The quilt patch titled
Subject: kasan: use stack_depot_put for tag-based modes
has been removed from the -mm tree. Its filename was
kasan-use-stack_depot_put-for-tag-based-modes.patch
This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Subject: kasan: use stack_depot_put for tag-based modes
Date: Mon, 20 Nov 2023 18:47:18 +0100
Make tag-based KASAN modes evict stack traces from the stack depot once
they are evicted from the stack ring.
Internally, pass STACK_DEPOT_FLAG_GET to stack_depot_save_flags (via
kasan_save_stack) to increment the refcount when saving a new entry to
stack ring and call stack_depot_put when removing an entry from stack
ring.
Link: https://lkml.kernel.org/r/b4773e5c1b0b9df6826ec0b65c1923feadfa78e5.1700502145.git.andreyknvl@xxxxxxxxxx
Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Reviewed-by: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Evgenii Stepanov <eugenis@xxxxxxxxxx>
Cc: Marco Elver <elver@xxxxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/kasan/tags.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
--- a/mm/kasan/tags.c~kasan-use-stack_depot_put-for-tag-based-modes
+++ a/mm/kasan/tags.c
@@ -97,12 +97,13 @@ static void save_stack_info(struct kmem_
gfp_t gfp_flags, bool is_free)
{
unsigned long flags;
- depot_stack_handle_t stack;
+ depot_stack_handle_t stack, old_stack;
u64 pos;
struct kasan_stack_ring_entry *entry;
void *old_ptr;
- stack = kasan_save_stack(gfp_flags, STACK_DEPOT_FLAG_CAN_ALLOC);
+ stack = kasan_save_stack(gfp_flags,
+ STACK_DEPOT_FLAG_CAN_ALLOC | STACK_DEPOT_FLAG_GET);
/*
* Prevent save_stack_info() from modifying stack ring
@@ -121,6 +122,8 @@ next:
if (!try_cmpxchg(&entry->ptr, &old_ptr, STACK_RING_BUSY_PTR))
goto next; /* Busy slot. */
+ old_stack = entry->stack;
+
entry->size = cache->object_size;
entry->pid = current->pid;
entry->stack = stack;
@@ -129,6 +132,9 @@ next:
entry->ptr = object;
read_unlock_irqrestore(&stack_ring.lock, flags);
+
+ if (old_stack)
+ stack_depot_put(old_stack);
}
void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags)
_
Patches currently in -mm which might be from andreyknvl@xxxxxxxxxx are
