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author | Joseph Myers <joseph@codesourcery.com> | 2015-03-25 15:17:54 +0000 |
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committer | Joseph Myers <joseph@codesourcery.com> | 2015-03-25 15:17:54 +0000 |
commit | a9fe4c5aa8e53ee30f7d0a1c878391d5d6324e6e (patch) | |
tree | b57c4c83b9a6758d50264de82f0e4a09c9bde4b1 /sysdeps/unix | |
parent | afcd9480feca651eef436d8438b783dde5c3bbb2 (diff) | |
download | glibc-a9fe4c5aa8e53ee30f7d0a1c878391d5d6324e6e.zip glibc-a9fe4c5aa8e53ee30f7d0a1c878391d5d6324e6e.tar.gz glibc-a9fe4c5aa8e53ee30f7d0a1c878391d5d6324e6e.tar.bz2 |
Support six-argument syscalls from C for 32-bit x86, use generic lowlevellock-futex.h (bug 18138).
This patch follows the approach outlined in
<https://sourceware.org/ml/libc-alpha/2015-03/msg00656.html> to
support six-argument syscalls from INTERNAL_SYSCALL for 32-bit x86,
making them call a function __libc_do_syscall that takes the syscall
number and three syscall arguments in the registers in which the
kernel expects them, along with a pointer to a structure containing
the other three arguments.
In turn, this allows the generic lowlevellock-futex.h to be used on
32-bit x86, so supporting lll_futex_timed_wait_bitset (and so allowing
FUTEX_CLOCK_REALTIME to be used in various cases, so fixing bug 18138
for 32-bit x86 and leaving hppa as the only architecture missing
lll_futex_timed_wait_bitset). The change to lowlevellock.h's
definition of SYS_futex is because the generic lowlevelloc-futex.h
ends up bringing in bits/syscall.h which defines SYS_futex to
__NR_futex, so resulting in redefinition errors. The revised
definition in lowlevellock.h is in line with what the x86_64 version
does.
__libc_do_syscall is only needed in libpthread at present (meaning
nothing special needs to be done to make it shared-only in most
libraries containing it, static in libc only, as on ARM).
Tested for 32-bit x86, with the glibc testsuite and with the test in
bug 18138. The failures seen
FAIL: nptl/tst-cleanupx4
FAIL: rt/tst-cpuclock2
are pre-existing.
[BZ #18138]
* sysdeps/unix/sysv/linux/i386/sysdep.h (struct
libc_do_syscall_args): New structure.
(INTERNAL_SYSCALL_MAIN_0): New macro.
(INTERNAL_SYSCALL_MAIN_1): Likewise.
(INTERNAL_SYSCALL_MAIN_2): Likewise.
(INTERNAL_SYSCALL_MAIN_3): Likewise.
(INTERNAL_SYSCALL_MAIN_4): Likewise.
(INTERNAL_SYSCALL_MAIN_5): Likewise.
(INTERNAL_SYSCALL_MAIN_6): Likewise. Call __libc_do_syscall.
(INTERNAL_SYSCALL): Define to use INTERNAL_SYSCALL_MAIN_##nr.
Replace conditional definitions by conditional definitions of ....
(INTERNAL_SYSCALL_MAIN_INLINE): ... this. New macro.
* sysdeps/unix/sysv/linux/i386/libc-do-syscall.S: New file.
* sysdeps/unix/sysv/linux/i386/Makefile [$(subdir) = nptl]
(libpthread-sysdep_routines): Add libc-do-syscall.
* sysdeps/unix/sysv/linux/i386/lowlevellock-futex.h: Remove file.
* sysdeps/unix/sysv/linux/i386/lowlevellock.h (SYS_futex): Define
to __NR_futex not 240.
