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author | H.J. Lu <hjl.tools@gmail.com> | 2015-12-16 06:50:42 -0800 |
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committer | H.J. Lu <hjl.tools@gmail.com> | 2015-12-16 06:50:42 -0800 |
commit | bf0e161423748feb7950110d6074ebbcd102cb7e (patch) | |
tree | 2ea352f400a4e4da763965639fc6550c84768db6 /stdlib/srand48.c | |
parent | 4c0dfefbdf950080746e48f6f95f449922bb5d0c (diff) | |
download | glibc-hjl/pr19371/master.tar.gz glibc-hjl/pr19371/master.tar.xz glibc-hjl/pr19371/master.zip |
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 'stdlib/srand48.c')
0 files changed, 0 insertions, 0 deletions