1
.long 2
.long 0
.long 4
.align 4
.type __param_str_fan_mult, @object
.size __param_str_fan_mult, 9
__param_str_fan_mult:
.string "fan_mult"
.align 4
.type __param_str_power_status, @object
.size __param_str_power_status, 13
__param_str_power_status:
.string "power_status"
.align 4
.type __param_str_restricted, @object
.size __param_str_restricted, 11
__param_str_restricted:
.string "restricted"
.align 4
.type __param_str_ignore_dmi, @object
.size __param_str_ignore_dmi, 11
__param_str_ignore_dmi:
.string "ignore_dmi"
.align 4
.type __param_str_force, @object
.size __param_str_force, 6
__param_str_force:
.string "force"
.globl init_module
.set init_module,i8k_init
.globl cleanup_module
.set cleanup_module,i8k_exit
.ident "GCC: (GNU) 4.5.1"
.section .note.GNU-stack,"",@progbits
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 18:47 ` Jim Bos
@ 2010-11-15 18:52 ` Jim Bos
2010-11-15 19:13 ` Linus Torvalds
2010-11-15 19:22 ` Jakub Jelinek
2 siblings, 0 replies; 52+ messages in thread
From: Jim Bos @ 2010-11-15 18:52 UTC (permalink / raw)
To: Linus Torvalds
Cc: Jakub Jelinek, Andi Kleen, James Cloos,
Linux Kernel Mailing List, Andreas Schwab, Michael Matz,
Dave Korn, Richard Guenther, gcc
On 11/15/2010 07:30 PM, Jim Bos wrote:
> On 11/15/2010 07:08 PM, Linus Torvalds wrote:
>> On Mon, Nov 15, 2010 at 9:40 AM, Jim Bos <jim876@xs4all.nl> wrote:
>>>
>>> Hmm, that doesn't work.
>>>
>>> [ Not sure if you read to whole thread but initial workaround was to
>>> change the asm(..) to asm volatile(..) which did work. ]
>>
>> Since I have a different gcc than yours (and I'm not going to compile
>> my own), have you posted your broken .s file anywhere? In fact, with
>> the noinline (and the removal of the "+m" thing - iow just the patch
>> you tried), what does just the "i8k_smm" function assembly look like
>> for you after you've done a "make drivers/char/i8k.s"?
>>
>> If the asm just doesn't exist AT ALL, that's just odd. Because every
>> single call-site of i8k_smm() clearly looks at the return value. So
>> the volatile really shouldn't make any difference from that
>> standpoint. Odd.
>>
>> Linus
>>
>
> Attached version with plain 2.6.36 source and version with the committed
> patch, i.e with the '"+m" (*regs)'
>
>
> _
> Jim
>
>
And I just tried with your noninline patch which results in exactly the
same .s file as with plain 2.6.36 source, i.e. the noninline patch is
not doing anything here.
_
Jim
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-07 23:03 ` Andreas Schwab
2010-11-08 0:36 ` Andi Kleen
@ 2010-11-15 18:57 ` Jeff Law
1 sibling, 0 replies; 52+ messages in thread
From: Jeff Law @ 2010-11-15 18:57 UTC (permalink / raw)
To: Andreas Schwab; +Cc: Andi Kleen, Jim, Linux Kernel Mailing List, gcc
On 11/07/10 15:41, Andreas Schwab wrote:
> Andi Kleen<andi@firstfloor.org> writes:
>
>> Jim<jim876@xs4all.nl> writes:
>>
>>> After upgrading my Dell laptop, both OS+kernel the i8k interface was giving
>>> nonsensical output. As it turned out it's not the kernel but compiler
>>> upgrade which broke this.
>>>
>>> Guys at Archlinux have found the underlying cause (but don't seem to have
>>> submitted a patch yet):
>>> https://bbs.archlinux.org/viewtopic.php?pid=780692#p780692
>>> gcc seems to optimize the assembly statements away.
>>>
>>> And indeed, applying this patch makes the i8k interface work again,
>>> i.e. replacing the asm(..) construct by asm volatile(..)
>> The compiler really should not optimize the asm away, because
>> it has both input and output arguments which are later used.
>> "asm volatile" normally just means "don't move significantly"
> The asm fails to mention that it modifies *regs.
But there's a memory clobber, that should be sufficient to indicate
*regs is modified.
jeff
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-08 10:54 ` Richard Guenther
2010-11-08 11:20 ` Andi Kleen
@ 2010-11-15 19:11 ` Jeff Law
2010-11-15 19:51 ` Linus Torvalds
2010-11-15 22:31 ` Richard Guenther
1 sibling, 2 replies; 52+ messages in thread
From: Jeff Law @ 2010-11-15 19:11 UTC (permalink / raw)
To: Richard Guenther
Cc: Andi Kleen, Andreas Schwab, Jim, Linux Kernel Mailing List, gcc
On 11/08/10 03:49, Richard Guenther wrote:
> On Mon, Nov 8, 2010 at 12:03 AM, Andi Kleen<andi@firstfloor.org> wrote:
>> Andreas Schwab<schwab@linux-m68k.org> writes:
>>> The asm fails to mention that it modifies *regs.
