The patch titled
Subject: lib/stackdepot, kasan: add flags to __stack_depot_save and rename
has been added to the -mm mm-unstable branch. Its filename is
lib-stackdepot-kasan-add-flags-to-__stack_depot_save-and-rename.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/lib-stackdepot-kasan-add-flags-to-__stack_depot_save-and-rename.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Subject: lib/stackdepot, kasan: add flags to __stack_depot_save and rename
Date: Mon, 20 Nov 2023 18:47:13 +0100
Change the bool can_alloc argument of __stack_depot_save to a u32
argument that accepts a set of flags.
The following patch will add another flag to stack_depot_save_flags
besides the existing STACK_DEPOT_FLAG_CAN_ALLOC.
Also rename the function to stack_depot_save_flags, as
__stack_depot_save is a cryptic name,
Link: https://lkml.kernel.org/r/645fa15239621eebbd3a10331e5864b718839512.1700502145.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>
---
include/linux/stackdepot.h | 36 ++++++++++++++++++++++++-----------
lib/stackdepot.c | 16 ++++++++++-----
mm/kasan/common.c | 7 +++---
mm/kasan/generic.c | 9 ++++----
mm/kasan/kasan.h | 2 -
mm/kasan/tags.c | 3 +-
6 files changed, 48 insertions(+), 25 deletions(-)
--- a/include/linux/stackdepot.h~lib-stackdepot-kasan-add-flags-to-__stack_depot_save-and-rename
+++ a/include/linux/stackdepot.h
@@ -32,6 +32,17 @@ typedef u32 depot_stack_handle_t;
*/
#define STACK_DEPOT_EXTRA_BITS 5
+typedef u32 depot_flags_t;
+
+/*
+ * Flags that can be passed to stack_depot_save_flags(); see the comment next
+ * to its declaration for more details.
+ */
+#define STACK_DEPOT_FLAG_CAN_ALLOC ((depot_flags_t)0x0001)
+
+#define STACK_DEPOT_FLAGS_NUM 1
+#define STACK_DEPOT_FLAGS_MASK ((depot_flags_t)((1 << STACK_DEPOT_FLAGS_NUM) - 1))
+
/*
* Using stack depot requires its initialization, which can be done in 3 ways:
*
@@ -69,31 +80,34 @@ static inline int stack_depot_early_init
#endif
/**
- * __stack_depot_save - Save a stack trace to stack depot
+ * stack_depot_save_flags - Save a stack trace to stack depot
*
* @entries: Pointer to the stack trace
* @nr_entries: Number of frames in the stack
* @alloc_flags: Allocation GFP flags
- * @can_alloc: Allocate stack pools (increased chance of failure if false)
+ * @depot_flags: Stack depot flags
+ *
+ * Saves a stack trace from @entries array of size @nr_entries.
*
- * Saves a stack trace from @entries array of size @nr_entries. If @can_alloc is
- * %true, stack depot can replenish the stack pools in case no space is left
- * (allocates using GFP flags of @alloc_flags). If @can_alloc is %false, avoids
- * any allocations and fails if no space is left to store the stack trace.
+ * If STACK_DEPOT_FLAG_CAN_ALLOC is set in @depot_flags, stack depot can
+ * replenish the stack pools in case no space is left (allocates using GFP
+ * flags of @alloc_flags). Otherwise, stack depot avoids any allocations and
+ * fails if no space is left to store the stack trace.
*
* If the provided stack trace comes from the interrupt context, only the part
* up to the interrupt entry is saved.
*
- * Context: Any context, but setting @can_alloc to %false is required if
+ * Context: Any context, but setting STACK_DEPOT_FLAG_CAN_ALLOC is required if
* alloc_pages() cannot be used from the current context. Currently
* this is the case for contexts where neither %GFP_ATOMIC nor
* %GFP_NOWAIT can be used (NMI, raw_spin_lock).
*
* Return: Handle of the stack struct stored in depot, 0 on failure
*/
-depot_stack_handle_t __stack_depot_save(unsigned long *entries,
- unsigned int nr_entries,
- gfp_t gfp_flags, bool can_alloc);
+depot_stack_handle_t stack_depot_save_flags(unsigned long *entries,
+ unsigned int nr_entries,
+ gfp_t gfp_flags,
+ depot_flags_t depot_flags);
/**
* stack_depot_save - Save a stack trace to stack depot
@@ -103,7 +117,7 @@ depot_stack_handle_t __stack_depot_save(
* @alloc_flags: Allocation GFP flags
*
* Context: Contexts where allocations via alloc_pages() are allowed.
