If we get a SIGPROF on a non-Go thread, and the program has not called
runtime.SetCgoTraceback so we have no way to collect a stack trace, then
record a profile that is just the PC where the signal occurred. That
will at least point the user to the right area.
Retrieving the PC from the sigctxt in a signal handler on a non-G thread
required marking a number of trivial sigctxt methods as nosplit, and,
for extra safety, nowritebarrierrec.
The test shows that the existing test CgoPprofThread test does not test
the stack trace, just the profile signal. Leaving that for later.
Change-Id: I8f8f3ff09ac099fc9d9df94b5a9d210ffc20c4ab
Reviewed-on: https://go-review.googlesource.com/30252
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
The current runtime attempts to forward signals generated by non-Go
code to the original signal handler. If it can't call the original
handler directly, it currently attempts to re-raise the signal after
resetting the handler. In this case, the original context is lost.
This fix prevents that problem by simply returning from the go signal
handler after resetting the original handler. It only does this when
the original handler is the system default handler, which in all cases
is known to not recover. The signal is not reset, so it is retriggered
and the original handler takes over with the proper context.
Fixes#14899
Change-Id: Ib1c19dfa4b50d9732d7a453de3784c8141e1cbb3
Reviewed-on: https://go-review.googlesource.com/21006
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Memory management was consolitated with the BSD ports, since
it was almost identical.
Assembly thunks are gone, being replaced by the new //go:linkname
feature.
This change supersedes CL 138390043 (runtime: convert solaris
netpoll to Go), which was previously reviewed and tested.
This change is only the first step, the port now builds,
but doesn't run. Binaries fail to exec:
ld.so.1: 6.out: fatal: 6.out: TLS requirement failure : TLS support is unavailable
Killed
This seems to happen because binaries don't link with libc.so
anymore. We will have to solve that in a different CL.
Also this change is just a rough translation of the original
C code, cleanup will come in a different CL.
[This CL is part of the removal of C code from package runtime.
See golang.org/s/dev.cc for an overview.]
LGTM=rsc
R=rsc, dave
CC=golang-codereviews, iant, khr, minux, r, rlh
https://golang.org/cl/174960043
