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authorLinus Torvalds2022-05-26 12:32:41 -0700
committerLinus Torvalds2022-05-26 12:32:41 -0700
commit98931dd95fd489fcbfa97da563505a6f071d7c77 (patch)
tree44683fc4a92efa614acdca2742a7ff19d26da1e3 /mm/kfence
parentdf202b452fe6c6d6f1351bad485e2367ef1e644e (diff)
parentf403f22f8ccb12860b2b62fec3173c6ccd45938b (diff)
Merge tag 'mm-stable-2022-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton: "Almost all of MM here. A few things are still getting finished off, reviewed, etc. - Yang Shi has improved the behaviour of khugepaged collapsing of readonly file-backed transparent hugepages. - Johannes Weiner has arranged for zswap memory use to be tracked and managed on a per-cgroup basis. - Munchun Song adds a /proc knob ("hugetlb_optimize_vmemmap") for runtime enablement of the recent huge page vmemmap optimization feature. - Baolin Wang contributes a series to fix some issues around hugetlb pagetable invalidation. - Zhenwei Pi has fixed some interactions between hwpoisoned pages and virtualization. - Tong Tiangen has enabled the use of the presently x86-only page_table_check debugging feature on arm64 and riscv. - David Vernet has done some fixup work on the memcg selftests. - Peter Xu has taught userfaultfd to handle write protection faults against shmem- and hugetlbfs-backed files. - More DAMON development from SeongJae Park - adding online tuning of the feature and support for monitoring of fixed virtual address ranges. Also easier discovery of which monitoring operations are available. - Nadav Amit has done some optimization of TLB flushing during mprotect(). - Neil Brown continues to labor away at improving our swap-over-NFS support. - David Hildenbrand has some fixes to anon page COWing versus get_user_pages(). - Peng Liu fixed some errors in the core hugetlb code. - Joao Martins has reduced the amount of memory consumed by device-dax's compound devmaps. - Some cleanups of the arch-specific pagemap code from Anshuman Khandual. - Muchun Song has found and fixed some errors in the TLB flushing of transparent hugepages. - Roman Gushchin has done more work on the memcg selftests. ... and, of course, many smaller fixes and cleanups. Notably, the customary million cleanup serieses from Miaohe Lin" * tag 'mm-stable-2022-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (381 commits) mm: kfence: use PAGE_ALIGNED helper selftests: vm: add the "settings" file with timeout variable selftests: vm: add "test_hmm.sh" to TEST_FILES selftests: vm: check numa_available() before operating "merge_across_nodes" in ksm_tests selftests: vm: add migration to the .gitignore selftests/vm/pkeys: fix typo in comment ksm: fix typo in comment selftests: vm: add process_mrelease tests Revert "mm/vmscan: never demote for memcg reclaim" mm/kfence: print disabling or re-enabling message include/trace/events/percpu.h: cleanup for "percpu: improve percpu_alloc_percpu event trace" include/trace/events/mmflags.h: cleanup for "tracing: incorrect gfp_t conversion" mm: fix a potential infinite loop in start_isolate_page_range() MAINTAINERS: add Muchun as co-maintainer for HugeTLB zram: fix Kconfig dependency warning mm/shmem: fix shmem folio swapoff hang cgroup: fix an error handling path in alloc_pagecache_max_30M() mm: damon: use HPAGE_PMD_SIZE tracing: incorrect isolate_mote_t cast in mm_vmscan_lru_isolate nodemask.h: fix compilation error with GCC12 ...
