| Message ID | 20150910131412.GD9542@gmail.com |
|---|---|
| State | New |
| Headers | show |
On 10-09-2015 10:14, H.J. Lu wrote: > OK for master? > > H.J. > --- > Define INLINE_SYSCALL_ERROR_RETURN so that i386 can optimize setting > errno by branching to the internal __syscall_error without PLT. > > Since GCC 5 and above can properly spill %ebx when needed, we can inline > syscalls with 6 arguments if GCC 5 or above is used to compile glibc. > This patch rewrites INTERNAL_SYSCALL macros and skips __libc_do_syscall > for GCC 5. > > For sysdeps/unix/sysv/linux/i386/brk.c, with -O2 -march=i686 > -mtune=generic, GCC 5.2 now generates: You can use this refactoring to cleanup some duplicate code as well, since i386 brk.c, setegid.c, and seteuid.c can be replaces by generic implementation. Also for *stat* implementations i386 could override overflow.h and redefine stat_overflow with stat64 logic. For lockf64.c I also think it can be feasible to change default implementation to accommodate i386 requirements (use flock64 instead of flock). The only implementation is really i386 specific is sigaction.c, but I can't tell how much of the assembly hackery it requires nowadays. > > <__brk>: > 0: push %ebx > 1: mov $0x2d,%eax > 6: mov 0x8(%esp),%ebx > a: call b <__brk+0xb> b: R_386_PC32 __x86.get_pc_thunk.dx > f: add $0x2,%edx 11: R_386_GOTPC _GLOBAL_OFFSET_TABLE_ > 15: call *%gs:0x10 > 1c: mov 0x0(%edx),%edx 1e: R_386_GOT32 __curbrk > 22: cmp %eax,%ebx > 24: mov %eax,(%edx) > 26: ja 30 <__brk+0x30> > 28: xor %eax,%eax > 2a: pop %ebx > 2b: ret > > instead of > > <__brk>: > 0: push %ebx > 1: mov 0x8(%esp),%ecx > 5: call 6 <__brk+0x6> 6: R_386_PC32 __x86.get_pc_thunk.bx > a: add $0x2,%ebx c: R_386_GOTPC _GLOBAL_OFFSET_TABLE_ > 10: xchg %ecx,%ebx > 12: mov $0x2d,%eax > 17: call *%gs:0x10 > 1e: xchg %ecx,%ebx > 20: mov %eax,%edx > 22: mov 0x0(%ebx),%eax 24: R_386_GOT32 __curbrk > 28: mov %edx,(%eax) > 2a: xor %eax,%eax > 2c: cmp %edx,%ecx > 2e: ja 38 <__brk+0x38> > 30: pop %ebx > 31: ret > > The new one is shorter by 2 instructions. > > * sysdeps/unix/sysv/linux/i386/Makefile [$(subdir) == csu] > (sysdep-dl-routines): Add sysdep. > [$(subdir) == nptl] (libpthread-routines): Likewise. > [$(subdir) == rt] (librt-routines): Likewise. > * sysdeps/unix/sysv/linux/i386/brk.c (__brk): Add > INTERNAL_SYSCALL_DECL. Use INLINE_SYSCALL_ERROR_RETURN. > * sysdeps/unix/sysv/linux/i386/clone.S (__clone): Don't check > PIC when branching to SYSCALL_ERROR_LABEL. > * sysdeps/unix/sysv/linux/i386/fxstat.c (__fxstat): Likewise. > * sysdeps/unix/sysv/linux/i386/fxstatat.c (__fxstatat): > Likewise. > * sysdeps/unix/sysv/linux/i386/lockf64.c (lockf64): Likewise. > * sysdeps/unix/sysv/linux/i386/lxstat.c (__lxstat): Likewise. > * sysdeps/unix/sysv/linux/i386/setegid.c (setegid): Likewise. > * sysdeps/unix/sysv/linux/i386/seteuid.c (seteuid): Likewise. > * sysdeps/unix/sysv/linux/i386/sigaction.c (__libc_sigaction): > Likewise. > * sysdeps/unix/sysv/linux/i386/xstat.c (__xstat): Likewise. > * sysdeps/unix/sysv/linux/i386/libc-do-syscall.S > (__libc_do_syscall): Defined only if !__GNUC_PREREQ (5,0). > * sysdeps/unix/sysv/linux/i386/sysdep.S: Removed. > * sysdeps/unix/sysv/linux/i386/sysdep.c: New file. > * sysdeps/unix/sysv/linux/i386/sysdep.h: Define assembler macros > only if !__GNUC_PREREQ (5,0). > (SYSCALL_ERROR_LABEL): Changed to __syscall_error. > (SYSCALL_ERROR_HANDLER): Changed to empty. > (SYSCALL_ERROR_ERRNO): Removed. > (SYSCALL_ERROR_HANDLER_TLS_STORE): Likewise. > (__syscall_error): New prototype. > [IS_IN (libc)] (INLINE_SYSCALL): New macro. > (INLINE_SYSCALL_ERROR_RETURN): Likewise. > (LOADREGS_0): Likewise. > (ASMARGS_0): Likewise. > (LOADREGS_1): Likewise. > (ASMARGS_1): Likewise. > (LOADREGS_2): Likewise. > (ASMARGS_2): Likewise. > (LOADREGS_3): Likewise. > (ASMARGS_3): Likewise. > (LOADREGS_4): Likewise. > (ASMARGS_4): Likewise. > (LOADREGS_5): Likewise. > (ASMARGS_5): Likewise. > (LOADREGS_6): Likewise. > (ASMARGS_6): Likewise. > (INTERNAL_SYSCALL_MAIN_6): Optimize for GCC 5. > (INTERNAL_SYSCALL_MAIN_INLINE): Likewise. > (INTERNAL_SYSCALL_NCS): Likewise. > --- > sysdeps/unix/sysv/linux/i386/Makefile | 14 ++ > sysdeps/unix/sysv/linux/i386/brk.c | 12 +- > sysdeps/unix/sysv/linux/i386/clone.S | 8 -- > sysdeps/unix/sysv/linux/i386/fxstat.c | 10 +- > sysdeps/unix/sysv/linux/i386/fxstatat.c | 9 +- > sysdeps/unix/sysv/linux/i386/libc-do-syscall.S | 3 + > sysdeps/unix/sysv/linux/i386/lockf64.c | 13 +- > sysdeps/unix/sysv/linux/i386/lxstat.c | 10 +- > sysdeps/unix/sysv/linux/i386/setegid.c | 5 +- > sysdeps/unix/sysv/linux/i386/seteuid.c | 5 +- > sysdeps/unix/sysv/linux/i386/sigaction.c | 12 +- > sysdeps/unix/sysv/linux/i386/sysdep.S | 40 ------ > sysdeps/unix/sysv/linux/i386/sysdep.c | 30 ++++ > sysdeps/unix/sysv/linux/i386/sysdep.h | 192 ++++++++++++++++--------- > sysdeps/unix/sysv/linux/i386/xstat.c | 10 +- > 15 files changed, 212 insertions(+), 161 deletions(-) > delete mode 100644 sysdeps/unix/sysv/linux/i386/sysdep.S > create mode 100644 sysdeps/unix/sysv/linux/i386/sysdep.c > > diff --git a/sysdeps/unix/sysv/linux/i386/Makefile b/sysdeps/unix/sysv/linux/i386/Makefile > index 80da593..e10d133 100644 > --- a/sysdeps/unix/sysv/linux/i386/Makefile > +++ b/sysdeps/unix/sysv/linux/i386/Makefile > @@ -27,3 +27,17 @@ endif > ifeq ($(subdir),stdlib) > gen-as-const-headers += ucontext_i.sym > endif > + > +ifeq ($(subdir),csu) > +sysdep-dl-routines += sysdep > +endif > + > +ifeq ($(subdir),nptl) > +# pull in __syscall_error routine > +libpthread-routines += sysdep > +endif > + > +ifeq ($(subdir),rt) > +# pull in __syscall_error routine > +librt-routines += sysdep > +endif > diff --git a/sysdeps/unix/sysv/linux/i386/brk.c b/sysdeps/unix/sysv/linux/i386/brk.c > index 5b9a0ce..2d2daa5 100644 > --- a/sysdeps/unix/sysv/linux/i386/brk.c > +++ b/sysdeps/unix/sysv/linux/i386/brk.c > @@ -31,19 +31,11 @@ weak_alias (__curbrk, ___brk_addr) > int > __brk (void *addr) > { > - void *newbrk; > - > INTERNAL_SYSCALL_DECL (err); > - newbrk = (void *) INTERNAL_SYSCALL (brk, err, 1, addr); > - > + void *newbrk = (void *) INTERNAL_SYSCALL (brk, err, 1, addr); > __curbrk = newbrk; > - > if (newbrk < addr) > - { > - __set_errno (ENOMEM); > - return -1; > - } > - > + return INLINE_SYSCALL_ERROR_RETURN (ENOMEM); > return 0; > } > weak_alias (__brk, brk) > diff --git a/sysdeps/unix/sysv/linux/i386/clone.S b/sysdeps/unix/sysv/linux/i386/clone.S > index 243dbfe..2aafb3a 100644 > --- a/sysdeps/unix/sysv/linux/i386/clone.S > +++ b/sysdeps/unix/sysv/linux/i386/clone.S > @@ -47,19 +47,11 @@ ENTRY (__clone) > /* Sanity check arguments. */ > movl $-EINVAL,%eax > movl FUNC(%esp),%ecx /* no NULL function pointers */ > -#ifdef PIC > - jecxz SYSCALL_ERROR_LABEL > -#else > testl %ecx,%ecx > jz SYSCALL_ERROR_LABEL > -#endif > movl STACK(%esp),%ecx /* no NULL stack pointers */ > -#ifdef PIC > - jecxz SYSCALL_ERROR_LABEL > -#else > testl %ecx,%ecx > jz SYSCALL_ERROR_LABEL > -#endif > > /* Insert the argument onto the new stack. Make sure the new > thread is started with an alignment of (mod 16). */ > diff --git a/sysdeps/unix/sysv/linux/i386/fxstat.c b/sysdeps/unix/sysv/linux/i386/fxstat.c > index 2f7a8fe..3919e0c 100644 > --- a/sysdeps/unix/sysv/linux/i386/fxstat.c > +++ b/sysdeps/unix/sysv/linux/i386/fxstat.c > @@ -42,10 +42,12 @@ __fxstat (int vers, int fd, struct stat *buf) > { > struct stat64 buf64; > > - result = INLINE_SYSCALL (fstat64, 2, fd, &buf64); > - if (result == 0) > - result = __xstat32_conv (vers, &buf64, buf); > - return result; > + INTERNAL_SYSCALL_DECL (err); > + result = INTERNAL_SYSCALL (fstat64, err, 2, fd, &buf64); > + if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (result, ))) > + return INLINE_SYSCALL_ERROR_RETURN (-result); > + else > + return __xstat32_conv (vers, &buf64, buf); > } > } > > diff --git a/sysdeps/unix/sysv/linux/i386/fxstatat.c b/sysdeps/unix/sysv/linux/i386/fxstatat.c > index 6f3c251..c4be04d 100644 > --- a/sysdeps/unix/sysv/linux/i386/fxstatat.c > +++ b/sysdeps/unix/sysv/linux/i386/fxstatat.c > @@ -42,13 +42,10 @@ __fxstatat (int vers, int fd, const char *file, struct stat *st, int flag) > struct stat64 st64; > > result = INTERNAL_SYSCALL (fstatat64, err, 4, fd, file, &st64, flag); > - if (!__builtin_expect (INTERNAL_SYSCALL_ERROR_P (result, err), 1)) > - return __xstat32_conv (vers, &st64, st); > + if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (result, ))) > + return INLINE_SYSCALL_ERROR_RETURN (-result); > else > - { > - __set_errno (INTERNAL_SYSCALL_ERRNO (result, err)); > - return -1; > - } > + return __xstat32_conv (vers, &st64, st); > } > libc_hidden_def (__fxstatat) > #ifdef XSTAT_IS_XSTAT64 > diff --git a/sysdeps/unix/sysv/linux/i386/libc-do-syscall.S b/sysdeps/unix/sysv/linux/i386/libc-do-syscall.S > index af5c6f0..cdef3d5 100644 > --- a/sysdeps/unix/sysv/linux/i386/libc-do-syscall.S > +++ b/sysdeps/unix/sysv/linux/i386/libc-do-syscall.S > @@ -18,6 +18,8 @@ > > #include <sysdep.h> > > +#if !__GNUC_PREREQ (5,0) > + > /* %eax, %ecx, %edx and %esi contain the values expected by the kernel. > %edi points to a structure with the values of %ebx, %edi and %ebp. */ > > @@ -48,3 +50,4 @@ ENTRY (__libc_do_syscall) > cfi_restore (ebx) > ret > END (__libc_do_syscall) > +#endif > diff --git a/sysdeps/unix/sysv/linux/i386/lockf64.c b/sysdeps/unix/sysv/linux/i386/lockf64.c > index 61fcf22..ae0735c 100644 > --- a/sysdeps/unix/sysv/linux/i386/lockf64.c > +++ b/sysdeps/unix/sysv/linux/i386/lockf64.c > @@ -29,6 +29,7 @@ lockf64 (int fd, int cmd, off64_t len64) > { > struct flock64 fl64; > int cmd64; > + int result; > > memset ((char *) &fl64, '\0', sizeof (fl64)); > fl64.l_whence = SEEK_CUR; > @@ -41,12 +42,13 @@ lockf64 (int fd, int cmd, off64_t len64) > /* Test the lock: return 0 if FD is unlocked or locked by this process; > return -1, set errno to EACCES, if another process holds the lock. */ > fl64.l_type = F_RDLCK; > - if (INLINE_SYSCALL (fcntl64, 3, fd, F_GETLK64, &fl64) < 0) > - return -1; > + INTERNAL_SYSCALL_DECL (err); > + result = INTERNAL_SYSCALL (fcntl64, err, 3, fd, F_GETLK64, &fl64); > + if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (result, ))) > + return INLINE_SYSCALL_ERROR_RETURN (-result); > if (fl64.l_type == F_UNLCK || fl64.l_pid == __getpid ()) > return 0; > - __set_errno (EACCES); > - return -1; > + return INLINE_SYSCALL_ERROR_RETURN (EACCES); > case F_ULOCK: > fl64.l_type = F_UNLCK; > cmd64 = F_SETLK64; > @@ -61,8 +63,7 @@ lockf64 (int fd, int cmd, off64_t len64) > break; > > default: > - __set_errno (EINVAL); > - return -1; > + return INLINE_SYSCALL_ERROR_RETURN (EINVAL); > } > return INLINE_SYSCALL (fcntl64, 3, fd, cmd64, &fl64); > } > diff --git a/sysdeps/unix/sysv/linux/i386/lxstat.c b/sysdeps/unix/sysv/linux/i386/lxstat.c > index 0891127..759d240 100644 > --- a/sysdeps/unix/sysv/linux/i386/lxstat.c > +++ b/sysdeps/unix/sysv/linux/i386/lxstat.c > @@ -43,10 +43,12 @@ __lxstat (int vers, const char *name, struct stat *buf) > { > struct stat64 buf64; > > - result = INLINE_SYSCALL (lstat64, 2, name, &buf64); > - if (result == 0) > - result = __xstat32_conv (vers, &buf64, buf); > - return result; > + INTERNAL_SYSCALL_DECL (err); > + result = INTERNAL_SYSCALL (lstat64, err, 2, name, &buf64); > + if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (result, ))) > + return INLINE_SYSCALL_ERROR_RETURN (-result); > + else > + return __xstat32_conv (vers, &buf64, buf); > } > } > > diff --git a/sysdeps/unix/sysv/linux/i386/setegid.c b/sysdeps/unix/sysv/linux/i386/setegid.c > index 8c39784..851513e 100644 > --- a/sysdeps/unix/sysv/linux/i386/setegid.c > +++ b/sysdeps/unix/sysv/linux/i386/setegid.c > @@ -27,10 +27,7 @@ setegid (gid) > int result; > > if (gid == (gid_t) ~0) > - { > - __set_errno (EINVAL); > - return -1; > - } > + INLINE_SYSCALL_ERROR_RETURN (EINVAL); > > result = INLINE_SETXID_SYSCALL (setresgid32, 3, -1, gid, -1); > > diff --git