- * See __stack_depot_save() for more details.
+ * See stack_depot_save_flags() for more details.
*
* Return: Handle of the stack trace stored in depot, 0 on failure
*/
--- a/lib/stackdepot.c~lib-stackdepot-kasan-add-flags-to-__stack_depot_save-and-rename
+++ a/lib/stackdepot.c
@@ -450,19 +450,24 @@ static inline struct stack_record *find_
return NULL;
}
-depot_stack_handle_t __stack_depot_save(unsigned long *entries,
- unsigned int nr_entries,
- gfp_t alloc_flags, bool can_alloc)
+depot_stack_handle_t stack_depot_save_flags(unsigned long *entries,
+ unsigned int nr_entries,
+ gfp_t alloc_flags,
+ depot_flags_t depot_flags)
{
struct list_head *bucket;
struct stack_record *found = NULL;
depot_stack_handle_t handle = 0;
struct page *page = NULL;
void *prealloc = NULL;
+ bool can_alloc = depot_flags & STACK_DEPOT_FLAG_CAN_ALLOC;
bool need_alloc = false;
unsigned long flags;
u32 hash;
+ if (WARN_ON(depot_flags & ~STACK_DEPOT_FLAGS_MASK))
+ return 0;
+
/*
* If this stack trace is from an interrupt, including anything before
* interrupt entry usually leads to unbounded stack depot growth.
@@ -541,13 +546,14 @@ exit:
handle = found->handle.handle;
return handle;
}
-EXPORT_SYMBOL_GPL(__stack_depot_save);
+EXPORT_SYMBOL_GPL(stack_depot_save_flags);
depot_stack_handle_t stack_depot_save(unsigned long *entries,
unsigned int nr_entries,
gfp_t alloc_flags)
{
- return __stack_depot_save(entries, nr_entries, alloc_flags, true);
+ return stack_depot_save_flags(entries, nr_entries, alloc_flags,
+ STACK_DEPOT_FLAG_CAN_ALLOC);
}
EXPORT_SYMBOL_GPL(stack_depot_save);
--- a/mm/kasan/common.c~lib-stackdepot-kasan-add-flags-to-__stack_depot_save-and-rename
+++ a/mm/kasan/common.c
@@ -22,6 +22,7 @@
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/slab.h>
+#include <linux/stackdepot.h>
#include <linux/stacktrace.h>
#include <linux/string.h>
#include <linux/types.h>
@@ -37,19 +38,19 @@ struct slab *kasan_addr_to_slab(const vo
return NULL;
}
-depot_stack_handle_t kasan_save_stack(gfp_t flags, bool can_alloc)
+depot_stack_handle_t kasan_save_stack(gfp_t flags, depot_flags_t depot_flags)
{
unsigned long entries[KASAN_STACK_DEPTH];
unsigned int nr_entries;
nr_entries = stack_trace_save(entries, ARRAY_SIZE(entries), 0);
- return __stack_depot_save(entries, nr_entries, flags, can_alloc);
+ return stack_depot_save_flags(entries, nr_entries, flags, depot_flags);
}
void kasan_set_track(struct kasan_track *track, gfp_t flags)
{
track->pid = current->pid;
- track->stack = kasan_save_stack(flags, true);
+ track->stack = kasan_save_stack(flags, STACK_DEPOT_FLAG_CAN_ALLOC);
}
#if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS)
--- a/mm/kasan/generic.c~lib-stackdepot-kasan-add-flags-to-__stack_depot_save-and-rename
+++ a/mm/kasan/generic.c
@@ -25,6 +25,7 @@
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/slab.h>
+#include <linux/stackdepot.h>
#include <linux/stacktrace.h>
#include <linux/string.h>
#include <linux/types.h>
@@ -472,7 +473,7 @@ size_t kasan_metadata_size(struct kmem_c
sizeof(struct kasan_free_meta) : 0);
}
-static void __kasan_record_aux_stack(void *addr, bool can_alloc)
+static void __kasan_record_aux_stack(void *addr, depot_flags_t depot_flags)
{