>> It has a memory clobber, that should be enough, no?
> No. A memory clobber does not cover automatic storage.
A memory clobber should clobber anything in memory, including autos in
memory; if it doesn't, then that seems like a major problem. I'd like
to see the rationale behind not clobbering autos in memory.
Jeff
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 18:47 ` Jim Bos
2010-11-15 18:52 ` Jim Bos
@ 2010-11-15 19:13 ` Linus Torvalds
2010-11-15 19:22 ` Jakub Jelinek
2 siblings, 0 replies; 52+ messages in thread
From: Linus Torvalds @ 2010-11-15 19:13 UTC (permalink / raw)
To: Jim Bos
Cc: Jakub Jelinek, Andi Kleen, James Cloos,
Linux Kernel Mailing List, Andreas Schwab, Michael Matz,
Dave Korn, Richard Guenther, gcc
On Mon, Nov 15, 2010 at 10:30 AM, Jim Bos <jim876@xs4all.nl> wrote:
>
> Attached version with plain 2.6.36 source and version with the committed
> patch, i.e with the '"+m" (*regs)'
Looks 100% identical in i8k_smm() itself, and I'm not seeing anything
bad. The asm has certainly not been optimized away as implied in the
archlinux thread.
There are differences, but they are with code generation *elsewhere*.
To me it is starting to look like the real problem is that gcc has
decided that the "i8k_smm()" function is "__attribute__((const))".
Which is clearly totally bogus. If a function has an inline asm that
has a memory clobber, it is clearly *not* 'const'. But that does
explain the bug, and does explain why "+m" makes a difference and why
"noinline" does not.
So what I _think_ happens is that
- gcc logic for the automatic 'const' attribute for functions is
broken, so it marks that function 'const'.
- since the rule for a const function is that it only _looks_ at its
attributes and has no side effects, now the callers will decide that
'i8k_smm()' cannot change the passed-in structure, so they'll happily
optimize away all the accesses to it.
Linus
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 18:47 ` Jim Bos
2010-11-15 18:52 ` Jim Bos
2010-11-15 19:13 ` Linus Torvalds
@ 2010-11-15 19:22 ` Jakub Jelinek
2010-11-15 19:57 ` Jakub Jelinek
2 siblings, 1 reply; 52+ messages in thread
From: Jakub Jelinek @ 2010-11-15 19:22 UTC (permalink / raw)
To: Jim Bos
Cc: Linus Torvalds, Jakub Jelinek, Andi Kleen, James Cloos,
Linux Kernel Mailing List, Andreas Schwab, Michael Matz,
Dave Korn, Richard Guenther, gcc
On Mon, Nov 15, 2010 at 07:30:35PM +0100, Jim Bos wrote:
> On 11/15/2010 07:08 PM, Linus Torvalds wrote:
> > On Mon, Nov 15, 2010 at 9:40 AM, Jim Bos <jim876@xs4all.nl> wrote:
> >>
> >> Hmm, that doesn't work.
> >>
> >> [ Not sure if you read to whole thread but initial workaround was to
> >> change the asm(..) to asm volatile(..) which did work. ]
> >
> > Since I have a different gcc than yours (and I'm not going to compile
> > my own), have you posted your broken .s file anywhere? In fact, with
> > the noinline (and the removal of the "+m" thing - iow just the patch
> > you tried), what does just the "i8k_smm" function assembly look like
> > for you after you've done a "make drivers/char/i8k.s"?
> >
> > If the asm just doesn't exist AT ALL, that's just odd. Because every
> > single call-site of i8k_smm() clearly looks at the return value. So
> > the volatile really shouldn't make any difference from that
> > standpoint. Odd.
> >
> > Linus
> >
>
> Attached version with plain 2.6.36 source and version with the committed
> patch, i.e with the '"+m" (*regs)'
Thanks, this actually helped to see the problem.
The problem is not inside of i8k_smm, which is not inlined, but in the
callers.
ipa-pure-const.c pass thinks i8k_smm is a pure function, thus
regs = {};
regs.eax = 166;
x = i8k_smm (®s);
if (!x) x = regs.eax;
in the callers is optimized into
regs = {}
regs.eax = 166;
x = i8k_smm (®s);
if (!x) x = 166;
Now, not sure why this happens, as there is
case GIMPLE_ASM:
for (i = 0; i < gimple_asm_nclobbers (stmt); i++)
{
tree op = gimple_asm_clobber_op (stmt, i);
if (simple_cst_equal(TREE_VALUE (op), memory_identifier_string) == 1)
{
if (dump_file)
fprintf (dump_file, " memory asm clobber is not const/pure");
/* Abandon all hope, ye who enter here. */
local->pure_const_state = IPA_NEITHER;
}
}
Debugging...
