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[BZ #5807]
2009-03-15 Ulrich Drepper <drepper@redhat.com> [BZ #5807] * string/strlen.c (strlen): Fix omission in the expression to test for NUL bytes.
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Ulrich Drepper
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fad070abc4
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71a5bd3e17
@ -1,3 +1,9 @@
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2009-03-15 Ulrich Drepper <drepper@redhat.com>
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[BZ #5807]
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* string/strlen.c (strlen): Fix omission in the expression to test
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for NUL bytes.
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2009-03-14 Ulrich Drepper <drepper@redhat.com>
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* crypt/sha256test.c (main): Perform 100,000 'a' test in a second way.
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@ -1,3 +1,9 @@
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2009-03-15 Ulrich Drepper <drepper@redhat.com>
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* sysdeps/unix/sysv/linux/x86_64/pthread_cond_timedwait.S
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(__pthread_cond_timedwait): Change to use cfi directives instead of
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hand-coded unwind sections.
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2009-03-10 Ulrich Drepper <drepper@redhat.com>
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* init.c (nptl_freeres): Compile only for SHARED.
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@ -1,4 +1,4 @@
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/* Copyright (C) 2002, 2003, 2004, 2005, 2007 Free Software Foundation, Inc.
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/* Copyright (C) 2002-2005, 2007, 2009 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
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@ -37,16 +37,19 @@
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.type __pthread_cond_timedwait, @function
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.align 16
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__pthread_cond_timedwait:
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.LSTARTCODE:
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cfi_startproc
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pushq %r12
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.Lpush_r12:
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cfi_adjust_cfa_offset(8)
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cfi_rel_offset(%r12, 0)
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pushq %r13
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.Lpush_r13:
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cfi_adjust_cfa_offset(8)
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cfi_rel_offset(%r13, 0)
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pushq %r14
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.Lpush_r14:
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cfi_adjust_cfa_offset(8)
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cfi_rel_offset(%r14, 0)
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#define FRAME_SIZE 80
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subq $FRAME_SIZE, %rsp
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.Lsubq:
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cfi_adjust_cfa_offset(FRAME_SIZE)
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cmpq $1000000000, 8(%rdx)
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movl $EINVAL, %eax
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@ -305,19 +308,25 @@ __pthread_cond_timedwait:
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cmoveq %r14, %rax
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18: addq $FRAME_SIZE, %rsp
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.Laddq:
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cfi_adjust_cfa_offset(-FRAME_SIZE)
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popq %r14
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.Lpop_r14:
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cfi_adjust_cfa_offset(-8)
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cfi_restore(%r14)
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popq %r13
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.Lpop_r13:
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cfi_adjust_cfa_offset(-8)
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cfi_restore(%r13)
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popq %r12
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.Lpop_r12:
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cfi_adjust_cfa_offset(-8)
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cfi_restore(%r12)
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retq
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/* Initial locking failed. */
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1:
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.LSbl1:
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cfi_adjust_cfa_offset(3 * 8 + FRAME_SIZE)
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cfi_rel_offset(%r12, FRAME_SIZE + 16)
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cfi_rel_offset(%r13, FRAME_SIZE + 8)
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cfi_rel_offset(%r14, FRAME_SIZE)
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#if cond_lock != 0
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addq $cond_lock, %rdi
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#endif
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@ -414,97 +423,7 @@ __pthread_cond_timedwait:
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js 6b
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jmp 21b
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#endif
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.LENDCODE:
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cfi_endproc
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.size __pthread_cond_timedwait, .-__pthread_cond_timedwait
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versioned_symbol (libpthread, __pthread_cond_timedwait, pthread_cond_timedwait,
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GLIBC_2_3_2)
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.section .eh_frame,"a",@progbits
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.LSTARTFRAME:
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.long L(ENDCIE)-L(STARTCIE) # Length of the CIE.
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.LSTARTCIE:
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.long 0 # CIE ID.
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.byte 1 # Version number.
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#ifdef SHARED
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.string "zR" # NUL-terminated augmentation
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# string.
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#else
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.ascii "\0" # NUL-terminated augmentation
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# string.
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#endif
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.uleb128 1 # Code alignment factor.
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.sleb128 -8 # Data alignment factor.
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.byte 16 # Return address register
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# column.
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#ifdef SHARED
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.uleb128 1 # Augmentation value length.
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.byte 0x1b # Encoding: DW_EH_PE_pcrel
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# + DW_EH_PE_sdata4.
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#endif
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.byte 0x0c # DW_CFA_def_cfa
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.uleb128 7
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.uleb128 8
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.byte 0x90 # DW_CFA_offset, column 0x8
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.uleb128 1
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.align 8
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.LENDCIE:
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.long .LENDFDE-.LSTARTFDE # Length of the FDE.
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.LSTARTFDE:
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.long .LSTARTFDE-.LSTARTFRAME # CIE pointer.
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#ifdef SHARED
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.long .LSTARTCODE-. # PC-relative start address
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# of the code
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#else
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.long .LSTARTCODE # Start address of the code.
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#endif
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.long .LENDCODE-.LSTARTCODE # Length of the code.
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#ifdef SHARED
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.uleb128 0 # No augmentation data.