struct slab *slab = kasan_addr_to_slab(addr);
struct kmem_cache *cache;
@@ -489,17 +490,17 @@ static void __kasan_record_aux_stack(voi
return;
alloc_meta->aux_stack[1] = alloc_meta->aux_stack[0];
- alloc_meta->aux_stack[0] = kasan_save_stack(0, can_alloc);
+ alloc_meta->aux_stack[0] = kasan_save_stack(0, depot_flags);
}
void kasan_record_aux_stack(void *addr)
{
- return __kasan_record_aux_stack(addr, true);
+ return __kasan_record_aux_stack(addr, STACK_DEPOT_FLAG_CAN_ALLOC);
}
void kasan_record_aux_stack_noalloc(void *addr)
{
- return __kasan_record_aux_stack(addr, false);
+ return __kasan_record_aux_stack(addr, 0);
}
void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags)
--- a/mm/kasan/kasan.h~lib-stackdepot-kasan-add-flags-to-__stack_depot_save-and-rename
+++ a/mm/kasan/kasan.h
@@ -368,7 +368,7 @@ static inline void kasan_init_cache_meta
static inline void kasan_init_object_meta(struct kmem_cache *cache, const void *object) { }
#endif
-depot_stack_handle_t kasan_save_stack(gfp_t flags, bool can_alloc);
+depot_stack_handle_t kasan_save_stack(gfp_t flags, depot_flags_t depot_flags);
void kasan_set_track(struct kasan_track *track, gfp_t flags);
void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags);
void kasan_save_free_info(struct kmem_cache *cache, void *object);
--- a/mm/kasan/tags.c~lib-stackdepot-kasan-add-flags-to-__stack_depot_save-and-rename
+++ a/mm/kasan/tags.c
@@ -13,6 +13,7 @@
#include <linux/memblock.h>
#include <linux/memory.h>
#include <linux/mm.h>
+#include <linux/stackdepot.h>
#include <linux/static_key.h>
#include <linux/string.h>
#include <linux/types.h>
@@ -101,7 +102,7 @@ static void save_stack_info(struct kmem_
struct kasan_stack_ring_entry *entry;
void *old_ptr;
- stack = kasan_save_stack(gfp_flags, true);
+ stack = kasan_save_stack(gfp_flags, STACK_DEPOT_FLAG_CAN_ALLOC);
/*
* Prevent save_stack_info() from modifying stack ring
_
Patches currently in -mm which might be from andreyknvl@xxxxxxxxxx are
lib-stackdepot-print-disabled-message-only-if-truly-disabled.patch
lib-stackdepot-check-disabled-flag-when-fetching.patch
lib-stackdepot-simplify-__stack_depot_save.patch
lib-stackdepot-drop-valid-bit-from-handles.patch
lib-stackdepot-add-depot_fetch_stack-helper.patch
lib-stackdepot-use-fixed-sized-slots-for-stack-records.patch
lib-stackdepot-fix-and-clean-up-atomic-annotations.patch
lib-stackdepot-rework-helpers-for-depot_alloc_stack.patch
lib-stackdepot-rename-next_pool_required-to-new_pool_required.patch
lib-stackdepot-store-next-pool-pointer-in-new_pool.patch
lib-stackdepot-store-free-stack-records-in-a-freelist.patch
lib-stackdepot-use-read-write-lock.patch
lib-stackdepot-use-list_head-for-stack-record-links.patch
kmsan-use-stack_depot_save-instead-of-__stack_depot_save.patch
lib-stackdepot-kasan-add-flags-to-__stack_depot_save-and-rename.patch
lib-stackdepot-add-refcount-for-records.patch
lib-stackdepot-allow-users-to-evict-stack-traces.patch
kasan-remove-atomic-accesses-to-stack-ring-entries.patch
kasan-check-object_size-in-kasan_complete_mode_report_info.patch
kasan-use-stack_depot_put-for-tag-based-modes.patch
kasan-use-stack_depot_put-for-generic-mode.patch
lib-stackdepot-adjust-depot_pools_cap-for-kmsan.patch