Jakub
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 19:11 ` Jeff Law
@ 2010-11-15 19:51 ` Linus Torvalds
2010-11-15 22:31 ` Richard Guenther
1 sibling, 0 replies; 52+ messages in thread
From: Linus Torvalds @ 2010-11-15 19:51 UTC (permalink / raw)
To: Jeff Law
Cc: Richard Guenther, Andi Kleen, Andreas Schwab, Jim,
Linux Kernel Mailing List, gcc
On Mon, Nov 15, 2010 at 10:45 AM, Jeff Law <law@redhat.com> wrote:
>
> A memory clobber should clobber anything in memory, including autos in
> memory; if it doesn't, then that seems like a major problem. I'd like to
> see the rationale behind not clobbering autos in memory.
Yes. It turns out that the "asm optimized away" was entirely wrong (we
never saw that, it was just a report on another mailing list).
Looking at the asm posted, it seems to me that gcc actually compiles
the asm itself 100% correctly, and the "memory" clobber is working
fine inside that function. So the code generated for i8k_smm() itself
is all good.
But _while_ generating the good code, gcc doesn't seem to realize that
it writes to anything, so it decides to mark the function
"__attribute__((const))", which is obviously wrong (a memory clobber
definitely implies that it's not const). And as a result, the callers
will be mis-optimized, because they do things like
static int i8k_get_bios_version(void)
{
struct smm_regs regs = { .eax = I8K_SMM_BIOS_VERSION, };
return i8k_smm(®s) ? : regs.eax;
}
and since gcc has (incorrectly) decided that "i8k_smm()" is a const
function, it thinks that "regs.eax" hasn't changed, so it doesn't
bother to reload it: it "knows" that it is still I8K_SMM_BIOS_VERSION
that it initialized it with. So it will basically have rewritten that
final return statement as
return i8k_smm(®s) ? : I8K_SMM_BIOS_VERSION;
which obviously doesn't really work.
This also explains why adding "volatile" worked. The "asm volatile"
triggered "this is not a const function".
Similarly, the "+m" works, because it also makes clear that the asm is
writing to memory, and isn't a const function.
Now, the "memory" clobber should clearly also have done that, but I'd
be willing to bet that some version of gcc (possibly extra slackware
patches) had forgotten the trivial logic to say "a memory clobber also
makes the user function non-const".
Linus
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 18:45 ` Jakub Jelinek
@ 2010-11-15 19:53 ` Jim Bos
0 siblings, 0 replies; 52+ messages in thread
From: Jim Bos @ 2010-11-15 19:53 UTC (permalink / raw)
To: Jakub Jelinek
Cc: Andi Kleen, Linus Torvalds, James Cloos,
Linux Kernel Mailing List, Andreas Schwab, Michael Matz,
Dave Korn, Richard Guenther, gcc
On 11/15/2010 07:26 PM, Jakub Jelinek wrote:
> On Mon, Nov 15, 2010 at 07:17:31PM +0100, Jim Bos wrote:
>> # gcc -v
>> Reading specs from /usr/lib/gcc/i486-slackware-linux/4.5.1/specs
>> COLLECT_GCC=gcc
>> COLLECT_LTO_WRAPPER=/usr/libexec/gcc/i486-slackware-linux/4.5.1/lto-wrapper
>> Target: i486-slackware-linux
>> Configured with: ../gcc-4.5.1/configure --prefix=/usr --libdir=/usr/lib
>> --mandir=/usr/man --infodir=/usr/info --enable-shared --enable-bootstrap
>> --enable-languages=ada,c,c++,fortran,java,objc --enable-threads=posix
>> --enable-checking=release --with-system-zlib
>> --with-python-dir=/lib/python2.6/site-packages
>> --disable-libunwind-exceptions --enable-__cxa_atexit --enable-libssp
>> --with-gnu-ld --verbose --with-arch=i486 --target=i486-slackware-linux
>> --build=i486-slackware-linux --host=i486-slackware-linux
>> Thread model: posix
>> gcc version 4.5.1 (GCC)
>
> Does it have any patches applied? The gcc options look the same as what
> I've been already trying earlier.
> Thus, can you run gcc with those options on i8k.i and add -fverbose-asm
> to make it easier to read and post i8k.s you get?
>
> Jakub
>
Slackware is typically not patching much (and I'm just using the
pre-compiled binary). Here is the link to how it's built:
http://slackware.osuosl.org/slackware-current/source/d/gcc/
there doesn't appear to be anything relevant changed.
I already posted the .s files, plain 2.6.36 and the one with working
patch, I =think= that's already using -fverbose-asm, at least that shows
in the output.
