Rework -fno-omit-frame-pointer support on i386

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 [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.
This commit is contained in:
Adhemerval Zanella 2017-01-08 11:38:23 -02:00
parent 52ac22365a
commit 3b33d6ed60
6 changed files with 113 additions and 41 deletions

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@ -1,3 +1,52 @@
2017-01-17 Adhemerval Zanella <adhemerval.zanella@linaro.org>
[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.
2017-02-17 H.J. Lu <hongjiu.lu@intel.com>
* sysdeps/x86/cpu-features.c (init_cpu_features): Use

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@ -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

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@ -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)

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@ -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

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@ -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

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@ -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