Message ID | 87o84fkj06.fsf@oldenburg.str.redhat.com |
---|---|
State | New |
Headers | show |
Series | [v2] i386: Remove broken CAN_USE_REGISTER_ASM_EBP (bug 28771) | expand |
On Thu, Jan 13, 2022 at 2:49 AM Florian Weimer <fweimer@redhat.com> wrote: > > The configure check for CAN_USE_REGISTER_ASM_EBP tried to compile a > simple function that uses %ebp as an inline assembly operand. If > compilation failed, CAN_USE_REGISTER_ASM_EBP was set 0, which > eventually had these consequences: > > (1) %ebx was avoided as an inline assembly operand, with an > assembler macro hack to avoid unnecessary register moves. > (2) %ebp was avoided as an inline assembly operand, using an > out-of-line syscall function for 6-argument system calls. > > (1) is no longer needed for any GCC version that is supported for > building glibc. %ebx can be used directly as a register operand. > Therefore, this commit removes the %ebx avoidance completely. This > avoids the assembler macro hack, which turns out to be incompatible > with the current Systemtap probe macros (which switch to .altmacro > unconditionally). > > (2) is still needed in many build configurations. The existing > configure check cannot really capture that because the simple function > succeeds to compile, while the full glibc build still fails. > Therefore, this commit removes the check, the CAN_USE_REGISTER_ASM_EBP > macro, and uses the out-of-line syscall function for 6-argument system > calls unconditionally. > > --- > v2: Merged the two patches. Reference the new bug. > > config.h.in | 4 - > sysdeps/unix/sysv/linux/i386/configure | 39 ------ > sysdeps/unix/sysv/linux/i386/configure.ac | 17 --- > sysdeps/unix/sysv/linux/i386/sysdep.h | 222 ++++-------------------------- > 4 files changed, 27 insertions(+), 255 deletions(-) > > diff --git a/config.h.in b/config.h.in > index 82ade1cec4..ff8597413d 100644 > --- a/config.h.in > +++ b/config.h.in > @@ -277,10 +277,6 @@ > /* Define if static PIE is enabled. */ > #define ENABLE_STATIC_PIE 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 > - > /* The default value of x86 CET control. */ > #define DEFAULT_DL_X86_CET_CONTROL cet_elf_property > > diff --git a/sysdeps/unix/sysv/linux/i386/configure b/sysdeps/unix/sysv/linux/i386/configure > index 0327590486..f119e62fc3 100644 > --- a/sysdeps/unix/sysv/linux/i386/configure > +++ b/sysdeps/unix/sysv/linux/i386/configure > @@ -1,44 +1,5 @@ > # This file is generated from configure.ac by Autoconf. DO NOT EDIT! > # Local configure fragment for sysdeps/unix/sysv/linux/i386. > > -# 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 9e980784bb..64ab2cc2c8 100644 > --- a/sysdeps/unix/sysv/linux/i386/configure.ac > +++ b/sysdeps/unix/sysv/linux/i386/configure.ac > @@ -1,22 +1,5 @@ > GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory. > # Local configure fragment for