_
Jim
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 19:22 ` Jakub Jelinek
@ 2010-11-15 19:57 ` Jakub Jelinek
2010-11-15 20:23 ` Linus Torvalds
2010-11-15 20:52 ` Richard Henderson
0 siblings, 2 replies; 52+ messages in thread
From: Jakub Jelinek @ 2010-11-15 19:57 UTC (permalink / raw)
To: Linus Torvalds
Cc: Jim Bos, Andi Kleen, James Cloos, Linux Kernel Mailing List,
Andreas Schwab, Michael Matz, Dave Korn, Richard Guenther, gcc
[-- Attachment #1: Type: text/plain, Size: 1009 bytes --]
On Mon, Nov 15, 2010 at 07:58:48PM +0100, Jakub Jelinek wrote:
> Now, not sure why this happens, as there is
> case GIMPLE_ASM:
> for (i = 0; i < gimple_asm_nclobbers (stmt); i++)
> {
> tree op = gimple_asm_clobber_op (stmt, i);
> if (simple_cst_equal(TREE_VALUE (op), memory_identifier_string) == 1)
> {
> if (dump_file)
> fprintf (dump_file, " memory asm clobber is not const/pure");
> /* Abandon all hope, ye who enter here. */
> local->pure_const_state = IPA_NEITHER;
> }
> }
> Debugging...
Ah, the problem is that memory_identifier_string is only initialized in
ipa-reference.c's initialization, so it can be (and is in this case) NULL in
ipa-pure-const.c.
Two possible fixes (the latter is apparently what is used in
tree-ssa-operands.c, so is probably sufficient). Guess ipa-reference.c
should be changed to do the same and just drop memory_identifier_string.
Jakub
[-- Attachment #2: 1 --]
[-- Type: text/plain, Size: 706 bytes --]
--- gcc/ipa-pure-const.c.jj 2010-08-11 16:06:19.000000000 +0200
+++ gcc/ipa-pure-const.c 2010-11-15 20:06:36.121310614 +0100
@@ -460,7 +460,10 @@ check_stmt (gimple_stmt_iterator *gsip,
for (i = 0; i < gimple_asm_nclobbers (stmt); i++)
{
tree op = gimple_asm_clobber_op (stmt, i);
- if (simple_cst_equal(TREE_VALUE (op), memory_identifier_string) == 1)
+ if (TREE_CODE (TREE_VALUE (op)) == STRING_CST
+ && TREE_STRING_LENGTH (TREE_VALUE (op)) == sizeof ("memory")
+ && memcmp (TREE_STRING_POINTER (TREE_VALUE (op)), "memory",
+ sizeof ("memory")) == 0)
{
if (dump_file)
fprintf (dump_file, " memory asm clobber is not const/pure");
[-- Attachment #3: 2 --]
[-- Type: text/plain, Size: 561 bytes --]
--- gcc/ipa-pure-const.c.jj 2010-08-11 16:06:19.000000000 +0200
+++ gcc/ipa-pure-const.c 2010-11-15 20:07:51.463716989 +0100
@@ -460,7 +460,7 @@ check_stmt (gimple_stmt_iterator *gsip,
for (i = 0; i < gimple_asm_nclobbers (stmt); i++)
{
tree op = gimple_asm_clobber_op (stmt, i);
- if (simple_cst_equal(TREE_VALUE (op), memory_identifier_string) == 1)
+ if (strcmp (TREE_STRING_POINTER (TREE_VALUE (link)), "memory") == 0)
{
if (dump_file)
fprintf (dump_file, " memory asm clobber is not const/pure");
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 19:57 ` Jakub Jelinek
@ 2010-11-15 20:23 ` Linus Torvalds
2010-11-15 20:51 ` Jakub Jelinek
2010-11-15 20:52 ` Richard Henderson
1 sibling, 1 reply; 52+ messages in thread
From: Linus Torvalds @ 2010-11-15 20:23 UTC (permalink / raw)
To: Jakub Jelinek
Cc: Jim Bos, Andi Kleen, James Cloos, Linux Kernel Mailing List,
Andreas Schwab, Michael Matz, Dave Korn, Richard Guenther, gcc
On Mon, Nov 15, 2010 at 11:12 AM, Jakub Jelinek <jakub@redhat.com> wrote:
>
> Ah, the problem is that memory_identifier_string is only initialized in
> ipa-reference.c's initialization, so it can be (and is in this case) NULL in
> ipa-pure-const.c.
Ok. And I guess you can verify that all versions of gcc do this
correctly for "asm volatile"?
Because since we'll have to work around this problem in the kernel, I
suspect the simplest solution is to remove the "+m" that causes
register pressure problems, and then use "asm volatile" to work around
the const-function bug.
And add a large comment about why "asm volatile" is probably always a
good idea when you have a memory clobber and don't have any other
visible memory modifications.
I do wonder if this explains some of the problems we had with the
bitop asms too.
Hmm?