Diffstat (limited to 'sysdeps/unix')
-rw-r--r-- | sysdeps/unix/sysv/linux/i386/Makefile | 5 | ||||
-rw-r--r-- | sysdeps/unix/sysv/linux/i386/libc-do-syscall.S | 50 | ||||
-rw-r--r-- | sysdeps/unix/sysv/linux/i386/lowlevellock-futex.h | 137 | ||||
-rw-r--r-- | sysdeps/unix/sysv/linux/i386/lowlevellock.h | 2 | ||||
-rw-r--r-- | sysdeps/unix/sysv/linux/i386/sysdep.h | 65 |
5 files changed, 106 insertions, 153 deletions
diff --git a/sysdeps/unix/sysv/linux/i386/Makefile b/sysdeps/unix/sysv/linux/i386/Makefile index acc3021..d7a59d3 100644 --- a/sysdeps/unix/sysv/linux/i386/Makefile +++ b/sysdeps/unix/sysv/linux/i386/Makefile @@ -14,6 +14,11 @@ ifeq ($(subdir),io) sysdep_routines += call_sync_file_range endif +# libpthread uses six-argument inline syscalls. +ifeq ($(subdir),nptl) +libpthread-sysdep_routines += libc-do-syscall +endif + ifeq ($(subdir),resource) sysdep_routines += oldgetrlimit64 endif diff --git a/sysdeps/unix/sysv/linux/i386/libc-do-syscall.S b/sysdeps/unix/sysv/linux/i386/libc-do-syscall.S new file mode 100644 index 0000000..af5c6f0 --- /dev/null +++ b/sysdeps/unix/sysv/linux/i386/libc-do-syscall.S @@ -0,0 +1,50 @@ +/* Out-of-line syscall stub for six-argument syscalls from C. + 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 <sysdep.h> + +/* %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. */ + + .hidden __libc_do_syscall + +ENTRY (__libc_do_syscall) + pushl %ebx + cfi_adjust_cfa_offset (4) + cfi_rel_offset (ebx, 0) + pushl %edi + cfi_adjust_cfa_offset (4) + cfi_rel_offset (edi, 0) + pushl %ebp + cfi_adjust_cfa_offset (4) + cfi_rel_offset (ebp, 0) + movl 0(%edi), %ebx + movl 8(%edi), %ebp + movl 4(%edi), %edi + ENTER_KERNEL + popl %ebp + cfi_adjust_cfa_offset (-4) + cfi_restore (ebp) + popl %edi + cfi_adjust_cfa_offset (-4) + cfi_restore (edi) + popl %ebx + cfi_adjust_cfa_offset (-4) + cfi_restore (ebx) + ret +END (__libc_do_syscall) diff --git a/sysdeps/unix/sysv/linux/i386/lowlevellock-futex.h b/sysdeps/unix/sysv/linux/i386/lowlevellock-futex.h deleted file mode 100644 index f08b5b8..0000000 --- a/sysdeps/unix/sysv/linux/i386/lowlevellock-futex.h +++ /dev/null @@ -1,137 +0,0 @@ -/* Low-level locking access to futex facilities. Linux/i386 version. - Copyright (C) 2014-2015 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/>. */ - -#ifndef _LOWLEVELLOCK_FUTEX_H -#define _LOWLEVELLOCK_FUTEX_H 1 - -#define FUTEX_WAIT 0 -#define FUTEX_WAKE 1 -#define FUTEX_CMP_REQUEUE 4 -#define FUTEX_WAKE_OP 5 -#define FUTEX_LOCK_PI 6 -#define FUTEX_UNLOCK_PI 7 -#define FUTEX_TRYLOCK_PI 8 -#define FUTEX_WAIT_BITSET 9 -#define FUTEX_WAKE_BITSET 10 -#define FUTEX_WAIT_REQUEUE_PI 11 -#define FUTEX_CMP_REQUEUE_PI 12 -#define FUTEX_PRIVATE_FLAG 128 -#define FUTEX_CLOCK_REALTIME 256 - -#define FUTEX_BITSET_MATCH_ANY 0xffffffff - -#define FUTEX_OP_CLEAR_WAKE_IF_GT_ONE ((4 << 24) | 1) - -/* Values for 'private' parameter of locking macros. Yes, the - definition seems to be backwards. But it is not. The bit will be - reversed before passing to the system call. */ -#define LLL_PRIVATE 0 -#define LLL_SHARED FUTEX_PRIVATE_FLAG - - -#if IS_IN (libc) || IS_IN (rtld) -/* In libc.so or ld.so all futexes are private. */ -# ifdef __ASSUME_PRIVATE_FUTEX -# define __lll_private_flag(fl, private) \ - ((fl) | FUTEX_PRIVATE_FLAG) -# else -# define __lll_private_flag(fl, private) \ - ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex)) -# endif -#else -# ifdef __ASSUME_PRIVATE_FUTEX -# define __lll_private_flag(fl, private) \ - (((fl) | FUTEX_PRIVATE_FLAG) ^ (private)) -# else -# define __lll_private_flag(fl, private) \ - (__builtin_constant_p (private) \ - ? ((private) == 0 \ - ? ((fl) | THREAD_GETMEM (THREAD_SELF, header.private_futex)) \ - : (fl)) \ - : ({ unsigned int __fl = ((private) ^ FUTEX_PRIVATE_FLAG); \ - asm ("andl %%gs:%P1, %0" : "+r" (__fl) \ - : "i" (offsetof (struct pthread, header.private_futex))); \ - __fl | (fl); })) -# endif -#endif - - -#ifndef __ASSEMBLER__ - -/* To avoid naming conflicts with lowlevellock.h, use a different prefix - here. */ -#ifdef PIC -# define LLLF_EBX_LOAD "xchgl %2, %%ebx\n" -# define LLLF_EBX_REG "D" -#else -# define LLLF_EBX_LOAD -# define LLLF_EBX_REG "b" -#endif - -#ifdef I386_USE_SYSENTER -# ifdef SHARED -# define LLLF_ENTER_KERNEL "call *%%gs:%P6\n\t" -# else -# define LLLF_ENTER_KERNEL "call *_dl_sysinfo\n\t" -# endif -#else -# define LLLF_ENTER_KERNEL "int $0x80\n\t" -#endif - - -#define lll_futex_wait(futex, val, private) \ - lll_futex_timed_wait (futex, val, NULL, private) - - -#define lll_futex_timed_wait(futex, val, timeout, private) \ - ({ \ - int __status; \ - register __typeof (val) _val asm ("edx") = (val); \ - __asm __volatile (LLLF_EBX_LOAD \ - LLLF_ENTER_KERNEL \ - LLLF_EBX_LOAD \ - : "=a" (__status) \ - : "0" (SYS_futex), LLLF_EBX_REG (futex), "S" (timeout), \ - "c" (__lll_private_flag (FUTEX_WAIT, private)), \ - "d" (_val), "i" (offsetof (tcbhead_t, sysinfo)) \ - : "memory"); \ - __status; \ - }) - - -#define lll_futex_wake(futex, nr, private) \ - ({ \ - int __status; \ - register __typeof (nr) _nr asm ("edx") = (nr); \ - LIBC_PROBE (lll_futex_wake, 3, futex, nr, private); \ - __asm __volatile (LLLF_EBX_LOAD \ - LLLF_ENTER_KERNEL \ - LLLF_EBX_LOAD \ - : "=a" (__status) \ - : "0" (SYS_futex), LLLF_EBX_REG (futex), \ - "c" (__lll_private_flag (FUTEX_WAKE, private)), \ - "d" (_nr), \ - "i" (0) /* phony, to align next arg's number */, \ - "i" (offsetof (tcbhead_t, sysinfo))); \ - __status; \ - }) - - -#endif /* !__ASSEMBLER__ */ - -#endif /* lowlevellock-futex.h */ diff --git a/sysdeps/unix/sysv/linux/i386/lowlevellock.h b/sysdeps/unix/sysv/linux/i386/lowlevellock.h index 1132124..2bf251f 100644 --- a/sysdeps/unix/sysv/linux/i386/lowlevellock.h +++ b/sysdeps/unix/sysv/linux/i386/lowlevellock.h @@ -48,7 +48,7 @@ #include <lowlevellock-futex.h> /* XXX Remove when no assembler code uses futexes anymore. */ -#define SYS_futex 240 +#define SYS_futex __NR_futex #ifndef __ASSEMBLER__ diff --git a/sysdeps/unix/sysv/linux/i386/sysdep.h b/sysdeps/unix/sysv/linux/i386/sysdep.h index 180f334..7f6fcf3 100644 --- a/sysdeps/unix/sysv/linux/i386/sysdep.h +++ b/sysdeps/unix/sysv/linux/i386/sysdep.h @@ -304,6 +304,17 @@ asm (".L__X'%ebx = 1\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 + restores %ebp itself as a separate stack frame. This structure + stores the arguments not passed in registers; %edi is