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| author | Keith Randall <khr@golang.org> | 2017-02-02 18:50:45 -0800 |
|---|---|---|
| committer | Keith Randall <khr@golang.org> | 2017-02-03 05:08:54 +0000 |
| commit | 69e1634985f8d839f74f342925bd7546faea0a19 (patch) | |
| tree | 31dc8d4d50b6cb1ff9ebfb255de4e2acb0fe7f7d /src/runtime/sys_darwin_amd64.s | |
| parent | 64c5280844aa7d6cbec18c47750f9d3e65f5f72a (diff) | |
| download | go-69e1634985f8d839f74f342925bd7546faea0a19.tar.gz go-69e1634985f8d839f74f342925bd7546faea0a19.zip | |
runtime: darwin/amd64, don't depend on outarg slots being unmodified
sigtramp was calling sigtrampgo and depending on the fact that
the 3rd argument slot will not be modified on return. Our calling
convention doesn't guarantee that. Avoid that assumption.
There's no actual bug here, as sigtrampgo does not in fact modify its
argument slots. But I found this while working on the dead stack slot
clobbering tool. https://go-review.googlesource.com/c/23924/
Change-Id: Ia7e791a2b4c1c74fff24cba8169e7840b4b06ffc
Reviewed-on: https://go-review.googlesource.com/36216
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Diffstat (limited to 'src/runtime/sys_darwin_amd64.s')
| -rw-r--r-- | src/runtime/sys_darwin_amd64.s | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/src/runtime/sys_darwin_amd64.s b/src/runtime/sys_darwin_amd64.s index e68dafe6a6..f94482856c 100644 --- a/src/runtime/sys_darwin_amd64.s +++ b/src/runtime/sys_darwin_amd64.s @@ -252,14 +252,15 @@ TEXT runtime·sigfwd(SB),NOSPLIT,$0-32 POPQ BP RET -TEXT runtime·sigtramp(SB),NOSPLIT,$32 +TEXT runtime·sigtramp(SB),NOSPLIT,$40 MOVL SI, 24(SP) // save infostyle for sigreturn below + MOVQ R8, 32(SP) // save ctx MOVL DX, 0(SP) // sig MOVQ CX, 8(SP) // info MOVQ R8, 16(SP) // ctx MOVQ $runtime·sigtrampgo(SB), AX CALL AX - MOVQ 16(SP), DI // ctx + MOVQ 32(SP), DI // ctx MOVL 24(SP), SI // infostyle MOVL $(0x2000000+184), AX SYSCALL |