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| author | Austin Clements <austin@google.com> | 2017-11-22 21:58:57 -0500 |
|---|---|---|
| committer | Austin Clements <austin@google.com> | 2017-11-23 03:05:56 +0000 |
| commit | 294963fb7f8983c7f5560dc20ab75c869f30da14 (patch) | |
| tree | cf8a809df4ce8d0a5a3b34c07456d15a83365999 /src/runtime/signal_unix.go | |
| parent | b6cf58d5b82898a2c92d50aead07163d5bc3c184 (diff) | |
| download | go-294963fb7f8983c7f5560dc20ab75c869f30da14.tar.gz go-294963fb7f8983c7f5560dc20ab75c869f30da14.zip | |
runtime: document sigtrampgo better
Add an explanation of why sigtrampgo is nosplit.
Updates #21314.
Change-Id: I3f5909d2b2c180f9fa74d53df13e501826fd4316
Reviewed-on: https://go-review.googlesource.com/79615
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Diffstat (limited to 'src/runtime/signal_unix.go')
| -rw-r--r-- | src/runtime/signal_unix.go | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/src/runtime/signal_unix.go b/src/runtime/signal_unix.go index a616d46bac..9dae058f2c 100644 --- a/src/runtime/signal_unix.go +++ b/src/runtime/signal_unix.go @@ -275,6 +275,12 @@ func sigpipe() { // sigtrampgo is called from the signal handler function, sigtramp, // written in assembly code. // This is called by the signal handler, and the world may be stopped. +// +// It must be nosplit because getg() is still the G that was running +// (if any) when the signal was delivered, but it's (usually) called +// on the gsignal stack. Until this switches the G to gsignal, the +// stack bounds check won't work. +// //go:nosplit //go:nowritebarrierrec func sigtrampgo(sig uint32, info *siginfo, ctx unsafe.Pointer) { |