* [PATCH v2] hppa: Drop old parisc-specific MADV_* constants
@ 2023-02-10 13:28 Helge Deller
2023-02-10 21:48 ` Joseph Myers
2023-02-22 15:35 ` Joseph Myers
0 siblings, 2 replies; 6+ messages in thread
From: Helge Deller @ 2023-02-10 13:28 UTC (permalink / raw)
To: libc-alpha, dave.anglin, fweimer
The Linux kernel upstream commit 71bdea6f798b ("parisc: Align parisc
MADV_XXX constants with all other architectures") dropped the
parisc-specific MADV_* values in favour of the same constants as
other architectures. In the same commit a wrapper was added which
translates the old values to the standard MADV_* values to avoid
breakage of existing programs.
This upstream patch has been downported to all stable kernel trees as
well.
This patch now drops the parisc specific constants from glibc to
allow newly compliled programs to use the standard MADV_* constants.
Signed-off-by: Helge Deller <deller@gmx.de>
---
v2: Added NEWS section, based on feedback from Florian Weimer
diff --git a/NEWS b/NEWS
index a7979a9cd3..d1e0d5c874 100644
--- a/NEWS
+++ b/NEWS
@@ -13,7 +13,12 @@ Major new features:
Deprecated and removed features, and other changes affecting compatibility:
- [Add deprecations, removals and changes affecting compatibility here]
+* In the Linux kernel for the hppa/parisc architecture some of the
+ MADV_XXX constants were changed to have the same values as the other
+ architectures. New programs compiled with this glibc version and which
+ use the madvise call will require at least Linux kernel version 6.2,
+ alternatively stable kernels from versions 6.1.6, 5.15.87, 5.10.163,
+ 5.4.228, 4.19.270 or 4.14.303.
Changes to build and runtime requirements:
diff --git a/sysdeps/unix/sysv/linux/hppa/bits/mman.h b/sysdeps/unix/sysv/linux/hppa/bits/mman.h
index c315efceb0..f5a69693af 100644
--- a/sysdeps/unix/sysv/linux/hppa/bits/mman.h
+++ b/sysdeps/unix/sysv/linux/hppa/bits/mman.h
@@ -39,11 +39,6 @@
#define MAP_FIXED_NOREPLACE 0x100000 /* MAP_FIXED but do not unmap
underlying mapping. */
-/* Advice to "madvise" */
-#ifdef __USE_MISC
-# define MADV_SOFT_OFFLINE 101 /* Soft offline page for testing. */
-#endif
-
#include <bits/mman-linux.h>
#undef MAP_TYPE
@@ -59,26 +54,3 @@
#define MS_ASYNC 2 /* Sync memory asynchronously */
#undef MS_INVALIDATE
#define MS_INVALIDATE 4 /* Invalidate the caches */
-
-/* Advice to "madvise" */
-#ifdef __USE_MISC
-# undef MADV_MERGEABLE
-# define MADV_MERGEABLE 65 /* KSM may merge identical pages */
-# undef MADV_UNMERGEABLE
-# define MADV_UNMERGEABLE 66 /* KSM may not merge identical pages */
-# undef MADV_HUGEPAGE
-# define MADV_HUGEPAGE 67 /* Worth backing with hugepages */
-# undef MADV_NOHUGEPAGE
-# define MADV_NOHUGEPAGE 68 /* Not worth backing with hugepages */
-# undef MADV_DONTDUMP
-# define MADV_DONTDUMP 69 /* Explicity exclude from the core dump,
- overrides the coredump filter bits */
-# undef MADV_DODUMP
-# define MADV_DODUMP 70 /* Clear the MADV_NODUMP flag */
-# undef MADV_WIPEONFORK
-# define MADV_WIPEONFORK 71 /* Zero memory on fork, child only. */
-# undef MADV_KEEPONFORK
-# define MADV_KEEPONFORK 72 /* Undo MADV_WIPEONFORK. */
-# undef MADV_COLLAPSE
-# define MADV_COLLAPSE 73 /* Synchronous hugepage collapse. */
-#endif
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v2] hppa: Drop old parisc-specific MADV_* constants
2023-02-10 13:28 [PATCH v2] hppa: Drop old parisc-specific MADV_* constants Helge Deller
@ 2023-02-10 21:48 ` Joseph Myers
2023-02-11 6:37 ` Helge Deller
2023-02-22 15:35 ` Joseph Myers
1 sibling, 1 reply; 6+ messages in thread
From: Joseph Myers @ 2023-02-10 21:48 UTC (permalink / raw)
To: Helge Deller; +Cc: libc-alpha, dave.anglin, fweimer
On Fri, 10 Feb 2023, Helge Deller via Libc-alpha wrote:
> - [Add deprecations, removals and changes affecting compatibility here]
> +* In the Linux kernel for the hppa/parisc architecture some of the
> + MADV_XXX constants were changed to have the same values as the other
> + architectures. New programs compiled with this glibc version and which
> + use the madvise call will require at least Linux kernel version 6.2,
> + alternatively stable kernels from versions 6.1.6, 5.15.87, 5.10.163,
> + 5.4.228, 4.19.270 or 4.14.303.
