1berry/qtbase
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

qtestcase: make the stack trace generation more signal-safe

Browse Source 
This should work so long as there's no async-unsafe pthread_atfork()-
registered callback.

Pick-to: 6.3
Change-Id: I5ff8e16fcdcb4ffd9ab6fffd16eb72e4e313bc19
Reviewed-by: Marc Mutz <marc.mutz@qt.io>
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
This commit is contained in:
Thiago Macieira 2022-05-02 18:06:55 -07:00
parent 402ce8f266
commit c8d9b7291a
1 changed files with 44 additions and 25 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

69
src/testlib/qtestcase.cpp
View File

@ -77,10 +77,13 @@
#include <qt_windows.h> // for Sleep
#endif
#ifdef Q_OS_UNIX
#include <QtCore/private/qcore_unix_p.h>
#include <errno.h>
#include <signal.h>
#include <time.h>
#include <sys/uio.h>
#include <sys/wait.h>
#include <unistd.h>
# if !defined(Q_OS_INTEGRITY)
# include <sys/resource.h>
@ -232,7 +235,6 @@ static bool debuggerPresent()
#endif
}
#if !defined(Q_OS_WASM)
static bool hasSystemCrashReporter()
{
#if defined(Q_OS_MACOS)
@ -258,18 +260,19 @@ static void disableCoreDump()
}
Q_CONSTRUCTOR_FUNCTION(disableCoreDump);
static void stackTrace()
static std::array<char, 512> stackTraceCommand = {};
static void prepareStackTrace()
{
stackTraceCommand[0] = '\0';
bool ok = false;
const int disableStackDump = qEnvironmentVariableIntValue("QTEST_DISABLE_STACK_DUMP", &ok);
if (ok && disableStackDump)
return;
if (debuggerPresent() || hasSystemCrashReporter())
if (hasSystemCrashReporter())
return;
#if defined(Q_OS_LINUX) || defined(Q_OS_MACOS)
#if defined(Q_OS_MACOS)
#define CSR_ALLOW_UNRESTRICTED_FS (1 << 1)
std::optional<uint32_t> sipConfiguration = qt_mac_sipConfiguration();
@ -277,14 +280,10 @@ static void stackTrace()
return; // LLDB will fail to provide a valid stack trace
#endif
const int msecsFunctionTime = qRound(QTestLog::msecsFunctionTime());
const int msecsTotalTime = qRound(QTestLog::msecsTotalTime());
fprintf(stderr, "\n=== Received signal at function time: %dms, total time: %dms, dumping stack ===\n",
msecsFunctionTime, msecsTotalTime);
// prepare the command to be run (our PID shouldn't change!)
# ifdef Q_OS_LINUX
char cmd[512];
qsnprintf(cmd, 512, "gdb --pid %d 1>&2 2>/dev/null <<EOF\n"
qsnprintf(stackTraceCommand.data(), stackTraceCommand.size(),
"gdb --pid %d 1>&2 2>/dev/null <<EOF\n"
"set prompt\n"
"set height 0\n"
"thread apply all where full\n"
@ -292,24 +291,45 @@ static void stackTrace()
"quit\n"
"EOF\n",
static_cast<int>(getpid()));
if (system(cmd) == -1)
fprintf(stderr, "calling gdb failed\n");
fprintf(stderr, "=== End of stack trace ===\n");
# elif defined(Q_OS_MACOS)
char cmd[512];
qsnprintf(cmd, 512, "lldb -p %d 1>&2 2>/dev/null <<EOF\n"
qsnprintf(stackTraceCommand.data(), stackTraceCommand.size(),
"lldb -p %d 1>&2 2>/dev/null <<EOF\n"
"bt all\n"
"quit\n"
"EOF\n",
static_cast<int>(getpid()));
if (system(cmd) == -1)
fprintf(stderr, "calling lldb failed\n");
fprintf(stderr, "=== End of stack trace ===\n");
# endif
}
[[maybe_unused]] static void generateStackTrace()
{
if (stackTraceCommand[0] == '\0' || debuggerPresent())
return;
#if defined(Q_OS_LINUX) || defined(Q_OS_MACOS)
const int msecsFunctionTime = qRound(QTestLog::msecsFunctionTime());
const int msecsTotalTime = qRound(QTestLog::msecsTotalTime());
writeToStderr("\n=== Received signal at function time: ", asyncSafeToString(msecsFunctionTime),
"ms, total time: ", asyncSafeToString(msecsTotalTime),
"ms, dumping stack ===\n");
// Note: POSIX.1-2001 still has fork() in the list of async-safe functions,
// but in a future edition, it might be removed. It would be safer to wake
// up a babysitter thread to launch the debugger.
pid_t pid = fork();
if (pid == 0) {
// child process
execl("/bin/sh", "/bin/sh", "-c", stackTraceCommand.data(), nullptr);
_exit(1);
} else if (pid < 0) {
writeToStderr("Failed to start debugger.\n");
} else {
int ret;
EINTR_LOOP(ret, waitpid(pid, nullptr, 0));
}
writeToStderr("=== End of stack trace ===\n");
#endif
}
#endif // !Q_OS_WASM
static bool installCoverageTool(const char * appname, const char * testname)
{
@ -1168,9 +1188,7 @@ public:
case TestFunctionStart:
case TestFunctionEnd:
if (Q_UNLIKELY(!waitFor(locker, e))) {
#ifndef Q_OS_WASM
stackTrace();
#endif
generateStackTrace();
qFatal("Test function timed out");
}
}
@ -1921,7 +1939,7 @@ private:
const int msecsFunctionTime = qRound(QTestLog::msecsFunctionTime());
const int msecsTotalTime = qRound(QTestLog::msecsTotalTime());
if (signum != SIGINT) {
stackTrace();
generateStackTrace();
if (qEnvironmentVariableIsSet("QTEST_PAUSE_ON_CRASH")) {
writeToStderr("Pausing process ", asyncSafeToString(getpid()),
" for debugging\n");
@ -2079,6 +2097,7 @@ int QTest::qRun()
#endif
{
QScopedPointer<FatalSignalHandler> handler;
prepareStackTrace();
if (!noCrashHandler)
handler.reset(new FatalSignalHandler);