Linus
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 20:23 ` Linus Torvalds
@ 2010-11-15 20:51 ` Jakub Jelinek
2010-11-15 21:03 ` Jim Bos
2010-11-15 23:08 ` Andi Kleen
0 siblings, 2 replies; 52+ messages in thread
From: Jakub Jelinek @ 2010-11-15 20:51 UTC (permalink / raw)
To: Linus Torvalds
Cc: Jim Bos, Andi Kleen, James Cloos, Linux Kernel Mailing List,
Andreas Schwab, Michael Matz, Dave Korn, Richard Guenther, gcc
On Mon, Nov 15, 2010 at 11:21:30AM -0800, Linus Torvalds wrote:
> On Mon, Nov 15, 2010 at 11:12 AM, Jakub Jelinek <jakub@redhat.com> wrote:
> >
> > Ah, the problem is that memory_identifier_string is only initialized in
> > ipa-reference.c's initialization, so it can be (and is in this case) NULL in
> > ipa-pure-const.c.
>
> Ok. And I guess you can verify that all versions of gcc do this
> correctly for "asm volatile"?
Yes, reading 4.1/4.2/4.3/4.4/4.5/4.6 code ipa-pure-const.c handles
asm volatile correctly, in each case the function is no longer assumed to be
pure or const in the discovery (of course, user can still say the
function is const or pure). 4.0 and earlier didn't have ipa-pure-const.c.
Using the simplified
extern void abort (void);
__attribute__((noinline)) int
foo (int *p)
{
int r;
asm ("movl $6, (%1)\n\txorl %0, %0" : "=r" (r) : "r" (p) : "memory");
return r;
}
int
main (void)
{
int p = 8;
if ((foo (&p) ? : p) != 6)
abort ();
return 0;
}
testcase shows that in 4.1/4.2/4.3/4.4 this is miscompiled only when using
-fno-ipa-reference, in 4.5 it is miscompiled always when optimizing
unless -fno-ipa-pure-const (as 4.5 added local-pure-const pass which is run
before ipa-reference) and in 4.6 this has been fixed by Honza when
doing ipa cleanups.
> Because since we'll have to work around this problem in the kernel, I
> suspect the simplest solution is to remove the "+m" that causes
> register pressure problems, and then use "asm volatile" to work around
> the const-function bug.
Yes.
Jakub
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 19:57 ` Jakub Jelinek
2010-11-15 20:23 ` Linus Torvalds
@ 2010-11-15 20:52 ` Richard Henderson
2010-11-15 21:01 ` Jakub Jelinek
1 sibling, 1 reply; 52+ messages in thread
From: Richard Henderson @ 2010-11-15 20:52 UTC (permalink / raw)
To: Jakub Jelinek
Cc: Linus Torvalds, Jim Bos, Andi Kleen, James Cloos,
Linux Kernel Mailing List, Andreas Schwab, Michael Matz,
Dave Korn, Richard Guenther, gcc
On 11/15/2010 11:12 AM, Jakub Jelinek wrote:
> - if (simple_cst_equal(TREE_VALUE (op), memory_identifier_string) == 1)
> + if (strcmp (TREE_STRING_POINTER (TREE_VALUE (link)), "memory") == 0)
I prefer this solution. I think memory_identifier_string is over-engineering.
Patch to remove it entirely is pre-approved.
r~
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 20:52 ` Richard Henderson
@ 2010-11-15 21:01 ` Jakub Jelinek
0 siblings, 0 replies; 52+ messages in thread
From: Jakub Jelinek @ 2010-11-15 21:01 UTC (permalink / raw)
To: Richard Henderson; +Cc: gcc
On Mon, Nov 15, 2010 at 11:53:05AM -0800, Richard Henderson wrote:
> On 11/15/2010 11:12 AM, Jakub Jelinek wrote:
> > - if (simple_cst_equal(TREE_VALUE (op), memory_identifier_string) == 1)
> > + if (strcmp (TREE_STRING_POINTER (TREE_VALUE (link)), "memory") == 0)
>
> I prefer this solution. I think memory_identifier_string is over-engineering.
> Patch to remove it entirely is pre-approved.
Honza even committed this to the trunk in May, it is just release branches
that are broken (and only in 4.5 it matters a lot because it happens with
the default flags).
Jakub
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 20:51 ` Jakub Jelinek
@ 2010-11-15 21:03 ` Jim Bos
2010-11-15 23:08 ` Andi Kleen
1 sibling, 0 replies; 52+ messages in thread
From: Jim Bos @ 2010-11-15 21:03 UTC (permalink / raw)
To: Linus Torvalds
Cc: Jakub Jelinek, Andi Kleen, James Cloos,
Linux Kernel Mailing List, Andreas Schwab, Michael Matz,
Dave Korn, Richard Guenther, gcc
[-- Attachment #1: Type: text/plain, Size: 2021 bytes --]
On 11/15/2010 08:51 PM, Jakub Jelinek wrote:
> On Mon, Nov 15, 2010 at 11:21:30AM -0800, Linus Torvalds wrote:
>> On Mon, Nov 15, 2010 at 11:12 AM, Jakub Jelinek <jakub@redhat.com> wrote:
>>>
>>> Ah, the problem is that memory_identifier_string is only initialized in
>>> ipa-reference.c's initialization, so it can be (and is in this case) NULL in
>>> ipa-pure-const.c.
