diff options
Diffstat (limited to 'main/musl/0010-make-posix_spawn-and-functions-that-use-it-use-CLONE.patch')
| -rw-r--r-- | main/musl/0010-make-posix_spawn-and-functions-that-use-it-use-CLONE.patch | 50 |
1 files changed, 0 insertions, 50 deletions
diff --git a/main/musl/0010-make-posix_spawn-and-functions-that-use-it-use-CLONE.patch b/main/musl/0010-make-posix_spawn-and-functions-that-use-it-use-CLONE.patch deleted file mode 100644 index d6260a5f9d..0000000000 --- a/main/musl/0010-make-posix_spawn-and-functions-that-use-it-use-CLONE.patch +++ /dev/null @@ -1,50 +0,0 @@ -From 53761b469221fbe062629c50249e3d534573eda9 Mon Sep 17 00:00:00 2001 -From: Rich Felker <dalias@aerifal.cx> -Date: Wed, 17 Jul 2013 13:54:41 -0400 -Subject: [PATCH 10/10] make posix_spawn (and functions that use it) use - CLONE_VFORK flag - -this is both a minor scheduling optimization and a workaround for a -difficult-to-fix bug in qemu app-level emulation. - -from the scheduling standpoint, it makes no sense to schedule the -parent thread again until the child has exec'd or exited, since the -parent will immediately block again waiting for it. - -on the qemu side, as regular application code running on an underlying -libc, qemu cannot make arbitrary clone syscalls itself without -confusing the underlying implementation. instead, it breaks them down -into either fork-like or pthread_create-like cases. it was treating -the code in posix_spawn as pthread_create-like, due to CLONE_VM, which -caused horribly wrong behavior: CLONE_FILES broke the synchronization -mechanism, CLONE_SIGHAND broke the parent's signals, and CLONE_THREAD -caused the child's exec to end the parent -- if it hadn't already -crashed. however, qemu special-cases CLONE_VFORK and emulates that -with fork, even when CLONE_VM is also specified. this also gives -incorrect semantics for code that really needs the memory sharing, but -posix_spawn does not make use of the vm sharing except to avoid -momentary double commit charge. - -programs using posix_spawn (including via popen) should now work -correctly under qemu app-level emulation. ---- - src/process/posix_spawn.c | 3 ++- - 1 file changed, 2 insertions(+), 1 deletion(-) - -diff --git a/src/process/posix_spawn.c b/src/process/posix_spawn.c -index e6a031c..68cf795 100644 ---- a/src/process/posix_spawn.c -+++ b/src/process/posix_spawn.c -@@ -138,7 +138,8 @@ int __posix_spawnx(pid_t *restrict res, const char *restrict path, - args.envp = envp; - pthread_sigmask(SIG_BLOCK, SIGALL_SET, &args.oldmask); - -- pid = __clone(child, stack+sizeof stack, CLONE_VM|SIGCHLD, &args); -+ pid = __clone(child, stack+sizeof stack, -+ CLONE_VM|CLONE_VFORK|SIGCHLD, &args); - close(args.p[1]); - - if (pid > 0) { --- -1.8.3.2 - |