* [PATCH] Rework -fno-omit-frame-pointer support on i386
@ 2017-01-09 12:56 Adhemerval Zanella
2017-01-09 19:02 ` Nix
2017-02-16 19:25 ` H.J. Lu
0 siblings, 2 replies; 11+ messages in thread
From: Adhemerval Zanella @ 2017-01-09 12:56 UTC (permalink / raw)
To: libc-alpha
Commit 6b1df8b27f fixed the -OS build issue on i386 (BZ#20729) by
expliciting disabling frame pointer (-fomit-frame-pointer) on the
faulty objects. Although it does fix the issue, it is a subpar
workaround that adds complexity in build process (a rule for each
object to add the required compiler option and pontentially more
rules for objects that call {INLINE,INTERNAL}_SYSCALL) and does not
allow the implementations to get all the possible debug/calltrack
information possible (used mainly in debuggers and performance
measurement tools).
This patch fixes it by adding an explicit configure check to see
if -fno-omit-frame-pointer is set and to act accordingly (set or
not OPTIMIZE_FOR_GCC_5). The make rules is simplified and only
one is required: to add libc-do-syscall on loader due mmap
(which will be empty anyway for default build with
-fomit-frame-pointer).
Checked on i386-linux-gnu with GCC 6.2.1 with CFLAGS sets as
'-Os', '-O2 -fno-omit-frame-pointer', and '-O2 -fomit-frame-pointer'.
For '-Os' the testsuite issues described by BZ#19463 and BZ#15105
still applied.
It fixes BZ #21029, although it is marked as duplicated of #20729
(I reopened to track this cleanup).
[BZ #21029]
* config.h.in [NO_OMIT_FRAME_POINTER]: New define.
* sysdeps/unix/sysv/linux/i386/Makefile
[$(subdir) = elf] (sysdep-dl-routines): Add libc-do-syscall.
(uses-6-syscall-arguments): Remove.
[$(subdir) = misc] (CFLAGS-epoll_pwait.o): Likewise.
[$(subdir) = misc] (CFLAGS-epoll_pwait.os): Likewise.
[$(subdir) = misc] (CFLAGS-mmap.o): Likewise.
[$(subdir) = misc] (CFLAGS-mmap.os): Likewise.
[$(subdir) = misc] (CFLAGS-mmap64.o): Likewise.
[$(subdir) = misc] (CFLAGS-mmap64.os): Likewise.
[$(subdir) = misc] (CFLAGS-pselect.o): Likewise.
[$(subdir) = misc] (cflags-pselect.o): Likewise.
[$(subdir) = misc] (cflags-pselect.os): Likewise.
[$(subdir) = misc] (cflags-rtld-mmap.os): Likewise.
[$(subdir) = sysvipc] (cflags-semtimedop.o): Likewise.
[$(subdir) = sysvipc] (cflags-semtimedop.os): Likewise.
[$(subdir) = io] (CFLAGS-posix_fadvise64.o): Likewise.
[$(subdir) = io] (CFLAGS-posix_fadvise64.os): Likewise.
[$(subdir) = io] (CFLAGS-posix_fallocate.o): Likewise.
[$(subdir) = io] (CFLAGS-posix_fallocate.os): Likewise.
[$(subdir) = io] (CFLAGS-posix_fallocate64.o): Likewise.
[$(subdir) = io] (CFLAGS-posix_fallocate64.os): Likewise.
[$(subdir) = io] (CFLAGS-sync_file_range.o): Likewise.
[$(subdir) = io] (CFLAGS-sync_file_range.os): Likewise.
[$(subdir) = io] (CFLAGS-fallocate.o): Likewise.
[$(subdir) = io] (CFLAGS-fallocate.os): Likewise.
[$(subdir) = io] (CFLAGS-fallocate64.o): Likewise.
[$(subdir) = io] (CFLAGS-fallocate64.os): Likewise.
[$(subdir) = nptl] (CFLAGS-pthread_rwlock_timedrdlock.o):
Likewise.
[$(subdir) = nptl] (CFLAGS-pthread_rwlock_timedrdlock.os):
Likewise.
[$(subdir) = nptl] (CFLAGS-pthread_rwlock_timedrwlock.o):
Likewise.
[$(subdir) = nptl] (CFLAGS-pthread_rwlock_timedrwlock.os):
Likewise.
[$(subdir) = nptl] (CFLAGS-sem_wait.o): Likewise.
[$(subdir) = nptl] (CFLAGS-sem_wait.os): Likewise.
[$(subdir) = nptl] (CFLAGS-sem_timedwait.o): Likewise.
[$(subdir) = nptl] (CFLAGS-sem_timedwait.os): Likewise.
* sysdeps/unix/sysv/linux/i386/configure.ac: Add check for
-fno-omit-frame-pointer usage.
* sysdeps/unix/sysv/linux/i386/configure: Regenerate.
* sysdeps/unix/sysv/linux/i386/sysdep.h (OPTIMIZE_FOR_GCC_5):
Set iff NO_OMIT_FRAME_POINTER is not defined.
(check_consistency): Likewise.
---
ChangeLog | 50 +++++++++++++++++++++++++++++++
config.h.in | 3 ++
sysdeps/unix/sysv/linux/i386/Makefile | 39 +-----------------------
sysdeps/unix/sysv/linux/i386/configure | 31 +++++++++++++++++++
sysdeps/unix/sysv/linux/i386/configure.ac | 19 ++++++++++++
sysdeps/unix/sysv/linux/i386/sysdep.h | 9 +++---
6 files changed, 109 insertions(+), 42 deletions(-)
diff --git a/config.h.in b/config.h.in
index 7bfe923..50da4ba 100644
--- a/config.h.in
+++ b/config.h.in
@@ -259,4 +259,7 @@
/* Build glibc with tunables support. */
#define HAVE_TUNABLES 0
+/* Define if compiler flags sets -fno-omit-frame-pointer. */
+#undef NO_OMIT_FRAME_POINTER
+
#endif
diff --git a/sysdeps/unix/sysv/linux/i386/Makefile b/sysdeps/unix/sysv/linux/i386/Makefile
index 9609752..6aac0df 100644
--- a/sysdeps/unix/sysv/linux/i386/Makefile
+++ b/sysdeps/unix/sysv/linux/i386/Makefile
@@ -1,47 +1,18 @@
# The default ABI is 32.
default-abi := 32
-# %ebp is used to pass the 6th argument to system calls, so these
-# system calls are incompatible with a frame pointer.
-uses-6-syscall-arguments = -fomit-frame-pointer
-
ifeq ($(subdir),misc)
sysdep_routines += ioperm iopl vm86
-CFLAGS-epoll_pwait.o += $(uses-6-syscall-arguments)
-CFLAGS-epoll_pwait.os += $(uses-6-syscall-arguments)
-CFLAGS-mmap.o += $(uses-6-syscall-arguments)
-CFLAGS-mmap.os += $(uses-6-syscall-arguments)
-CFLAGS-mmap64.o += $(uses-6-syscall-arguments)
-CFLAGS-mmap64.os += $(uses-6-syscall-arguments)
-CFLAGS-pselect.o += $(uses-6-syscall-arguments)
-CFLAGS-pselect.os += $(uses-6-syscall-arguments)
-CFLAGS-rtld-mmap.os += $(uses-6-syscall-arguments)
-endif
-
-ifeq ($(subdir),sysvipc)
-CFLAGS-semtimedop.o += $(uses-6-syscall-arguments)
-CFLAGS-semtimedop.os += $(uses-6-syscall-arguments)
endif
ifeq ($(subdir),elf)
+sysdep-dl-routines += libc-do-syscall
sysdep-others += lddlibc4
install-bin += lddlibc4
endif
ifeq ($(subdir),io)
sysdep_routines += libc-do-syscall
-CFLAGS-posix_fadvise64.o += $(uses-6-syscall-arguments)
-CFLAGS-posix_fadvise64.os += $(uses-6-syscall-arguments)
-CFLAGS-posix_fallocate.o += $(uses-6-syscall-arguments)
-CFLAGS-posix_fallocate.os += $(uses-6-syscall-arguments)
-CFLAGS-posix_fallocate64.o += $(uses-6-syscall-arguments)
-CFLAGS-posix_fallocate64.os += $(uses-6-syscall-arguments)
-CFLAGS-sync_file_range.o += $(uses-6-syscall-arguments)
-CFLAGS-sync_file_range.os += $(uses-6-syscall-arguments)
-CFLAGS-fallocate.o += $(uses-6-syscall-arguments)
-CFLAGS-fallocate.os += $(uses-6-syscall-arguments)
-CFLAGS-fallocate64.o += $(uses-6-syscall-arguments)
-CFLAGS-fallocate64.os += $(uses-6-syscall-arguments)
endif
ifeq ($(subdir),nptl)
@@ -61,14 +32,6 @@ ifeq ($(subdir),nptl)
# pull in __syscall_error routine
libpthread-routines += sysdep
libpthread-shared-only-routines += sysdep
-CFLAGS-pthread_rwlock_timedrdlock.o += $(uses-6-syscall-arguments)
-CFLAGS-pthread_rwlock_timedrdlock.os += $(uses-6-syscall-arguments)
-CFLAGS-pthread_rwlock_timedwrlock.o += $(uses-6-syscall-arguments)
-CFLAGS-pthread_rwlock_timedwrlock.os += $(uses-6-syscall-arguments)
-CFLAGS-sem_wait.o += $(uses-6-syscall-arguments)
-CFLAGS-sem_wait.os += $(uses-6-syscall-arguments)
-CFLAGS-sem_timedwait.o += $(uses-6-syscall-arguments)
-CFLAGS-sem_timedwait.os += $(uses-6-syscall-arguments)
endif
ifeq ($(subdir),rt)
diff --git a/sysdeps/unix/sysv/linux/i386/configure b/sysdeps/unix/sysv/linux/i386/configure
index eb72659..a1381e6 100644
--- a/sysdeps/unix/sysv/linux/i386/configure
+++ b/sysdeps/unix/sysv/linux/i386/configure
@@ -3,5 +3,36 @@
arch_minimum_kernel=2.6.32
+# Check if CFLAGS sets -fno-omit-frame-pointer
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for if compiler flags sets -fno-omit-frame-pointer" >&5
+$as_echo_n "checking for if compiler flags sets -fno-omit-frame-pointer... " >&6; }
+if ${libc_cv_no_omit_frame_pointer+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+ cat > conftest.c << EOF
+ void foo (void) { }
+EOF
+ libc_cv_no_omit_frame_pointer=no
+ if { ac_try='${CC-cc} $CFLAGS -S conftest.c -o conftest.s 1>&5'
+ { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
+ (eval $ac_try) 2>&5
+ ac_status=$?
