From d3a61059c04bd82329707324fac0d48e191edbf4 Mon Sep 17 00:00:00 2001 From: Alexey Izbyshev Date: Thu, 29 Feb 2024 14:13:18 +0300 Subject: posix_spawn: fix child spinning on write to a broken pipe A child process created by posix_spawn reports errors to its parent via a pipe, retrying infinitely on any write error to prevent falsely reporting success. If the (original) parent dies before write is attempted, there is nobody to report to, but the child will remain stuck in the write loop forever if SIGPIPE is blocked or ignored. Fix this by not retrying write if it fails with EPIPE. --- src/process/posix_spawn.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'src') diff --git a/src/process/posix_spawn.c b/src/process/posix_spawn.c index 728551b3..8294598b 100644 --- a/src/process/posix_spawn.c +++ b/src/process/posix_spawn.c @@ -4,6 +4,7 @@ #include #include #include +#include #include #include "syscall.h" #include "lock.h" @@ -156,7 +157,11 @@ static int child(void *args_vp) fail: /* Since sizeof errno < PIPE_BUF, the write is atomic. */ ret = -ret; - if (ret) while (__syscall(SYS_write, p, &ret, sizeof ret) < 0); + if (ret) { + int r; + do r = __syscall(SYS_write, p, &ret, sizeof ret); + while (r<0 && r!=-EPIPE); + } _exit(127); } -- cgit 1.4.1