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#endif
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.byte 0x40+.Lpush_r12-.LSTARTCODE # DW_CFA_advance_loc+N
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.byte 14 # DW_CFA_def_cfa_offset
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.uleb128 16
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.byte 0x8c # DW_CFA_offset %r12
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.uleb128 2
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.byte 0x40+.Lpush_r13-.Lpush_r12 # DW_CFA_advance_loc+N
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.byte 14 # DW_CFA_def_cfa_offset
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.uleb128 24
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.byte 0x8d # DW_CFA_offset %r13
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.uleb128 3
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.byte 0x40+.Lpush_r14-.Lpush_r13 # DW_CFA_advance_loc+N
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.byte 14 # DW_CFA_def_cfa_offset
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.uleb128 32
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.byte 0x84 # DW_CFA_offset %r14
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.uleb128 4
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.byte 0x40+.Lsubq-.Lpush_r14 # DW_CFA_advance_loc+N
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.byte 14 # DW_CFA_def_cfa_offset
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.uleb128 32+FRAME_SIZE
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.byte 3 # DW_CFA_advance_loc2
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.2byte .Laddq-.Lsubq
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.byte 14 # DW_CFA_def_cfa_offset
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.uleb128 32
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.byte 0x40+.Lpop_r14-.Laddq # DW_CFA_advance_loc+N
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.byte 14 # DW_CFA_def_cfa_offset
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.uleb128 24
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.byte 0xce # DW_CFA_restore %r14
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.byte 0x40+.Lpop_r13-.Lpop_r14 # DW_CFA_advance_loc+N
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.byte 14 # DW_CFA_def_cfa_offset
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.uleb128 16
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.byte 0xcd # DW_CFA_restore %r13
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.byte 0x40+.Lpop_r12-.Lpop_r13 # DW_CFA_advance_loc+N
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.byte 14 # DW_CFA_def_cfa_offset
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.uleb128 8
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.byte 0xcc # DW_CFA_restore %r12
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.byte 0x40+.LSbl1-.Lpop_r12 # DW_CFA_advance_loc+N
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.byte 14 # DW_CFA_def_cfa_offset
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.uleb128 32+FRAME_SIZE
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.byte 0x8c # DW_CFA_offset %r12
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.uleb128 2
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.byte 0x8d # DW_CFA_offset %r13
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.uleb128 3
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.byte 0x84 # DW_CFA_offset %r14
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.uleb128 4
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.align 8
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.LENDFDE:
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@ -1,4 +1,4 @@
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/* Copyright (C) 1991, 1993, 1997, 2000, 2003 Free Software Foundation, Inc.
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/* Copyright (C) 1991,1993,1997,2000,2003,2009 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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Written by Torbjorn Granlund (tege@sics.se),
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with help from Dan Sahlin (dan@sics.se);
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@ -32,7 +32,7 @@ strlen (str)
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{
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const char *char_ptr;
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const unsigned long int *longword_ptr;
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unsigned long int longword, magic_bits, himagic, lomagic;
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unsigned long int longword, himagic, lomagic;
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/* Handle the first few characters by reading one character at a time.
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Do this until CHAR_PTR is aligned on a longword boundary. */
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@ -56,14 +56,12 @@ strlen (str)
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The 1-bits make sure that carries propagate to the next 0-bit.
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The 0-bits provide holes for carries to fall into. */
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magic_bits = 0x7efefeffL;
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himagic = 0x80808080L;
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lomagic = 0x01010101L;
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if (sizeof (longword) > 4)
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{
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/* 64-bit version of the magic. */
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/* Do the shift in two steps to avoid a warning if long has 32 bits. */
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magic_bits = ((0x7efefefeL << 16) << 16) | 0xfefefeffL;
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himagic = ((himagic << 16) << 16) | himagic;
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lomagic = ((lomagic << 16) << 16) | lomagic;
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}
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@ -75,53 +73,9 @@ strlen (str)
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if *any of the four* bytes in the longword in question are zero. */
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for (;;)
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{
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/* We tentatively exit the loop if adding MAGIC_BITS to
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LONGWORD fails to change any of the hole bits of LONGWORD.
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1) Is this safe? Will it catch all the zero bytes?
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Suppose there is a byte with all zeros. Any carry bits
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propagating from its left will fall into the hole at its
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least significant bit and stop. Since there will be no
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carry from its most significant bit, the LSB of the
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byte to the left will be unchanged, and the zero will be
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detected.
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2) Is this worthwhile? Will it ignore everything except
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zero bytes? Suppose every byte of LONGWORD has a bit set
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somewhere. There will be a carry into bit 8. If bit 8
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is set, this will carry into bit 16. If bit 8 is clear,
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one of bits 9-15 must be set, so there will be a carry
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into bit 16. Similarly, there will be a carry into bit
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24. If one of bits 24-30 is set, there will be a carry
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into bit 31, so all of the hole bits will be changed.
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The one misfire occurs when bits 24-30 are clear and bit
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31 is set; in this case, the hole at bit 31 is not
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changed. If we had access to the processor carry flag,
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we could close this loophole by putting the fourth hole
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at bit 32!
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So it ignores everything except 128's, when they're aligned
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properly. */
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longword = *longword_ptr++;
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if (
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#if 0
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/* Add MAGIC_BITS to LONGWORD. */
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(((longword + magic_bits)
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/* Set those bits that were unchanged by the addition. */
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^ ~longword)
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/* Look at only the hole bits. If any of the hole bits
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are unchanged, most likely one of the bytes was a
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zero. */
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& ~magic_bits)
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#else
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((longword - lomagic) & himagic)
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#endif
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!= 0)
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if (((longword - lomagic) & ~longword & himagic) != 0)
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{
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/* Which of the bytes was the zero? If none of them were, it was
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a misfire; continue the search. */
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