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| author | Tony Luck <tony.luck@intel.com> | 2012-07-11 10:20:47 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-08-09 08:31:29 -0700 |
| commit | 7b689c5d930f281e417597af9f817ba03dc9d898 (patch) | |
| tree | 75bb26f8fc89a58f25377e60cf2af6879fb795b0 /mm | |
| parent | 2830f9a08c084bcf40819942f04d0ca500faf4b8 (diff) | |
| download | lwn-7b689c5d930f281e417597af9f817ba03dc9d898.tar.gz lwn-7b689c5d930f281e417597af9f817ba03dc9d898.zip | |
x86/mce: Fix siginfo_t->si_addr value for non-recoverable memory faults
commit 6751ed65dc6642af64f7b8a440a75563c8aab7ae upstream.
In commit dad1743e5993f1 ("x86/mce: Only restart instruction after machine
check recovery if it is safe") we fixed mce_notify_process() to force a
signal to the current process if it was not restartable (RIPV bit not
set in MCG_STATUS). But doing it here means that the process doesn't
get told the virtual address of the fault via siginfo_t->si_addr. This
would prevent application level recovery from the fault.
Make a new MF_MUST_KILL flag bit for memory_failure() et al. to use so
that we will provide the right information with the signal.
Signed-off-by: Tony Luck <tony.luck@intel.com>
Acked-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memory-failure.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 97cc2733551a..0de20d7168f7 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -345,14 +345,14 @@ static void add_to_kill(struct task_struct *tsk, struct page *p, * Also when FAIL is set do a force kill because something went * wrong earlier. */ -static void kill_procs(struct list_head *to_kill, int doit, int trapno, +static void kill_procs(struct list_head *to_kill, int forcekill, int trapno, int fail, struct page *page, unsigned long pfn, int flags) { struct to_kill *tk, *next; list_for_each_entry_safe (tk, next, to_kill, nd) { - if (doit) { + if (forcekill) { /* * In case something went wrong with munmapping * make sure the process doesn't catch the @@ -858,7 +858,7 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn, struct address_space *mapping; LIST_HEAD(tokill); int ret; - int kill = 1; + int kill = 1, forcekill; struct page *hpage = compound_head(p); struct page *ppage; @@ -888,7 +888,7 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn, * be called inside page lock (it's recommended but not enforced). */ mapping = page_mapping(hpage); - if (!PageDirty(hpage) && mapping && + if (!(flags & MF_MUST_KILL) && !PageDirty(hpage) && mapping && mapping_cap_writeback_dirty(mapping)) { if (page_mkclean(hpage)) { SetPageDirty(hpage); @@ -965,12 +965,14 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn, * Now that the dirty bit has been propagated to the * struct page and all unmaps done we can decide if * killing is needed or not. Only kill when the page - * was dirty, otherwise the tokill list is merely + * was dirty or the process is not restartable, + * otherwise the tokill list is merely * freed. When there was a problem unmapping earlier * use a more force-full uncatchable kill to prevent * any accesses to the poisoned memory. */ - kill_procs(&tokill, !!PageDirty(ppage), trapno, + forcekill = PageDirty(ppage) || (flags & MF_MUST_KILL); + kill_procs(&tokill, forcekill, trapno, ret != SWAP_SUCCESS, p, pfn, flags); return ret; |