+ $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
+ test $ac_status = 0; }; }; then
+ if grep 'push.*%ebp' conftest.s >/dev/null &&
+ grep 'pop.*%ebp' conftest.s >/dev/null; then
+ libc_cv_no_omit_frame_pointer=yes
+ fi
+ fi
+ rm -f conftest.c conftest.s
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_no_omit_frame_pointer" >&5
+$as_echo "$libc_cv_no_omit_frame_pointer" >&6; }
+if test $libc_cv_no_omit_frame_pointer = yes; then
+ $as_echo "#define NO_OMIT_FRAME_POINTER 1" >>confdefs.h
+
+fi
+
libc_cv_gcc_unwind_find_fde=yes
ldd_rewrite_script=sysdeps/unix/sysv/linux/ldd-rewrite.sed
diff --git a/sysdeps/unix/sysv/linux/i386/configure.ac b/sysdeps/unix/sysv/linux/i386/configure.ac
index 1a11da6..06ccb7b 100644
--- a/sysdeps/unix/sysv/linux/i386/configure.ac
+++ b/sysdeps/unix/sysv/linux/i386/configure.ac
@@ -3,5 +3,24 @@ GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
arch_minimum_kernel=2.6.32
+# Check if CFLAGS sets -fno-omit-frame-pointer
+AC_CACHE_CHECK(for if compiler flags sets -fno-omit-frame-pointer,
+ libc_cv_no_omit_frame_pointer,
+ [cat > conftest.c << EOF
+ void foo (void) { }
+EOF
+ libc_cv_no_omit_frame_pointer=no
+ if AC_TRY_COMMAND(${CC-cc} $CFLAGS -S conftest.c -o conftest.s 1>&AS_MESSAGE_LOG_FD); then
+ if grep 'push.*%ebp' conftest.s >/dev/null &&
+ grep 'pop.*%ebp' conftest.s >/dev/null; then
+ libc_cv_no_omit_frame_pointer=yes
+ fi
+ fi
+ rm -f conftest.c conftest.s
+ ])
+if test $libc_cv_no_omit_frame_pointer = yes; then
+ AC_DEFINE(NO_OMIT_FRAME_POINTER)
+fi
+
libc_cv_gcc_unwind_find_fde=yes
ldd_rewrite_script=sysdeps/unix/sysv/linux/ldd-rewrite.sed
diff --git a/sysdeps/unix/sysv/linux/i386/sysdep.h b/sysdeps/unix/sysv/linux/i386/sysdep.h
index baf4642..591aaf7 100644
--- a/sysdeps/unix/sysv/linux/i386/sysdep.h
+++ b/sysdeps/unix/sysv/linux/i386/sysdep.h
@@ -44,9 +44,9 @@
/* Since GCC 5 and above can properly spill %ebx with PIC when needed,
we can inline syscalls with 6 arguments if GCC 5 or above is used
to compile glibc. Disable GCC 5 optimization when compiling for
- profiling since asm ("ebp") can't be used to put the 6th argument
- in %ebp for syscall. */
-#if __GNUC_PREREQ (5,0) && !defined PROF
+ profiling or when -fno-omit-frame-pointer is used since asm ("ebp")
+ can't be used to put the 6th argument in %ebp for syscall. */
+#if __GNUC_PREREQ (5,0) && !defined PROF && !defined NO_OMIT_FRAME_POINTER
# define OPTIMIZE_FOR_GCC_5
#endif
@@ -611,7 +611,8 @@ struct libc_do_syscall_args
#endif
/* Consistency check for position-independent code. */
-#if defined __PIC__ && !defined OPTIMIZE_FOR_GCC_5
+#if defined __PIC__ && !defined OPTIMIZE_FOR_GCC_5 \
+ && !defined NO_OMIT_FRAME_POINTER
# define check_consistency() \
({ int __res; \
__asm__ __volatile__ \
--
2.7.4
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH] Rework -fno-omit-frame-pointer support on i386
2017-01-09 12:56 [PATCH] Rework -fno-omit-frame-pointer support on i386 Adhemerval Zanella
@ 2017-01-09 19:02 ` Nix
2017-01-10 14:03 ` Adhemerval Zanella
2017-02-16 19:25 ` H.J. Lu
1 sibling, 1 reply; 11+ messages in thread
From: Nix @ 2017-01-09 19:02 UTC (permalink / raw)
To: Adhemerval Zanella; +Cc: libc-alpha
On 9 Jan 2017, Adhemerval Zanella stated:
> ifeq ($(subdir),misc)
> sysdep_routines += ioperm iopl vm86
> -CFLAGS-epoll_pwait.o += $(uses-6-syscall-arguments)
> -CFLAGS-epoll_pwait.os += $(uses-6-syscall-arguments)
> -CFLAGS-mmap.o += $(uses-6-syscall-arguments)
> -CFLAGS-mmap.os += $(uses-6-syscall-arguments)
> -CFLAGS-mmap64.o += $(uses-6-syscall-arguments)
> -CFLAGS-mmap64.os += $(uses-6-syscall-arguments)
> -CFLAGS-pselect.o += $(uses-6-syscall-arguments)
> -CFLAGS-pselect.os += $(uses-6-syscall-arguments)
> -CFLAGS-rtld-mmap.os += $(uses-6-syscall-arguments)
> -endif
Nice!
> diff --git a/sysdeps/unix/sysv/linux/i386/configure.ac b/sysdeps/unix/sysv/linux/i386/configure.ac
> index 1a11da6..06ccb7b 100644
> --- a/sysdeps/unix/sysv/linux/i386/configure.ac
> +++ b/sysdeps/unix/sysv/linux/i386/configure.ac
> @@ -3,5 +3,24 @@ GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
>
> arch_minimum_kernel=2.6.32
>
> +# Check if CFLAGS sets -fno-omit-frame-pointer
> +AC_CACHE_CHECK(for if compiler flags sets -fno-omit-frame-pointer,
Perhaps "for -fno-omit-frame-pointer in CFLAGS" might read better.
--
NULL && (void)
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH] Rework -fno-omit-frame-pointer support on i386
2017-01-09 19:02 ` Nix
@ 2017-01-10 14:03 ` Adhemerval Zanella
2017-01-17 10:24 ` Adhemerval Zanella
0 siblings, 1 reply; 11+ messages in thread
From: Adhemerval Zanella @ 2017-01-10 14:03 UTC (permalink / raw)
To: Nix; +Cc: libc-alpha
On 09/01/2017 17:02, Nix wrote:
> On 9 Jan 2017, Adhemerval Zanella stated:
>
>> ifeq ($(subdir),misc)
>> sysdep_routines += ioperm iopl vm86
>> -CFLAGS-epoll_pwait.o += $(uses-6-syscall-arguments)
>> -CFLAGS-epoll_pwait.os += $(uses-6-syscall-arguments)
>> -CFLAGS-mmap.o += $(uses-6-syscall-arguments)
>> -CFLAGS-mmap.os += $(uses-6-syscall-arguments)
>> -CFLAGS-mmap64.o += $(uses-6-syscall-arguments)
>> -CFLAGS-mmap64.os += $(uses-6-syscall-arguments)
>> -CFLAGS-pselect.o += $(uses-6-syscall-arguments)
>> -CFLAGS-pselect.os += $(uses-6-syscall-arguments)
>> -CFLAGS-rtld-mmap.os += $(uses-6-syscall-arguments)
>> -endif
>
> Nice!
>
>> diff --git a/sysdeps/unix/sysv/linux/i386/configure.ac b/sysdeps/unix/sysv/linux/i386/configure.ac
>> index 1a11da6..06ccb7b 100644
>> --- a/sysdeps/unix/sysv/linux/i386/configure.ac
>> +++ b/sysdeps/unix/sysv/linux/i386/configure.ac
>> @@ -3,5 +3,24 @@ GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
>>
>> arch_minimum_kernel=2.6.32
>>
>> +# Check if CFLAGS sets -fno-omit-frame-pointer
>> +AC_CACHE_CHECK(for if compiler flags sets -fno-omit-frame-pointer,
>
> Perhaps "for -fno-omit-frame-pointer in CFLAGS" might read better.
Indeed, I changed it locally.