sysdeps/unix/sysv/linux/i386. > > -# 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 66c2833a49..4558ab66cb 100644 > --- a/sysdeps/unix/sysv/linux/i386/sysdep.h > +++ b/sysdeps/unix/sysv/linux/i386/sysdep.h > @@ -42,15 +42,6 @@ > # endif > #endif > > -/* 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 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 !defined PROF && CAN_USE_REGISTER_ASM_EBP > -# define OPTIMIZE_FOR_GCC_5 > -#endif > - > #ifdef __ASSEMBLER__ > > /* Linux uses a negative return value to indicate syscall errors, > @@ -238,36 +229,6 @@ > extern int __syscall_error (int) > attribute_hidden __attribute__ ((__regparm__ (1))); > > -#ifndef OPTIMIZE_FOR_GCC_5 > -/* We need some help from the assembler to generate optimal code. We > - define some macros here which later will be used. */ > -asm (".L__X'%ebx = 1\n\t" > - ".L__X'%ecx = 2\n\t" > - ".L__X'%edx = 2\n\t" > - ".L__X'%eax = 3\n\t" > - ".L__X'%esi = 3\n\t" > - ".L__X'%edi = 3\n\t" > - ".L__X'%ebp = 3\n\t" > - ".L__X'%esp = 3\n\t" > - ".macro bpushl name reg\n\t" > - ".if 1 - \\name\n\t" > - ".if 2 - \\name\n\t" > - "error\n\t" > - ".else\n\t" > - "xchgl \\reg, %ebx\n\t" > - ".endif\n\t" > - ".endif\n\t" > - ".endm\n\t" > - ".macro bpopl name reg\n\t" > - ".if 1 - \\name\n\t" > - ".if 2 - \\name\n\t" > - "error\n\t" > - ".else\n\t" > - "xchgl \\reg, %ebx\n\t" > - ".endif\n\t" > - ".endif\n\t" > - ".endm\n\t"); > - > /* Six-argument syscalls use an out-of-line helper, because an inline > asm using all registers apart from %esp cannot work reliably and > the assembler does not support describing an asm that saves and > @@ -278,7 +239,6 @@ struct libc_do_syscall_args > { > int ebx, edi, ebp; > }; > -#endif > > # define VDSO_NAME "LINUX_2.6" > # define VDSO_HASH 61765110 > @@ -331,14 +291,8 @@ struct libc_do_syscall_args > > /* Each object using 6-argument inline syscalls must include a > definition of __libc_do_syscall. */ > -#ifdef OPTIMIZE_FOR_GCC_5 > -# define INTERNAL_SYSCALL_MAIN_6(name, args...) \ > - INTERNAL_SYSCALL_MAIN_INLINE(name, 6, args) > -# define INTERNAL_SYSCALL_MAIN_NCS_6(name, args...) \ > - INTERNAL_SYSCALL_MAIN_NCS(name, 6, args) > -#else /* GCC 5 */ > -# define INTERNAL_SYSCALL_MAIN_6(name, arg1, arg2, arg3, \ > - arg4, arg5, arg6) \ > +#define INTERNAL_SYSCALL_MAIN_6(name, arg1, arg2, arg3, \ > + arg4, arg5, arg6) \ > struct libc_do_syscall_args _xv = \ > { \ > (int) (arg1), \ > @@ -351,8 +305,8 @@ struct libc_do_syscall_args > : "=a" (resultvar) \ > : "i" (__NR_##name), "c" (arg2), "d" (arg3), "S" (arg4), "D" (&_xv) \ > : "memory", "cc") > -# define INTERNAL_SYSCALL_MAIN_NCS_6(name, arg1, arg2, arg3, \ > - arg4, arg5, arg6) \ > +#define INTERNAL_SYSCALL_MAIN_NCS_6(name, arg1, arg2, arg3, \ > + arg4, arg5, arg6) \ > struct libc_do_syscall_args _xv = \ > { \ > (int) (arg1), \ > @@ -365,7 +319,6 @@ struct libc_do_syscall_args > : "=a" (resultvar) \ > : "a" (name), "c" (arg2), "d" (arg3), "S" (arg4), "D" (&_xv) \ > : "memory", "cc") > -#endif /* GCC 5 */ > > #define INTERNAL_SYSCALL(name, nr, args...) \ > ({ \ > @@ -379,193 +332,72 @@ struct libc_do_syscall_args > (int) resultvar; }) > > #if I386_USE_SYSENTER > -# ifdef OPTIMIZE_FOR_GCC_5 > -# ifdef PIC > -# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ > +# ifdef PIC > +# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ > LOADREGS_##nr(args) \ > asm volatile ( \ > "call *%%gs:%P2" \ > : "=a" (resultvar) \ > : "a" (__NR_##name), "i" (offsetof (tcbhead_t, sysinfo)) \ > ASMARGS_##nr(args) : "memory", "cc") > -# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ > +# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ > LOADREGS_##nr(args) \ > asm volatile ( \ > "call *%%gs:%P2" \ > : "=a" (resultvar) \ > : "a" (name), "i" (offsetof (tcbhead_t, sysinfo)) \ > ASMARGS_##nr(args) : "memory", "cc") > -# else > -# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ > +# else /* I386_USE_SYSENTER && !PIC */ > +# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ > LOADREGS_##nr(args) \ > asm volatile ( \ > "call *_dl_sysinfo" \ > : "=a" (resultvar) \ > : "a" (__NR_##name) ASMARGS_##nr(args) : "memory", "cc") > -# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ > +# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ > LOADREGS_##nr(args) \ > asm volatile ( \ > "call *_dl_sysinfo" \ > : "=a" (resultvar) \ > : "a" (name) ASMARGS_##nr(args) : "memory", "cc") > -# endif > -# else /* GCC 5 */ > -# ifdef PIC > -# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ > - EXTRAVAR_##nr \ > - asm volatile ( \ > - LOADARGS_##nr \ > - "movl %1, %%eax\n\t" \ > - "call *%%gs:%P2\n\t" \ > - RESTOREARGS_##nr \ > - : "=a" (resultvar) \ > - : "i" (__NR_##name), "i" (offsetof (tcbhead_t, sysinfo)) \ > - ASMFMT_##nr(args) : "memory", "cc") > -# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ > - EXTRAVAR_##nr \ > - asm volatile ( \ > - LOADARGS_##nr \ > - "call *%%gs:%P2\n\t" \ > - RESTOREARGS_##nr \ > - : "=a" (resultvar) \ > - : "0" (name), "i" (offsetof (tcbhead_t, sysinfo)) \ > - ASMFMT_##nr(args) : "memory", "cc") > -# else > -# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ > - EXTRAVAR_##nr \ > - asm volatile ( \ > - LOADARGS_##nr \ > - "movl %1, %%eax\n\t" \ > - "call *_dl_sysinfo\n\t" \ > - RESTOREARGS_##nr \ > - : "=a" (resultvar) \ > - : "i" (__NR_##name) ASMFMT_##nr(args) : "memory", "cc") > -# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ > - EXTRAVAR_##nr \ > - asm volatile ( \ > - LOADARGS_##nr \ > - "call *_dl_sysinfo\n\t" \ > - RESTOREARGS_##nr \ > - : "=a" (resultvar) \ > - : "0" (name) ASMFMT_##nr(args) : "memory", "cc") > -# endif > -# endif /* GCC 5 */ > -#else > -# ifdef OPTIMIZE_FOR_GCC_5 > -# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ > +# endif /* I386_USE_SYSENTER && !PIC */ > +#else /* !I386_USE_SYSENTER */ > +# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ > LOADREGS_##nr(args) \ > asm volatile ( \ > "int $0x80" \ > : "=a" (resultvar) \ > : "a" (__NR_##name) ASMARGS_##nr(args) : "memory", "cc") > -# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ > +# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ > LOADREGS_##nr(args) \ > asm volatile ( \ > "int $0x80" \ > : "=a" (resultvar) \ > : "a" (name) ASMARGS_##nr(args) : "memory", "cc") > -# else /* GCC 5 */ > -# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ > - EXTRAVAR_##nr \ > - asm volatile ( \ > - LOADARGS_##nr \ > - "movl %1, %%eax\n\t" \ > - "int $0x80\n\t" \ > - RESTOREARGS_##nr \ > - : "=a" (resultvar) \ > - : "i" (__NR_##name) ASMFMT_##nr(args) : "memory", "cc") > -# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ > - EXTRAVAR_##nr \ > - asm volatile ( \ > - LOADARGS_##nr \ > - "int $0x80\n\t" \ > - RESTOREARGS_##nr \ > - : "=a" (resultvar) \ > - : "0" (name) ASMFMT_##nr(args) : "memory", "cc") > -# endif /* GCC 5 */ > -#endif > - > -#define LOADARGS_0 > -#ifdef __PIC__ > -# if I386_USE_SYSENTER && defined PIC > -# define LOADARGS_1 \ > - "bpushl .L__X'%k3, %k3\n\t" > -# define LOADARGS_5 \ > - "movl %%ebx, %4\n\t" \ > - "movl %3, %%ebx\n\t" > -# else > -# define LOADARGS_1 \ > - "bpushl .L__X'%k2, %k2\n\t" > -# define LOADARGS_5 \ > - "movl %%ebx, %3\n\t" \ > - "movl %2, %%ebx\n\t" > -# endif > -# define LOADARGS_2 LOADARGS_1 > -# define LOADARGS_3 \ > - "xchgl %%ebx, %%edi\n\t" > -# define LOADARGS_4 LOADARGS_3 > -#else > -# define LOADARGS_1 > -# define LOADARGS_2 > -# define LOADARGS_3 > -# define LOADARGS_4 > -# define LOADARGS_5 > -#endif > - > -#define RESTOREARGS_0 > -#ifdef __PIC__ > -# if I386_USE_SYSENTER && defined PIC > -# define RESTOREARGS_1 \ > - "bpopl .L__X'%k3, %k3\n\t" > -# define RESTOREARGS_5 \ > - "movl %4, %%ebx" > -# else > -# define RESTOREARGS_1 \ > - "bpopl .L__X'%k2, %k2\n\t" > -# define RESTOREARGS_5 \ > - "movl %3, %%ebx" > -# endif > -# define RESTOREARGS_2 RESTOREARGS_1 > -# define RESTOREARGS_3 \ > - "xchgl %%edi, %%ebx\n\t" > -# define RESTOREARGS_4 RESTOREARGS_3 > -#else > -# define RESTOREARGS_1 > -# define RESTOREARGS_2 > -# define RESTOREARGS_3 > -# define RESTOREARGS_4 > -# define RESTOREARGS_5 > -#endif > +#endif /* !I386_USE_SYSENTER */ > > -#ifdef OPTIMIZE_FOR_GCC_5 > -# define LOADREGS_0() > -# define ASMARGS_0() > -# define LOADREGS_1(arg1) \ > +#define LOADREGS_0() > +#define ASMARGS_0() > +#define LOADREGS_1(arg1) \ > LOADREGS_0 () > -# define ASMARGS_1(arg1) \ > +#define ASMARGS_1(arg1) \ > ASMARGS_0 (), "b" ((unsigned int) (arg1)) > -# define LOADREGS_2(arg1, arg2) \ > +#define LOADREGS_2(arg1, arg2) \ > LOADREGS_1 (arg1) > -# define ASMARGS_2(arg1, arg2) \ > +#define ASMARGS_2(arg1, arg2) \ > ASMARGS_1 (arg1), "c" ((unsigned