Diffstat (limited to 'mm/kfence')
-rw-r--r--mm/kfence/core.c40
-rw-r--r--mm/kfence/kfence_test.c5
2 files changed, 41 insertions, 4 deletions
diff --git a/mm/kfence/core.c b/mm/kfence/core.c
index 11a954763be9..4e7cd4c8e687 100644
--- a/mm/kfence/core.c
+++ b/mm/kfence/core.c
@@ -21,6 +21,8 @@
#include <linux/log2.h>
#include <linux/memblock.h>
#include <linux/moduleparam.h>
+#include <linux/notifier.h>
+#include <linux/panic_notifier.h>
#include <linux/random.h>
#include <linux/rcupdate.h>
#include <linux/sched/clock.h>
@@ -67,8 +69,11 @@ static int param_set_sample_interval(const char *val, const struct kernel_param
if (ret < 0)
return ret;
- if (!num) /* Using 0 to indicate KFENCE is disabled. */
+ /* Using 0 to indicate KFENCE is disabled. */
+ if (!num && READ_ONCE(kfence_enabled)) {
+ pr_info("disabled\n");
WRITE_ONCE(kfence_enabled, false);
+ }
*((unsigned long *)kp->arg) = num;
@@ -99,6 +104,10 @@ module_param_named(skip_covered_thresh, kfence_skip_covered_thresh, ulong, 0644)
static bool kfence_deferrable __read_mostly = IS_ENABLED(CONFIG_KFENCE_DEFERRABLE);
module_param_named(deferrable, kfence_deferrable, bool, 0444);
+/* If true, check all canary bytes on panic. */
+static bool kfence_check_on_panic __read_mostly;
+module_param_named(check_on_panic, kfence_check_on_panic, bool, 0444);
+
/* The pool of pages used for guard pages and objects. */
char *__kfence_pool __read_mostly;
EXPORT_SYMBOL(__kfence_pool); /* Export for test modules. */
@@ -737,6 +746,31 @@ static int __init kfence_debugfs_init(void)
late_initcall(kfence_debugfs_init);
+/* === Panic Notifier ====================================================== */
+
+static void kfence_check_all_canary(void)
+{
+ int i;
+
+ for (i = 0; i < CONFIG_KFENCE_NUM_OBJECTS; i++) {
+ struct kfence_metadata *meta = &kfence_metadata[i];
+
+ if (meta->state == KFENCE_OBJECT_ALLOCATED)
+ for_each_canary(meta, check_canary_byte);
+ }
+}
+
+static int kfence_check_canary_callback(struct notifier_block *nb,
+ unsigned long reason, void *arg)
+{
+ kfence_check_all_canary();
+ return NOTIFY_OK;
+}
+
+static struct notifier_block kfence_check_canary_notifier = {
+ .notifier_call = kfence_check_canary_callback,
+};
+
/* === Allocation Gate Timer ================================================ */
static struct delayed_work kfence_timer;
@@ -814,6 +848,9 @@ static void kfence_init_enable(void)
else
INIT_DELAYED_WORK(&kfence_timer, toggle_allocation_gate);
+ if (kfence_check_on_panic)
+ atomic_notifier_chain_register(&panic_notifier_list, &kfence_check_canary_notifier);
+
WRITE_ONCE(kfence_enabled, true);
queue_delayed_work(system_unbound_wq, &kfence_timer, 0);
@@ -874,6 +911,7 @@ static int kfence_enable_late(void)
WRITE_ONCE(kfence_enabled, true);
queue_delayed_work(system_unbound_wq, &kfence_timer, 0);
+ pr_info("re-enabled\n");
return 0;
}
diff --git a/mm/kfence/kfence_test.c b/mm/kfence/kfence_test.c
index 96206a4ee9ab..a97bffe0cc3e 100644
--- a/mm/kfence/kfence_test.c
+++ b/mm/kfence/kfence_test.c
@@ -296,10 +296,9 @@ static void *test_alloc(struct kunit *test, size_t size, gfp_t gfp, enum allocat
if (policy == ALLOCATE_ANY)
return alloc;
- if (policy == ALLOCATE_LEFT && IS_ALIGNED((unsigned long)alloc, PAGE_SIZE))
+ if (policy == ALLOCATE_LEFT && PAGE_ALIGNED(alloc))
return alloc;
- if (policy == ALLOCATE_RIGHT &&
- !IS_ALIGNED((unsigned long)alloc, PAGE_SIZE))
+ if (policy == ALLOCATE_RIGHT && !PAGE_ALIGNED(alloc))
return alloc;
} else if (policy == ALLOCATE_NONE)
return alloc;