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH] Rework -fno-omit-frame-pointer support on i386
2017-01-10 14:03 ` Adhemerval Zanella
@ 2017-01-17 10:24 ` Adhemerval Zanella
2017-01-24 20:14 ` Adhemerval Zanella
0 siblings, 1 reply; 11+ messages in thread
From: Adhemerval Zanella @ 2017-01-17 10:24 UTC (permalink / raw)
To: Nix; +Cc: libc-alpha
On 10/01/2017 12:02, Adhemerval Zanella wrote:
>
>
> On 09/01/2017 17:02, Nix wrote:
>> On 9 Jan 2017, Adhemerval Zanella stated:
>>
>>> ifeq ($(subdir),misc)
>>> sysdep_routines += ioperm iopl vm86
>>> -CFLAGS-epoll_pwait.o += $(uses-6-syscall-arguments)
>>> -CFLAGS-epoll_pwait.os += $(uses-6-syscall-arguments)
>>> -CFLAGS-mmap.o += $(uses-6-syscall-arguments)
>>> -CFLAGS-mmap.os += $(uses-6-syscall-arguments)
>>> -CFLAGS-mmap64.o += $(uses-6-syscall-arguments)
>>> -CFLAGS-mmap64.os += $(uses-6-syscall-arguments)
>>> -CFLAGS-pselect.o += $(uses-6-syscall-arguments)
>>> -CFLAGS-pselect.os += $(uses-6-syscall-arguments)
>>> -CFLAGS-rtld-mmap.os += $(uses-6-syscall-arguments)
>>> -endif
>>
>> Nice!
>>
>>> diff --git a/sysdeps/unix/sysv/linux/i386/configure.ac b/sysdeps/unix/sysv/linux/i386/configure.ac
>>> index 1a11da6..06ccb7b 100644
>>> --- a/sysdeps/unix/sysv/linux/i386/configure.ac
>>> +++ b/sysdeps/unix/sysv/linux/i386/configure.ac
>>> @@ -3,5 +3,24 @@ GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
>>>
>>> arch_minimum_kernel=2.6.32
>>>
>>> +# Check if CFLAGS sets -fno-omit-frame-pointer
>>> +AC_CACHE_CHECK(for if compiler flags sets -fno-omit-frame-pointer,
>>
>> Perhaps "for -fno-omit-frame-pointer in CFLAGS" might read better.
>
> Indeed, I changed it locally.
>
Ping.
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH] Rework -fno-omit-frame-pointer support on i386
2017-01-17 10:24 ` Adhemerval Zanella
@ 2017-01-24 20:14 ` Adhemerval Zanella
2017-02-16 18:04 ` Adhemerval Zanella
0 siblings, 1 reply; 11+ messages in thread
From: Adhemerval Zanella @ 2017-01-24 20:14 UTC (permalink / raw)
To: Nix; +Cc: libc-alpha
On 17/01/2017 08:23, Adhemerval Zanella wrote:
>
>
> On 10/01/2017 12:02, Adhemerval Zanella wrote:
>>
>>
>> On 09/01/2017 17:02, Nix wrote:
>>> On 9 Jan 2017, Adhemerval Zanella stated:
>>>
>>>> ifeq ($(subdir),misc)
>>>> sysdep_routines += ioperm iopl vm86
>>>> -CFLAGS-epoll_pwait.o += $(uses-6-syscall-arguments)
>>>> -CFLAGS-epoll_pwait.os += $(uses-6-syscall-arguments)
>>>> -CFLAGS-mmap.o += $(uses-6-syscall-arguments)
>>>> -CFLAGS-mmap.os += $(uses-6-syscall-arguments)
>>>> -CFLAGS-mmap64.o += $(uses-6-syscall-arguments)
>>>> -CFLAGS-mmap64.os += $(uses-6-syscall-arguments)
>>>> -CFLAGS-pselect.o += $(uses-6-syscall-arguments)
>>>> -CFLAGS-pselect.os += $(uses-6-syscall-arguments)
>>>> -CFLAGS-rtld-mmap.os += $(uses-6-syscall-arguments)
>>>> -endif
>>>
>>> Nice!
>>>
>>>> diff --git a/sysdeps/unix/sysv/linux/i386/configure.ac b/sysdeps/unix/sysv/linux/i386/configure.ac
>>>> index 1a11da6..06ccb7b 100644
>>>> --- a/sysdeps/unix/sysv/linux/i386/configure.ac
>>>> +++ b/sysdeps/unix/sysv/linux/i386/configure.ac
>>>> @@ -3,5 +3,24 @@ GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
>>>>
>>>> arch_minimum_kernel=2.6.32
>>>>
>>>> +# Check if CFLAGS sets -fno-omit-frame-pointer
>>>> +AC_CACHE_CHECK(for if compiler flags sets -fno-omit-frame-pointer,
>>>
>>> Perhaps "for -fno-omit-frame-pointer in CFLAGS" might read better.
>>
>> Indeed, I changed it locally.
>>
>
> Ping.
>
Ping.
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH] Rework -fno-omit-frame-pointer support on i386
2017-01-24 20:14 ` Adhemerval Zanella
@ 2017-02-16 18:04 ` Adhemerval Zanella
0 siblings, 0 replies; 11+ messages in thread
From: Adhemerval Zanella @ 2017-02-16 18:04 UTC (permalink / raw)
To: Nix; +Cc: libc-alpha
Ping.
On 24/01/2017 18:14, Adhemerval Zanella wrote:
>
>
> On 17/01/2017 08:23, Adhemerval Zanella wrote:
>>
>>
>> On 10/01/2017 12:02, Adhemerval Zanella wrote:
>>>
>>>
>>> On 09/01/2017 17:02, Nix wrote:
>>>> On 9 Jan 2017, Adhemerval Zanella stated:
>>>>
>>>>> ifeq ($(subdir),misc)
>>>>> sysdep_routines += ioperm iopl vm86
>>>>> -CFLAGS-epoll_pwait.o += $(uses-6-syscall-arguments)
>>>>> -CFLAGS-epoll_pwait.os += $(uses-6-syscall-arguments)
>>>>> -CFLAGS-mmap.o += $(uses-6-syscall-arguments)
>>>>> -CFLAGS-mmap.os += $(uses-6-syscall-arguments)
>>>>> -CFLAGS-mmap64.o += $(uses-6-syscall-arguments)
>>>>> -CFLAGS-mmap64.os += $(uses-6-syscall-arguments)
>>>>> -CFLAGS-pselect.o += $(uses-6-syscall-arguments)
>>>>> -CFLAGS-pselect.os += $(uses-6-syscall-arguments)
>>>>> -CFLAGS-rtld-mmap.os += $(uses-6-syscall-arguments)
>>>>> -endif
>>>>
>>>> Nice!
>>>>
>>>>> diff --git a/sysdeps/unix/sysv/linux/i386/configure.ac b/sysdeps/unix/sysv/linux/i386/configure.ac
>>>>> index 1a11da6..06ccb7b 100644
>>>>> --- a/sysdeps/unix/sysv/linux/i386/configure.ac
>>>>> +++ b/sysdeps/unix/sysv/linux/i386/configure.ac
>>>>> @@ -3,5 +3,24 @@ GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
>>>>>
>>>>> arch_minimum_kernel=2.6.32
>>>>>
>>>>> +# Check if CFLAGS sets -fno-omit-frame-pointer
>>>>> +AC_CACHE_CHECK(for if compiler flags sets -fno-omit-frame-pointer,
>>>>
>>>> Perhaps "for -fno-omit-frame-pointer in CFLAGS" might read better.
>>>
>>> Indeed, I changed it locally.
>>>
>>
>> Ping.
>>
>
> Ping.
>
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH] Rework -fno-omit-frame-pointer support on i386
2017-01-09 12:56 [PATCH] Rework -fno-omit-frame-pointer support on i386 Adhemerval Zanella
2017-01-09 19:02 ` Nix
@ 2017-02-16 19:25 ` H.J. Lu
2017-02-17 14:48 ` Adhemerval Zanella
1 sibling, 1 reply; 11+ messages in thread
From: H.J. Lu @ 2017-02-16 19:25 UTC (permalink / raw)
To: Adhemerval Zanella; +Cc: GNU C Library
On Mon, Jan 9, 2017 at 4:55 AM, Adhemerval Zanella
<adhemerval.zanella@linaro.org> wrote:
> Commit 6b1df8b27f fixed the -OS build issue on i386 (BZ#20729) by
> expliciting disabling frame pointer (-fomit-frame-pointer) on the
> faulty objects. Although it does fix the issue, it is a subpar
> workaround that adds complexity in build process (a rule for each
> object to add the required compiler option and pontentially more
> rules for objects that call {INLINE,INTERNAL}_SYSCALL) and does not
> allow the implementations to get all the possible debug/calltrack
> information possible (used mainly in debuggers and performance
> measurement tools).
>
> This patch fixes it by adding an explicit configure check to see
> if -fno-omit-frame-pointer is set and to act accordingly (set or
> not OPTIMIZE_FOR_GCC_5). The make rules is simplified and only
> one is required: to add libc-do-syscall on loader due mmap
> (which will be empty anyway for default build with
> -fomit-frame-pointer).
>
> Checked on i386-linux-gnu with GCC 6.2.1 with CFLAGS sets as
> '-Os', '-O2 -fno-omit-frame-pointer', and '-O2 -fomit-frame-pointer'.
> For '-Os' the testsuite issues described by BZ#19463 and BZ#15105
> still applied.
>
> It fixes BZ #21029, although it is marked as duplicated of #20729
> (I reopened to track this cleanup).
>
> [BZ #21029]
> * config.h.in [NO_OMIT_FRAME_POINTER]: New define.
> * sysdeps/unix/sysv/linux/i386/Makefile
> [$(subdir) = elf] (sysdep-dl-routines): Add libc-do-syscall.
> (uses-6-syscall-arguments): Remove.
> [$(subdir) = misc] (CFLAGS-epoll_pwait.o): Likewise.
> [$(subdir) = misc] (CFLAGS-epoll_pwait.os): Likewise.
> [$(subdir) = misc] (CFLAGS-mmap.o): Likewise.
> [$(subdir) = misc] (CFLAGS-mmap.os): Likewise.
