The patch titled
uml: don't kill pid 0
has been removed from the -mm tree. Its filename was
uml-dont-kill-pid-0.patch
This patch was dropped because it was merged into mainline or a subsystem tree
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: uml: don't kill pid 0
From: Jeff Dike <jdike@xxxxxxxxxxx>
A bit of defensive programming - during development, it ocassionally
happens that a call to init_new_context is missed, resulting in
context holding a host pid of zero. When that address space is torn
down, destroy_context does a kill(0), which instantly kills the whole
UML without any errors whatsoever.
This patch add a check for pids less than 2, to also catch 1 and
negative pids.
Signed-off-by: Jeff Dike <jdike@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/um/kernel/skas/mmu.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff -puN arch/um/kernel/skas/mmu.c~uml-dont-kill-pid-0 arch/um/kernel/skas/mmu.c
--- a/arch/um/kernel/skas/mmu.c~uml-dont-kill-pid-0
+++ a/arch/um/kernel/skas/mmu.c
@@ -164,8 +164,20 @@ void destroy_context(struct mm_struct *m
if (proc_mm)
os_close_file(mmu->id.u.mm_fd);
- else
+ else {
+ /*
+ * If init_new_context wasn't called, this will be
+ * zero, resulting in a kill(0), which will result in the
+ * whole UML suddenly dying. Also, cover negative and
+ * 1 cases, since they shouldn't happen either.
+ */
+ if (mmu->id.u.pid < 2) {
+ printk(KERN_ERR "corrupt mm_context - pid = %d\n",
+ mmu->id.u.pid);
+ return;
+ }
os_kill_ptraced_process(mmu->id.u.pid, 1);
+ }
if (skas_needs_stub)
free_page(mmu->id.stack);
_
Patches currently in -mm which might be from jdike@xxxxxxxxxxx are
origin.patch
git-kvm.patch
fix-__const_udelay-declaration-and-definition-mismatches.patch
iget-stop-hostfs-from-using-iget-and-read_inode.patch
iget-stop-hostfs-from-using-iget-and-read_inode-checkpatch-fixes.patch
aout-suppress-aout-library-support-if-config_arch_supports_aout-uml-re-remove-accidentally-restored-code.patch
random-add-async-notification-support-to-dev-random.patch
mount-options-fix-hostfs.patch
-
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