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Diffstat (limited to 'mm/memory-failure.c')
-rw-r--r--mm/memory-failure.c90
1 files changed, 63 insertions, 27 deletions
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 90002ea43638..33365e9ce6a7 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -208,9 +208,9 @@ static int kill_proc(struct task_struct *t, unsigned long addr, int trapno,
#endif
si.si_addr_lsb = compound_order(compound_head(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
@@ -384,20 +384,51 @@ static void kill_procs(struct list_head *to_kill, int forcekill, int trapno,
}
}
-static int task_early_kill(struct task_struct *tsk)
+/*
+ * Find a dedicated thread which is supposed to handle SIGBUS(BUS_MCEERR_AO)
+ * on behalf of the thread group. Return task_struct of the (first found)
+ * dedicated thread if found, and return NULL otherwise.
+ *
+ * We already hold read_lock(&tasklist_lock) in the caller, so we don't
+ * have to call rcu_read_lock/unlock() in this function.
+ */
+static struct task_struct *find_early_kill_thread(struct task_struct *tsk)
{
+ struct task_struct *t;
+
+ for_each_thread(tsk, t)
+ if ((t->flags & PF_MCE_PROCESS) && (t->flags & PF_MCE_EARLY))
+ return t;
+ return NULL;
+}
+
+/*
+ * Determine whether a given process is "early kill" process which expects
+ * to be signaled when some page under the process is hwpoisoned.
+ * Return task_struct of the dedicated thread (main thread unless explicitly
+ * specified) if the process is "early kill," and otherwise returns NULL.
+ */
+static struct task_struct *task_early_kill(struct task_struct *tsk,
+ int force_early)
+{
+ struct task_struct *t;
if (!tsk->mm)
- return 0;
- if (tsk->flags & PF_MCE_PROCESS)
- return !!(tsk->flags & PF_MCE_EARLY);
- return sysctl_memory_failure_early_kill;
+ return NULL;
+ if (force_early)
+ return tsk;
+ t = find_early_kill_thread(tsk);
+ if (t)
+ return t;
+ if (sysctl_memory_failure_early_kill)
+ return tsk;
+ return NULL;
}
/*
* Collect processes when the error hit an anonymous page.
*/
static void collect_procs_anon(struct page *page, struct list_head *to_kill,
- struct to_kill **tkc)
+ struct to_kill **tkc, int force_early)
{
struct vm_area_struct *vma;
struct task_struct *tsk;
@@ -412,16 +443,17 @@ static void collect_procs_anon(struct page *page, struct list_head *to_kill,
read_lock(&tasklist_lock);
for_each_process (tsk) {
struct anon_vma_chain *vmac;
+ struct task_struct *t = task_early_kill(tsk, force_early);
- if (!task_early_kill(tsk))
+ if (!t)
continue;
anon_vma_interval_tree_foreach(vmac, &av->rb_root,
pgoff, pgoff) {
vma = vmac->vma;
if (!page_mapped_in_vma(page, vma))
continue;
- if (vma->vm_mm == tsk->mm)
- add_to_kill(tsk, page, vma, to_kill, tkc);
+ if (vma->vm_mm == t->mm)
+ add_to_kill(t, page, vma, to_kill, tkc);
}
}
read_unlock(&tasklist_lock);
@@ -432,7 +464,7 @@ static void collect_procs_anon(struct page *page, struct list_head *to_kill,
* Collect processes when the error hit a file mapped page.
*/
static void collect_procs_file(struct page *page, struct list_head *to_kill,
- struct to_kill **tkc)
+ struct to_kill **tkc, int force_early)
{
struct vm_area_struct *vma;
struct task_struct *tsk;
@@ -442,10 +474,10 @@ static void collect_procs_file(struct page *page, struct list_head *to_kill,
read_lock(&tasklist_lock);
for_each_process(tsk) {
pgoff_t pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
+ struct task_struct *t = task_early_kill(tsk, force_early);
- if (!task_early_kill(tsk))
+ if (!t)
continue;
-
vma_interval_tree_foreach(vma, &mapping->i_mmap, pgoff,
pgoff) {
/*
@@ -455,8 +487,8 @@ static void collect_procs_file(struct page *page, struct list_head *to_kill,
* Assume applications who requested early kill want
* to be informed of all such data corruptions.
*/
- if (vma->vm_mm == tsk->mm)
- add_to_kill(tsk, page, vma, to_kill, tkc);
+ if (vma->vm_mm == t->mm)
+ add_to_kill(t, page, vma, to_kill, tkc);
}
}
read_unlock(&tasklist_lock);
@@ -469,7 +501,8 @@ static void collect_procs_file(struct page *page, struct list_head *to_kill,
* First preallocate one tokill structure outside the spin locks,
* so that we can kill at least one process reasonably reliable.
*/
-static void collect_procs(struct page *page, struct list_head *tokill)
+static void collect_procs(struct page *page, struct list_head *tokill,
+ int force_early)
{
struct to_kill *tk;
@@ -480,9 +513,9 @@ static void collect_procs(struct page *page, struct list_head *tokill)
if (!tk)
return;
if (PageAnon(page))
- collect_procs_anon(page, tokill, &tk);
+ collect_procs_anon(page, tokill, &tk, force_early);
else
- collect_procs_file(page, tokill, &tk);
+ collect_procs_file(page, tokill, &tk, force_early);
kfree(tk);
}
@@ -967,7 +1000,7 @@ static int hwpoison_user_mappings(struct page *p, unsigned long pfn,
* there's nothing that can be done.
*/
if (kill)
- collect_procs(ppage, &tokill);
+ collect_procs(ppage, &tokill, flags & MF_ACTION_REQUIRED);
ret = try_to_unmap(ppage, ttu);
if (ret != SWAP_SUCCESS)
@@ -1085,15 +1118,16 @@ int memory_failure(unsigned long pfn, int trapno, int flags)
return 0;
} else if (PageHuge(hpage)) {
/*
- * Check "just unpoisoned", "filter hit", and
- * "race with other subpage."
+ * Check "filter hit" and "race with other subpage."
*/
lock_page(hpage);
- if (!PageHWPoison(hpage)
- || (hwpoison_filter(p) && TestClearPageHWPoison(p))
- || (p != hpage && TestSetPageHWPoison(hpage))) {
- atomic_long_sub(nr_pages, &num_poisoned_pages);
- return 0;
+ if (PageHWPoison(hpage)) {
+ if ((hwpoison_filter(p) && TestClearPageHWPoison(p))
+ || (p != hpage && TestSetPageHWPoison(hpage))) {
+ atomic_long_sub(nr_pages, &num_poisoned_pages);
+ unlock_page(hpage);
+ return 0;
+ }
}
set_page_hwpoison_huge_page(hpage);
res = dequeue_hwpoisoned_huge_page(hpage);
@@ -1156,6 +1190,8 @@ int memory_failure(unsigned long pfn, int trapno, int flags)
*/
if (!PageHWPoison(p)) {
printk(KERN_ERR "MCE %#lx: just unpoisoned\n", pfn);
+ atomic_long_sub(nr_pages, &num_poisoned_pages);
+ put_page(hpage);
res = 0;
goto out;
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-30 10:36:58 +0000