> [$(subdir) = misc] (CFLAGS-mmap64.o): Likewise.
> [$(subdir) = misc] (CFLAGS-mmap64.os): Likewise.
> [$(subdir) = misc] (CFLAGS-pselect.o): Likewise.
> [$(subdir) = misc] (cflags-pselect.o): Likewise.
> [$(subdir) = misc] (cflags-pselect.os): Likewise.
> [$(subdir) = misc] (cflags-rtld-mmap.os): Likewise.
> [$(subdir) = sysvipc] (cflags-semtimedop.o): Likewise.
> [$(subdir) = sysvipc] (cflags-semtimedop.os): Likewise.
> [$(subdir) = io] (CFLAGS-posix_fadvise64.o): Likewise.
> [$(subdir) = io] (CFLAGS-posix_fadvise64.os): Likewise.
> [$(subdir) = io] (CFLAGS-posix_fallocate.o): Likewise.
> [$(subdir) = io] (CFLAGS-posix_fallocate.os): Likewise.
> [$(subdir) = io] (CFLAGS-posix_fallocate64.o): Likewise.
> [$(subdir) = io] (CFLAGS-posix_fallocate64.os): Likewise.
> [$(subdir) = io] (CFLAGS-sync_file_range.o): Likewise.
> [$(subdir) = io] (CFLAGS-sync_file_range.os): Likewise.
> [$(subdir) = io] (CFLAGS-fallocate.o): Likewise.
> [$(subdir) = io] (CFLAGS-fallocate.os): Likewise.
> [$(subdir) = io] (CFLAGS-fallocate64.o): Likewise.
> [$(subdir) = io] (CFLAGS-fallocate64.os): Likewise.
> [$(subdir) = nptl] (CFLAGS-pthread_rwlock_timedrdlock.o):
> Likewise.
> [$(subdir) = nptl] (CFLAGS-pthread_rwlock_timedrdlock.os):
> Likewise.
> [$(subdir) = nptl] (CFLAGS-pthread_rwlock_timedrwlock.o):
> Likewise.
> [$(subdir) = nptl] (CFLAGS-pthread_rwlock_timedrwlock.os):
> Likewise.
> [$(subdir) = nptl] (CFLAGS-sem_wait.o): Likewise.
> [$(subdir) = nptl] (CFLAGS-sem_wait.os): Likewise.
> [$(subdir) = nptl] (CFLAGS-sem_timedwait.o): Likewise.
> [$(subdir) = nptl] (CFLAGS-sem_timedwait.os): Likewise.
> * sysdeps/unix/sysv/linux/i386/configure.ac: Add check for
> -fno-omit-frame-pointer usage.
> * sysdeps/unix/sysv/linux/i386/configure: Regenerate.
> * sysdeps/unix/sysv/linux/i386/sysdep.h (OPTIMIZE_FOR_GCC_5):
> Set iff NO_OMIT_FRAME_POINTER is not defined.
> (check_consistency): Likewise.
> ---
> ChangeLog | 50 +++++++++++++++++++++++++++++++
> config.h.in | 3 ++
> sysdeps/unix/sysv/linux/i386/Makefile | 39 +-----------------------
> sysdeps/unix/sysv/linux/i386/configure | 31 +++++++++++++++++++
> sysdeps/unix/sysv/linux/i386/configure.ac | 19 ++++++++++++
> sysdeps/unix/sysv/linux/i386/sysdep.h | 9 +++---
> 6 files changed, 109 insertions(+), 42 deletions(-)
>
> diff --git a/config.h.in b/config.h.in
> index 7bfe923..50da4ba 100644
> --- a/config.h.in
> +++ b/config.h.in
> @@ -259,4 +259,7 @@
> /* Build glibc with tunables support. */
> #define HAVE_TUNABLES 0
>
> +/* Define if compiler flags sets -fno-omit-frame-pointer. */
> +#undef NO_OMIT_FRAME_POINTER
> +
> #endif
> diff --git a/sysdeps/unix/sysv/linux/i386/Makefile b/sysdeps/unix/sysv/linux/i386/Makefile
> index 9609752..6aac0df 100644
> --- a/sysdeps/unix/sysv/linux/i386/Makefile
> +++ b/sysdeps/unix/sysv/linux/i386/Makefile
> @@ -1,47 +1,18 @@
> # The default ABI is 32.
> default-abi := 32
>
> -# %ebp is used to pass the 6th argument to system calls, so these
> -# system calls are incompatible with a frame pointer.
> -uses-6-syscall-arguments = -fomit-frame-pointer
> -
> ifeq ($(subdir),misc)
> sysdep_routines += ioperm iopl vm86
> -CFLAGS-epoll_pwait.o += $(uses-6-syscall-arguments)
> -CFLAGS-epoll_pwait.os += $(uses-6-syscall-arguments)
> -CFLAGS-mmap.o += $(uses-6-syscall-arguments)
> -CFLAGS-mmap.os += $(uses-6-syscall-arguments)
> -CFLAGS-mmap64.o += $(uses-6-syscall-arguments)
> -CFLAGS-mmap64.os += $(uses-6-syscall-arguments)
> -CFLAGS-pselect.o += $(uses-6-syscall-arguments)
> -CFLAGS-pselect.os += $(uses-6-syscall-arguments)
> -CFLAGS-rtld-mmap.os += $(uses-6-syscall-arguments)
> -endif
> -
> -ifeq ($(subdir),sysvipc)
> -CFLAGS-semtimedop.o += $(uses-6-syscall-arguments)
> -CFLAGS-semtimedop.os += $(uses-6-syscall-arguments)
> endif
>
> ifeq ($(subdir),elf)
> +sysdep-dl-routines += libc-do-syscall
> sysdep-others += lddlibc4
> install-bin += lddlibc4
> endif
>
> ifeq ($(subdir),io)
> sysdep_routines += libc-do-syscall
> -CFLAGS-posix_fadvise64.o += $(uses-6-syscall-arguments)
> -CFLAGS-posix_fadvise64.os += $(uses-6-syscall-arguments)
> -CFLAGS-posix_fallocate.o += $(uses-6-syscall-arguments)
> -CFLAGS-posix_fallocate.os += $(uses-6-syscall-arguments)
> -CFLAGS-posix_fallocate64.o += $(uses-6-syscall-arguments)
> -CFLAGS-posix_fallocate64.os += $(uses-6-syscall-arguments)
> -CFLAGS-sync_file_range.o += $(uses-6-syscall-arguments)
> -CFLAGS-sync_file_range.os += $(uses-6-syscall-arguments)
> -CFLAGS-fallocate.o += $(uses-6-syscall-arguments)
> -CFLAGS-fallocate.os += $(uses-6-syscall-arguments)
> -CFLAGS-fallocate64.o += $(uses-6-syscall-arguments)
> -CFLAGS-fallocate64.os += $(uses-6-syscall-arguments)
> endif
>
> ifeq ($(subdir),nptl)
> @@ -61,14 +32,6 @@ ifeq ($(subdir),nptl)
> # pull in __syscall_error routine
> libpthread-routines += sysdep
> libpthread-shared-only-routines += sysdep
> -CFLAGS-pthread_rwlock_timedrdlock.o += $(uses-6-syscall-arguments)
> -CFLAGS-pthread_rwlock_timedrdlock.os += $(uses-6-syscall-arguments)
> -CFLAGS-pthread_rwlock_timedwrlock.o += $(uses-6-syscall-arguments)
> -CFLAGS-pthread_rwlock_timedwrlock.os += $(uses-6-syscall-arguments)
> -CFLAGS-sem_wait.o += $(uses-6-syscall-arguments)
> -CFLAGS-sem_wait.os += $(uses-6-syscall-arguments)
> -CFLAGS-sem_timedwait.o += $(uses-6-syscall-arguments)
> -CFLAGS-sem_timedwait.os += $(uses-6-syscall-arguments)
> endif
>
> ifeq ($(subdir),rt)
> diff --git a/sysdeps/unix/sysv/linux/i386/configure b/sysdeps/unix/sysv/linux/i386/configure
> index eb72659..a1381e6 100644
> --- a/sysdeps/unix/sysv/linux/i386/configure
> +++ b/sysdeps/unix/sysv/linux/i386/configure
> @@ -3,5 +3,36 @@
>
> arch_minimum_kernel=2.6.32
>
> +# Check if CFLAGS sets -fno-omit-frame-pointer
> +{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for if compiler flags sets -fno-omit-frame-pointer" >&5
> +$as_echo_n "checking for if compiler flags sets -fno-omit-frame-pointer... " >&6; }
> +if ${libc_cv_no_omit_frame_pointer+:} false; then :
> + $as_echo_n "(cached) " >&6
> +else
> + cat > conftest.c << EOF
> + void foo (void) { }
> +EOF
> + libc_cv_no_omit_frame_pointer=no
> + if { ac_try='${CC-cc} $CFLAGS -S conftest.c -o conftest.s 1>&5'
> + { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
> + (eval $ac_try) 2>&5
> + ac_status=$?
