diff options
| author | Russ Cox <rsc@golang.org> | 2014-06-12 16:34:54 -0400 |
|---|---|---|
| committer | Russ Cox <rsc@golang.org> | 2014-06-12 16:34:54 -0400 |
| commit | 9e0b48ce682f99edbddb5421518c68ec6b918bb7 (patch) | |
| tree | 1a44893a143e4869e572a0f4b84611c77cb458c0 /src/pkg/runtime/asm_arm.s | |
| parent | 9cd9737190e90ac51bd82311de18c49bcfad6f24 (diff) | |
| download | go-9e0b48ce682f99edbddb5421518c68ec6b918bb7.tar.gz | |
runtime: do not trace past jmpdefer during pprof traceback on arm
jmpdefer modifies PC, SP, and LR, and not atomically,
so walking past jmpdefer will often end up in a state
where the three are not a consistent execution snapshot.
This was causing warning messages a few frames later
when the traceback realized it was confused, but given
the right memory it could easily crash instead.
Update issue 8153
LGTM=minux, iant
R=golang-codereviews, minux, iant
CC=golang-codereviews, r
https://codereview.appspot.com/107970043
Diffstat (limited to 'src/pkg/runtime/asm_arm.s')
| -rw-r--r-- | src/pkg/runtime/asm_arm.s | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/src/pkg/runtime/asm_arm.s b/src/pkg/runtime/asm_arm.s index 024649be0..1aea9036a 100644 --- a/src/pkg/runtime/asm_arm.s +++ b/src/pkg/runtime/asm_arm.s @@ -394,6 +394,10 @@ TEXT runtime·lessstack(SB), NOSPLIT, $-4-0 // 1. grab stored LR for caller // 2. sub 4 bytes to get back to BL deferreturn // 3. B to fn +// TODO(rsc): Push things on stack and then use pop +// to load all registers simultaneously, so that a profiling +// interrupt can never see mismatched SP/LR/PC. +// (And double-check that pop is atomic in that way.) TEXT runtime·jmpdefer(SB), NOSPLIT, $0-8 MOVW 0(SP), LR MOVW $-4(LR), LR // BL deferreturn |