From nobody Sun Dec 14 05:53:25 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4E150C2BB3F for ; Mon, 20 Nov 2023 17:50:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234664AbjKTRuQ (ORCPT ); Mon, 20 Nov 2023 12:50:16 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49314 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234309AbjKTRtu (ORCPT ); Mon, 20 Nov 2023 12:49:50 -0500 Received: from out-176.mta0.migadu.com (out-176.mta0.migadu.com [91.218.175.176]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4B36A10E6 for ; Mon, 20 Nov 2023 09:49:41 -0800 (PST) X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1700502579; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=aXTF/ovgO7tSDGaC/rtVyVWMqky+xGAg2LPsWIiIw38=; b=HqbyNSHD4r9vYA816UIOJaXgIqcjElz6erC2e41iS8jUsO6pNaIMU40yawD+G8CERk8/mB qdv7+Ypo8jZ0ZcLL7hUCGbmu0MDX0b6jRsskfd3hDjPvU8Dgx5Nmli1NgQFC70MO8T/FHR /N3gcwtihjoZvi89Omg8LoW5wxj9aNk= From: andrey.konovalov@linux.dev To: Andrew Morton Cc: Andrey Konovalov , Marco Elver , Alexander Potapenko , Dmitry Vyukov , Vlastimil Babka , kasan-dev@googlegroups.com, Evgenii Stepanov , Oscar Salvador , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrey Konovalov Subject: [PATCH v4 15/22] lib/stackdepot, kasan: add flags to __stack_depot_save and rename Date: Mon, 20 Nov 2023 18:47:13 +0100 Message-Id: <645fa15239621eebbd3a10331e5864b718839512.1700502145.git.andreyknvl@google.com> In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: Andrey Konovalov 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, Reviewed-by: Alexander Potapenko Signed-off-by: Andrey Konovalov --- Changes v2->v3: - WARN_ON invalid flags in stack_depot_save_flags. Changes v1->v2: - This is a new patch. --- 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(-) diff --git a/include/linux/stackdepot.h b/include/linux/stackdepot.h index e58306783d8e..0b262e14144e 100644 --- a/include/linux/stackdepot.h +++ b/include/linux/stackdepot.h @@ -32,6 +32,17 @@ typedef u32 depot_stack_handle_t; */ #define STACK_DEPOT_EXTRA_BITS 5 =20 +typedef u32 depot_flags_t; + +/* + * Flags that can be passed to stack_depot_save_flags(); see the comment n= ext + * 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_NU= M) - 1)) + /* * Using stack depot requires its initialization, which can be done in 3 w= ays: * @@ -69,31 +80,34 @@ static inline int stack_depot_early_init(void) { return= 0; } #endif =20 /** - * __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_al= loc is - * %true, stack depot can replenish the stack pools in case no space is le= ft - * (allocates using GFP flags of @alloc_flags). If @can_alloc is %false, a= voids - * 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 a= nd + * 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 require= d if * alloc_pages() cannot be used from the current context. Current= ly * 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); =20 /** * stack_depot_save - Save a stack trace to stack depot @@ -103,7 +117,7 @@ depot_stack_handle_t __stack_depot_save(unsigned long *= entries, * @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 */ diff --git a/lib/stackdepot.c b/lib/stackdepot.c index 4bb0af423f82..59d61d5c09a7 100644 --- a/lib/stackdepot.c +++ b/lib/stackdepot.c @@ -450,19 +450,24 @@ static inline struct stack_record *find_stack(struct = list_head *bucket, return NULL; } =20 -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 =3D NULL; depot_stack_handle_t handle =3D 0; struct page *page =3D NULL; void *prealloc =3D NULL; + bool can_alloc =3D depot_flags & STACK_DEPOT_FLAG_CAN_ALLOC; bool need_alloc =3D false; unsigned long flags; u32 hash; =20 + 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 @@ depot_stack_handle_t __stack_depot_save(unsigned long= *entries, handle =3D found->handle.handle; return handle; } -EXPORT_SYMBOL_GPL(__stack_depot_save); +EXPORT_SYMBOL_GPL(stack_depot_save_flags); =20 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); =20 diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 256930da578a..825a0240ec02 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include #include @@ -37,19 +38,19 @@ struct slab *kasan_addr_to_slab(const void *addr) return NULL; } =20 -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_fla= gs) { unsigned long entries[KASAN_STACK_DEPTH]; unsigned int nr_entries; =20 nr_entries =3D 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); } =20 void kasan_set_track(struct kasan_track *track, gfp_t flags) { track->pid =3D current->pid; - track->stack =3D kasan_save_stack(flags, true); + track->stack =3D kasan_save_stack(flags, STACK_DEPOT_FLAG_CAN_ALLOC); } =20 #if defined(CONFIG_KASAN_GENERIC) || defined(CONFIG_KASAN_SW_TAGS) diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c index 4d837ab83f08..5d168c9afb32 100644 --- a/mm/kasan/generic.c +++ b/mm/kasan/generic.c @@ -25,6 +25,7 @@ #include #include #include +#include #include #include #include @@ -472,7 +473,7 @@ size_t kasan_metadata_size(struct kmem_cache *cache, bo= ol in_object) sizeof(struct kasan_free_meta) : 0); } =20 -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 =3D kasan_addr_to_slab(addr); struct kmem_cache *cache; @@ -489,17 +490,17 @@ static void __kasan_record_aux_stack(void *addr, bool= can_alloc) return; =20 alloc_meta->aux_stack[1] =3D alloc_meta->aux_stack[0]; - alloc_meta->aux_stack[0] =3D kasan_save_stack(0, can_alloc); + alloc_meta->aux_stack[0] =3D kasan_save_stack(0, depot_flags); } =20 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); } =20 void kasan_record_aux_stack_noalloc(void *addr) { - return __kasan_record_aux_stack(addr, false); + return __kasan_record_aux_stack(addr, 0); } =20 void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t f= lags) diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index 8b06bab5c406..b29d46b83d1f 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -368,7 +368,7 @@ static inline void kasan_init_cache_meta(struct kmem_ca= che *cache, unsigned int static inline void kasan_init_object_meta(struct kmem_cache *cache, const = void *object) { } #endif =20 -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_fla= gs); void kasan_set_track(struct kasan_track *track, gfp_t flags); void kasan_save_alloc_info(struct kmem_cache *cache, void *object, gfp_t f= lags); void kasan_save_free_info(struct kmem_cache *cache, void *object); diff --git a/mm/kasan/tags.c b/mm/kasan/tags.c index 7dcfe341d48e..4fd32121b0fd 100644 --- a/mm/kasan/tags.c +++ b/mm/kasan/tags.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include #include @@ -101,7 +102,7 @@ static void save_stack_info(struct kmem_cache *cache, v= oid *object, struct kasan_stack_ring_entry *entry; void *old_ptr; =20 - stack =3D kasan_save_stack(gfp_flags, true); + stack =3D kasan_save_stack(gfp_flags, STACK_DEPOT_FLAG_CAN_ALLOC); =20 /* * Prevent save_stack_info() from modifying stack ring --=20 2.25.1