From mboxrd@z Thu Jan 1 00:00:00 1970 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 F0FB2C43219 for ; Mon, 3 Oct 2022 21:14:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229924AbiJCVOj (ORCPT ); Mon, 3 Oct 2022 17:14:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56206 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230072AbiJCVNV (ORCPT ); Mon, 3 Oct 2022 17:13:21 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ADBED52E5C for ; Mon, 3 Oct 2022 14:08:08 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 64D57B811BF for ; Mon, 3 Oct 2022 21:08:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 10364C433C1; Mon, 3 Oct 2022 21:08:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1664831286; bh=5DY0ve27uGT2hb0ubKnitk8TP1sC5IwfXIkBw/1svEo=; h=Date:To:From:Subject:From; b=012/rRnH1BFxrzUzTjmpIL2m0em88q4jexRGGXg+bT05lYbZBJYjxGLLwUJ4eO7pe H75hQr0r8lPTAWSJOkLWk3aSAUaXWNZj00azrJZA46Yx89UG3RtpB09dX31OuzhDpi QTSTLyDTjQdmffsCkN1u5OuWvud43uZDvLvw02uE= Date: Mon, 03 Oct 2022 14:08:05 -0700 To: mm-commits@vger.kernel.org, willy@infradead.org, viro@zeniv.linux.org.uk, vegard.nossum@oracle.com, vbabka@suse.cz, tglx@linutronix.de, sfr@canb.auug.org.au, rostedt@goodmis.org, rientjes@google.com, pmladek@suse.com, peterz@infradead.org, penberg@kernel.org, mst@redhat.com, mingo@redhat.com, mark.rutland@arm.com, luto@kernel.org, keescook@chromium.org, iii@linux.ibm.com, iamjoonsoo.kim@lge.com, herbert@gondor.apana.org.au, hch@lst.de, gregkh@linuxfoundation.org, gor@linux.ibm.com, elver@google.com, edumazet@google.com, ebiggers@kernel.org, ebiggers@google.com, dvyukov@google.com, cl@linux.com, bp@alien8.de, axboe@kernel.dk, ast@kernel.org, arnd@arndb.de, andreyknvl@google.com, andreyknvl@gmail.com, glider@google.com, akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] stackdepot-reserve-5-extra-bits-in-depot_stack_handle_t.patch removed from -mm tree Message-Id: <20221003210806.10364C433C1@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The quilt patch titled Subject: stackdepot: reserve 5 extra bits in depot_stack_handle_t has been removed from the -mm tree. Its filename was stackdepot-reserve-5-extra-bits-in-depot_stack_handle_t.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: Alexander Potapenko Subject: stackdepot: reserve 5 extra bits in depot_stack_handle_t Date: Thu, 15 Sep 2022 17:03:36 +0200 Some users (currently only KMSAN) may want to use spare bits in depot_stack_handle_t. Let them do so by adding @extra_bits to __stack_depot_save() to store arbitrary flags, and providing stack_depot_get_extra_bits() to retrieve those flags. Also adapt KASAN to the new prototype by passing extra_bits=0, as KASAN does not intend to store additional information in the stack handle. Link: https://lkml.kernel.org/r/20220915150417.722975-3-glider@google.com Signed-off-by: Alexander Potapenko Reviewed-by: Marco Elver Cc: Alexander Viro Cc: Alexei Starovoitov Cc: Andrey Konovalov Cc: Andrey Konovalov Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Christoph Hellwig Cc: Christoph Lameter Cc: David Rientjes Cc: Dmitry Vyukov Cc: Eric Biggers Cc: Eric Biggers Cc: Eric Dumazet Cc: Greg Kroah-Hartman Cc: Herbert Xu Cc: Ilya Leoshkevich Cc: Ingo Molnar Cc: Jens Axboe Cc: Joonsoo Kim Cc: Kees Cook Cc: Mark Rutland Cc: Matthew Wilcox Cc: Michael S. Tsirkin Cc: Pekka Enberg Cc: Peter Zijlstra Cc: Petr Mladek Cc: Stephen Rothwell Cc: Steven Rostedt Cc: Thomas Gleixner Cc: Vasily Gorbik Cc: Vegard Nossum Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- include/linux/stackdepot.h | 8 ++++++++ lib/stackdepot.c | 29 ++++++++++++++++++++++++----- mm/kasan/common.c | 2 +- 3 files changed, 33 insertions(+), 6 deletions(-) --- a/include/linux/stackdepot.h~stackdepot-reserve-5-extra-bits-in-depot_stack_handle_t +++ a/include/linux/stackdepot.h @@ -14,9 +14,15 @@ #include typedef u32 depot_stack_handle_t; +/* + * Number of bits in the handle that stack depot doesn't use. Users may store + * information in them. + */ +#define STACK_DEPOT_EXTRA_BITS 5 depot_stack_handle_t __stack_depot_save(unsigned long *entries, unsigned