From 599f97360389911c293e0ca4c5eb49e007377fba Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Fri, 19 Oct 2012 15:02:37 -0400 Subject: [PATCH] fix usage of locks with vfork __release_ptc() is only valid in the parent; if it's performed in the child, the lock will be unlocked early then double-unlocked later, corrupting the lock state. --- src/process/posix_spawn.c | 2 +- src/process/system.c | 3 ++- src/stdio/popen.c | 2 +- 3 files changed, 4 insertions(+), 3 deletions(-) diff --git a/src/process/posix_spawn.c b/src/process/posix_spawn.c index c3e800b8..5eb516b0 100644 --- a/src/process/posix_spawn.c +++ b/src/process/posix_spawn.c @@ -35,9 +35,9 @@ int __posix_spawnx(pid_t *restrict res, const char *restrict path, __acquire_ptc(); pid = __vfork(); - __release_ptc(); if (pid) { + __release_ptc(); sigprocmask(SIG_SETMASK, &oldmask, 0); if (pid < 0) return -pid; *res = pid; diff --git a/src/process/system.c b/src/process/system.c index c8f26008..ebe207f5 100644 --- a/src/process/system.c +++ b/src/process/system.c @@ -29,7 +29,8 @@ int system(const char *cmd) __acquire_ptc(); pid = __vfork(); - __release_ptc(); + + if (pid) __release_ptc(); if (pid > 0) { sigset_t new = old; diff --git a/src/stdio/popen.c b/src/stdio/popen.c index 0c9f24e3..5a47509e 100644 --- a/src/stdio/popen.c +++ b/src/stdio/popen.c @@ -38,9 +38,9 @@ FILE *popen(const char *cmd, const char *mode) __acquire_ptc(); pid = __vfork(); - __release_ptc(); if (pid) { + __release_ptc(); __syscall(SYS_close, p[1-op]); sigprocmask(SIG_BLOCK, SIGALL_SET, &old); if (pid < 0) { -- 2.25.1