path: root/arch/um/os-Linux/util.c
diff options
authorStanislaw Gruszka <stf_xl@wp.pl>2007-12-17 16:19:46 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-12-17 19:28:15 -0800
commit4dbed85a35ed37d9608f4f32e5d69efa775d6223 (patch)
tree67ab558db8ccaf8d706a25e5ce87b78be241cffb /arch/um/os-Linux/util.c
parentrevert "Hibernation: Use temporary page tables for kernel text mapping on x86_64" (diff)
uml: stop gdb from deleting breakpoints when running UML
Sometimes when UML is debugged gdb miss breakpoints. When process traced by gdb do fork, debugger remove breakpoints from child address space. There is possibility to trace more than one fork, but this not work with UML, I guess (only guess) there is a deadlock - gdb waits for UML and UML waits for gdb. When clone() is called with SIGCHLD and CLONE_VM flags, gdb see this as PTRACE_EVENT_FORK not as PTRACE_EVENT_CLONE and remove breakpoints from child and at the same time from traced process, because either have the same address space. Maybe it is possible to do fix in gdb, but I'm not sure if there is easy way to find out if traced and child processes share memory. So I do fix for UML, it simply do not call clone() with both SIGCHLD and CLONE_VM flags together. Additionally __WALL flag is used for waitpid() to assure not miss clone and normal process events. [ jdike - checkpatch fixes ] Signed-off-by: Stanislaw Gruszka <stf_xl@wp.pl> Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to '')
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/um/os-Linux/util.c b/arch/um/os-Linux/util.c
index ef095436a78c..3e058ce9ffb6 100644
--- a/arch/um/os-Linux/util.c
+++ b/arch/um/os-Linux/util.c
@@ -141,7 +141,7 @@ void os_dump_core(void)
* nothing reasonable to do if that fails.
- while ((pid = waitpid(-1, NULL, WNOHANG)) > 0)
+ while ((pid = waitpid(-1, NULL, WNOHANG | __WALL)) > 0)
os_kill_ptraced_process(pid, 0);