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authorH.J. Lu <hjl.tools@gmail.com>2015-12-16 06:50:42 -0800
committerH.J. Lu <hjl.tools@gmail.com>2015-12-16 06:50:42 -0800
commitbf0e161423748feb7950110d6074ebbcd102cb7e (patch)
tree2ea352f400a4e4da763965639fc6550c84768db6 /wctype
parent4c0dfefbdf950080746e48f6f95f449922bb5d0c (diff)
downloadglibc-hjl/pr19371/master.tar.gz
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Properly handle x32 syscall hjl/pr19371/master
X32 syscall() may return 64-bit integer as lseek, time and times.  Its
return type should be __syscall_slong_t instead of long int.  We need
to properly return 64-bit error value.

Before the patch:

Dump of assembler code for function syscall:
   0x000dab20 <+0>:	mov    %rdi,%rax
   0x000dab23 <+3>:	mov    %rsi,%rdi
   0x000dab26 <+6>:	mov    %rdx,%rsi
   0x000dab29 <+9>:	mov    %rcx,%rdx
   0x000dab2c <+12>:	mov    %r8,%r10
   0x000dab2f <+15>:	mov    %r9,%r8
   0x000dab32 <+18>:	mov    0x8(%rsp),%r9
   0x000dab37 <+23>:	syscall
   0x000dab39 <+25>:	cmp    $0xfffffffffffff001,%rax
   0x000dab3f <+31>:	jae    0xdab42 <syscall+34>
   0x000dab41 <+33>:	retq
   0x000dab42 <+34>:	mov    0x2b3367(%rip),%rcx        # 0x38deb0
   0x000dab49 <+41>:	neg    %eax
   0x000dab4b <+43>:	mov    %eax,%fs:(%rcx)
   0x000dab4e <+46>:	or     $0xffffffff,%eax
                        ^^^^^^^^^^^^^^^^^^ This is 32-bit error return.
   0x000dab51 <+49>:	retq
End of assembler dump.

After the patch:

Dump of assembler code for function syscall:
   0x000daaf0 <+0>:	mov    %rdi,%rax
   0x000daaf3 <+3>:	mov    %rsi,%rdi
   0x000daaf6 <+6>:	mov    %rdx,%rsi
   0x000daaf9 <+9>:	mov    %rcx,%rdx
   0x000daafc <+12>:	mov    %r8,%r10
   0x000daaff <+15>:	mov    %r9,%r8
   0x000dab02 <+18>:	mov    0x8(%rsp),%r9
   0x000dab07 <+23>:	syscall
   0x000dab09 <+25>:	cmp    $0xfffffffffffff001,%rax
   0x000dab0f <+31>:	jae    0xdab12 <syscall+34>
   0x000dab11 <+33>:	retq
   0x000dab12 <+34>:	mov    0x2b3397(%rip),%rcx        # 0x38deb0
   0x000dab19 <+41>:	neg    %eax
   0x000dab1b <+43>:	mov    %eax,%fs:(%rcx)
   0x000dab1e <+46>:	or     $0xffffffffffffffff,%rax
   0x000dab22 <+50>:	retq
End of assembler dump.

	[BZ #19371]
	* posix/unistd.h (syscall): Use __syscall_slong_t for return
	type.
	* sysdeps/unix/sysv/linux/x86_64/x32/syscall.S: New file.
Diffstat (limited to 'wctype')
0 files changed, 0 insertions, 0 deletions