passed with a + pointer to this structure. */ +struct libc_do_syscall_args +{ + int ebx, edi, ebp; +}; + /* Define a macro which expands inline into the wrapper code for a system call. */ #undef INLINE_SYSCALL @@ -325,11 +336,42 @@ asm (".L__X'%ebx = 1\n\t" The _NCS variant allows non-constant syscall numbers but it is not possible to use more than four parameters. */ #undef INTERNAL_SYSCALL -#ifdef I386_USE_SYSENTER -# ifdef SHARED -# define INTERNAL_SYSCALL(name, err, nr, args...) \ +#define INTERNAL_SYSCALL_MAIN_0(name, err, args...) \ + INTERNAL_SYSCALL_MAIN_INLINE(name, err, 0, args) +#define INTERNAL_SYSCALL_MAIN_1(name, err, args...) \ + INTERNAL_SYSCALL_MAIN_INLINE(name, err, 1, args) +#define INTERNAL_SYSCALL_MAIN_2(name, err, args...) \ + INTERNAL_SYSCALL_MAIN_INLINE(name, err, 2, args) +#define INTERNAL_SYSCALL_MAIN_3(name, err, args...) \ + INTERNAL_SYSCALL_MAIN_INLINE(name, err, 3, args) +#define INTERNAL_SYSCALL_MAIN_4(name, err, args...) \ + INTERNAL_SYSCALL_MAIN_INLINE(name, err, 4, args) +#define INTERNAL_SYSCALL_MAIN_5(name, err, 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) \ + struct libc_do_syscall_args _xv = \ + { \ + (int) (arg1), \ + (int) (arg5), \ + (int) (arg6) \ + }; \ + asm volatile ( \ + "movl %1, %%eax\n\t" \ + "call __libc_do_syscall" \ + : "=a" (resultvar) \ + : "i" (__NR_##name), "c" (arg2), "d" (arg3), "S" (arg4), "D" (&_xv) \ + : "memory", "cc") +#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...) \ EXTRAVAR_##nr \ asm volatile ( \ LOADARGS_##nr \ @@ -338,8 +380,7 @@ asm (".L__X'%ebx = 1\n\t" RESTOREARGS_##nr \ : "=a" (resultvar) \ : "i" (__NR_##name), "i" (offsetof (tcbhead_t, sysinfo)) \ - ASMFMT_##nr(args) : "memory", "cc"); \ - (int) resultvar; }) + ASMFMT_##nr(args) : "memory", "cc") # define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \ ({ \ register unsigned int resultvar; \ @@ -353,9 +394,7 @@ asm (".L__X'%ebx = 1\n\t" ASMFMT_##nr(args) : "memory", "cc"); \ (int) resultvar; }) # else -# define INTERNAL_SYSCALL(name, err, nr, args...) \ - ({ \ - register unsigned int resultvar; \ +# define INTERNAL_SYSCALL_MAIN_INLINE(name, err, nr, args...) \ EXTRAVAR_##nr \ asm volatile ( \ LOADARGS_##nr \ @@ -363,8 +402,7 @@ asm (".L__X'%ebx = 1\n\t" "call *_dl_sysinfo\n\t" \ RESTOREARGS_##nr \ : "=a" (resultvar) \ - : "i" (__NR_##name) ASMFMT_##nr(args) : "memory", "cc"); \ - (int) resultvar; }) + : "i" (__NR_##name) ASMFMT_##nr(args) : "memory", "cc") # define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \ ({ \ register unsigned int resultvar; \ @@ -378,9 +416,7 @@ asm (".L__X'%ebx = 1\n\t" (int) resultvar; }) # endif #else -# define INTERNAL_SYSCALL(name, err, nr, args...) \ - ({ \ - register unsigned int resultvar; \ +# define INTERNAL_SYSCALL_MAIN_INLINE(name, err, nr, args...) \ EXTRAVAR_##nr \ asm volatile ( \ LOADARGS_##nr \ @@ -388,8 +424,7 @@ asm (".L__X'%ebx = 1\n\t" "int $0x80\n\t" \ RESTOREARGS_##nr \ : "=a" (resultvar) \ - : "i" (__NR_##name) ASMFMT_##nr(args) : "memory", "cc"); \ - (int) resultvar; }) + : "i" (__NR_##name) ASMFMT_##nr(args) : "memory", "cc") # define INTERNAL_SYSCALL_NCS(name, err, nr, args...) \ ({ \ register unsigned int resultvar; \ |