>>
>> Ok. And I guess you can verify that all versions of gcc do this
>> correctly for "asm volatile"?
>
> Yes, reading 4.1/4.2/4.3/4.4/4.5/4.6 code ipa-pure-const.c handles
> asm volatile correctly, in each case the function is no longer assumed to be
> pure or const in the discovery (of course, user can still say the
> function is const or pure). 4.0 and earlier didn't have ipa-pure-const.c.
>
> Using the simplified
>
> extern void abort (void);
>
> __attribute__((noinline)) int
> foo (int *p)
> {
> int r;
> asm ("movl $6, (%1)\n\txorl %0, %0" : "=r" (r) : "r" (p) : "memory");
> return r;
> }
>
> int
> main (void)
> {
> int p = 8;
> if ((foo (&p) ? : p) != 6)
> abort ();
> return 0;
> }
>
> testcase shows that in 4.1/4.2/4.3/4.4 this is miscompiled only when using
> -fno-ipa-reference, in 4.5 it is miscompiled always when optimizing
> unless -fno-ipa-pure-const (as 4.5 added local-pure-const pass which is run
> before ipa-reference) and in 4.6 this has been fixed by Honza when
> doing ipa cleanups.
>
>> Because since we'll have to work around this problem in the kernel, I
>> suspect the simplest solution is to remove the "+m" that causes
>> register pressure problems, and then use "asm volatile" to work around
>> the const-function bug.
>
> Yes.
>
> Jakub
>
Linus,
In case you didn't already fixed this, here's the follow-up patch.
---
The fix to work around the gcc miscompiling i8k.c to add "+m (*regs)"
caused register pressure problems. Changing the 'asm' statement to
'asm volatile' instead should prevent that and works around the gcc
bug as well.
Signed-off-by: Jim Bos <jim876@xs4all.nl>
[-- Attachment #2: PATCH2.i8k.c --]
[-- Type: text/plain, Size: 916 bytes --]
--- linux/drivers/char/i8k.c.ORIG 2010-11-15 21:04:19.000000000 +0100
+++ linux/drivers/char/i8k.c 2010-11-15 21:02:32.000000000 +0100
@@ -119,7 +119,7 @@
int eax = regs->eax;
#if defined(CONFIG_X86_64)
- asm("pushq %%rax\n\t"
+ asm volatile("pushq %%rax\n\t"
"movl 0(%%rax),%%edx\n\t"
"pushq %%rdx\n\t"
"movl 4(%%rax),%%ebx\n\t"
@@ -141,11 +141,11 @@
"lahf\n\t"
"shrl $8,%%eax\n\t"
"andl $1,%%eax\n"
- :"=a"(rc), "+m" (*regs)
+ :"=a"(rc)
: "a"(regs)
: "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
#else
- asm("pushl %%eax\n\t"
+ asm volatile("pushl %%eax\n\t"
"movl 0(%%eax),%%edx\n\t"
"push %%edx\n\t"
"movl 4(%%eax),%%ebx\n\t"
@@ -167,7 +167,7 @@
"lahf\n\t"
"shrl $8,%%eax\n\t"
"andl $1,%%eax\n"
- :"=a"(rc), "+m" (*regs)
+ :"=a"(rc)
: "a"(regs)
: "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
#endif
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 19:11 ` Jeff Law
2010-11-15 19:51 ` Linus Torvalds
@ 2010-11-15 22:31 ` Richard Guenther
2010-11-15 23:39 ` Jeff Law
1 sibling, 1 reply; 52+ messages in thread
From: Richard Guenther @ 2010-11-15 22:31 UTC (permalink / raw)
To: Jeff Law; +Cc: Andi Kleen, Andreas Schwab, Jim, Linux Kernel Mailing List, gcc
On Mon, Nov 15, 2010 at 7:45 PM, Jeff Law <law@redhat.com> wrote:
> On 11/08/10 03:49, Richard Guenther wrote:
>>
>> On Mon, Nov 8, 2010 at 12:03 AM, Andi Kleen<andi@firstfloor.org> wrote:
>>>
>>> Andreas Schwab<schwab@linux-m68k.org> writes:
>>>>
>>>> The asm fails to mention that it modifies *regs.
>>>
>>> It has a memory clobber, that should be enough, no?
>>
>> No. A memory clobber does not cover automatic storage.
>
> A memory clobber should clobber anything in memory, including autos in
> memory; if it doesn't, then that seems like a major problem. I'd like to
> see the rationale behind not clobbering autos in memory.
Non-address taken automatic storage. (note that we don't excercise this
in optimization yet)
It's difficult to model thins kind of non-aliased memory with this kind
of aliasing mechanism (apart from taking all asms as clobbering
everything as we currently do).
Richard.