a/sysdeps/unix/sysv/linux/i386/seteuid.c b/sysdeps/unix/sysv/linux/i386/seteuid.c > index d6a7a27..bebca30 100644 > --- a/sysdeps/unix/sysv/linux/i386/seteuid.c > +++ b/sysdeps/unix/sysv/linux/i386/seteuid.c > @@ -26,10 +26,7 @@ seteuid (uid_t uid) > int result; > > if (uid == (uid_t) ~0) > - { > - __set_errno (EINVAL); > - return -1; > - } > + INLINE_SYSCALL_ERROR_RETURN (EINVAL); > > result = INLINE_SETXID_SYSCALL (setresuid32, 3, -1, uid, -1); > > diff --git a/sysdeps/unix/sysv/linux/i386/sigaction.c b/sysdeps/unix/sysv/linux/i386/sigaction.c > index b20a9b9..00df354 100644 > --- a/sysdeps/unix/sysv/linux/i386/sigaction.c > +++ b/sysdeps/unix/sysv/linux/i386/sigaction.c > @@ -69,11 +69,13 @@ __libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact) > > /* XXX The size argument hopefully will have to be changed to the > real size of the user-level sigset_t. */ > - result = INLINE_SYSCALL (rt_sigaction, 4, > - sig, act ? &kact : NULL, > - oact ? &koact : NULL, _NSIG / 8); > - > - if (oact && result >= 0) > + INTERNAL_SYSCALL_DECL (err); > + result = INTERNAL_SYSCALL (rt_sigaction, err, 4, > + sig, act ? &kact : NULL, > + oact ? &koact : NULL, _NSIG / 8); > + if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (result, ))) > + return INLINE_SYSCALL_ERROR_RETURN (-result); > + else if (oact && result >= 0) > { > oact->sa_handler = koact.k_sa_handler; > memcpy (&oact->sa_mask, &koact.sa_mask, sizeof (sigset_t)); > diff --git a/sysdeps/unix/sysv/linux/i386/sysdep.S b/sysdeps/unix/sysv/linux/i386/sysdep.S > deleted file mode 100644 > index 4e6c262..0000000 > --- a/sysdeps/unix/sysv/linux/i386/sysdep.S > +++ /dev/null > @@ -1,40 +0,0 @@ > -/* Copyright (C) 1995-2015 Free Software Foundation, Inc. > - This file is part of the GNU C Library. > - > - The GNU C Library is free software; you can redistribute it and/or > - modify it under the terms of the GNU Lesser General Public > - License as published by the Free Software Foundation; either > - version 2.1 of the License, or (at your option) any later version. > - > - The GNU C Library is distributed in the hope that it will be useful, > - but WITHOUT ANY WARRANTY; without even the implied warranty of > - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > - Lesser General Public License for more details. > - > - You should have received a copy of the GNU Lesser General Public > - License along with the GNU C Library; if not, see > - <http://www.gnu.org/licenses/>. */ > - > -#include <sysdep.h> > - > -/* The following code is only used in the shared library when we > - compile the reentrant version. Otherwise each system call defines > - each own version. */ > - > -#ifndef PIC > - > -/* The syscall stubs jump here when they detect an error. > - The code for Linux is almost identical to the canonical Unix/i386 > - code, except that the error number in %eax is negated. */ > - > -#undef CALL_MCOUNT > -#define CALL_MCOUNT /* Don't insert the profiling call, it clobbers %eax. */ > - > - .text > -ENTRY (__syscall_error) > - negl %eax > - > -#define __syscall_error __syscall_error_1 > -#include <sysdeps/unix/i386/sysdep.S> > - > -#endif /* !PIC */ > diff --git a/sysdeps/unix/sysv/linux/i386/sysdep.c b/sysdeps/unix/sysv/linux/i386/sysdep.c > new file mode 100644 > index 0000000..141105e > --- /dev/null > +++ b/sysdeps/unix/sysv/linux/i386/sysdep.c > @@ -0,0 +1,30 @@ > +/* Copyright (C) 2015 Free Software Foundation, Inc. > + This file is part of the GNU C Library. > + > + The GNU C Library is free software; you can redistribute it and/or > + modify it under the terms of the GNU Lesser General Public > + License as published by the Free Software Foundation; either > + version 2.1 of the License, or (at your option) any later version. > + > + The GNU C Library is distributed in the hope that it will be useful, > + but WITHOUT ANY WARRANTY; without even the implied warranty of > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU > + Lesser General Public License for more details. > + > + You should have received a copy of the GNU Lesser General Public > + License along with the GNU C Library; if not, see > + <http://www.gnu.org/licenses/>. */ > + > +#include <errno.h> > +#include <sysdep.h> > + > +/* This routine is jumped to by all the syscall handlers, to stash > + an error number into errno. ERROR is the negative error number > + returned from the x86 kernel. */ > +int > +__attribute__ ((__regparm__ (1))) > +__syscall_error (int error) > +{ > + __set_errno (-error); > + return -1; > +} > diff --git a/sysdeps/unix/sysv/linux/i386/sysdep.h b/sysdeps/unix/sysv/linux/i386/sysdep.h > index aac3e7b..1515fa6 100644 > --- a/sysdeps/unix/sysv/linux/i386/sysdep.h > +++ b/sysdeps/unix/sysv/linux/i386/sysdep.h > @@ -56,11 +56,7 @@ > > /* We don't want the label for the error handle to be global when we define > it here. */ > -#ifdef PIC > -# define SYSCALL_ERROR_LABEL 0f > -#else > -# define SYSCALL_ERROR_LABEL syscall_error > -#endif > +#define SYSCALL_ERROR_LABEL __syscall_error > > #undef PSEUDO > #define PSEUDO(name, syscall_name, args) \ > @@ -101,55 +97,7 @@ > > #define ret_ERRVAL ret > > -#ifndef PIC > -# define SYSCALL_ERROR_HANDLER /* Nothing here; code in sysdep.S is used. */ > -#else > - > -# if RTLD_PRIVATE_ERRNO > -# define SYSCALL_ERROR_HANDLER \ > -0:SETUP_PIC_REG(cx); \ > - addl $_GLOBAL_OFFSET_TABLE_, %ecx; \ > - negl %eax; \ > - movl %eax, rtld_errno@GOTOFF(%ecx); \ > - orl $-1, %eax; \ > - ret; > - > -# elif defined _LIBC_REENTRANT > - > -# if IS_IN (libc) > -# define SYSCALL_ERROR_ERRNO __libc_errno > -# else > -# define SYSCALL_ERROR_ERRNO errno > -# endif > -# define SYSCALL_ERROR_HANDLER \ > -0:SETUP_PIC_REG (cx); \ > - addl $_GLOBAL_OFFSET_TABLE_, %ecx; \ > - movl SYSCALL_ERROR_ERRNO@GOTNTPOFF(%ecx), %ecx; \ > - negl %eax; \ > - SYSCALL_ERROR_HANDLER_TLS_STORE (%eax, %ecx); \ > - orl $-1, %eax; \ > - ret; > -# ifndef NO_TLS_DIRECT_SEG_REFS > -# define SYSCALL_ERROR_HANDLER_TLS_STORE(src, destoff) \ > - movl src, %gs:(destoff) > -# else > -# define SYSCALL_ERROR_HANDLER_TLS_STORE(src, destoff) \ > - addl %gs:0, destoff; \ > - movl src, (destoff) > -# endif > -# else > -/* Store (- %eax) into errno through the GOT. */ > -# define SYSCALL_ERROR_HANDLER \ > -0:SETUP_PIC_REG(cx); \ > - addl $_GLOBAL_OFFSET_TABLE_, %ecx; \ > - negl %eax; \ > - movl errno@GOT(%ecx), %ecx; \ > - movl %eax, (%ecx); \ > - orl $-1, %eax; \ > - ret; > -# endif /* _LIBC_REENTRANT */ > -#endif /* PIC */ > - > +#define SYSCALL_ERROR_HANDLER /* Nothing here; code in sysdep.c is used. */ > > /* The original calling convention for system calls on Linux/i386 is > to use int $0x80. */ > @@ -276,6 +224,10 @@ > > #else /* !