diff options
| -rw-r--r-- | erts/emulator/sys/unix/erl_child_setup.c | 14 | ||||
| -rw-r--r-- | erts/emulator/sys/unix/sys.c | 12 |
2 files changed, 19 insertions, 7 deletions
diff --git a/erts/emulator/sys/unix/erl_child_setup.c b/erts/emulator/sys/unix/erl_child_setup.c index 6b9ddd8da4..69fc6c2879 100644 --- a/erts/emulator/sys/unix/erl_child_setup.c +++ b/erts/emulator/sys/unix/erl_child_setup.c @@ -348,7 +348,7 @@ child_error: * for posterity. */ static void handle_sigchld(int sig) { - int buff[2], res; + int buff[2], res, __preverrno = errno; sys_sigblock(SIGCHLD); @@ -362,6 +362,16 @@ static void handle_sigchld(int sig) { } sys_sigrelease(SIGCHLD); + + /* We save and restore the original errno as otherwise + the thread we are running in may end up with an + unexpected errno. An example of when this happened + was when the select in main had gotten an EINTR but + before the errno was checked the signal handler + was called and set errno to ECHILD from waitpid + which caused erl_child_setup to abort as it does + not expect ECHILD to be set after select */ + errno = __preverrno; } #if defined(__ANDROID__) @@ -423,7 +433,7 @@ main(int argc, char *argv[]) sigemptyset(&sa.sa_mask); sa.sa_flags = SA_RESTART | SA_NOCLDSTOP; if (sigaction(SIGCHLD, &sa, 0) == -1) { - perror(0); + perror(NULL); exit(1); } diff --git a/erts/emulator/sys/unix/sys.c b/erts/emulator/sys/unix/sys.c index 6fb86f6dda..089efec3e8 100644 --- a/erts/emulator/sys/unix/sys.c +++ b/erts/emulator/sys/unix/sys.c @@ -715,11 +715,13 @@ static RETSIGTYPE suspend_signal(void) static RETSIGTYPE suspend_signal(int signum) #endif { - int res; - int buf[1]; - do { - res = read(sig_suspend_fds[0], buf, sizeof(int)); - } while (res < 0 && errno == EINTR); + int res, buf[1], __errno = errno; + do { + res = read(sig_suspend_fds[0], buf, sizeof(int)); + } while (res < 0 && errno == EINTR); + + /* restore previous errno in case read changed it */ + errno = __errno; } #endif /* #ifdef ERTS_SYS_SUSPEND_SIGNAL */ |