> + $as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
> + test $ac_status = 0; }; }; then
> + if grep 'push.*%ebp' conftest.s >/dev/null &&
> + grep 'pop.*%ebp' conftest.s >/dev/null; then
> + libc_cv_no_omit_frame_pointer=yes
> + fi
> + fi
> + rm -f conftest.c conftest.s
> +
> +fi
> +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_no_omit_frame_pointer" >&5
> +$as_echo "$libc_cv_no_omit_frame_pointer" >&6; }
> +if test $libc_cv_no_omit_frame_pointer = yes; then
> + $as_echo "#define NO_OMIT_FRAME_POINTER 1" >>confdefs.h
> +
> +fi
> +
> libc_cv_gcc_unwind_find_fde=yes
> ldd_rewrite_script=sysdeps/unix/sysv/linux/ldd-rewrite.sed
> diff --git a/sysdeps/unix/sysv/linux/i386/configure.ac b/sysdeps/unix/sysv/linux/i386/configure.ac
> index 1a11da6..06ccb7b 100644
> --- a/sysdeps/unix/sysv/linux/i386/configure.ac
> +++ b/sysdeps/unix/sysv/linux/i386/configure.ac
> @@ -3,5 +3,24 @@ GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
>
> arch_minimum_kernel=2.6.32
>
> +# Check if CFLAGS sets -fno-omit-frame-pointer
> +AC_CACHE_CHECK(for if compiler flags sets -fno-omit-frame-pointer,
> + libc_cv_no_omit_frame_pointer,
> + [cat > conftest.c << EOF
> + void foo (void) { }
> +EOF
> + libc_cv_no_omit_frame_pointer=no
> + if AC_TRY_COMMAND(${CC-cc} $CFLAGS -S conftest.c -o conftest.s 1>&AS_MESSAGE_LOG_FD); then
> + if grep 'push.*%ebp' conftest.s >/dev/null &&
> + grep 'pop.*%ebp' conftest.s >/dev/null; then
> + libc_cv_no_omit_frame_pointer=yes
> + fi
> + fi
> + rm -f conftest.c conftest.s
> + ])
I prefer something like
[hjl@gnu-6 tmp]$ cat ebp.c
void
foo (int i)
{
register int reg asm ("ebp") = i;
asm ("# %0" : : "r" (reg));
}
[hjl@gnu-6 tmp]$ gcc -S -m32 -Os ebp.c
ebp.c: In function ‘foo’:
ebp.c:6:1: error: bp cannot be used in asm here
}
^
[hjl@gnu-6 tmp]$ gcc -S -m32 -O2 ebp.c
[hjl@gnu-6 tmp]$
> +if test $libc_cv_no_omit_frame_pointer = yes; then
> + AC_DEFINE(NO_OMIT_FRAME_POINTER)
> +fi
How about something like CAN_USE_REGISTER_ASM_EBP?
> +
> libc_cv_gcc_unwind_find_fde=yes
> ldd_rewrite_script=sysdeps/unix/sysv/linux/ldd-rewrite.sed
> diff --git a/sysdeps/unix/sysv/linux/i386/sysdep.h b/sysdeps/unix/sysv/linux/i386/sysdep.h
> index baf4642..591aaf7 100644
> --- a/sysdeps/unix/sysv/linux/i386/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/i386/sysdep.h
> @@ -44,9 +44,9 @@
> /* Since GCC 5 and above can properly spill %ebx with PIC when needed,
> we can inline syscalls with 6 arguments if GCC 5 or above is used
> to compile glibc. Disable GCC 5 optimization when compiling for
> - profiling since asm ("ebp") can't be used to put the 6th argument
> - in %ebp for syscall. */
> -#if __GNUC_PREREQ (5,0) && !defined PROF
> + profiling or when -fno-omit-frame-pointer is used since asm ("ebp")
> + can't be used to put the 6th argument in %ebp for syscall. */
> +#if __GNUC_PREREQ (5,0) && !defined PROF && !defined NO_OMIT_FRAME_POINTER
> # define OPTIMIZE_FOR_GCC_5
> #endif
>
> @@ -611,7 +611,8 @@ struct libc_do_syscall_args
> #endif
>
> /* Consistency check for position-independent code. */
> -#if defined __PIC__ && !defined OPTIMIZE_FOR_GCC_5
> +#if defined __PIC__ && !defined OPTIMIZE_FOR_GCC_5 \
> + && !defined NO_OMIT_FRAME_POINTER
> # define check_consistency() \
> ({ int __res; \
> __asm__ __volatile__ \
> --
> 2.7.4
>
--
H.J.
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH] Rework -fno-omit-frame-pointer support on i386
2017-02-16 19:25 ` H.J. Lu
@ 2017-02-17 14:48 ` Adhemerval Zanella
2017-02-17 15:45 ` H.J. Lu
0 siblings, 1 reply; 11+ messages in thread
From: Adhemerval Zanella @ 2017-02-17 14:48 UTC (permalink / raw)
To: H.J. Lu; +Cc: GNU C Library
On 16/02/2017 17:24, H.J. Lu wrote:
> On Mon, Jan 9, 2017 at 4:55 AM, Adhemerval Zanella
>> +# Check if CFLAGS sets -fno-omit-frame-pointer
>> +AC_CACHE_CHECK(for if compiler flags sets -fno-omit-frame-pointer,
>> + libc_cv_no_omit_frame_pointer,
>> + [cat > conftest.c << EOF
>> + void foo (void) { }
>> +EOF
>> + libc_cv_no_omit_frame_pointer=no
>> + if AC_TRY_COMMAND(${CC-cc} $CFLAGS -S conftest.c -o conftest.s 1>&AS_MESSAGE_LOG_FD); then
>> + if grep 'push.*%ebp' conftest.s >/dev/null &&
>> + grep 'pop.*%ebp' conftest.s >/dev/null; then
>> + libc_cv_no_omit_frame_pointer=yes
>> + fi
>> + fi
>> + rm -f conftest.c conftest.s
>> + ])
>
> I prefer something like
>
> [hjl@gnu-fer something like
>
> [hjl@gnu-6 tmp]$ cat ebp.c
> void
> foo (int i)
> {
> register int reg asm ("ebp") = i;
> asm ("# %0" : : "r" (reg));
> }
> [hjl@gnu-6 tmp]$ gcc -S -m32 -Os ebp.c
> ebp.c: In function ‘foo’:
> ebp.c:6:1: error: bp cannot be used in asm here
> }
> ^
> [hjl@gnu-6 tmp]$ gcc -S -m32 -O2 ebp.c
> [hjl@gnu-6 tmp]$
>
>> +if test $libc_cv_no_omit_frame_pointer = yes; then
>> + AC_DEFINE(NO_OMIT_FRAME_POINTER)
>> +fi
>
> How about something like CAN_USE_REGISTER_ASM_EBP?
I implemented both your suggestions in this version:
[BZ #21029]
* config.h.in [CAN_USE_REGISTER_ASM_EBP]: New define.
* sysdeps/unix/sysv/linux/i386/Makefile
[$(subdir) = elf] (sysdep-dl-routines): Add libc-do-syscall.
(uses-6-syscall-arguments): Remove.
[$(subdir) = misc] (CFLAGS-epoll_pwait.o): Likewise.
[$(subdir) = misc] (CFLAGS-epoll_pwait.os): Likewise.
[$(subdir) = misc] (CFLAGS-mmap.o): Likewise.
[$(subdir) = misc] (CFLAGS-mmap.os): Likewise.
[$(subdir) = misc] (CFLAGS-mmap64.o): Likewise.
[$(subdir) = misc] (CFLAGS-mmap64.os): Likewise.
[$(subdir) = misc] (CFLAGS-pselect.o): Likewise.
[$(subdir) = misc] (cflags-pselect.o): Likewise.
[$(subdir) = misc] (cflags-pselect.os): Likewise.
[$(subdir) = misc] (cflags-rtld-mmap.os): Likewise.
[$(subdir) = sysvipc] (cflags-semtimedop.o): Likewise.
[$(subdir) = sysvipc] (cflags-semtimedop.os): Likewise.
[$(subdir) = io] (CFLAGS-posix_fadvise64.o): Likewise.
[$(subdir) = io] (CFLAGS-posix_fadvise64.os): Likewise.
[$(subdir) = io] (CFLAGS-posix_fallocate.o): Likewise.
[$(subdir) = io] (CFLAGS-posix_fallocate.os): Likewise.
[$(subdir) = io] (CFLAGS-posix_fallocate64.o): Likewise.
[$(subdir) = io] (CFLAGS-posix_fallocate64.os): Likewise.
[$(subdir) = io] (CFLAGS-sync_file_range.o): Likewise.
[$(subdir) = io] (CFLAGS-sync_file_range.os): Likewise.
[$(subdir) = io] (CFLAGS-fallocate.o): Likewise.
[$(subdir) = io] (CFLAGS-fallocate.os): Likewise.
[$(subdir) = io] (CFLAGS-fallocate64.o): Likewise.
[$(subdir) = io] (CFLAGS-fallocate64.os): Likewise.
[$(subdir) = nptl] (CFLAGS-pthread_rwlock_timedrdlock.o):
Likewise.
[$(subdir) = nptl] (CFLAGS-pthread_rwlock_timedrdlock.os):
Likewise.
[$(subdir) = nptl] (CFLAGS-pthread_rwlock_timedrwlock.o):
Likewise.
[$(subdir) = nptl] (CFLAGS-pthread_rwlock_timedrwlock.os):
Likewise.
[$(subdir) = nptl] (CFLAGS-sem_wait.o): Likewise.
[$(subdir) = nptl] (CFLAGS-sem_wait.os): Likewise.
[$(subdir) = nptl] (CFLAGS-sem_timedwait.o): Likewise.
[$(subdir) = nptl] (CFLAGS-sem_timedwait.os): Likewise.
* sysdeps/unix/sysv/linux/i386/configure.ac: Add check if compiler allows
ebp on inline assembly.
* sysdeps/unix/sysv/linux/i386/configure: Regenerate.
* sysdeps/unix/sysv/linux/i386/sysdep.h (OPTIMIZE_FOR_GCC_5):
Set if CAN_USE_REGISTER_ASM_EBP is set.
(check_consistency): Likewise.
