tequilaOS/platform_system_core
2
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

init: Document that ReapOneProcess() does not modify 'pid'

Browse source 
It is essential for correct operation of ReapAnyOutstandingChildren()
that ReapOneProcess() does not modify 'pid'. Make it easier to verify
for humans that ReapOneProcess() does not modify the 'pid' local
variable. Document the value of siginfo.si_signo with DCHECK_EQ()
statements.

Bug: 213617178
Change-Id: I14baaa7adbe5416b7f777f32fb76896f2ae27b4e
Signed-off-by: Bart Van Assche <bvanassche@google.com>
This commit is contained in:
Bart Van Assche 2022-10-19 10:52:23 -07:00
parent 1b2d443626
commit c7d7ed0eae
1 changed files with 7 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

9
init/sigchld_handler.cpp
View file

@ -53,8 +53,13 @@ static pid_t ReapOneProcess() {
return 0;
}
auto pid = siginfo.si_pid;
if (pid == 0) return 0;
const pid_t pid = siginfo.si_pid;
if (pid == 0) {
DCHECK_EQ(siginfo.si_signo, 0);
return 0;
}
DCHECK_EQ(siginfo.si_signo, SIGCHLD);
// At this point we know we have a zombie pid, so we use this scopeguard to reap the pid
// whenever the function returns from this point forward.