go/misc
Andrew G. Morgan f2e58c6d42 syscall: improve TestSetuidEtc() /proc/ parsing against races
TestSetuidEtc() was failing sporadically on linux-ppc64. From the
three https://build.golang.org/ logs, it looked like the logged
errors could be associated with threads dying, but proc reads
were, in some way, racing with their demise.

Exploring ways to increase thread demise, revealed that races
of this type can happen on non-ppc64 systems, and that
os.IsNotExist(err) was not a sufficient error condition test
for a thread's status file disappearing. This change includes a
fix for that to.

The actual issue on linux-ppc64 appears to be tied to PID reaping
and reuse latency on whatever the build test environment is for
linux-ppc64-buildlet. I suspect this can happen on any linux
system, however, especially where the container has a limited PID
range.

The fix for this, limited to the test (the runtime syscall support
is unchanged), is to confirm that the Pid for the interrogated
thread's /proc/<TID>/status file confirms that it is still
associated with the test-process' PID.

linux-ppc64-buildlet:
  go/bin/go test syscall -run=TestSetuidEtc -count=10000
  ok      syscall 104.285s

Fixes #42462

Change-Id: I55c84ab8361003570a405fa52ffec4949bf91113
Reviewed-on: https://go-review.googlesource.com/c/go/+/268717
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Tobias Klauser <tobias.klauser@gmail.com>
2020-11-11 20:49:53 +00:00
..
android misc/android: fix a typo in README 2019-05-17 06:01:17 +00:00
arm all: make copyright headers consistent with one space after period 2016-05-02 13:43:18 +00:00
cgo syscall: improve TestSetuidEtc() /proc/ parsing against races 2020-11-11 20:49:53 +00:00
chrome/gophertool misc/chrome/gophertool: replace deprecated tabs.getSelected method 2019-11-18 18:14:37 +00:00
ios misc/ios: fixup review comments from CL 255257 2020-10-05 16:04:18 +00:00
linkcheck misc/linkcheck: better redirect handling, use meaningful exit code 2013-10-25 17:31:02 +03:00
reboot misc: remove use of relative directories in overlayDir functions 2019-11-25 16:26:15 +00:00
swig cmd/go: fix swig support and run swig tests during run.bash 2017-11-16 17:19:19 +00:00
trace cmd/trace: update to use WebComponents V0 polyfill 2020-02-20 19:12:11 +00:00
wasm misc/wasm: check type of argument to Go.run 2020-11-02 13:02:40 +00:00
editors all: don't refer to code.google.com/p/go{,-wiki}/ 2015-02-06 14:41:47 +00:00
go.mod misc: add go.mod file 2019-02-27 17:47:31 +00:00