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author | Carlos O'Donell <carlos@systemhalted.org> | 2015-01-21 00:46:16 -0500 |
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committer | Carlos O'Donell <carlos@systemhalted.org> | 2015-01-21 00:46:16 -0500 |
commit | 042e1521c794a945edc43b5bfa7e69ad70420524 (patch) | |
tree | 74f44d4b065d801cfe6ace654827ca8ef351bff8 /sysdeps/unix/sysv/linux/i386/i486/sem_wait.S | |
parent | a8db092ec0c6742a9d41e1715946e90d4edfeec1 (diff) | |
download | glibc-042e1521c794a945edc43b5bfa7e69ad70420524.tar.gz glibc-042e1521c794a945edc43b5bfa7e69ad70420524.tar.xz glibc-042e1521c794a945edc43b5bfa7e69ad70420524.zip |
Fix semaphore destruction (bug 12674).
This commit fixes semaphore destruction by either using 64b atomic operations (where available), or by using two separate fields when only 32b atomic operations are available. In the latter case, we keep a conservative estimate of whether there are any waiting threads in one bit of the field that counts the number of available tokens, thus allowing sem_post to atomically both add a token and determine whether it needs to call futex_wake. See: https://sourceware.org/ml/libc-alpha/2014-12/msg00155.html
Diffstat (limited to 'sysdeps/unix/sysv/linux/i386/i486/sem_wait.S')
-rw-r--r-- | sysdeps/unix/sysv/linux/i386/i486/sem_wait.S | 343 |
1 files changed, 0 insertions, 343 deletions
diff --git a/sysdeps/unix/sysv/linux/i386/i486/sem_wait.S b/sysdeps/unix/sysv/linux/i386/i486/sem_wait.S deleted file mode 100644 index 9121041ecc..0000000000 --- a/sysdeps/unix/sysv/linux/i386/i486/sem_wait.S +++ /dev/null @@ -1,343 +0,0 @@ -/* Copyright (C) 2002-2015 Free Software Foundation, Inc. - This file is part of the GNU C Library. - Contributed by Ulrich Drepper <drepper@redhat.com>, 2002. - - 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> -#include <shlib-compat.h> -#include <pthread-errnos.h> -#include <structsem.h> -#include <lowlevellock.h> - - -#if VALUE != 0 -# error "code needs to be rewritten for VALUE != 0" -#endif - - .text - - .globl __new_sem_wait - .type __new_sem_wait,@function - .align 16 -__new_sem_wait: -.LSTARTCODE: - pushl %ebx -.Lpush_ebx: - pushl %esi -.Lpush_esi: - subl $4, %esp -.Lsub_esp: - - movl 16(%esp), %ebx - - movl (%ebx), %eax -2: testl %eax, %eax - je 1f - - leal -1(%eax), %edx - LOCK - cmpxchgl %edx, (%ebx) - jne 2b -7: xorl %eax, %eax - -9: movl 4(%esp), %esi - movl 8(%esp), %ebx - addl $12, %esp -.Ladd_esp: - ret - -.Lafter_ret: -1: LOCK - incl NWAITERS(%ebx) - -.LcleanupSTART: -6: call __pthread_enable_asynccancel - movl %eax, (%esp) - -#if FUTEX_WAIT == 0 - movl PRIVATE(%ebx), %ecx -#else - movl $FUTEX_WAIT, %ecx - orl PRIVATE(%ebx), %ecx -#endif - xorl %esi, %esi - xorl %edx, %edx - movl $SYS_futex, %eax - ENTER_KERNEL - movl %eax, %esi - - movl (%esp), %eax - call __pthread_disable_asynccancel -.LcleanupEND: - - testl %esi, %esi - je 3f - cmpl $-EWOULDBLOCK, %esi - jne 4f - -3: - movl (%ebx), %eax -5: testl %eax, %eax - je 6b - - leal -1(%eax), %edx - LOCK - cmpxchgl %edx, (%ebx) - jne 5b - - LOCK - decl NWAITERS(%ebx) - jmp 7b - -4: LOCK - decl NWAITERS(%ebx) - - negl %esi -#ifdef PIC - SETUP_PIC_REG(bx) -#else - movl $8f, %ebx -8: -#endif - addl $_GLOBAL_OFFSET_TABLE_, %ebx -#ifdef NO_TLS_DIRECT_SEG_REFS - movl errno@gotntpoff(%ebx), %edx - addl %gs:0, %edx - movl %esi, (%edx) -#else - movl errno@gotntpoff(%ebx), %edx - movl %esi, %gs:(%edx) -#endif - orl $-1, %eax - - jmp 9b - .size __new_sem_wait,.-__new_sem_wait - versioned_symbol(libpthread, __new_sem_wait, sem_wait, GLIBC_2_1) - - - .type sem_wait_cleanup,@function -sem_wait_cleanup: - LOCK - decl NWAITERS(%ebx) - movl %eax, (%esp) -.LcallUR: - call _Unwind_Resume@PLT - hlt -.LENDCODE: - .size sem_wait_cleanup,.-sem_wait_cleanup - - - .section .gcc_except_table,"a",@progbits -.LexceptSTART: - .byte 0xff # @LPStart format (omit) - .byte 0xff # @TType format (omit) - .byte 0x01 # call-site format - # DW_EH_PE_uleb128 - .uleb128 .Lcstend-.Lcstbegin -.Lcstbegin: - .uleb128 .LcleanupSTART-.LSTARTCODE - .uleb128 .LcleanupEND-.LcleanupSTART - .uleb128 sem_wait_cleanup-.LSTARTCODE - .uleb128 0 - .uleb128 .LcallUR-.LSTARTCODE - .uleb128 .LENDCODE-.LcallUR - .uleb128 0 - .uleb128 0 -.Lcstend: - - - .section .eh_frame,"a",@progbits -.LSTARTFRAME: - .long .LENDCIE-.LSTARTCIE # Length of the CIE. -.LSTARTCIE: - .long 0 # CIE ID. - .byte 1 # Version number. -#ifdef SHARED - .string "zPLR" # NUL-terminated augmentation - # string. -#else - .string "zPL" # NUL-terminated augmentation - # string. -#endif - .uleb128 1 # Code alignment factor. - .sleb128 -4 # Data alignment factor. - .byte 8 # Return address register - # column. -#ifdef SHARED - .uleb128 7 # Augmentation value length. - .byte 0x9b # Personality: DW_EH_PE_pcrel - # + DW_EH_PE_sdata4 - # + DW_EH_PE_indirect - .long DW.ref.__gcc_personality_v0-. - .byte 0x1b # LSDA Encoding: DW_EH_PE_pcrel - # + DW_EH_PE_sdata4. - .byte 0x1b # FDE Encoding: DW_EH_PE_pcrel - # + DW_EH_PE_sdata4. -#else - .uleb128 6 # Augmentation value length. - .byte 0x0 # Personality: absolute - .long __gcc_personality_v0 - .byte 0x0 # LSDA Encoding: absolute -#endif - .byte 0x0c # DW_CFA_def_cfa - .uleb128 4 - .uleb128 4 - .byte 0x88 # DW_CFA_offset, column 0x10 - .uleb128 1 - .align 4 -.LENDCIE: - - .long .LENDFDE-.LSTARTFDE # Length of the FDE. -.LSTARTFDE: - .long .LSTARTFDE-.LSTARTFRAME # CIE pointer. -#ifdef SHARED - .long .LSTARTCODE-. # PC-relative start address - # of the code. -#else - .long .LSTARTCODE # Start address of the code. -#endif - .long .LENDCODE-.LSTARTCODE # Length of the code. - .uleb128 4 # Augmentation size -#ifdef SHARED - .long .LexceptSTART-. -#else - .long .LexceptSTART -#endif - - .byte 4 # DW_CFA_advance_loc4 - .long .Lpush_ebx-.LSTARTCODE - .byte 14 # DW_CFA_def_cfa_offset - .uleb128 8 - .byte 0x83 # DW_CFA_offset %ebx - .uleb128 2 - .byte 4 # DW_CFA_advance_loc4 - .long .Lpush_esi-.Lpush_ebx - .byte 14 # DW_CFA_def_cfa_offset - .uleb128 12 - .byte 0x86 # DW_CFA_offset %esi - .uleb128 3 - .byte 4 # DW_CFA_advance_loc4 - .long .Lsub_esp-.Lpush_esi - .byte 14 # DW_CFA_def_cfa_offset - .uleb128 16 - .byte 4 # DW_CFA_advance_loc4 - .long .Ladd_esp-.Lsub_esp - .byte 14 # DW_CFA_def_cfa_offset - .uleb128 4 - .byte 0xc3 # DW_CFA_restore %ebx - .byte 0xc6 # DW_CFA_restore %esi - .byte 4 # DW_CFA_advance_loc4 - .long .Lafter_ret-.Ladd_esp - .byte 14 # DW_CFA_def_cfa_offset - .uleb128 16 - .byte 0x83 # DW_CFA_offset %ebx - .uleb128 2 - .byte 0x86 # DW_CFA_offset %esi - .uleb128 3 - .align 4 -.LENDFDE: - - -#ifdef SHARED - .hidden DW.ref.__gcc_personality_v0 - .weak DW.ref.__gcc_personality_v0 - .section .gnu.linkonce.d.DW.ref.__gcc_personality_v0,"aw",@progbits - .align 4 - .type DW.ref.__gcc_personality_v0, @object - .size DW.ref.__gcc_personality_v0, 4 -DW.ref.__gcc_personality_v0: - .long __gcc_personality_v0 -#endif - - -#if SHLIB_COMPAT(libpthread, GLIBC_2_0, GLIBC_2_1) - .section ".text.compat", "ax" - .global __old_sem_wait - .type __old_sem_wait,@function - .align 16 - cfi_startproc -__old_sem_wait: - pushl %ebx - cfi_adjust_cfa_offset(4) - pushl %esi - cfi_adjust_cfa_offset(4) - subl $4, %esp - cfi_adjust_cfa_offset(4) - - movl 16(%esp), %ebx - cfi_offset(ebx, -8) - - cfi_offset(esi, -12) -3: movl (%ebx), %eax -2: testl %eax, %eax - je 1f - - leal -1(%eax), %edx - LOCK - cmpxchgl %edx, (%ebx) - jne 2b - xorl %eax, %eax - -5: movl 4(%esp), %esi - movl 8(%esp), %ebx - addl $12, %esp - cfi_restore(ebx) - cfi_restore(esi) - cfi_adjust_cfa_offset(-12) - ret - - cfi_adjust_cfa_offset(12) - cfi_offset(ebx, -8) - cfi_offset(esi, -12) -1: call __pthread_enable_asynccancel - movl %eax, (%esp) - - xorl %esi, %esi - movl $SYS_futex, %eax - movl %esi, %ecx - movl %esi, %edx - ENTER_KERNEL - movl %eax, %esi - - movl (%esp), %eax - call __pthread_disable_asynccancel - - testl %esi, %esi - je 3b - cmpl $-EWOULDBLOCK, %esi - je 3b - negl %esi -#ifdef PIC - SETUP_PIC_REG(bx) -#else - movl $4f, %ebx -4: -#endif - addl $_GLOBAL_OFFSET_TABLE_, %ebx -#ifdef NO_TLS_DIRECT_SEG_REFS - movl errno@gotntpoff(%ebx), %edx - addl %gs:0, %edx - movl %esi, (%edx) -#else - movl errno@gotntpoff(%ebx), %edx - movl %esi, %gs:(%edx) -#endif - orl $-1, %eax - jmp 5b - cfi_endproc - .size __old_sem_wait,.-__old_sem_wait - compat_symbol(libpthread, __old_sem_wait, sem_wait, GLIBC_2_0) -#endif |