> Jeff
>
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 20:51 ` Jakub Jelinek
2010-11-15 21:03 ` Jim Bos
@ 2010-11-15 23:08 ` Andi Kleen
2010-11-15 23:37 ` Jakub Jelinek
1 sibling, 1 reply; 52+ messages in thread
From: Andi Kleen @ 2010-11-15 23:08 UTC (permalink / raw)
To: Jakub Jelinek
Cc: Linus Torvalds, Jim Bos, Andi Kleen, James Cloos,
Linux Kernel Mailing List, Andreas Schwab, Michael Matz,
Dave Korn, Richard Guenther, gcc
> testcase shows that in 4.1/4.2/4.3/4.4 this is miscompiled only when using
> -fno-ipa-reference, in 4.5 it is miscompiled always when optimizing
> unless -fno-ipa-pure-const (as 4.5 added local-pure-const pass which is run
> before ipa-reference) and in 4.6 this has been fixed by Honza when
> doing ipa cleanups.
Maybe it would be better to simply change the kernel Makefiles to pass
-fno-ipa-pure-const instead of adding volatiles everywhere.
-Andi
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 23:08 ` Andi Kleen
@ 2010-11-15 23:37 ` Jakub Jelinek
0 siblings, 0 replies; 52+ messages in thread
From: Jakub Jelinek @ 2010-11-15 23:37 UTC (permalink / raw)
To: Andi Kleen
Cc: Linus Torvalds, Jim Bos, James Cloos, Linux Kernel Mailing List,
Andreas Schwab, Michael Matz, Dave Korn, Richard Guenther, gcc
On Mon, Nov 15, 2010 at 11:43:22PM +0100, Andi Kleen wrote:
> > testcase shows that in 4.1/4.2/4.3/4.4 this is miscompiled only when using
> > -fno-ipa-reference, in 4.5 it is miscompiled always when optimizing
> > unless -fno-ipa-pure-const (as 4.5 added local-pure-const pass which is run
> > before ipa-reference) and in 4.6 this has been fixed by Honza when
> > doing ipa cleanups.
>
> Maybe it would be better to simply change the kernel Makefiles to pass
> -fno-ipa-pure-const instead of adding volatiles everywhere.
If you do this, please do it for 4.5.[012] only. If you disable all gcc
passes that ever had any bugs in it, you'd need to disable most of them if
not all.
Jakub
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 22:31 ` Richard Guenther
@ 2010-11-15 23:39 ` Jeff Law
2010-11-16 0:27 ` Richard Guenther
0 siblings, 1 reply; 52+ messages in thread
From: Jeff Law @ 2010-11-15 23:39 UTC (permalink / raw)
To: Richard Guenther
Cc: Andi Kleen, Andreas Schwab, Jim, Linux Kernel Mailing List, gcc
On 11/15/10 15:07, Richard Guenther wrote:
> On Mon, Nov 15, 2010 at 7:45 PM, Jeff Law<law@redhat.com> wrote:
>> On 11/08/10 03:49, Richard Guenther wrote:
>>> On Mon, Nov 8, 2010 at 12:03 AM, Andi Kleen<andi@firstfloor.org> wrote:
>>>> Andreas Schwab<schwab@linux-m68k.org> writes:
>>>>> The asm fails to mention that it modifies *regs.
>>>> It has a memory clobber, that should be enough, no?
>>> No. A memory clobber does not cover automatic storage.
>> A memory clobber should clobber anything in memory, including autos in
>> memory; if it doesn't, then that seems like a major problem. I'd like to
>> see the rationale behind not clobbering autos in memory.
> Non-address taken automatic storage. (note that we don't excercise this
> in optimization yet)
If the address of the auto isn't taken, then why is the object in memory
to begin with (with the obvious exception for aggregates).
Jeff
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-15 23:39 ` Jeff Law
@ 2010-11-16 0:27 ` Richard Guenther
2010-11-16 9:48 ` Jeff Law
0 siblings, 1 reply; 52+ messages in thread
From: Richard Guenther @ 2010-11-16 0:27 UTC (permalink / raw)
To: Jeff Law; +Cc: Andi Kleen, Andreas Schwab, Jim, Linux Kernel Mailing List, gcc
On Mon, Nov 15, 2010 at 11:58 PM, Jeff Law <law@redhat.com> wrote:
> On 11/15/10 15:07, Richard Guenther wrote:
>>
>> On Mon, Nov 15, 2010 at 7:45 PM, Jeff Law<law@redhat.com> wrote:
>>>
>>> On 11/08/10 03:49, Richard Guenther wrote:
>>>>
>>>> On Mon, Nov 8, 2010 at 12:03 AM, Andi Kleen<andi@firstfloor.org>
>>>> wrote:
>>>>>
>>>>> Andreas Schwab<schwab@linux-m68k.org> writes:
>>>>>>
>>>>>> The asm fails to mention that it modifies *regs.
>>>>>
>>>>> It has a memory clobber, that should be enough, no?
>>>>
>>>> No. A memory clobber does not cover automatic storage.
>>>
>>> A memory clobber should clobber anything in memory, including autos in
>>> memory; if it doesn't, then that seems like a major problem. I'd like to
>>> see the rationale behind not clobbering autos in memory.