---
diff --git a/config.h.in b/config.h.in
index 7bfe923..fb2cc51 100644
--- a/config.h.in
+++ b/config.h.in
@@ -259,4 +259,8 @@
/* Build glibc with tunables support. */
#define HAVE_TUNABLES 0
+/* Some compiler options may now allow to use ebp in __asm__ (used mainly
+ in i386 6 argument syscall issue). */
+#define CAN_USE_REGISTER_ASM_EBP 0
+
#endif
diff --git a/sysdeps/unix/sysv/linux/i386/Makefile b/sysdeps/unix/sysv/linux/i386/Makefile
index 9609752..6aac0df 100644
--- a/sysdeps/unix/sysv/linux/i386/Makefile
+++ b/sysdeps/unix/sysv/linux/i386/Makefile
@@ -1,47 +1,18 @@
# The default ABI is 32.
default-abi := 32
-# %ebp is used to pass the 6th argument to system calls, so these
-# system calls are incompatible with a frame pointer.
-uses-6-syscall-arguments = -fomit-frame-pointer
-
ifeq ($(subdir),misc)
sysdep_routines += ioperm iopl vm86
-CFLAGS-epoll_pwait.o += $(uses-6-syscall-arguments)
-CFLAGS-epoll_pwait.os += $(uses-6-syscall-arguments)
-CFLAGS-mmap.o += $(uses-6-syscall-arguments)
-CFLAGS-mmap.os += $(uses-6-syscall-arguments)
-CFLAGS-mmap64.o += $(uses-6-syscall-arguments)
-CFLAGS-mmap64.os += $(uses-6-syscall-arguments)
-CFLAGS-pselect.o += $(uses-6-syscall-arguments)
-CFLAGS-pselect.os += $(uses-6-syscall-arguments)
-CFLAGS-rtld-mmap.os += $(uses-6-syscall-arguments)
-endif
-
-ifeq ($(subdir),sysvipc)
-CFLAGS-semtimedop.o += $(uses-6-syscall-arguments)
-CFLAGS-semtimedop.os += $(uses-6-syscall-arguments)
endif
ifeq ($(subdir),elf)
+sysdep-dl-routines += libc-do-syscall
sysdep-others += lddlibc4
install-bin += lddlibc4
endif
ifeq ($(subdir),io)
sysdep_routines += libc-do-syscall
-CFLAGS-posix_fadvise64.o += $(uses-6-syscall-arguments)
-CFLAGS-posix_fadvise64.os += $(uses-6-syscall-arguments)
-CFLAGS-posix_fallocate.o += $(uses-6-syscall-arguments)
-CFLAGS-posix_fallocate.os += $(uses-6-syscall-arguments)
-CFLAGS-posix_fallocate64.o += $(uses-6-syscall-arguments)
-CFLAGS-posix_fallocate64.os += $(uses-6-syscall-arguments)
-CFLAGS-sync_file_range.o += $(uses-6-syscall-arguments)
-CFLAGS-sync_file_range.os += $(uses-6-syscall-arguments)
-CFLAGS-fallocate.o += $(uses-6-syscall-arguments)
-CFLAGS-fallocate.os += $(uses-6-syscall-arguments)
-CFLAGS-fallocate64.o += $(uses-6-syscall-arguments)
-CFLAGS-fallocate64.os += $(uses-6-syscall-arguments)
endif
ifeq ($(subdir),nptl)
@@ -61,14 +32,6 @@ ifeq ($(subdir),nptl)
# pull in __syscall_error routine
libpthread-routines += sysdep
libpthread-shared-only-routines += sysdep
-CFLAGS-pthread_rwlock_timedrdlock.o += $(uses-6-syscall-arguments)
-CFLAGS-pthread_rwlock_timedrdlock.os += $(uses-6-syscall-arguments)
-CFLAGS-pthread_rwlock_timedwrlock.o += $(uses-6-syscall-arguments)
-CFLAGS-pthread_rwlock_timedwrlock.os += $(uses-6-syscall-arguments)
-CFLAGS-sem_wait.o += $(uses-6-syscall-arguments)
-CFLAGS-sem_wait.os += $(uses-6-syscall-arguments)
-CFLAGS-sem_timedwait.o += $(uses-6-syscall-arguments)
-CFLAGS-sem_timedwait.os += $(uses-6-syscall-arguments)
endif
ifeq ($(subdir),rt)
diff --git a/sysdeps/unix/sysv/linux/i386/configure b/sysdeps/unix/sysv/linux/i386/configure
index eb72659..ae2c356 100644
--- a/sysdeps/unix/sysv/linux/i386/configure
+++ b/sysdeps/unix/sysv/linux/i386/configure
@@ -3,5 +3,44 @@
arch_minimum_kernel=2.6.32
+# Check if CFLAGS allows compiler to use ebp register in inline assembly.
+
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking if compiler flags allows ebp in inline assembly" >&5
+$as_echo_n "checking if compiler flags allows ebp in inline assembly... " >&6; }
+if ${libc_cv_can_use_register_asm_ebp+:} false; then :
+ $as_echo_n "(cached) " >&6
+else
+
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+
+ void foo (int i)
+ {
+ register int reg asm ("ebp") = i;
+ asm ("# %0" : : "r" (reg));
+ }
+int
+main ()
+{
+
+ ;
+ return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"; then :
+ libc_cv_can_use_register_asm_ebp=yes
+else
+ libc_cv_can_use_register_asm_ebp=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
+
+fi
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_can_use_register_asm_ebp" >&5
+$as_echo "$libc_cv_can_use_register_asm_ebp" >&6; }
+if test $libc_cv_can_use_register_asm_ebp = yes; then
+ $as_echo "#define CAN_USE_REGISTER_ASM_EBP 1" >>confdefs.h
+
+fi
+
libc_cv_gcc_unwind_find_fde=yes
ldd_rewrite_script=sysdeps/unix/sysv/linux/ldd-rewrite.sed
diff --git a/sysdeps/unix/sysv/linux/i386/configure.ac b/sysdeps/unix/sysv/linux/i386/configure.ac
index 1a11da6..1cd632e 100644
--- a/sysdeps/unix/sysv/linux/i386/configure.ac
+++ b/sysdeps/unix/sysv/linux/i386/configure.ac
@@ -3,5 +3,22 @@ GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
arch_minimum_kernel=2.6.32
+# Check if CFLAGS allows compiler to use ebp register in inline assembly.
+AC_CACHE_CHECK([if compiler flags allows ebp in inline assembly],
+ libc_cv_can_use_register_asm_ebp, [
+AC_COMPILE_IFELSE(
+ [AC_LANG_PROGRAM([
+ void foo (int i)
+ {
+ register int reg asm ("ebp") = i;
+ asm ("# %0" : : "r" (reg));
+ }])],
+ [libc_cv_can_use_register_asm_ebp=yes],
+ [libc_cv_can_use_register_asm_ebp=no])
+])
+if test $libc_cv_can_use_register_asm_ebp = yes; then
+ AC_DEFINE(CAN_USE_REGISTER_ASM_EBP)
+fi
+
libc_cv_gcc_unwind_find_fde=yes
ldd_rewrite_script=sysdeps/unix/sysv/linux/ldd-rewrite.sed
diff --git a/sysdeps/unix/sysv/linux/i386/sysdep.h b/sysdeps/unix/sysv/linux/i386/sysdep.h
index baf4642..c40db59 100644
--- a/sysdeps/unix/sysv/linux/i386/sysdep.h
+++ b/sysdeps/unix/sysv/linux/i386/sysdep.h
@@ -44,9 +44,9 @@
/* Since GCC 5 and above can properly spill %ebx with PIC when needed,
we can inline syscalls with 6 arguments if GCC 5 or above is used
to compile glibc. Disable GCC 5 optimization when compiling for
- profiling since asm ("ebp") can't be used to put the 6th argument
- in %ebp for syscall. */
-#if __GNUC_PREREQ (5,0) && !defined PROF
+ profiling or when -fno-omit-frame-pointer is used since asm ("ebp")
+ can't be used to put the 6th argument in %ebp for syscall. */
+#if __GNUC_PREREQ (5,0) && !defined PROF && CAN_USE_REGISTER_ASM_EBP
# define OPTIMIZE_FOR_GCC_5
#endif
@@ -611,7 +611,8 @@ struct libc_do_syscall_args
#endif
/* Consistency check for position-independent code. */
-#if defined __PIC__ && !defined OPTIMIZE_FOR_GCC_5
+#if defined __PIC__ && !defined OPTIMIZE_FOR_GCC_5 \
+ && !CAN_USE_REGISTER_ASM_EBP
# define check_consistency() \
({ int __res; \
__asm__ __volatile__ \
--
2.7.4
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH] Rework -fno-omit-frame-pointer support on i386
2017-02-17 14:48 ` Adhemerval Zanella
@ 2017-02-17 15:45 ` H.J. Lu
2017-02-17 17:08 ` Adhemerval Zanella
0 siblings, 1 reply; 11+ messages in thread
From: H.J. Lu @ 2017-02-17 15:45 UTC (permalink / raw)
To: Adhemerval Zanella; +Cc: GNU C Library
On Fri, Feb 17, 2017 at 6:47 AM, Adhemerval Zanella
<adhemerval.zanella@linaro.org> wrote:
>
>
> On 16/02/2017 17:24, H.J. Lu wrote:
>> On Mon, Jan 9, 2017 at 4:55 AM, Adhemerval Zanella
>>> +# Check if CFLAGS sets -fno-omit-frame-pointer
>>> +AC_CACHE_CHECK(for if compiler flags sets -fno-omit-frame-pointer,
>>> + libc_cv_no_omit_frame_pointer,
>>> + [cat > conftest.c << EOF
>>> + void foo (void) { }
>>> +EOF
>>> + libc_cv_no_omit_frame_pointer=no
>>> + if AC_TRY_COMMAND(${CC-cc} $CFLAGS -S conftest.c -o conftest.s 1>&AS_MESSAGE_LOG_FD); then
>>> + if grep 'push.*%ebp' conftest.s >/dev/null &&
>>> + grep 'pop.*%ebp' conftest.s >/dev/null; then
>>> + libc_cv_no_omit_frame_pointer=yes
>>> + fi
>>> + fi
>>> + rm -f conftest.c conftest.s
>>> + ])
>>
>> I prefer something like
>>
>> [hjl@gnu-fer something like
>>
>> [hjl@gnu-6 tmp]$ cat ebp.c
>> void
>> foo (int i)
>> {
>> register int reg asm ("ebp") = i;
>> asm ("# %0" : : "r" (reg));
>> }
>> [hjl@gnu-6 tmp]$ gcc -S -m32 -Os ebp.c
>> ebp.c: In function ‘foo’:
>> ebp.c:6:1: error: bp cannot be used in asm here
>> }
>> ^
>> [hjl@gnu-6 tmp]$ gcc -S -m32 -O2 ebp.c
>> [hjl@gnu-6 tmp]$
>>
>>> +if test $libc_cv_no_omit_frame_pointer = yes; then
>>> + AC_DEFINE(NO_OMIT_FRAME_POINTER)
>>> +fi
>>
>> How about something like CAN_USE_REGISTER_ASM_EBP?