__ASSEMBLER__ */ > > +extern int __syscall_error (int) > + attribute_hidden __attribute__ ((__regparm__ (1))); > + > +#if !__GNUC_PREREQ (5,0) > /* 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" > @@ -315,11 +267,20 @@ struct libc_do_syscall_args > { > int ebx, edi, ebp; > }; > +#endif > > /* Define a macro which expands inline into the wrapper code for a system > call. */ > #undef INLINE_SYSCALL > -#define INLINE_SYSCALL(name, nr, args...) \ > +#if IS_IN (libc) > +# define INLINE_SYSCALL(name, nr, args...) \ > + ({ \ > + unsigned int resultvar = INTERNAL_SYSCALL (name, , nr, args); \ > + __glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (resultvar, )) \ > + ? __syscall_error (-INTERNAL_SYSCALL_ERRNO (resultvar, )) \ > + : (int) resultvar; }) > +#else > +# define INLINE_SYSCALL(name, nr, args...) \ > ({ \ > unsigned int resultvar = INTERNAL_SYSCALL (name, , nr, args); \ > if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (resultvar, ))) \ > @@ -328,6 +289,14 @@ struct libc_do_syscall_args > resultvar = 0xffffffff; \ > } \ > (int) resultvar; }) > +#endif > + > +/* Set error number and return -1. Return the internal function, > + __syscall_error, which sets errno from the negative error number > + and returns -1, to avoid PIC. */ > +#undef INLINE_SYSCALL_ERROR_RETURN > +#define INLINE_SYSCALL_ERROR_RETURN(resultvar) \ > + __syscall_error (-(resultvar)) > > /* List of system calls which are supported as vsyscalls. */ > # define HAVE_CLOCK_GETTIME_VSYSCALL 1 > @@ -355,8 +324,12 @@ struct libc_do_syscall_args > INTERNAL_SYSCALL_MAIN_INLINE(name, err, 5, args) > /* Each object using 6-argument inline syscalls must include a > definition of __libc_do_syscall. */ > -#define INTERNAL_SYSCALL_MAIN_6(name, err, arg1, arg2, arg3, \ > - arg4, arg5, arg6) \ > +#if __GNUC_PREREQ (5,0) > +# define INTERNAL_SYSCALL_MAIN_6(name, err, args...) \ > + INTERNAL_SYSCALL_MAIN_INLINE(name, err, 6, args) > +#else /* GCC 5 */ > +# define INTERNAL_SYSCALL_MAIN_6(name, err, arg1, arg2, arg3, \ > + arg4, arg5, arg6) \ > struct libc_do_syscall_args _xv = \ > { \ > (int) (arg1), \ > @@ -369,14 +342,52 @@ struct libc_do_syscall_args > : "=a" (resultvar) \ > : "i" (__NR_##name), "c" (arg2), "d" (arg3), "S" (arg4), "D" (&_xv) \ > : "memory", "cc") > +#endif /* GCC 5 */ > #define INTERNAL_SYSCALL(name, err, nr, args...) \ > ({ \ > register unsigned int resultvar; \ > INTERNAL_SYSCALL_MAIN_##nr (name, err, args); \ > (int) resultvar; }) > #ifdef I386_USE_SYSENTER > -# ifdef SHARED > -# define INTERNAL_SYSCALL_MAIN_INLINE(name, err, nr, args...) \ > +# if __GNUC_PREREQ (5,0) > +# ifdef SHARED > +# define INTERNAL_SYSCALL_MAIN_INLINE(name, err, 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_NCS(name, err, nr, args...) \ > + ({ \ > + register unsigned int resultvar; \ > + LOADREGS_##nr(args) \ > + asm volatile ( \ > + "call *%%gs:%P2" \ > + : "=a" (resultvar) \ > + : "a" (name), "i" (offsetof (tcbhead_t, sysinfo)) \ > + ASMARGS_##nr(args) : "memory", "cc"); \ > + (int) resultvar; }) > +# else > +# define INTERNAL_SYSCALL_MAIN_INLINE(name, err, nr, args...) \ > + LOADREGS_##nr(args) \ > + asm volatile ( \ > + "call *_dl_sysinfo" \ > + : "=a" (resultvar) \ > + : "a" (__NR_##name) ASMARGS_##nr(args) : "memory", "cc") > +# define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \ > + ({ \ > + register unsigned int resultvar; \ > + LOADREGS_##nr(args) \ > + asm volatile ( \ > + "call *_dl_sysinfo" \ > + : "=a" (resultvar) \ > + : "a" (name) ASMARGS_##nr(args) : "memory", "cc"); \ > + (int) resultvar; }) > +# endif > +# else /* GCC 5 */ > +# ifdef SHARED > +# define INTERNAL_SYSCALL_MAIN_INLINE(name, err, nr, args...) \ > EXTRAVAR_##nr \ > asm volatile ( \ > LOADARGS_##nr \ > @@ -386,7 +397,7 @@ struct libc_do_syscall_args > : "=a" (resultvar) \ > : "i" (__NR_##name), "i" (offsetof (tcbhead_t, sysinfo)) \ > ASMFMT_##nr(args) : "memory", "cc") > -# define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \ > +# define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \ > ({ \ > register unsigned int resultvar; \ > EXTRAVAR_##nr \ > @@ -398,8 +409,8 @@ struct libc_do_syscall_args > : "0" (name), "i" (offsetof (tcbhead_t, sysinfo)) \ > ASMFMT_##nr(args) : "memory", "cc"); \ > (int) resultvar; }) > -# else > -# define INTERNAL_SYSCALL_MAIN_INLINE(name, err, nr, args...) \ > +# else > +# define INTERNAL_SYSCALL_MAIN_INLINE(name, err, nr, args...) \ > EXTRAVAR_##nr \ > asm volatile ( \ > LOADARGS_##nr \ > @@ -408,7 +419,7 @@ struct libc_do_syscall_args > RESTOREARGS_##nr \ > : "=a" (resultvar) \ > : "i" (__NR_##name) ASMFMT_##nr(args) : "memory", "cc") > -# define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \ > +# define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \ > ({ \ > register unsigned int resultvar; \ > EXTRAVAR_##nr \ > @@ -419,9 +430,27 @@ struct libc_do_syscall_args > : "=a" (resultvar) \ > : "0" (name) ASMFMT_##nr(args) : "memory", "cc"); \ > (int) resultvar; }) > -# endif > +# endif > +# endif /* GCC 5 */ > #else > -# define INTERNAL_SYSCALL_MAIN_INLINE(name, err, nr, args...) \ > +# if __GNUC_PREREQ (5,0) > +# define INTERNAL_SYSCALL_MAIN_INLINE(name, err, nr, args...) \ > + LOADREGS_##nr(args) \ > + asm volatile ( \ > + "int $0x80" \ > + : "=a" (resultvar) \ > + : "a" (__NR_##name) ASMARGS_##nr(args) : "memory", "cc") > +# define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \ > + ({ \ > + register unsigned int resultvar; \ > + LOADREGS_##nr(args) \ > + asm volatile ( \ > + "int $0x80" \ > + : "=a" (resultvar) \ > + : "a" (name) ASMARGS_##nr(args) : "memory", "cc"); \ > + (int) resultvar; }) > +# else /* GCC 5 */ > +# define INTERNAL_SYSCALL_MAIN_INLINE(name, err, nr, args...) \ > EXTRAVAR_##nr \ > asm volatile ( \ > LOADARGS_##nr \ > @@ -430,7 +459,7 @@ struct libc_do_syscall_args > RESTOREARGS_##nr \ > : "=a" (resultvar) \ > : "i" (__NR_##name) ASMFMT_##nr(args) : "memory", "cc") > -# define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \ > +# define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \ > ({ \ > register unsigned int resultvar; \ > EXTRAVAR_##nr \ > @@ -441,6 +470,7 @@ struct libc_do_syscall_args > : "=a" (resultvar) \ > : "0" (name) ASMFMT_##nr(args) : "memory", "cc"); \ > (int) resultvar; }) > +# endif /* GCC 5 */ > #endif > > #undef INTERNAL_SYSCALL_DECL > @@ -505,6 +535,36 @@ struct libc_do_syscall_args > # define RESTOREARGS_5 > #endif > > +#if __GNUC_PREREQ (5,0) > +# define LOADREGS_0() > +# define ASMARGS_0() > +# define LOADREGS_1(arg1) \ > + LOADREGS_0 () > +# define ASMARGS_1(arg1) \ > + ASMARGS_0 (), "b" ((unsigned int) (arg1)) > +# define LOADREGS_2(arg1, arg2) \ > + LOADREGS_1 (arg1) > +# define ASMARGS_2(arg1, arg2) \ > + ASMARGS_1 (arg1), "c" ((unsigned int) (arg2)) > +# define LOADREGS_3(arg1, arg2, arg3) \ > + LOADREGS_2 (arg1, arg2) > +# define ASMARGS_3(arg1, arg2, arg3) \ > + ASMARGS_2 (arg1, arg2), "d" ((unsigned int) (arg3)) > +# define LOADREGS_4(arg1, arg2, arg3, arg4) \ > + LOADREGS_3 (arg1, arg2, arg3) > +# define ASMARGS_4(arg1, arg2, arg3, arg4) \ > + ASMARGS_3 (arg1, arg2, arg3), "S" ((unsigned int) (arg4)) > +# define LOADREGS_5(arg1, arg2, arg3, arg4, arg5) \ > + LOADREGS_4 (arg1, arg2, arg3, arg4) > +# 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__ > # define ASMFMT_1(arg1) \ > diff --git a/sysdeps/unix/sysv/linux/i386/xstat.c b/sysdeps/unix/sysv/linux/i386/xstat.c > index 2424434..4dce122 100644 > --- a/sysdeps/unix/sysv/linux/i386/xstat.c > +++ b/sysdeps/unix/sysv/linux/i386/xstat.c > @@ -43,10 +43,12 @@ __xstat (int vers, const char *name, struct stat *buf) > { > struct stat64 buf64; > > - result = INLINE_SYSCALL (stat64, 2, name, &buf64); > - if (result == 0) > - result = __xstat32_conv (vers, &buf64, buf); > - return result; > + INTERNAL_SYSCALL_DECL (err); > + result = INTERNAL_SYSCALL (stat64, err, 2, name, &buf64); > + if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (result, ))) > + return INLINE_SYSCALL_ERROR_RETURN (-result); > + else > + return __xstat32_conv (vers, &buf64, buf); > } > } > hidden_def (__xstat) >
On Thu, Sep 10, 2015 at 10:23 AM, Adhemerval Zanella <adhemerval.zanella@linaro.org> wrote: > > > On 10-09-2015 10:14, H.J. Lu wrote: >> OK for master? >> >> H.J. >> --- >> Define INLINE_SYSCALL_ERROR_RETURN so that i386 can optimize setting >> errno by branching to the internal __syscall_error without PLT. >> >> Since GCC 5 and above can properly spill %ebx when needed, we can inline >> syscalls with 6 arguments if GCC 5 or above is used to compile glibc. >> This patch rewrites INTERNAL_SYSCALL macros and skips __libc_do_syscall >> for GCC 5. >> >> For sysdeps/unix/sysv/linux/i386/brk.c, with -O2 -march=i686 >> -mtune=generic, GCC 5.2 now generates: > > You can use this refactoring to cleanup some duplicate code as well, > since i386 brk.c, setegid.c, and seteuid.c can be replaces by generic > implementation. > > Also for *stat* implementations i386 could override overflow.h and > redefine stat_overflow with stat64 logic. > > For lockf64.c I also think it can be feasible to change default > implementation to accommodate i386 requirements (use flock64 > instead of flock). > > The only implementation is really i386 specific is sigaction.c, > but I can't tell how much of the assembly hackery it requires > nowadays. > I'd like to keep my changes as mechanical as possible. These cleanups belong to separate patches after my patches are checked-in.
diff --git a/sysdeps/unix/sysv/linux/i386/Makefile b/sysdeps/unix/sysv/linux/i386/Makefile index 80da593..e10d133 100644 --- a/sysdeps/unix/sysv/linux/i386/Makefile +++ b/sysdeps/unix/sysv/linux/i386/Makefile @@ -27,3 +27,17 @@ endif ifeq ($(subdir),stdlib) gen-as-const-headers += ucontext_i.sym endif + +ifeq ($(subdir),csu) +sysdep-dl-routines += sysdep +endif + +ifeq ($(subdir),nptl) +# pull in __syscall_error routine +libpthread-routines += sysdep +endif + +ifeq ($(subdir),rt) +# pull in __syscall_error routine +librt-routines += sysdep +endif diff --git a/sysdeps/unix/sysv/linux/i386/brk.c b/sysdeps/unix/sysv/linux/i386/brk.c index 5b9a0ce..2d2daa5 100644 --- a/sysdeps/unix/sysv/linux/i386/brk.c +++ b/sysdeps/unix/sysv/linux/i386/brk.c @@ -31,19 +31,11 @@ weak_alias (__curbrk, ___brk_addr) int __brk (void *addr) { - void *newbrk; - INTERNAL_SYSCALL_DECL (err); - newbrk = (void *) INTERNAL_SYSCALL (brk, err, 1, addr); - + void *newbrk = (void *) INTERNAL_SYSCALL (brk, err, 1, addr); __curbrk = newbrk; - if (newbrk < addr) - { - __set_errno (ENOMEM); - return -1; - } - + return INLINE_SYSCALL_ERROR_RETURN (ENOMEM); return 0; } weak_alias (__brk, brk) diff --git a/sysdeps/unix/sysv/linux/i386/clone.S b/sysdeps/unix/sysv/linux/i386/clone.S index 243dbfe..2aafb3a 100644 --- a/sysdeps/unix/sysv/linux/i386/clone.S +++ b/sysdeps/unix/sysv/linux/i386/clone.S @@ -47,19 +47,11 @@ ENTRY (__clone) /* Sanity check arguments. */ movl $-EINVAL,%eax movl FUNC(%esp),%ecx /* no NULL function pointers */ -#ifdef PIC - jecxz SYSCALL_ERROR_LABEL -#else testl %ecx,%ecx jz SYSCALL_ERROR_LABEL -#endif movl STACK(%esp),%ecx /* no NULL stack pointers */ -#ifdef PIC - jecxz SYSCALL_ERROR_LABEL -#else testl %ecx,%ecx jz SYSCALL_ERROR_LABEL -#endif /* Insert the argument onto the new stack. Make sure the new thread is started with an alignment of (mod 16). */ diff --git a/sysdeps/unix/sysv/linux/i386/fxstat.c b/sysdeps/unix/sysv/linux/i386/fxstat.c index 2f7a8fe..3919e0c 100644 --- a/sysdeps/unix/sysv/linux/i386/fxstat.c +++ b/sysdeps/unix/sysv/linux/i386/fxstat.c @@ -42,10 +42,12 @@ __fxstat (int vers, int fd, struct stat *buf) { struct stat64 buf64; - result = INLINE_SYSCALL (fstat64, 2, fd, &buf64); - if (result == 0) - result = __xstat32_conv (vers, &buf64, buf); - return result; + INTERNAL_SYSCALL_DECL (err); + result = INTERNAL_SYSCALL (fstat64, err, 2, fd, &buf64); + if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (result, ))) + return INLINE_SYSCALL_ERROR_RETURN (-result); + else + return __xstat32_conv (vers, &buf64, buf); } } diff --git a/sysdeps/unix/sysv/linux/i386/fxstatat.c b/sysdeps/unix/sysv/linux/i386/fxstatat.c index 6f3c251..c4be04d 100644 --- a/sysdeps/unix/sysv/linux/i386/fxstatat.c +++ b/sysdeps/unix/sysv/linux/i386/fxstatat.c @@ -42,13 +42,10 @@ __fxstatat (int vers, int fd, const char *file, struct stat *st, int flag) struct stat64 st64; result = INTERNAL_SYSCALL (fstatat64, err, 4, fd, file, &st64, flag); - if (!__builtin_expect (INTERNAL_SYSCALL_ERROR_P (result, err), 1)) - return __xstat32_conv (vers, &st64, st); + if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (result, ))) + return INLINE_SYSCALL_ERROR_RETURN (-result); else - { - __set_errno (INTERNAL_SYSCALL_ERRNO (result, err)); - return -1; - } + return __xstat32_conv (vers, &st64, st); } libc_hidden_def (__fxstatat) #ifdef XSTAT_IS_XSTAT64 diff --git a/sysdeps/unix/sysv/linux/i386/libc-do-syscall.S b/sysdeps/unix/sysv/linux/i386/libc-do-syscall.S index af5c6f0..cdef3d5 100644 --- a/sysdeps/unix/sysv/linux/i386/libc-do-syscall.S +++ b/sysdeps/unix/sysv/linux/i386/libc-do-syscall.S @@ -18,6 +18,8 @@ #include <sysdep.h> +#if !__GNUC_PREREQ (5,0) + /* %eax, %ecx, %edx and %esi contain the values expected by the kernel. %edi points to a structure with the values of %ebx, %edi and %ebp. */ @@ -48,3 +50,4 @@ ENTRY (__libc_do_syscall) cfi_restore (ebx) ret END (__libc_do_syscall) +#endif diff --git a/sysdeps/unix/sysv/linux/i386/lockf64.c b/sysdeps/unix/sysv/linux/i386/lockf64.c index 61fcf22..ae0735c 100644 --- a/sysdeps/unix/sysv/linux/i386/lockf64.c +++ b/sysdeps/unix/sysv/linux/i386/lockf64.c @@ -29,6 +29,7 @@ lockf64 (int fd, int cmd, off64_t len64) { struct flock64 fl64; int cmd64; + int result; memset ((char *) &fl64, '\0', sizeof (fl64)); fl64.l_whence = SEEK_CUR; @@ -41,12 +42,13 @@ lockf64 (int fd, int cmd, off64_t len64) /* Test the lock: return 0 if FD is unlocked or locked by this process; return -1, set errno to EACCES, if another process holds the lock. */ fl64.l_type = F_RDLCK; - if (INLINE_SYSCALL (fcntl64, 3, fd, F_GETLK64, &fl64) < 0) - return -1; + INTERNAL_SYSCALL_DECL (err); + result = INTERNAL_SYSCALL (fcntl64, err, 3, fd, F_GETLK64, &fl64); + if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (result, ))) + return INLINE_SYSCALL_ERROR_RETURN (-result); if (fl64.l_type == F_UNLCK || fl64.l_pid == __getpid ()) return 0; - __set_errno (EACCES); - return -1; + return INLINE_SYSCALL_ERROR_RETURN (EACCES); case F_ULOCK: fl64.l_type = F_UNLCK; cmd64 = F_SETLK64; @@ -61,8 +63,7 @@ lockf64 (int fd, int cmd, off64_t len64) break; default: - __set_errno (EINVAL); - return -1; + return INLINE_SYSCALL_ERROR_RETURN (EINVAL); } return INLINE_SYSCALL (fcntl64, 3, fd, cmd64, &fl64); } diff --git a/sysdeps/unix/sysv/linux/i386/lxstat.c b/sysdeps/unix/sysv/linux/i386/lxstat.c index 0891127..759d240 100644 --- a/sysdeps/unix/sysv/linux/i386/lxstat.c +++ b/sysdeps/unix/sysv/linux/i386/lxstat.c @@ -43,10 +43,12 @@ __lxstat (int vers, const char *name, struct stat *buf) { struct stat64 buf64; - result = INLINE_SYSCALL (lstat64, 2, name, &buf64); - if (result == 0) - result = __xstat32_conv (vers, &buf64, buf); - return result; + INTERNAL_SYSCALL_DECL (err); + result = INTERNAL_SYSCALL (lstat64, err, 2, name, &buf64); + if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (result, ))) + return INLINE_SYSCALL_ERROR_RETURN (-result); + else + return __xstat32_conv (vers, &buf64, buf); } } diff --git a/sysdeps/unix/sysv/linux/i386/setegid.c b/sysdeps/unix/sysv/linux/i386/setegid.c index 8c39784..851513e 100644 --- a/sysdeps/unix/sysv/linux/i386/setegid.c +++ b/sysdeps/unix/sysv/linux/i386/setegid.c @@ -27,10 +27,7 @@ setegid (gid) int result; if (gid == (gid_t) ~0) - { - __set_errno (EINVAL); - return -1; - } + INLINE_SYSCALL_ERROR_RETURN (EINVAL); result = INLINE_SETXID_SYSCALL (setresgid32, 3, -1, gid, -1); diff --git a/sysdeps/unix/sysv/linux/i386/seteuid.c b/sysdeps/unix/sysv/linux/i386/seteuid.c index d6a7a27..bebca30 100644 --- a/sysdeps/unix/sysv/linux/i386/seteuid.c +++ b/sysdeps/unix/sysv/linux/i386/seteuid.c @@ -26,10 +26,7 @@ seteuid (uid_t uid) int result; if (uid == (uid_t) ~0) - { - __set_errno (EINVAL); - return -1; - } + INLINE_SYSCALL_ERROR_RETURN (EINVAL); result = INLINE_SETXID_SYSCALL (setresuid32, 3, -1, uid, -1); diff --git a/sysdeps/unix/sysv/linux/i386/sigaction.c b/sysdeps/unix/sysv/linux/i386/sigaction.c index b20a9b9..00df354 100644 --- a/sysdeps/unix/sysv/linux/i386/sigaction.c +++ b/sysdeps/unix/sysv/linux/i386/sigaction.c @@ -69,11 +69,13 @@ __libc_sigaction (int sig, const struct sigaction *act, struct sigaction *oact) /* XXX The size argument hopefully will have to be changed to the real size of the user-level sigset_t. */ - result = INLINE_SYSCALL (rt_sigaction, 4, - sig, act ? &kact : NULL, - oact ? &koact : NULL, _NSIG / 8); - - if (oact && result >= 0) + INTERNAL_SYSCALL_DECL (err); + result = INTERNAL_SYSCALL (rt_sigaction, err, 4, + sig, act ? &kact : NULL, + oact ? &koact : NULL, _NSIG / 8); + if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (result, ))) + return INLINE_SYSCALL_ERROR_RETURN (-result); + else if (oact && result >= 0) { oact->sa_handler = koact.k_sa_handler; memcpy (&oact->sa_mask, &koact.sa_mask, sizeof (sigset_t)); diff --git a/sysdeps/unix/sysv/linux/i386/sysdep.S b/sysdeps/unix/sysv/linux/i386/sysdep.S deleted file mode 100644 index 4e6c262..0000000 --- a/sysdeps/unix/sysv/linux/i386/sysdep.S +++ /dev/null @@ -1,40 +0,0 @@ -/* Copyright (C) 1995-2015 Free Software Foundation, Inc. - This file is part of the GNU C Library. - - The GNU C Library is free software; you can redistribute it and/or - modify it under the terms of the GNU Lesser General Public - License as published by the Free Software Foundation; either - version 2.1 of the License, or (at your option) any later version. - - The GNU C Library is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - Lesser General Public License for more details. - - You should have received a copy of the GNU Lesser General Public - License along with the GNU C Library; if not, see - <http://www.gnu.org/licenses/>. */ - -#include <sysdep.h> - -/* The following code is only used in the shared library when we - compile the reentrant version. Otherwise each system call defines - each own version. */ - -#ifndef PIC - -/* The syscall stubs jump here when they detect an error. - The code for Linux is almost identical to the canonical Unix/i386 - code, except that the error number in %eax is negated. */ - -#undef CALL_MCOUNT -#define CALL_MCOUNT /* Don't insert the profiling call, it clobbers %eax. */ - - .text -ENTRY (__syscall_error) - negl %eax - -#define __syscall_error __syscall_error_1 -#include <sysdeps/unix/i386/sysdep.S> - -#endif /* !PIC */ diff --git a/sysdeps/unix/sysv/linux/i386/sysdep.c b/sysdeps/unix/sysv/linux/i386/sysdep.c new file mode 100644 index 0000000..141105e --- /dev/null +++ b/sysdeps/unix/sysv/linux/i386/sysdep.c @@ -0,0 +1,30 @@ +/* Copyright (C) 2015 Free Software Foundation, Inc. + This file is part of the GNU C Library. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <errno.h> +#include <sysdep.h> + +/* This routine is jumped to by all the syscall handlers, to stash + an error number into errno. ERROR is the negative error number + returned from the x86 kernel. */ +int +__attribute__ ((__regparm__ (1))) +__syscall_error (int error) +{ + __set_errno (-error); + return -1; +} diff --git a/sysdeps/unix/sysv/linux/i386/sysdep.h b/sysdeps/unix/sysv/linux/i386/sysdep.h index aac3e7b..1515fa6 100644 --- a/sysdeps/unix/sysv/linux/i386/sysdep.h +++ b/sysdeps/unix/sysv/linux/i386/sysdep.h @@ -56,11 +56,7 @@ /* We don't want the label for the error handle to be global when we define it here. */ -#ifdef PIC -# define SYSCALL_ERROR_LABEL 0f -#else -# define SYSCALL_ERROR_LABEL syscall_error -#endif +#define SYSCALL_ERROR_LABEL __syscall_error #undef PSEUDO #define PSEUDO(name, syscall_name, args) \ @@ -101,55 +97,7 @@ #define ret_ERRVAL ret -#ifndef PIC -# define SYSCALL_ERROR_HANDLER /* Nothing here; code in sysdep.S is used. */ -#else - -# if RTLD_PRIVATE_ERRNO -# define SYSCALL_ERROR_HANDLER \ -0:SETUP_PIC_REG(cx); \ - addl $_GLOBAL_OFFSET_TABLE_, %ecx; \ - negl %eax; \ - movl %eax, rtld_errno@GOTOFF(%ecx); \ - orl $-1, %eax; \ - ret; - -# elif defined _LIBC_REENTRANT - -# if IS_IN (libc) -# define SYSCALL_ERROR_ERRNO __libc_errno -# else -# define SYSCALL_ERROR_ERRNO errno -# endif -# define SYSCALL_ERROR_HANDLER \ -0:SETUP_PIC_REG (cx); \ - addl $_GLOBAL_OFFSET_TABLE_, %ecx; \ - movl SYSCALL_ERROR_ERRNO@GOTNTPOFF(%ecx), %ecx; \ - negl %eax; \ - SYSCALL_ERROR_HANDLER_TLS_STORE (%eax, %ecx); \ - orl $-1, %eax; \ - ret; -# ifndef NO_TLS_DIRECT_SEG_REFS -# define SYSCALL_ERROR_HANDLER_TLS_STORE(src, destoff) \ - movl src, %gs:(destoff) -# else -# define SYSCALL_ERROR_HANDLER_TLS_STORE(src, destoff) \ - addl %gs:0, destoff; \ - movl src, (destoff) -# endif -# else -/* Store (- %eax) into errno through the GOT. */ -# define SYSCALL_ERROR_HANDLER \ -0:SETUP_PIC_REG(cx); \ - addl $_GLOBAL_OFFSET_TABLE_, %ecx; \ - negl %eax; \ - movl errno@GOT(%ecx), %ecx; \ - movl %eax, (%ecx); \ - orl $-1, %eax; \ - ret; -# endif /* _LIBC_REENTRANT */ -#endif /* PIC */ - +#define SYSCALL_ERROR_HANDLER /* Nothing here; code in sysdep.c is used. */ /* The original calling convention for system calls on Linux/i386 is to use int $0x80. */ @@ -276,6 +224,10 @@ #else /* !__ASSEMBLER__ */ +extern int __syscall_error (int) + attribute_hidden __attribute__ ((__regparm__ (1))); + +#if !__GNUC_PREREQ (5,0) /* 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" @@ -315,11 +267,20 @@ struct libc_do_syscall_args { int ebx, edi, ebp; }; +#endif /* Define a macro which expands inline into the wrapper code for a system call. */ #undef INLINE_SYSCALL -#define INLINE_SYSCALL(name, nr, args...) \ +#if IS_IN (libc) +# define INLINE_SYSCALL(name, nr, args...) \ + ({ \ + unsigned int resultvar = INTERNAL_SYSCALL (name, , nr, args); \ + __glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (resultvar, )) \ + ? __syscall_error (-INTERNAL_SYSCALL_ERRNO (resultvar, )) \ + : (int) resultvar; }) +#else +# define INLINE_SYSCALL(name, nr, args...) \ ({ \ unsigned int resultvar = INTERNAL_SYSCALL (name, , nr, args); \ if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (resultvar, ))) \ @@ -328,6 +289,14 @@ struct libc_do_syscall_args resultvar = 0xffffffff; \ } \ (int) resultvar; }) +#endif + +/* Set error number and return -1. Return the internal function, + __syscall_error, which sets errno from the negative error number + and returns -1, to avoid PIC. */ +#undef INLINE_SYSCALL_ERROR_RETURN +#define INLINE_SYSCALL_ERROR_RETURN(resultvar) \ + __syscall_error (-(resultvar)) /* List of system calls which are supported as vsyscalls. */ # define HAVE_CLOCK_GETTIME_VSYSCALL 1 @@ -355,8 +324,12 @@ struct libc_do_syscall_args INTERNAL_SYSCALL_MAIN_INLINE(name, err, 5, args) /* Each object using 6-argument inline syscalls must include a definition of __libc_do_syscall. */ -#define INTERNAL_SYSCALL_MAIN_6(name, err, arg1, arg2, arg3, \ - arg4, arg5, arg6) \ +#if __GNUC_PREREQ (5,0) +# define INTERNAL_SYSCALL_MAIN_6(name, err, args...) \ + INTERNAL_SYSCALL_MAIN_INLINE(name, err, 6, args) +#else /* GCC 5 */ +# define INTERNAL_SYSCALL_MAIN_6(name, err, arg1, arg2, arg3, \ + arg4, arg5, arg6) \ struct libc_do_syscall_args _xv = \ { \ (int) (arg1), \ @@ -369,14 +342,52 @@ struct libc_do_syscall_args : "=a" (resultvar) \ : "i" (__NR_##name), "c" (arg2), "d" (arg3), "S" (arg4), "D" (&_xv) \ : "memory", "cc") +#endif /* GCC 5 */ #define INTERNAL_SYSCALL(name, err, nr, args...) \ ({ \ register unsigned int resultvar; \ INTERNAL_SYSCALL_MAIN_##nr (name, err, args); \ (int) resultvar; }) #ifdef I386_USE_SYSENTER -# ifdef SHARED -# define INTERNAL_SYSCALL_MAIN_INLINE(name, err, nr, args...) \ +# if __GNUC_PREREQ (5,0) +# ifdef SHARED +# define INTERNAL_SYSCALL_MAIN_INLINE(name, err, 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_NCS(name, err, nr, args...) \ + ({ \ + register unsigned int resultvar; \ + LOADREGS_##nr(args) \ + asm volatile ( \ + "call *%%gs:%P2" \ + : "=a" (resultvar) \ + : "a" (name), "i" (offsetof (tcbhead_t, sysinfo)) \ + ASMARGS_##nr(args) : "memory", "cc"); \ + (int) resultvar; }) +# else +# define INTERNAL_SYSCALL_MAIN_INLINE(name, err, nr, args...) \ + LOADREGS_##nr(args) \ + asm volatile ( \ + "call *_dl_sysinfo" \ + : "=a" (resultvar) \ + : "a" (__NR_##name) ASMARGS_##nr(args) : "memory", "cc") +# define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \ + ({ \ + register unsigned int resultvar; \ + LOADREGS_##nr(args) \ + asm volatile ( \ + "call *_dl_sysinfo" \ + : "=a" (resultvar) \ + : "a" (name) ASMARGS_##nr(args) : "memory", "cc"); \ + (int) resultvar; }) +# endif +# else /* GCC 5 */ +# ifdef SHARED +# define INTERNAL_SYSCALL_MAIN_INLINE(name, err, nr, args...) \ EXTRAVAR_##nr \ asm volatile ( \ LOADARGS_##nr \ @@ -386,7 +397,7 @@ struct libc_do_syscall_args : "=a" (resultvar) \ : "i" (__NR_##name), "i" (offsetof (tcbhead_t, sysinfo)) \ ASMFMT_##nr(args) : "memory", "cc") -# define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \ +# define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \ ({ \ register unsigned int resultvar; \ EXTRAVAR_##nr \ @@ -398,8 +409,8 @@ struct libc_do_syscall_args : "0" (name), "i" (offsetof (tcbhead_t, sysinfo)) \ ASMFMT_##nr(args) : "memory", "cc"); \ (int) resultvar; }) -# else -# define INTERNAL_SYSCALL_MAIN_INLINE(name, err, nr, args...) \ +# else +# define INTERNAL_SYSCALL_MAIN_INLINE(name, err, nr, args...) \ EXTRAVAR_##nr \ asm volatile ( \ LOADARGS_##nr \ @@ -408,7 +419,7 @@ struct libc_do_syscall_args RESTOREARGS_##nr \ : "=a" (resultvar) \ : "i" (__NR_##name) ASMFMT_##nr(args) : "memory", "cc") -# define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \ +# define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \ ({ \ register unsigned int resultvar; \ EXTRAVAR_##nr \ @@ -419,9 +430,27 @@ struct libc_do_syscall_args : "=a" (resultvar) \ : "0" (name) ASMFMT_##nr(args) : "memory", "cc"); \ (int) resultvar; }) -# endif +# endif +# endif /* GCC 5 */ #else -# define INTERNAL_SYSCALL_MAIN_INLINE(name, err, nr, args...) \ +# if __GNUC_PREREQ (5,0) +# define INTERNAL_SYSCALL_MAIN_INLINE(name, err, nr, args...) \ + LOADREGS_##nr(args) \ + asm volatile ( \ + "int $0x80" \ + : "=a" (resultvar) \ + : "a" (__NR_##name) ASMARGS_##nr(args) : "memory", "cc") +# define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \ + ({ \ + register unsigned int resultvar; \ + LOADREGS_##nr(args) \ + asm volatile ( \ + "int $0x80" \ + : "=a" (resultvar) \ + : "a" (name) ASMARGS_##nr(args) : "memory", "cc"); \ + (int) resultvar; }) +# else /* GCC 5 */ +# define INTERNAL_SYSCALL_MAIN_INLINE(name, err, nr, args...) \ EXTRAVAR_##nr \ asm volatile ( \ LOADARGS_##nr \ @@ -430,7 +459,7 @@ struct libc_do_syscall_args RESTOREARGS_##nr \ : "=a" (resultvar) \ : "i" (__NR_##name) ASMFMT_##nr(args) : "memory", "cc") -# define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \ +# define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \ ({ \ register unsigned int resultvar; \ EXTRAVAR_##nr \ @@ -441,6 +470,7 @@ struct libc_do_syscall_args : "=a" (resultvar) \ : "0" (name) ASMFMT_##nr(args) : "memory", "cc"); \ (int) resultvar; }) +# endif /* GCC 5 */ #endif #undef INTERNAL_SYSCALL_DECL @@ -505,6 +535,36 @@ struct libc_do_syscall_args # define RESTOREARGS_5 #endif +#if __GNUC_PREREQ (5,0) +# define LOADREGS_0() +# define ASMARGS_0() +# define LOADREGS_1(arg1) \ + LOADREGS_0 () +# define ASMARGS_1(arg1) \ + ASMARGS_0 (), "b" ((unsigned int) (arg1)) +# define LOADREGS_2(arg1, arg2) \ + LOADREGS_1 (arg1) +# define ASMARGS_2(arg1, arg2) \ + ASMARGS_1 (arg1), "c" ((unsigned int) (arg2)) +# define LOADREGS_3(arg1, arg2, arg3) \ + LOADREGS_2 (arg1, arg2) +# define ASMARGS_3(arg1, arg2, arg3) \ + ASMARGS_2 (arg1, arg2), "d" ((unsigned int) (arg3)) +# define LOADREGS_4(arg1, arg2, arg3, arg4) \ + LOADREGS_3 (arg1, arg2, arg3) +# define ASMARGS_4(arg1, arg2, arg3, arg4) \ + ASMARGS_3 (arg1, arg2, arg3), "S" ((unsigned int) (arg4)) +# define LOADREGS_5(arg1, arg2, arg3, arg4, arg5) \ + LOADREGS_4 (arg1, arg2, arg3, arg4) +# 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__ # define ASMFMT_1(arg1) \ diff --git a/sysdeps/unix/sysv/linux/i386/xstat.c b/sysdeps/unix/sysv/linux/i386/xstat.c index 2424434..4dce122 100644 --- a/sysdeps/unix/sysv/linux/i386/xstat.c +++ b/sysdeps/unix/sysv/linux/i386/xstat.c @@ -43,10 +43,12 @@ __xstat (int vers, const char *name, struct stat *buf) { struct stat64 buf64; - result = INLINE_SYSCALL (stat64, 2, name, &buf64); - if (result == 0) - result = __xstat32_conv (vers, &buf64, buf); - return result; + INTERNAL_SYSCALL_DECL (err); + result = INTERNAL_SYSCALL (stat64, err, 2, name, &buf64); + if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (result, ))) + return INLINE_SYSCALL_ERROR_RETURN (-result); + else + return __xstat32_conv (vers, &buf64, buf); } } hidden_def (__xstat)