int nr_entries, + unsigned int extra_bits, gfp_t gfp_flags, bool can_alloc); /* @@ -59,6 +65,8 @@ depot_stack_handle_t stack_depot_save(un unsigned int stack_depot_fetch(depot_stack_handle_t handle, unsigned long **entries); +unsigned int stack_depot_get_extra_bits(depot_stack_handle_t handle); + int stack_depot_snprint(depot_stack_handle_t handle, char *buf, size_t size, int spaces); --- a/lib/stackdepot.c~stackdepot-reserve-5-extra-bits-in-depot_stack_handle_t +++ a/lib/stackdepot.c @@ -43,7 +43,8 @@ #define STACK_ALLOC_OFFSET_BITS (STACK_ALLOC_ORDER + PAGE_SHIFT - \ STACK_ALLOC_ALIGN) #define STACK_ALLOC_INDEX_BITS (DEPOT_STACK_BITS - \ - STACK_ALLOC_NULL_PROTECTION_BITS - STACK_ALLOC_OFFSET_BITS) + STACK_ALLOC_NULL_PROTECTION_BITS - \ + STACK_ALLOC_OFFSET_BITS - STACK_DEPOT_EXTRA_BITS) #define STACK_ALLOC_SLABS_CAP 8192 #define STACK_ALLOC_MAX_SLABS \ (((1LL << (STACK_ALLOC_INDEX_BITS)) < STACK_ALLOC_SLABS_CAP) ? \ @@ -56,6 +57,7 @@ union handle_parts { u32 slabindex : STACK_ALLOC_INDEX_BITS; u32 offset : STACK_ALLOC_OFFSET_BITS; u32 valid : STACK_ALLOC_NULL_PROTECTION_BITS; + u32 extra : STACK_DEPOT_EXTRA_BITS; }; }; @@ -77,6 +79,14 @@ static int next_slab_inited; static size_t depot_offset; static DEFINE_RAW_SPINLOCK(depot_lock); +unsigned int stack_depot_get_extra_bits(depot_stack_handle_t handle) +{ + union handle_parts parts = { .handle = handle }; + + return parts.extra; +} +EXPORT_SYMBOL(stack_depot_get_extra_bits); + static bool init_stack_slab(void **prealloc) { if (!*prealloc) @@ -140,6 +150,7 @@ depot_alloc_stack(unsigned long *entries stack->handle.slabindex = depot_index; stack->handle.offset = depot_offset >> STACK_ALLOC_ALIGN; stack->handle.valid = 1; + stack->handle.extra = 0; memcpy(stack->entries, entries, flex_array_size(stack, entries, size)); depot_offset += required_size; @@ -382,6 +393,7 @@ EXPORT_SYMBOL_GPL(stack_depot_fetch); * * @entries: Pointer to storage array * @nr_entries: Size of the storage array + * @extra_bits: Flags to store in unused bits of depot_stack_handle_t * @alloc_flags: Allocation gfp flags * @can_alloc: Allocate stack slabs (increased chance of failure if false) * @@ -393,6 +405,10 @@ EXPORT_SYMBOL_GPL(stack_depot_fetch); * If the stack trace in @entries is from an interrupt, only the portion up to * interrupt entry is saved. * + * Additional opaque flags can be passed in @extra_bits, stored in the unused + * bits of the stack handle, and retrieved using stack_depot_get_extra_bits() + * without calling stack_depot_fetch(). + * * Context: Any context, but setting @can_alloc to %false is required if * alloc_pages() cannot be used from the current context. Currently * this is the case from contexts where neither %GFP_ATOMIC nor @@ -402,10 +418,11 @@ EXPORT_SYMBOL_GPL(stack_depot_fetch); */ depot_stack_handle_t __stack_depot_save(unsigned long *entries, unsigned int nr_entries, + unsigned int extra_bits, gfp_t alloc_flags, bool can_alloc) { struct stack_record *found = NULL, **bucket; - depot_stack_handle_t retval = 0; + union handle_parts retval = { .handle = 0 }; struct page *page = NULL; void *prealloc = NULL; unsigned long flags; @@ -489,9 +506,11 @@ exit: free_pages((unsigned long)prealloc, STACK_ALLOC_ORDER); } if (found) - retval = found->handle.handle; + retval.handle = found->handle.handle; fast_exit: - return retval; + retval.extra = extra_bits; + + return retval.handle; } EXPORT_SYMBOL_GPL(__stack_depot_save); @@ -511,6 +530,6 @@ depot_stack_handle_t stack_depot_save(un unsigned int nr_entries, gfp_t alloc_flags) { - return __stack_depot_save(entries, nr_entries, alloc_flags, true); + return __stack_depot_save(entries, nr_entries, 0, alloc_flags, true); } EXPORT_SYMBOL_GPL(stack_depot_save); --- a/mm/kasan/common.c~stackdepot-reserve-5-extra-bits-in-depot_stack_handle_t +++ a/mm/kasan/common.c @@ -43,7 +43,7 @@ depot_stack_handle_t kasan_save_stack(gf 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(entries, nr_entries, 0, flags, can_alloc); } void kasan_set_track(struct kasan_track *track, gfp_t flags) _ Patches currently in -mm which might be from glider@google.com are