Elliott Hughes 011e111d29 Ensure __set_errno is still visible on LP32.
The use of the .hidden directive to avoid going via the PLT for
__set_errno had the side-effect of actually making __set_errno
hidden (which is odd because assembler directives don't usually
affect symbols defined in a different file --- you can't even
create a weak reference to a symbol that's defined in a different
file).

This change switches the system call stubs over to a new always-hidden
__set_errno_internal and has a visible __set_errno on LP32 just for
binary compatibility with old NDK apps.

(cherry-pick of 7efad83d430f4d824f2aaa75edea5106f6ff8aae.)

Bug: 17423135
Change-Id: I6b6d7a05dda85f923d22e5ffd169a91e23499b7b
2014-09-08 16:46:50 -07:00

51 lines
1.1 KiB
ArmAsm

/*
* Generic syscall call.
* Upon entry:
* %eax: system call number - caller save
* %ebx: arg0 to system call - callee save
* %ecx: arg1 - caller save
* %edx: arg2 - caller save
* %esi: arg3 - callee save
* %edi: arg4 - callee save
* %ebp: arg5 - callee save
*/
#include <private/bionic_asm.h>
ENTRY(syscall)
# Push the callee save registers.
push %ebx
push %esi
push %edi
push %ebp
# Load all the arguments from the calling frame.
# (Not all will be valid, depending on the syscall.)
mov 20(%esp),%eax
mov 24(%esp),%ebx
mov 28(%esp),%ecx
mov 32(%esp),%edx
mov 36(%esp),%esi
mov 40(%esp),%edi
mov 44(%esp),%ebp
# Make the system call.
int $0x80
# Error?
cmpl $-MAX_ERRNO, %eax
jb 1f
# Yes, so set errno.
negl %eax
pushl %eax
call __set_errno_internal
addl $4, %esp
1:
# Restore the callee save registers.
pop %ebp
pop %edi
pop %esi
pop %ebx
ret
END(syscall)