>>
>> Non-address taken automatic storage. (note that we don't excercise this
>> in optimization yet)
>
> If the address of the auto isn't taken, then why is the object in memory to
> begin with (with the obvious exception for aggregates).
Exactly sort of my point. If people pass the address of &x to an asm
and modify &x + 8 expecting the "adjacent" stack location to be changed
I want to tell them that's not a supported way to get to another stack
variable (even if they clobber "memory"). Or consider the C-decl guy
who wants to access adjacent parameters by address arithmetic on
the address of the first param ...
Richard.
> Jeff
>
^ permalink raw reply [flat|nested] 52+ messages in thread
* Re: gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ?
2010-11-16 0:27 ` Richard Guenther
@ 2010-11-16 9:48 ` Jeff Law
0 siblings, 0 replies; 52+ messages in thread
From: Jeff Law @ 2010-11-16 9:48 UTC (permalink / raw)
To: Richard Guenther
Cc: Andi Kleen, Andreas Schwab, Jim, Linux Kernel Mailing List, gcc
On 11/15/10 16:07, Richard Guenther wrote:
>>
>> If the address of the auto isn't taken, then why is the object in memory to
>> begin with (with the obvious exception for aggregates).
> Exactly sort of my point. If people pass the address of&x to an asm
> and modify&x + 8 expecting the "adjacent" stack location to be changed
> I want to tell them that's not a supported way to get to another stack
> variable (even if they clobber "memory"). Or consider the C-decl guy
> who wants to access adjacent parameters by address arithmetic on
> the address of the first param ...
Well, in that case, I think we can easily say that the programmer has
gone off the deep end and has entered the realm of undefined behavior.
Presumably we rooted out all relevant instances of the latter over the
last 20 years... It was fairly common in the past, but I doubt anyone
worth caring about is still writing code assuming they can take the
address of parameter A, offset it and get parameters B, C, D, etc.
jeff
^ permalink raw reply [flat|nested] 52+ messages in thread
end of thread, other threads:[~2010-11-16 4:11 UTC | newest]
Thread overview: 52+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
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2010-11-07 22:07 ` gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ? Andi Kleen
2010-11-07 23:03 ` Andreas Schwab
2010-11-08 0:36 ` Andi Kleen
2010-11-08 10:54 ` Richard Guenther
2010-11-08 11:20 ` Andi Kleen
2010-11-08 11:48 ` Richard Guenther
2010-11-08 11:54 ` Paul Koning
2010-11-08 12:20 ` Jakub Jelinek
2010-11-08 12:36 ` Michael Matz
2010-11-08 20:20 ` Dave Korn
2010-11-09 13:48 ` Michael Matz
2010-11-09 14:19 ` Andi Kleen
2010-11-09 15:54 ` Andreas Schwab
2010-11-09 17:45 ` Jim
2010-11-13 16:01 ` [PATCH] i8k: Tell gcc that *regs gets clobbered Jim Bos
2010-11-15 8:56 ` gcc 4.5.1 / as 2.20.51.0.11 miscompiling drivers/char/i8k.c ? James Cloos
2010-11-15 9:13 ` Linus Torvalds
2010-11-15 10:03 ` Jakub Jelinek
2010-11-15 10:24 ` Andi Kleen
2010-11-15 10:55 ` Jakub Jelinek
2010-11-15 11:38 ` Jakub Jelinek
2010-11-15 12:29 ` Andi Kleen
2010-11-15 14:40 ` Jakub Jelinek
2010-11-15 14:56 ` Andi Kleen
2010-11-15 18:10 ` Jim Bos
2010-11-15 18:26 ` Jakub Jelinek
2010-11-15 18:43 ` Jim Bos
2010-11-15 18:45 ` Jakub Jelinek
2010-11-15 19:53 ` Jim Bos
2010-11-15 17:06 ` Linus Torvalds
2010-11-15 18:18 ` Jim Bos
2010-11-15 18:38 ` Linus Torvalds
2010-11-15 18:47 ` Jim Bos
2010-11-15 18:52 ` Jim Bos
2010-11-15 19:13 ` Linus Torvalds
2010-11-15 19:22 ` Jakub Jelinek
2010-11-15 19:57 ` Jakub Jelinek
2010-11-15 20:23 ` Linus Torvalds
2010-11-15 20:51 ` Jakub Jelinek
2010-11-15 21:03 ` Jim Bos
2010-11-15 23:08 ` Andi Kleen
2010-11-15 23:37 ` Jakub Jelinek
2010-11-15 20:52 ` Richard Henderson
2010-11-15 21:01 ` Jakub Jelinek
2010-11-15 12:04 ` Richard Guenther
2010-11-15 19:11 ` Jeff Law
2010-11-15 19:51 ` Linus Torvalds
2010-11-15 22:31 ` Richard Guenther
2010-11-15 23:39 ` Jeff Law
2010-11-16 0:27 ` Richard Guenther
2010-11-16 9:48 ` Jeff Law
2010-11-15 18:57 ` Jeff Law
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