linux_core_dumper: add explicit casts for exception fields

Some of the fields we save might have signed types depending on the
system (e.g. `typedef int pid_t`).  Depending on the toolchain, we
can trip -Werror=narrowing failures like:
src/client/linux/minidump_writer/linux_core_dumper.cc:248:66: error:
  narrowing conversion of ‘(__pid_t)info->siginfo_t::_sifields.siginfo_t::<anonymous union>::_kill.siginfo_t::<anonymous union>::<anonymous struct>::si_pid’
  from ‘__pid_t {aka int}’ to ‘long unsigned int’ inside { } [-Werror=narrowing]
             set_crash_exception_info({info->si_pid, info->si_uid});
                                             ^^^^^^
src/client/linux/minidump_writer/linux_core_dumper.cc:252:71: error:
  narrowing conversion of ‘(int)info->siginfo_t::_sifields.siginfo_t::<anonymous union>::_sigsys.siginfo_t::<anonymous union>::<anonymous struct>::_syscall’
  from ‘int’ to ‘long unsigned int’ inside { } [-Werror=narrowing]
             set_crash_exception_info({info->si_syscall, info->si_arch});
                                             ^^^^^^^^^^

Since the exception info fields are all uint64_t which should be large
enough to handle all the fields in the siginfo_t structure, add casts
for all the assignments to avoid these errors.  We have implicit casts
even without them, so we aren't changing behavior.

Bug: google-breakpad:791
Bug: chromium:945653
Change-Id: Ib04e015998f08b857159ac13e9a065a66d228d49
Reviewed-on: https://chromium-review.googlesource.com/c/breakpad/breakpad/+/1544862
Reviewed-by: Mark Mentovai <mark@chromium.org>
This commit is contained in:
Mike Frysinger 2019-03-29 14:14:27 -04:00
parent b4a0eb2d06
commit e2b3b80e43

View file

@ -242,14 +242,21 @@ bool LinuxCoreDumper::EnumerateThreads() {
break;
}
// Set crash_exception_info for common signals.
// Set crash_exception_info for common signals. Since exception info is
// unsigned, but some of these fields might be signed, we always cast.
switch (info->si_signo) {
case MD_EXCEPTION_CODE_LIN_SIGKILL:
set_crash_exception_info({info->si_pid, info->si_uid});
set_crash_exception_info({
static_cast<uint64_t>(info->si_pid),
static_cast<uint64_t>(info->si_uid),
});
break;
case MD_EXCEPTION_CODE_LIN_SIGSYS:
#ifdef si_syscall
set_crash_exception_info({info->si_syscall, info->si_arch});
set_crash_exception_info({
static_cast<uint64_t>(info->si_syscall),
static_cast<uint64_t>(info->si_arch),
});
#endif
break;
}