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| author | Ian Lance Taylor <ian@gcc.gnu.org> | 2018-07-02 16:28:43 +0000 |
|---|---|---|
| committer | Ian Lance Taylor <ian@gcc.gnu.org> | 2018-07-02 16:28:43 +0000 |
| commit | 7edd4c1885f4ecc31b80f157f7aa96ccd40d1075 (patch) | |
| tree | a4a2df0f6300e9b015628e22a0fe093e880ef8d2 | |
| parent | a08acce83a052a8b800eddaaae36e51e8de57643 (diff) | |
| download | gcc-7edd4c1885f4ecc31b80f157f7aa96ccd40d1075.zip gcc-7edd4c1885f4ecc31b80f157f7aa96ccd40d1075.tar.gz gcc-7edd4c1885f4ecc31b80f157f7aa96ccd40d1075.tar.bz2 | |
re PR go/86331 (the gccgo's "go" tool looks like failing to invoke any sub go command)
PR go/86331
os: check return value as well as error from waitid
https://gcc.gnu.org/PR86331 indicates that if a signal handler runs it
is possible for syscall.Syscall6 to return a non-zero errno value even
if no error occurs. That is a problem in general, but this fix will
let us work around the general problem for the specific case of
calling waitid.
Reviewed-on: https://go-review.googlesource.com/121595
From-SVN: r262313
| -rw-r--r-- | gcc/go/gofrontend/MERGE | 2 | ||||
| -rw-r--r-- | libgo/go/os/wait_waitid.go | 7 |
2 files changed, 6 insertions, 3 deletions
diff --git a/gcc/go/gofrontend/MERGE b/gcc/go/gofrontend/MERGE index 237c46d..e65c0bc 100644 --- a/gcc/go/gofrontend/MERGE +++ b/gcc/go/gofrontend/MERGE @@ -1,4 +1,4 @@ -e1fcce0aec27b1f50ac0e736f39f4c806c2a5baa +94738979a3422e845acf358a766aabf8b9275d43 The first line of this file holds the git revision number of the last merge done from the gofrontend repository. diff --git a/libgo/go/os/wait_waitid.go b/libgo/go/os/wait_waitid.go index 5a62b27..a6284aa 100644 --- a/libgo/go/os/wait_waitid.go +++ b/libgo/go/os/wait_waitid.go @@ -28,9 +28,12 @@ func (p *Process) blockUntilWaitable() (bool, error) { // We don't care about the values it returns. var siginfo [16]uint64 psig := &siginfo[0] - _, _, e := syscall.Syscall6(syscall.SYS_WAITID, _P_PID, uintptr(p.Pid), uintptr(unsafe.Pointer(psig)), syscall.WEXITED|syscall.WNOWAIT, 0, 0) + r, _, e := syscall.Syscall6(syscall.SYS_WAITID, _P_PID, uintptr(p.Pid), uintptr(unsafe.Pointer(psig)), syscall.WEXITED|syscall.WNOWAIT, 0, 0) runtime.KeepAlive(p) - if e != 0 { + // Check r as well as e because syscall.Syscall6 currently + // just returns errno, and the SIGCHLD signal handler may + // change errno. See https://gcc.gnu.org/PR86331. + if r != 0 && e != 0 { // waitid has been available since Linux 2.6.9, but // reportedly is not available in Ubuntu on Windows. // See issue 16610. |