>
> I implemented both your suggestions in this version:
>
> [BZ #21029]
> * config.h.in [CAN_USE_REGISTER_ASM_EBP]: New define.
> * sysdeps/unix/sysv/linux/i386/Makefile
> [$(subdir) = elf] (sysdep-dl-routines): Add libc-do-syscall.
> (uses-6-syscall-arguments): Remove.
> [$(subdir) = misc] (CFLAGS-epoll_pwait.o): Likewise.
> [$(subdir) = misc] (CFLAGS-epoll_pwait.os): Likewise.
> [$(subdir) = misc] (CFLAGS-mmap.o): Likewise.
> [$(subdir) = misc] (CFLAGS-mmap.os): Likewise.
> [$(subdir) = misc] (CFLAGS-mmap64.o): Likewise.
> [$(subdir) = misc] (CFLAGS-mmap64.os): Likewise.
> [$(subdir) = misc] (CFLAGS-pselect.o): Likewise.
> [$(subdir) = misc] (cflags-pselect.o): Likewise.
> [$(subdir) = misc] (cflags-pselect.os): Likewise.
> [$(subdir) = misc] (cflags-rtld-mmap.os): Likewise.
> [$(subdir) = sysvipc] (cflags-semtimedop.o): Likewise.
> [$(subdir) = sysvipc] (cflags-semtimedop.os): Likewise.
> [$(subdir) = io] (CFLAGS-posix_fadvise64.o): Likewise.
> [$(subdir) = io] (CFLAGS-posix_fadvise64.os): Likewise.
> [$(subdir) = io] (CFLAGS-posix_fallocate.o): Likewise.
> [$(subdir) = io] (CFLAGS-posix_fallocate.os): Likewise.
> [$(subdir) = io] (CFLAGS-posix_fallocate64.o): Likewise.
> [$(subdir) = io] (CFLAGS-posix_fallocate64.os): Likewise.
> [$(subdir) = io] (CFLAGS-sync_file_range.o): Likewise.
> [$(subdir) = io] (CFLAGS-sync_file_range.os): Likewise.
> [$(subdir) = io] (CFLAGS-fallocate.o): Likewise.
> [$(subdir) = io] (CFLAGS-fallocate.os): Likewise.
> [$(subdir) = io] (CFLAGS-fallocate64.o): Likewise.
> [$(subdir) = io] (CFLAGS-fallocate64.os): Likewise.
> [$(subdir) = nptl] (CFLAGS-pthread_rwlock_timedrdlock.o):
> Likewise.
> [$(subdir) = nptl] (CFLAGS-pthread_rwlock_timedrdlock.os):
> Likewise.
> [$(subdir) = nptl] (CFLAGS-pthread_rwlock_timedrwlock.o):
> Likewise.
> [$(subdir) = nptl] (CFLAGS-pthread_rwlock_timedrwlock.os):
> Likewise.
> [$(subdir) = nptl] (CFLAGS-sem_wait.o): Likewise.
> [$(subdir) = nptl] (CFLAGS-sem_wait.os): Likewise.
> [$(subdir) = nptl] (CFLAGS-sem_timedwait.o): Likewise.
> [$(subdir) = nptl] (CFLAGS-sem_timedwait.os): Likewise.
> * sysdeps/unix/sysv/linux/i386/configure.ac: Add check if compiler allows
> ebp on inline assembly.
> * sysdeps/unix/sysv/linux/i386/configure: Regenerate.
> * sysdeps/unix/sysv/linux/i386/sysdep.h (OPTIMIZE_FOR_GCC_5):
> Set if CAN_USE_REGISTER_ASM_EBP is set.
> (check_consistency): Likewise.
> ---
>
> diff --git a/config.h.in b/config.h.in
> index 7bfe923..fb2cc51 100644
> --- a/config.h.in
> +++ b/config.h.in
> @@ -259,4 +259,8 @@
> /* Build glibc with tunables support. */
> #define HAVE_TUNABLES 0
>
> +/* Some compiler options may now allow to use ebp in __asm__ (used mainly
> + in i386 6 argument syscall issue). */
> +#define CAN_USE_REGISTER_ASM_EBP 0
> +
> #endif
> diff --git a/sysdeps/unix/sysv/linux/i386/Makefile b/sysdeps/unix/sysv/linux/i386/Makefile
> index 9609752..6aac0df 100644
> --- a/sysdeps/unix/sysv/linux/i386/Makefile
> +++ b/sysdeps/unix/sysv/linux/i386/Makefile
> @@ -1,47 +1,18 @@
> # The default ABI is 32.
> default-abi := 32
>
> -# %ebp is used to pass the 6th argument to system calls, so these
> -# system calls are incompatible with a frame pointer.
> -uses-6-syscall-arguments = -fomit-frame-pointer
> -
> ifeq ($(subdir),misc)
> sysdep_routines += ioperm iopl vm86
> -CFLAGS-epoll_pwait.o += $(uses-6-syscall-arguments)
> -CFLAGS-epoll_pwait.os += $(uses-6-syscall-arguments)
> -CFLAGS-mmap.o += $(uses-6-syscall-arguments)
> -CFLAGS-mmap.os += $(uses-6-syscall-arguments)
> -CFLAGS-mmap64.o += $(uses-6-syscall-arguments)
> -CFLAGS-mmap64.os += $(uses-6-syscall-arguments)
> -CFLAGS-pselect.o += $(uses-6-syscall-arguments)
> -CFLAGS-pselect.os += $(uses-6-syscall-arguments)
> -CFLAGS-rtld-mmap.os += $(uses-6-syscall-arguments)
> -endif
> -
> -ifeq ($(subdir),sysvipc)
> -CFLAGS-semtimedop.o += $(uses-6-syscall-arguments)
> -CFLAGS-semtimedop.os += $(uses-6-syscall-arguments)
> endif
>
> ifeq ($(subdir),elf)
> +sysdep-dl-routines += libc-do-syscall
> sysdep-others += lddlibc4
> install-bin += lddlibc4
> endif
>
> ifeq ($(subdir),io)
> sysdep_routines += libc-do-syscall
> -CFLAGS-posix_fadvise64.o += $(uses-6-syscall-arguments)
> -CFLAGS-posix_fadvise64.os += $(uses-6-syscall-arguments)
> -CFLAGS-posix_fallocate.o += $(uses-6-syscall-arguments)
> -CFLAGS-posix_fallocate.os += $(uses-6-syscall-arguments)
> -CFLAGS-posix_fallocate64.o += $(uses-6-syscall-arguments)
> -CFLAGS-posix_fallocate64.os += $(uses-6-syscall-arguments)
> -CFLAGS-sync_file_range.o += $(uses-6-syscall-arguments)
> -CFLAGS-sync_file_range.os += $(uses-6-syscall-arguments)
> -CFLAGS-fallocate.o += $(uses-6-syscall-arguments)
> -CFLAGS-fallocate.os += $(uses-6-syscall-arguments)
> -CFLAGS-fallocate64.o += $(uses-6-syscall-arguments)
> -CFLAGS-fallocate64.os += $(uses-6-syscall-arguments)
> endif
>
> ifeq ($(subdir),nptl)
> @@ -61,14 +32,6 @@ ifeq ($(subdir),nptl)
> # pull in __syscall_error routine
> libpthread-routines += sysdep
> libpthread-shared-only-routines += sysdep
> -CFLAGS-pthread_rwlock_timedrdlock.o += $(uses-6-syscall-arguments)
> -CFLAGS-pthread_rwlock_timedrdlock.os += $(uses-6-syscall-arguments)
> -CFLAGS-pthread_rwlock_timedwrlock.o += $(uses-6-syscall-arguments)
> -CFLAGS-pthread_rwlock_timedwrlock.os += $(uses-6-syscall-arguments)
> -CFLAGS-sem_wait.o += $(uses-6-syscall-arguments)
> -CFLAGS-sem_wait.os += $(uses-6-syscall-arguments)
> -CFLAGS-sem_timedwait.o += $(uses-6-syscall-arguments)
> -CFLAGS-sem_timedwait.os += $(uses-6-syscall-arguments)
> endif
>
> ifeq ($(subdir),rt)
> diff --git a/sysdeps/unix/sysv/linux/i386/configure b/sysdeps/unix/sysv/linux/i386/configure
> index eb72659..ae2c356 100644
> --- a/sysdeps/unix/sysv/linux/i386/configure
> +++ b/sysdeps/unix/sysv/linux/i386/configure
> @@ -3,5 +3,44 @@
>
> arch_minimum_kernel=2.6.32
>
> +# Check if CFLAGS allows compiler to use ebp register in inline assembly.
