diff options
author | Jeff Dike <jdike@addtoit.com> | 2006-07-10 07:45:11 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-07-10 16:24:24 -0400 |
commit | 61232f2fe44f7ac12d7512d099a8f10923eff7ea (patch) | |
tree | f1f17d310daf7f5b60ad6713a7a1ac7011ae45e8 /arch/um/os-Linux | |
parent | 8e64d96aeb495709c13307e2d79f3ee37e96aa4e (diff) |
[PATCH] uml: fix exitcall ordering bug
This fixes an exitcall ordering bug - calls to ignore_sigio_fd can come from
exitcalls that come after the sigio thread has been killed. This would cause
shutdown to hang or crash.
Fixed by having ignore_sigio_fd check that the thread is present before trying
to communicate with it.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/um/os-Linux')
-rw-r--r-- | arch/um/os-Linux/sigio.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/um/os-Linux/sigio.c b/arch/um/os-Linux/sigio.c index 0d2422a7d72c..d22623e8fced 100644 --- a/arch/um/os-Linux/sigio.c +++ b/arch/um/os-Linux/sigio.c | |||
@@ -191,6 +191,13 @@ int ignore_sigio_fd(int fd) | |||
191 | struct pollfd *p; | 191 | struct pollfd *p; |
192 | int err = 0, i, n = 0; | 192 | int err = 0, i, n = 0; |
193 | 193 | ||
194 | /* This is called from exitcalls elsewhere in UML - if | ||
195 | * sigio_cleanup has already run, then update_thread will hang | ||
196 | * or fail because the thread is no longer running. | ||
197 | */ | ||
198 | if(write_sigio_pid == -1) | ||
199 | return -EIO; | ||
200 | |||
194 | sigio_lock(); | 201 | sigio_lock(); |
195 | for(i = 0; i < current_poll.used; i++){ | 202 | for(i = 0; i < current_poll.used; i++){ |
196 | if(current_poll.poll[i].fd == fd) break; | 203 | if(current_poll.poll[i].fd == fd) break; |
@@ -215,7 +222,7 @@ int ignore_sigio_fd(int fd) | |||
215 | update_thread(); | 222 | update_thread(); |
216 | out: | 223 | out: |
217 | sigio_unlock(); | 224 | sigio_unlock(); |
218 | return(err); | 225 | return err; |
219 | } | 226 | } |
220 | 227 | ||
221 | static struct pollfd *setup_initial_poll(int fd) | 228 | static struct pollfd *setup_initial_poll(int fd) |