int) (arg2)) > -# define LOADREGS_3(arg1, arg2, arg3) \ > +#define LOADREGS_3(arg1, arg2, arg3) \ > LOADREGS_2 (arg1, arg2) > -# define ASMARGS_3(arg1, arg2, arg3) \ > +#define ASMARGS_3(arg1, arg2, arg3) \ > ASMARGS_2 (arg1, arg2), "d" ((unsigned int) (arg3)) > -# define LOADREGS_4(arg1, arg2, arg3, arg4) \ > +#define LOADREGS_4(arg1, arg2, arg3, arg4) \ > LOADREGS_3 (arg1, arg2, arg3) > -# define ASMARGS_4(arg1, arg2, arg3, arg4) \ > +#define ASMARGS_4(arg1, arg2, arg3, arg4) \ > ASMARGS_3 (arg1, arg2, arg3), "S" ((unsigned int) (arg4)) > -# define LOADREGS_5(arg1, arg2, arg3, arg4, arg5) \ > +#define LOADREGS_5(arg1, arg2, arg3, arg4, arg5) \ > LOADREGS_4 (arg1, arg2, arg3, arg4) > -# define ASMARGS_5(arg1, arg2, arg3, arg4, arg5) \ > +#define ASMARGS_5(arg1, arg2, arg3, arg4, arg5) \ > ASMARGS_4 (arg1, arg2, arg3, arg4), "D" ((unsigned int) (arg5)) > -# define LOADREGS_6(arg1, arg2, arg3, arg4, arg5, arg6) \ > - register unsigned int _a6 asm ("ebp") = (unsigned int) (arg6); \ > - LOADREGS_5 (arg1, arg2, arg3, arg4, arg5) > -# define ASMARGS_6(arg1, arg2, arg3, arg4, arg5, arg6) \ > - ASMARGS_5 (arg1, arg2, arg3, arg4, arg5), "r" (_a6) > -#endif /* GCC 5 */ > > #define ASMFMT_0() > #ifdef __PIC__ > LGTM. Reviewed-by: H.J. Lu <hjl.tools@gmail.com> Thanks.
diff --git a/config.h.in b/config.h.in index 82ade1cec4..ff8597413d 100644 --- a/config.h.in +++ b/config.h.in @@ -277,10 +277,6 @@ /* Define if static PIE is enabled. */ #define ENABLE_STATIC_PIE 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 - /* The default value of x86 CET control. */ #define DEFAULT_DL_X86_CET_CONTROL cet_elf_property diff --git a/sysdeps/unix/sysv/linux/i386/configure b/sysdeps/unix/sysv/linux/i386/configure index 0327590486..f119e62fc3 100644 --- a/sysdeps/unix/sysv/linux/i386/configure +++ b/sysdeps/unix/sysv/linux/i386/configure @@ -1,44 +1,5 @@ # This file is generated from configure.ac by Autoconf. DO NOT EDIT! # Local configure fragment for sysdeps/unix/sysv/linux/i386. -# 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 9e980784bb..64ab2cc2c8 100644 --- a/sysdeps/unix/sysv/linux/i386/configure.ac +++ b/sysdeps/unix/sysv/linux/i386/configure.ac @@ -1,22 +1,5 @@ GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory. # Local configure fragment for sysdeps/unix/sysv/linux/i386. -# 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 66c2833a49..4558ab66cb 100644 --- a/sysdeps/unix/sysv/linux/i386/sysdep.h +++ b/sysdeps/unix/sysv/linux/i386/sysdep.h @@ -42,15 +42,6 @@ # endif #endif -/* 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 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 !defined PROF && CAN_USE_REGISTER_ASM_EBP -# define OPTIMIZE_FOR_GCC_5 -#endif - #ifdef __ASSEMBLER__ /* Linux uses a negative return value to indicate syscall errors, @@ -238,36 +229,6 @@ extern int __syscall_error (int) attribute_hidden __attribute__ ((__regparm__ (1))); -#ifndef OPTIMIZE_FOR_GCC_5 -/* We need some help from the assembler to generate optimal code. We - define some macros here which later will be used. */ -asm (".L__X'%ebx = 1\n\t" - ".L__X'%ecx = 2\n\t" - ".L__X'%edx = 2\n\t" - ".L__X'%eax = 3\n\t" - ".L__X'%esi = 3\n\t" - ".L__X'%edi = 3\n\t" - ".L__X'%ebp = 3\n\t" - ".L__X'%esp = 3\n\t" - ".macro bpushl name reg\n\t" - ".if 1 - \\name\n\t" - ".if 2 - \\name\n\t" - "error\n\t" - ".else\n\t" - "xchgl \\reg, %ebx\n\t" - ".endif\n\t" - ".endif\n\t" - ".endm\n\t" - ".macro bpopl name reg\n\t" - ".if 1 - \\name\n\t" - ".if 2 - \\name\n\t" - "error\n\t" - ".else\n\t" - "xchgl \\reg, %ebx\n\t" - ".endif\n\t" - ".endif\n\t" - ".endm\n\t"); - /* Six-argument syscalls use an out-of-line helper, because an inline asm using all registers apart from %esp cannot work reliably and the assembler does not support describing an asm that saves and @@ -278,7 +239,6 @@ struct libc_do_syscall_args { int ebx, edi, ebp; }; -#endif # define VDSO_NAME "LINUX_2.6" # define VDSO_HASH 61765110 @@ -331,14 +291,8 @@ struct libc_do_syscall_args /* Each object using 6-argument inline syscalls must include a definition of __libc_do_syscall. */ -#ifdef OPTIMIZE_FOR_GCC_5 -# define INTERNAL_SYSCALL_MAIN_6(name, args...) \ - INTERNAL_SYSCALL_MAIN_INLINE(name, 6, args) -# define INTERNAL_SYSCALL_MAIN_NCS_6(name, args...) \ - INTERNAL_SYSCALL_MAIN_NCS(name, 6, args) -#else /* GCC 5 */ -# define INTERNAL_SYSCALL_MAIN_6(name, arg1, arg2, arg3, \ - arg4, arg5, arg6) \ +#define INTERNAL_SYSCALL_MAIN_6(name, arg1, arg2, arg3, \ + arg4, arg5, arg6) \ struct libc_do_syscall_args _xv = \ { \ (int) (arg1), \ @@ -351,8 +305,8 @@ struct libc_do_syscall_args : "=a" (resultvar) \ : "i" (__NR_##name), "c" (arg2), "d" (arg3), "S" (arg4), "D" (&_xv) \ : "memory", "cc") -# define INTERNAL_SYSCALL_MAIN_NCS_6(name, arg1, arg2, arg3, \ - arg4, arg5, arg6) \ +#define INTERNAL_SYSCALL_MAIN_NCS_6(name, arg1, arg2, arg3, \ + arg4, arg5, arg6) \ struct libc_do_syscall_args _xv = \ { \ (int) (arg1), \ @@ -365,7 +319,6 @@ struct libc_do_syscall_args : "=a" (resultvar) \ : "a" (name), "c" (arg2), "d" (arg3), "S" (arg4), "D" (&_xv) \ : "memory", "cc") -#endif /* GCC 5 */ #define INTERNAL_SYSCALL(name, nr, args...) \ ({ \ @@ -379,193 +332,72 @@ struct libc_do_syscall_args (int) resultvar; }) #if I386_USE_SYSENTER -# ifdef OPTIMIZE_FOR_GCC_5 -# ifdef PIC -# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ +# ifdef PIC +# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ LOADREGS_##nr(args) \ asm volatile ( \ "call *%%gs:%P2" \ : "=a" (resultvar) \ : "a" (__NR_##name), "i" (offsetof (tcbhead_t, sysinfo)) \ ASMARGS_##nr(args) : "memory", "cc") -# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ +# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ LOADREGS_##nr(args) \ asm volatile ( \ "call *%%gs:%P2" \ : "=a" (resultvar) \ : "a" (name), "i" (offsetof (tcbhead_t, sysinfo)) \ ASMARGS_##nr(args) : "memory", "cc") -# else -# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ +# else /* I386_USE_SYSENTER && !PIC */ +# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ LOADREGS_##nr(args) \ asm volatile ( \ "call *_dl_sysinfo" \ : "=a" (resultvar) \ : "a" (__NR_##name) ASMARGS_##nr(args) : "memory", "cc") -# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ +# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ LOADREGS_##nr(args) \ asm volatile ( \ "call *_dl_sysinfo" \ : "=a" (resultvar) \ : "a" (name) ASMARGS_##nr(args) : "memory", "cc") -# endif -# else /* GCC 5 */ -# ifdef PIC -# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ - EXTRAVAR_##nr \ - asm volatile ( \ - LOADARGS_##nr \ - "movl %1, %%eax\n\t" \ - "call *%%gs:%P2\n\t" \ - RESTOREARGS_##nr \ - : "=a" (resultvar) \ - : "i" (__NR_##name), "i" (offsetof (tcbhead_t, sysinfo)) \ - ASMFMT_##nr(args) : "memory", "cc") -# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ - EXTRAVAR_##nr \ - asm volatile ( \ - LOADARGS_##nr \ - "call *%%gs:%P2\n\t" \ - RESTOREARGS_##nr \ - : "=a" (resultvar) \ - : "0" (name), "i" (offsetof (tcbhead_t, sysinfo)) \ - ASMFMT_##nr(args) : "memory", "cc") -# else -# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ - EXTRAVAR_##nr \ - asm volatile ( \ - LOADARGS_##nr \ - "movl %1, %%eax\n\t" \ - "call *_dl_sysinfo\n\t" \ - RESTOREARGS_##nr \ - : "=a" (resultvar) \ - : "i" (__NR_##name) ASMFMT_##nr(args) : "memory", "cc") -# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ - EXTRAVAR_##nr \ - asm volatile ( \ - LOADARGS_##nr \ - "call *_dl_sysinfo\n\t" \ - RESTOREARGS_##nr \ - : "=a" (resultvar) \ - : "0" (name) ASMFMT_##nr(args) : "memory", "cc") -# endif -# endif /* GCC 5 */ -#else -# ifdef OPTIMIZE_FOR_GCC_5 -# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ +# endif /* I386_USE_SYSENTER && !PIC */ +#else /* !I386_USE_SYSENTER */ +# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ LOADREGS_##nr(args) \ asm volatile ( \ "int $0x80" \ : "=a" (resultvar) \ : "a" (__NR_##name) ASMARGS_##nr(args) : "memory", "cc") -# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ +# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ LOADREGS_##nr(args) \ asm volatile ( \ "int $0x80" \ : "=a" (resultvar) \ : "a" (name) ASMARGS_##nr(args) : "memory", "cc") -# else /* GCC 5 */ -# define INTERNAL_SYSCALL_MAIN_INLINE(name, nr, args...) \ - EXTRAVAR_##nr \ - asm volatile ( \ - LOADARGS_##nr \ - "movl %1, %%eax\n\t" \ - "int $0x80\n\t" \ - RESTOREARGS_##nr \ - : "=a" (resultvar) \ - : "i" (__NR_##name) ASMFMT_##nr(args) : "memory", "cc") -# define INTERNAL_SYSCALL_MAIN_NCS(name, nr, args...) \ - EXTRAVAR_##nr \ - asm volatile ( \ - LOADARGS_##nr \ - "int $0x80\n\t" \ - RESTOREARGS_##nr \ - : "=a" (resultvar) \ - : "0" (name) ASMFMT_##nr(args) : "memory", "cc") -# endif /* GCC 5 */ -#endif - -#define LOADARGS_0 -#ifdef __PIC__ -# if I386_USE_SYSENTER && defined PIC -# define LOADARGS_1 \ - "bpushl .L__X'%k3, %k3\n\t" -# define LOADARGS_5 \ - "movl %%ebx, %4\n\t" \ - "movl %3, %%ebx\n\t" -# else -# define LOADARGS_1 \ - "bpushl .L__X'%k2, %k2\n\t" -# define LOADARGS_5 \ - "movl %%ebx, %3\n\t" \ - "movl %2, %%ebx\n\t" -# endif -# define LOADARGS_2 LOADARGS_1 -# define LOADARGS_3 \ - "xchgl %%ebx, %%edi\n\t" -# define LOADARGS_4 LOADARGS_3 -#else -# define LOADARGS_1 -# define LOADARGS_2 -# define LOADARGS_3 -# define LOADARGS_4 -# define LOADARGS_5 -#endif - -#define RESTOREARGS_0 -#ifdef __PIC__ -# if I386_USE_SYSENTER && defined PIC -# define RESTOREARGS_1 \ - "bpopl .L__X'%k3, %k3\n\t" -# define RESTOREARGS_5 \ - "movl %4, %%ebx" -# else -# define RESTOREARGS_1 \ - "bpopl .L__X'%k2, %k2\n\t" -# define RESTOREARGS_5 \ - "movl %3, %%ebx" -# endif -# define RESTOREARGS_2 RESTOREARGS_1 -# define RESTOREARGS_3 \ - "xchgl %%edi, %%ebx\n\t" -# define RESTOREARGS_4 RESTOREARGS_3 -#else -# define RESTOREARGS_1 -# define RESTOREARGS_2 -# define RESTOREARGS_3 -# define RESTOREARGS_4 -# define RESTOREARGS_5 -#endif +#endif /* !I386_USE_SYSENTER */ -#ifdef OPTIMIZE_FOR_GCC_5 -# define LOADREGS_0() -# define ASMARGS_0() -# define LOADREGS_1(arg1) \ +#define LOADREGS_0() +#define ASMARGS_0() +#define LOADREGS_1(arg1) \ LOADREGS_0 () -# define ASMARGS_1(arg1) \ +#define ASMARGS_1(arg1) \ ASMARGS_0 (), "b" ((unsigned int) (arg1)) -# define LOADREGS_2(arg1, arg2) \ +#define LOADREGS_2(arg1, arg2) \ LOADREGS_1 (arg1) -# define ASMARGS_2(arg1, arg2) \ +#define ASMARGS_2(arg1, arg2) \ ASMARGS_1 (arg1), "c" ((unsigned int) (arg2)) -# define LOADREGS_3(arg1, arg2, arg3) \ +#define LOADREGS_3(arg1, arg2, arg3) \ LOADREGS_2 (arg1, arg2) -# define ASMARGS_3(arg1, arg2, arg3) \ +#define ASMARGS_3(arg1, arg2, arg3) \ ASMARGS_2 (arg1, arg2), "d" ((unsigned int) (arg3)) -# define LOADREGS_4(arg1, arg2, arg3, arg4) \ +#define LOADREGS_4(arg1, arg2, arg3, arg4) \ LOADREGS_3 (arg1, arg2, arg3) -# define ASMARGS_4(arg1, arg2, arg3, arg4) \ +#define ASMARGS_4(arg1, arg2, arg3, arg4) \ ASMARGS_3 (arg1, arg2, arg3), "S" ((unsigned int) (arg4)) -# define LOADREGS_5(arg1, arg2, arg3, arg4, arg5) \ +#define LOADREGS_5(arg1, arg2, arg3, arg4, arg5) \ LOADREGS_4 (arg1, arg2, arg3, arg4) -# define ASMARGS_5(arg1, arg2, arg3, arg4, arg5) \ +#define ASMARGS_5(arg1, arg2, arg3, arg4, arg5) \ ASMARGS_4 (arg1, arg2, arg3, arg4), "D" ((unsigned int) (arg5)) -# define LOADREGS_6(arg1, arg2, arg3, arg4, arg5, arg6) \ - register unsigned int _a6 asm ("ebp") = (unsigned int) (arg6); \ - LOADREGS_5 (arg1, arg2, arg3, arg4, arg5) -# define ASMARGS_6(arg1, arg2, arg3, arg4, arg5, arg6) \ - ASMARGS_5 (arg1, arg2, arg3, arg4, arg5), "r" (_a6) -#endif /* GCC 5 */ #define ASMFMT_0() #ifdef __PIC__