Normally we'd be a lot more conservative about kernel version
requirements, but if we require a new kernel we'd put it in
arch_minimum_kernel in the relevant configure.ac.
--
Joseph S. Myers
joseph@codesourcery.com
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2] hppa: Drop old parisc-specific MADV_* constants
2023-02-10 21:48 ` Joseph Myers
@ 2023-02-11 6:37 ` Helge Deller
2023-02-11 15:56 ` John David Anglin
0 siblings, 1 reply; 6+ messages in thread
From: Helge Deller @ 2023-02-11 6:37 UTC (permalink / raw)
To: Joseph Myers; +Cc: libc-alpha, dave.anglin, fweimer
On 2/10/23 22:48, Joseph Myers wrote:
> On Fri, 10 Feb 2023, Helge Deller via Libc-alpha wrote:
>
>> - [Add deprecations, removals and changes affecting compatibility here]
>> +* In the Linux kernel for the hppa/parisc architecture some of the
>> + MADV_XXX constants were changed to have the same values as the other
>> + architectures. New programs compiled with this glibc version and which
>> + use the madvise call will require at least Linux kernel version 6.2,
>> + alternatively stable kernels from versions 6.1.6, 5.15.87, 5.10.163,
>> + 5.4.228, 4.19.270 or 4.14.303.
>
> Normally we'd be a lot more conservative about kernel version
> requirements, but if we require a new kernel we'd put it in
> arch_minimum_kernel in the relevant configure.ac.
Basically, programs compiled with the new MADV values should work even
on all older kernels since it's just an advise for the kernel which it may
ignore and for which programs should allow the syscall to fail.
The only program I've found so far to be more strict is the
tor-browser, which refuses to start if MADV_WIPEONFORK fails.
But it's unlikely people will use tor on parisc, and IMHO
if you care about security you should use a more recent kernel anyway.
That said, I can add arch_minimum_kernel=4.14.303 (or 6.2?) but I don't
think it's necessary.
Helge
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2] hppa: Drop old parisc-specific MADV_* constants
2023-02-11 6:37 ` Helge Deller
@ 2023-02-11 15:56 ` John David Anglin
0 siblings, 0 replies; 6+ messages in thread
From: John David Anglin @ 2023-02-11 15:56 UTC (permalink / raw)
To: Helge Deller, Joseph Myers; +Cc: libc-alpha, fweimer
On 2023-02-11 1:37 a.m., Helge Deller wrote:
> On 2/10/23 22:48, Joseph Myers wrote:
>> On Fri, 10 Feb 2023, Helge Deller via Libc-alpha wrote:
>>
>>> - [Add deprecations, removals and changes affecting compatibility here]
>>> +* In the Linux kernel for the hppa/parisc architecture some of the
>>> + MADV_XXX constants were changed to have the same values as the other
>>> + architectures. New programs compiled with this glibc version and which
>>> + use the madvise call will require at least Linux kernel version 6.2,
>>> + alternatively stable kernels from versions 6.1.6, 5.15.87, 5.10.163,
>>> + 5.4.228, 4.19.270 or 4.14.303.
>>
>> Normally we'd be a lot more conservative about kernel version
>> requirements, but if we require a new kernel we'd put it in
>> arch_minimum_kernel in the relevant configure.ac.
