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authorMiklos Szeredi <miklos@szeredi.hu>2006-06-22 14:47:22 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-22 15:05:57 -0700
commitc89681ed7d0e4a61d35bdc12c06c6733b718b2cb (patch)
tree170d7c54d578480ba231dd690243aa21067ca253 /fs/binfmt_elf.c
parent09d967c6f32b35eab15b45862ae16e4f06259d8e (diff)
downloadconfigs-c89681ed7d0e4a61d35bdc12c06c6733b718b2cb.tar.gz
[PATCH] remove steal_locks()
This patch removes the steal_locks() function. steal_locks() doesn't work correctly with any filesystem that does it's own lock management, including NFS, CIFS, etc. In addition it has weird semantics on local filesystems in case tasks sharing file-descriptor tables are doing POSIX locking operations in parallel to execve(). The steal_locks() function has an effect on applications doing: clone(CLONE_FILES) /* in child */ lock execve lock POSIX locks acquired before execve (by "child", "parent" or any further task sharing files_struct) will after the execve be owned exclusively by "child". According to Chris Wright some LSB/LTP kind of suite triggers without the stealing behavior, but there's no known real-world application that would also fail. Apps using NPTL are not affected, since all other threads are killed before execve. Apps using LinuxThreads are only affected if they - have multiple threads during exec (LinuxThreads doesn't kill other threads, the app may do it with pthread_kill_other_threads_np()) - rely on POSIX locks being inherited across exec Both conditions are documented, but not their interaction. Apps using clone() natively are affected if they - use clone(CLONE_FILES) - rely on POSIX locks being inherited across exec The above scenarios are unlikely, but possible. If the patch is vetoed, there's a plan B, that involves mostly keeping the weird stealing semantics, but changing the way lock ownership is handled so that network and local filesystems work consistently. That would add more complexity though, so this solution seems to be preferred by most people. Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Matthew Wilcox <willy@debian.org> Cc: Chris Wright <chrisw@sous-sol.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Steven French <sfrench@us.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs/binfmt_elf.c')
-rw-r--r--fs/binfmt_elf.c1
1 files changed, 0 insertions, 1 deletions
diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
index 537893a1601..8a04216e8b4 100644
--- a/fs/binfmt_elf.c
+++ b/fs/binfmt_elf.c
@@ -759,7 +759,6 @@ static int load_elf_binary(struct linux_binprm * bprm, struct pt_regs * regs)
/* Discard our unneeded old files struct */
if (files) {
- steal_locks(files);
put_files_struct(files);
files = NULL;
}