glibc/sysdeps/unix/sysv/linux/i386/libc-do-syscall.S

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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.
2015-03-25 15:17:54 +00:00
/* 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)