Commit 4210930a authored by Bryan C. Mills's avatar Bryan C. Mills Committed by Bryan Mills

runtime/cgo: return correct sa_flags

A typo in the previous revision ("act" instead of "oldact") caused us
to return the sa_flags from the new (or zeroed) sigaction rather than
the old one.

In the presence of a signal handler registered before
runtime.libpreinit, this caused setsigstack to erroneously zero out
important sa_flags (such as SA_SIGINFO) in its attempt to re-register
the existing handler with SA_ONSTACK.

Change-Id: I3cd5152a38ec0d44ae611f183bc1651d65b8a115
Reviewed-on: https://go-review.googlesource.com/37852
Run-TryBot: Bryan Mills <bcmills@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarIan Lance Taylor <iant@golang.org>
parent e57350f4
......@@ -77,7 +77,7 @@ testmsanshared() {
fi
go build -msan -buildmode=c-shared $suffix -o ${TMPDIR}/libmsanshared.$libext msan_shared.go
echo 'int main() { return 0; }' > ${TMPDIR}/testmsanshared.c
echo 'int main() { return 0; }' > ${TMPDIR}/testmsanshared.c
$CC $(go env GOGCCFLAGS) -fsanitize=memory -o ${TMPDIR}/testmsanshared ${TMPDIR}/testmsanshared.c ${TMPDIR}/libmsanshared.$libext
if ! LD_LIBRARY_PATH=. ${TMPDIR}/testmsanshared; then
......@@ -131,6 +131,25 @@ if test "$msan" = "yes"; then
testmsanshared
fi
testtsanshared() {
goos=$(go env GOOS)
suffix="-installsuffix tsan"
libext="so"
if [ "$goos" == "darwin" ]; then
libext="dylib"
fi
go build -buildmode=c-shared $suffix -o ${TMPDIR}/libtsanshared.$libext tsan_shared.go
echo 'int main() { return 0; }' > ${TMPDIR}/testtsanshared.c
$CC $(go env GOGCCFLAGS) -fsanitize=thread -o ${TMPDIR}/testtsanshared ${TMPDIR}/testtsanshared.c ${TMPDIR}/libtsanshared.$libext
if ! LD_LIBRARY_PATH=. ${TMPDIR}/testtsanshared; then
echo "FAIL: tsan_shared"
status=1
fi
rm -f ${TMPDIR}/{testtsanshared,testtsanshared.c,libtsanshared.$libext}
}
if test "$tsan" = "yes"; then
echo 'int main() { return 0; }' > ${TMPDIR}/testsanitizers$$.c
ok=yes
......@@ -196,6 +215,8 @@ if test "$tsan" = "yes"; then
testtsan tsan7.go "CGO_CFLAGS=-fsanitize=thread CGO_LDFLAGS=-fsanitize=thread" "-installsuffix=tsan"
testtsan tsan10.go "CGO_CFLAGS=-fsanitize=thread CGO_LDFLAGS=-fsanitize=thread" "-installsuffix=tsan"
testtsan tsan11.go "CGO_CFLAGS=-fsanitize=thread CGO_LDFLAGS=-fsanitize=thread" "-installsuffix=tsan"
testtsanshared
fi
fi
......
// Copyright 2017 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package main
// This program failed with SIGSEGV when run under the C/C++ ThreadSanitizer.
// The Go runtime had re-registered the C handler with the wrong flags due to a
// typo, resulting in null pointers being passed for the info and context
// parameters to the handler.
/*
#cgo CFLAGS: -fsanitize=thread
#cgo LDFLAGS: -fsanitize=thread
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ucontext.h>
void check_params(int signo, siginfo_t *info, void *context) {
ucontext_t* uc = (ucontext_t*)(context);
if (info->si_signo != signo) {
fprintf(stderr, "info->si_signo does not match signo.\n");
abort();
}
if (uc->uc_stack.ss_size == 0) {
fprintf(stderr, "uc_stack has size 0.\n");
abort();
}
}
// Set up the signal handler in a high priority constructor, so
// that it is installed before the Go code starts.
static void register_handler(void) __attribute__ ((constructor (200)));
static void register_handler() {
struct sigaction sa;
memset(&sa, 0, sizeof(sa));
sigemptyset(&sa.sa_mask);
sa.sa_flags = SA_SIGINFO;
sa.sa_sigaction = check_params;
if (sigaction(SIGUSR1, &sa, NULL) != 0) {
perror("failed to register SIGUSR1 handler");
exit(EXIT_FAILURE);
}
}
*/
import "C"
import "syscall"
func init() {
C.raise(C.int(syscall.SIGUSR1))
}
func main() {}
......@@ -65,11 +65,11 @@ x_cgo_sigaction(intptr_t signum, const go_sigaction_t *goact, go_sigaction_t *ol
}
oldgoact->mask = 0;
for (i = 0; i < 8 * sizeof(oldgoact->mask); i++) {
if (sigismember(&act.sa_mask, i+1) == 1) {
if (sigismember(&oldact.sa_mask, i+1) == 1) {
oldgoact->mask |= (uint64_t)(1)<<i;
}
}
oldgoact->flags = act.sa_flags;
oldgoact->flags = oldact.sa_flags;
}
return ret;
......
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