Subject: + memory-failure-send-right-signal-code-to-correct-thread.patch added to -mm tree
To: tony.luck@xxxxxxxxx,andi@xxxxxxxxxxxxxx,bp@xxxxxxx,gong.chen@xxxxxxxxxxxxxxxxxx,n-horiguchi@xxxxxxxxxxxxx,otto.g.bruggeman@xxxxxxxxx,stable@xxxxxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Mon, 02 Jun 2014 15:45:12 -0700
The patch titled
Subject: mm/memory-failure.c-failure: send right signal code to correct thread
has been added to the -mm tree. Its filename is
memory-failure-send-right-signal-code-to-correct-thread.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/memory-failure-send-right-signal-code-to-correct-thread.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/memory-failure-send-right-signal-code-to-correct-thread.patch
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------------------------------------------------------
From: Tony Luck <tony.luck@xxxxxxxxx>
Subject: mm/memory-failure.c-failure: send right signal code to correct thread
When a thread in a multi-threaded application hits a machine check because
of an uncorrectable error in memory - we want to send the SIGBUS with
si.si_code = BUS_MCEERR_AR to that thread. Currently we fail to do that
if the active thread is not the primary thread in the process.
collect_procs() just finds primary threads and this test:
if ((flags & MF_ACTION_REQUIRED) && t == current) {
will see that the thread we found isn't the current thread and so send a
si.si_code = BUS_MCEERR_AO to the primary (and nothing to the active
thread at this time).
We can fix this by checking whether "current" shares the same mm with the
process that collect_procs() said owned the page. If so, we send the
SIGBUS to current (with code BUS_MCEERR_AR).
Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Reported-by: Otto Bruggeman <otto.g.bruggeman@xxxxxxxxx>
Cc: Andi Kleen <andi@xxxxxxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxx>
Cc: Chen Gong <gong.chen@xxxxxxxxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> [3.2+]
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory-failure.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff -puN mm/memory-failure.c~memory-failure-send-right-signal-code-to-correct-thread mm/memory-failure.c
--- a/mm/memory-failure.c~memory-failure-send-right-signal-code-to-correct-thread
+++ a/mm/memory-failure.c
@@ -204,9 +204,9 @@ static int kill_proc(struct task_struct
#endif
si.si_addr_lsb = page_size_order(page) + PAGE_SHIFT;
- if ((flags & MF_ACTION_REQUIRED) && t == current) {
+ if ((flags & MF_ACTION_REQUIRED) && t->mm == current->mm) {
si.si_code = BUS_MCEERR_AR;
- ret = force_sig_info(SIGBUS, &si, t);
+ ret = force_sig_info(SIGBUS, &si, current);
} else {
/*
* Don't use force here, it's convenient if the signal
_
Patches currently in -mm which might be from tony.luck@xxxxxxxxx are
hugetlb-restrict-hugepage_migration_support-to-x86_64.patch
memory-failure-send-right-signal-code-to-correct-thread.patch
memory-failure-dont-let-collect_procs-skip-over-processes-for-mf_action_required.patch
mm-memory-failurec-support-dedicated-thread-to-handle-sigbusbus_mceerr_ao.patch
lib-scatterlist-make-arch_has_sg_chain-an-actual-kconfig.patch
lib-scatterlist-clean-up-useless-architecture-versions-of-scatterlisth.patch
linux-next.patch
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