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| author | Michael Hudson-Doyle <michael.hudson@canonical.com> | 2015-11-17 20:00:20 +1300 |
|---|---|---|
| committer | Michael Hudson-Doyle <michael.hudson@canonical.com> | 2015-11-17 20:22:47 +0000 |
| commit | 90e26f52c6d2012d293ebfe8d272f03462213045 (patch) | |
| tree | 26b7e5bdb7f0a84e20d48cfa4d8b2430a016f821 /src/syscall | |
| parent | f4a9bd87ba84ce900dd2ba97974c48a0f4a01047 (diff) | |
| download | go-git-90e26f52c6d2012d293ebfe8d272f03462213045.tar.gz | |
runtime, syscall: use int $0x80 to invoke syscalls on android/386
golang.org/cl/16796 broke android/386 by assuming behaviour specific to glibc's
dynamic linker. Copy bionic by using int $0x80 to invoke syscalls on
android/386 as the old alternative (CALL *runtime_vdso(SB)) cannot be compiled
without text relocations, which we want to get rid of on android.
Also remove "CALL *runtime_vdso(SB)" variant from the syscall package.
Change-Id: I6c01849f8dcbd073d000ddc8f13948a836b8b261
Reviewed-on: https://go-review.googlesource.com/16996
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Reviewed-by: Hyang-Ah Hana Kim <hyangah@gmail.com>
Diffstat (limited to 'src/syscall')
| -rw-r--r-- | src/syscall/asm_linux_386.s | 27 |
1 files changed, 20 insertions, 7 deletions
diff --git a/src/syscall/asm_linux_386.s b/src/syscall/asm_linux_386.s index ec7487b4b9..c94060571b 100644 --- a/src/syscall/asm_linux_386.s +++ b/src/syscall/asm_linux_386.s @@ -12,6 +12,19 @@ // func Syscall(trap uintptr, a1, a2, a3 uintptr) (r1, r2, err uintptr); // Trap # in AX, args in BX CX DX SI DI, return in AX +// Most linux systems use glibc's dynamic linker, which puts the +// __kernel_vsyscall vdso helper at 0x10(GS) for easy access from position +// independent code and setldt in runtime does the same in the statically +// linked case. Android, however, uses bionic's dynamic linker, which does not +// save the helper anywhere, and so the only way to invoke a syscall from +// position independent code is boring old int $0x80 (which is also what +// bionic's syscall wrappers use). +#ifdef GOOS_android +#define INVOKE_SYSCALL INT $0x80 +#else +#define INVOKE_SYSCALL CALL 0x10(GS) +#endif + TEXT ·Syscall(SB),NOSPLIT,$0-28 CALL runtime·entersyscall(SB) MOVL trap+0(FP), AX // syscall entry @@ -20,7 +33,7 @@ TEXT ·Syscall(SB),NOSPLIT,$0-28 MOVL a3+12(FP), DX MOVL $0, SI MOVL $0, DI - CALL *runtime·_vdso(SB) + INVOKE_SYSCALL CMPL AX, $0xfffff001 JLS ok MOVL $-1, r1+16(FP) @@ -46,7 +59,7 @@ TEXT ·Syscall6(SB),NOSPLIT,$0-40 MOVL a4+16(FP), SI MOVL a5+20(FP), DI MOVL a6+24(FP), BP - CALL *runtime·_vdso(SB) + INVOKE_SYSCALL CMPL AX, $0xfffff001 JLS ok6 MOVL $-1, r1+28(FP) @@ -70,7 +83,7 @@ TEXT ·RawSyscall(SB),NOSPLIT,$0-28 MOVL a3+12(FP), DX MOVL $0, SI MOVL $0, DI - CALL *runtime·_vdso(SB) + INVOKE_SYSCALL CMPL AX, $0xfffff001 JLS ok1 MOVL $-1, r1+16(FP) @@ -93,7 +106,7 @@ TEXT ·RawSyscall6(SB),NOSPLIT,$0-40 MOVL a4+16(FP), SI MOVL a5+20(FP), DI MOVL a6+24(FP), BP - CALL *runtime·_vdso(SB) + INVOKE_SYSCALL CMPL AX, $0xfffff001 JLS ok2 MOVL $-1, r1+28(FP) @@ -119,7 +132,7 @@ TEXT ·socketcall(SB),NOSPLIT,$0-36 MOVL $0, DX MOVL $0, SI MOVL $0, DI - CALL *runtime·_vdso(SB) + INVOKE_SYSCALL CMPL AX, $0xfffff001 JLS oksock MOVL $-1, n+28(FP) @@ -142,7 +155,7 @@ TEXT ·rawsocketcall(SB),NOSPLIT,$0-36 MOVL $0, DX MOVL $0, SI MOVL $0, DI - CALL *runtime·_vdso(SB) + INVOKE_SYSCALL CMPL AX, $0xfffff001 JLS oksock1 MOVL $-1, n+28(FP) @@ -168,7 +181,7 @@ TEXT ·seek(SB),NOSPLIT,$0-28 MOVL offset_lo+4(FP), DX LEAL newoffset_lo+16(FP), SI // result pointer MOVL whence+12(FP), DI - CALL *runtime·_vdso(SB) + INVOKE_SYSCALL CMPL AX, $0xfffff001 JLS okseek MOVL $-1, newoffset_lo+16(FP) |