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authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2017-01-08 11:38:23 -0200
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2017-02-17 18:06:29 -0200
commit3b33d6ed6096c1d20d05a650b06026d673f7399a (patch)
treeaaca20724918d38903fe3ffe780fd17a9de3b9eb
parent52ac22365a332cacf7aa97f1b41b3a0adfaff778 (diff)
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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. [$(subdir) = nptl] (CFLAGS-sem_timedwait.os): Likewise. * sysdeps/unix/sysv/linux/i386/configure.ac: Add check if compiler allows ebp on inline assembly. * sysdeps/unix/sysv/linux/i386/configure: Regenerate. * sysdeps/unix/sysv/linux/i386/sysdep.h (OPTIMIZE_FOR_GCC_5): Set if CAN_USE_REGISTER_ASM_EBP is set. (check_consistency): Likewise.
-rw-r--r--ChangeLog49
-rw-r--r--config.h.in4
-rw-r--r--sysdeps/unix/sysv/linux/i386/Makefile39
-rw-r--r--sysdeps/unix/sysv/linux/i386/configure39
-rw-r--r--sysdeps/unix/sysv/linux/i386/configure.ac17
-rw-r--r--sysdeps/unix/sysv/linux/i386/sysdep.h6
6 files changed, 113 insertions, 41 deletions
diff --git a/ChangeLog b/ChangeLog
index c846949c94..842d5765ef 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,52 @@
+2017-01-17 Adhemerval Zanella <adhemerval.zanella@linaro.org>
+
+ [BZ #21029]
+ * config.h.in [CAN_USE_REGISTER_ASM_EBP]: New define.
+ * sysdeps/unix/sysv/linux/i386/Makefile
+ [$(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
diff --git a/config.h.in b/config.h.in
index 7bfe923c06..fb2cc51c03 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 9609752256..6aac0dfe15 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 eb72659dc3..ae2c3567c5 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 1a11da6dad..1cd632e5c6 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 baf46421b2..449b23e49b 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