> +
> +{ $as_echo "$as_me:${as_lineno-$LINENO}: checking if compiler flags allows ebp in inline assembly" >&5
> +$as_echo_n "checking if compiler flags allows ebp in inline assembly... " >&6; }
> +if ${libc_cv_can_use_register_asm_ebp+:} false; then :
> + $as_echo_n "(cached) " >&6
> +else
> +
> +cat confdefs.h - <<_ACEOF >conftest.$ac_ext
> +/* end confdefs.h. */
> +
> + void foo (int i)
> + {
> + register int reg asm ("ebp") = i;
> + asm ("# %0" : : "r" (reg));
> + }
> +int
> +main ()
> +{
> +
> + ;
> + return 0;
> +}
> +_ACEOF
> +if ac_fn_c_try_compile "$LINENO"; then :
> + libc_cv_can_use_register_asm_ebp=yes
> +else
> + libc_cv_can_use_register_asm_ebp=no
> +fi
> +rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
> +
> +fi
> +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $libc_cv_can_use_register_asm_ebp" >&5
> +$as_echo "$libc_cv_can_use_register_asm_ebp" >&6; }
> +if test $libc_cv_can_use_register_asm_ebp = yes; then
> + $as_echo "#define CAN_USE_REGISTER_ASM_EBP 1" >>confdefs.h
> +
> +fi
> +
> libc_cv_gcc_unwind_find_fde=yes
> ldd_rewrite_script=sysdeps/unix/sysv/linux/ldd-rewrite.sed
> diff --git a/sysdeps/unix/sysv/linux/i386/configure.ac b/sysdeps/unix/sysv/linux/i386/configure.ac
> index 1a11da6..1cd632e 100644
> --- a/sysdeps/unix/sysv/linux/i386/configure.ac
> +++ b/sysdeps/unix/sysv/linux/i386/configure.ac
> @@ -3,5 +3,22 @@ GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
>
> arch_minimum_kernel=2.6.32
>
> +# Check if CFLAGS allows compiler to use ebp register in inline assembly.
> +AC_CACHE_CHECK([if compiler flags allows ebp in inline assembly],
> + libc_cv_can_use_register_asm_ebp, [
> +AC_COMPILE_IFELSE(
> + [AC_LANG_PROGRAM([
> + void foo (int i)
> + {
> + register int reg asm ("ebp") = i;
> + asm ("# %0" : : "r" (reg));
> + }])],
> + [libc_cv_can_use_register_asm_ebp=yes],
> + [libc_cv_can_use_register_asm_ebp=no])
> +])
> +if test $libc_cv_can_use_register_asm_ebp = yes; then
> + AC_DEFINE(CAN_USE_REGISTER_ASM_EBP)
> +fi
> +
> libc_cv_gcc_unwind_find_fde=yes
> ldd_rewrite_script=sysdeps/unix/sysv/linux/ldd-rewrite.sed
> diff --git a/sysdeps/unix/sysv/linux/i386/sysdep.h b/sysdeps/unix/sysv/linux/i386/sysdep.h
> index baf4642..c40db59 100644
> --- a/sysdeps/unix/sysv/linux/i386/sysdep.h
> +++ b/sysdeps/unix/sysv/linux/i386/sysdep.h
> @@ -44,9 +44,9 @@
> /* Since GCC 5 and above can properly spill %ebx with PIC when needed,
> we can inline syscalls with 6 arguments if GCC 5 or above is used
> to compile glibc. Disable GCC 5 optimization when compiling for
> - profiling since asm ("ebp") can't be used to put the 6th argument
> - in %ebp for syscall. */
> -#if __GNUC_PREREQ (5,0) && !defined PROF
> + profiling or when -fno-omit-frame-pointer is used since asm ("ebp")
> + can't be used to put the 6th argument in %ebp for syscall. */
> +#if __GNUC_PREREQ (5,0) && !defined PROF && CAN_USE_REGISTER_ASM_EBP
Should it be "defined CAN_USE_REGISTER_ASM_EBP"
since CAN_USE_REGISTER_ASM_EBP may not be defined.
> # define OPTIMIZE_FOR_GCC_5
> #endif
>
> @@ -611,7 +611,8 @@ struct libc_do_syscall_args
> #endif
>
> /* Consistency check for position-independent code. */
> -#if defined __PIC__ && !defined OPTIMIZE_FOR_GCC_5
> +#if defined __PIC__ && !defined OPTIMIZE_FOR_GCC_5 \
> + && !CAN_USE_REGISTER_ASM_EBP
No need for this. If CAN_USE_REGISTER_ASM_EBP
isn't defined, OPTIMIZE_FOR_GCC_5 won't be defined.
> # define check_consistency() \
> ({ int __res; \
> __asm__ __volatile__ \
> --
> 2.7.4
>
--
H.J.
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH] Rework -fno-omit-frame-pointer support on i386
2017-02-17 15:45 ` H.J. Lu
@ 2017-02-17 17:08 ` Adhemerval Zanella
2017-02-17 17:44 ` H.J. Lu
0 siblings, 1 reply; 11+ messages in thread
From: Adhemerval Zanella @ 2017-02-17 17:08 UTC (permalink / raw)
To: H.J. Lu; +Cc: GNU C Library
>> -#if __GNUC_PREREQ (5,0) && !defined PROF
>> + profiling or when -fno-omit-frame-pointer is used since asm ("ebp")
>> + can't be used to put the 6th argument in %ebp for syscall. */
>> +#if __GNUC_PREREQ (5,0) && !defined PROF && CAN_USE_REGISTER_ASM_EBP
>
> Should it be "defined CAN_USE_REGISTER_ASM_EBP"
> since CAN_USE_REGISTER_ASM_EBP may not be defined.
In fact since it is defined in config.h.in as default being 0, it will
always be defined (also I check with -O2 and -Os without --disable-werror
to confirm it.
>
>> # define OPTIMIZE_FOR_GCC_5
>> #endif
>>
>> @@ -611,7 +611,8 @@ struct libc_do_syscall_args
>> #endif
>>
>> /* Consistency check for position-independent code. */
>> -#if defined __PIC__ && !defined OPTIMIZE_FOR_GCC_5
>> +#if defined __PIC__ && !defined OPTIMIZE_FOR_GCC_5 \
>> + && !CAN_USE_REGISTER_ASM_EBP
>
> No need for this. If CAN_USE_REGISTER_ASM_EBP
> isn't defined, OPTIMIZE_FOR_GCC_5 won't be defined.
>
>> # define check_consistency() \
>> ({ int __res; \
>> __asm__ __volatile__ \
>> --
>> 2.7.4
>>
Right, I will remove it. I presume with this fix it is ok to commit.
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH] Rework -fno-omit-frame-pointer support on i386
2017-02-17 17:08 ` Adhemerval Zanella
@ 2017-02-17 17:44 ` H.J. Lu
0 siblings, 0 replies; 11+ messages in thread
From: H.J. Lu @ 2017-02-17 17:44 UTC (permalink / raw)
To: Adhemerval Zanella; +Cc: GNU C Library
On Fri, Feb 17, 2017 at 9:08 AM, Adhemerval Zanella
<adhemerval.zanella@linaro.org> wrote:
>
>>> -#if __GNUC_PREREQ (5,0) && !defined PROF
>>> + profiling or when -fno-omit-frame-pointer is used since asm ("ebp")
>>> + can't be used to put the 6th argument in %ebp for syscall. */
>>> +#if __GNUC_PREREQ (5,0) && !defined PROF && CAN_USE_REGISTER_ASM_EBP
>>
>> Should it be "defined CAN_USE_REGISTER_ASM_EBP"
>> since CAN_USE_REGISTER_ASM_EBP may not be defined.
>
> In fact since it is defined in config.h.in as default being 0, it will
> always be defined (also I check with -O2 and -Os without --disable-werror
> to confirm it.
>
>>
>>> # define OPTIMIZE_FOR_GCC_5
>>> #endif
>>>
>>> @@ -611,7 +611,8 @@ struct libc_do_syscall_args
>>> #endif
>>>
>>> /* Consistency check for position-independent code. */
>>> -#if defined __PIC__ && !defined OPTIMIZE_FOR_GCC_5
>>> +#if defined __PIC__ && !defined OPTIMIZE_FOR_GCC_5 \
>>> + && !CAN_USE_REGISTER_ASM_EBP
>>
>> No need for this. If CAN_USE_REGISTER_ASM_EBP
>> isn't defined, OPTIMIZE_FOR_GCC_5 won't be defined.
>>
>>> # define check_consistency() \
>>> ({ int __res; \
>>> __asm__ __volatile__ \
>>> --
>>> 2.7.4
>>>
>
> Right, I will remove it. I presume with this fix it is ok to commit.
Yes, it is OK with this change.
Thanks for working on this.
--
H.J.
^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2017-02-17 17:44 UTC | newest]
Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-01-09 12:56 [PATCH] Rework -fno-omit-frame-pointer support on i386 Adhemerval Zanella
2017-01-09 19:02 ` Nix
2017-01-10 14:03 ` Adhemerval Zanella
2017-01-17 10:24 ` Adhemerval Zanella
2017-01-24 20:14 ` Adhemerval Zanella
2017-02-16 18:04 ` Adhemerval Zanella
2017-02-16 19:25 ` H.J. Lu
2017-02-17 14:48 ` Adhemerval Zanella
2017-02-17 15:45 ` H.J. Lu
2017-02-17 17:08 ` Adhemerval Zanella
2017-02-17 17:44 ` H.J. Lu
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