>
> Basically, programs compiled with the new MADV values should work even
> on all older kernels since it's just an advise for the kernel which it may
> ignore and for which programs should allow the syscall to fail.
> The only program I've found so far to be more strict is the
> tor-browser, which refuses to start if MADV_WIPEONFORK fails.
> But it's unlikely people will use tor on parisc, and IMHO
> if you care about security you should use a more recent kernel anyway.
>
> That said, I can add arch_minimum_kernel=4.14.303 (or 6.2?) but I don't
> think it's necessary.
I don't think adding a arch_minimum_kernel define would help much. I don't know about
gentoo, but the current Debian kernel for hppa is already past the minimum for the new values.
The biggest risk is for people like me that keep a collection of old kernels around to check
for regressions in behavior. As long as there is no major breakage with old kernels running
new applications, we can make the switch.
Dave
--
John David Anglin dave.anglin@bell.net
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v2] hppa: Drop old parisc-specific MADV_* constants
2023-02-10 13:28 [PATCH v2] hppa: Drop old parisc-specific MADV_* constants Helge Deller
2023-02-10 21:48 ` Joseph Myers
@ 2023-02-22 15:35 ` Joseph Myers
2023-02-25 20:09 ` Helge Deller
1 sibling, 1 reply; 6+ messages in thread
From: Joseph Myers @ 2023-02-22 15:35 UTC (permalink / raw)
To: Helge Deller; +Cc: libc-alpha, dave.anglin, fweimer
On Fri, 10 Feb 2023, Helge Deller via Libc-alpha wrote:
> The Linux kernel upstream commit 71bdea6f798b ("parisc: Align parisc
> MADV_XXX constants with all other architectures") dropped the
> parisc-specific MADV_* values in favour of the same constants as
> other architectures. In the same commit a wrapper was added which
I'd like to enquire about another part of that commit. It removes the
#define of MAP_VARIABLE to 0, so resulting in tst-mman-consts failing if I
update build-many-glibcs.py to use Linux 6.2. So we'll need to change
tst-mman-consts.py to allow variation between userspace and kernel
regarding whether that macro is defined (the expectation of the test being
that newer kernels only add macros tested for, not remove them), but
should we also remove that define in glibc?
--
Joseph S. Myers
joseph@codesourcery.com
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v2] hppa: Drop old parisc-specific MADV_* constants
2023-02-22 15:35 ` Joseph Myers
@ 2023-02-25 20:09 ` Helge Deller
0 siblings, 0 replies; 6+ messages in thread
From: Helge Deller @ 2023-02-25 20:09 UTC (permalink / raw)
To: Joseph Myers; +Cc: libc-alpha, dave.anglin, fweimer
Hi Joseph,
On 2/22/23 16:35, Joseph Myers wrote:
> On Fri, 10 Feb 2023, Helge Deller via Libc-alpha wrote:
>
>> The Linux kernel upstream commit 71bdea6f798b ("parisc: Align parisc
>> MADV_XXX constants with all other architectures") dropped the
>> parisc-specific MADV_* values in favour of the same constants as
>> other architectures. In the same commit a wrapper was added which
>
> I'd like to enquire about another part of that commit. It removes the
> #define of MAP_VARIABLE to 0, so resulting in tst-mman-consts failing if I
> update build-many-glibcs.py to use Linux 6.2.
Oh, didn't knew that.
Basically it wasn't necessary to drop MAP_VARIABLE, but since no other arch
defined it either and as it's not used anywhere in the kernel I assumed it's
ok to drop it.
> So we'll need to change
> tst-mman-consts.py to allow variation between userspace and kernel
> regarding whether that macro is defined (the expectation of the test being
> that newer kernels only add macros tested for, not remove them), but
> should we also remove that define in glibc?
Yes, I think that's the best solution. Keeps glibc and kernel in sync.
Thank you!
Helge
^ permalink raw reply [flat|nested] 6+ messages in thread
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2023-02-10 13:28 [PATCH v2] hppa: Drop old parisc-specific MADV_* constants Helge Deller
2023-02-10 21:48 ` Joseph Myers
2023-02-11 6:37 ` Helge Deller
2023-02-11 15:56 ` John David Anglin
2023-02-22 15:35 ` Joseph Myers
2023-02-25 20:09 ` Helge Deller
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