From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 81DC35684 for ; Thu, 20 Jun 2024 00:58:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718845130; cv=none; b=pK31n91rebAqNeA8KXnaQHWzd0Zhxbp2CmwFjOzi33K8z5HKHASkUSChLJK4pCL3vwJ6HtoOJa7VV5bXo7oGb67PIjd0sTD4j1Vpy3xykXvQlDUVAzNDmteo8UnmsFnJlAZXe0v5o9qekQVbtkA5tdFV7+A7gxeYzP8GNFMABPs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718845130; c=relaxed/simple; bh=kmNat4ChqAX97LQEvDmx+SoRGwXsNgbcFv1Eydq/FdY=; h=Date:To:From:Subject:Message-Id; b=Qc5xhUW5Ce88Rf6maiS2giCdCY0qw3QFC3GyUGwTqL+xPFI4u74FIup+4c14jnQCxzVjYGQwZtQMHHZ4GdV1+ydel5s73fTh9alHa0zZwYZlahuSZPNB8mP79wzPvs96eqkQTB47raLAviqzgJCJ+GaQNKV3CoUgURjjkZLex4Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=PuiKoXbw; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="PuiKoXbw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 52650C2BBFC; Thu, 20 Jun 2024 00:58:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1718845130; bh=kmNat4ChqAX97LQEvDmx+SoRGwXsNgbcFv1Eydq/FdY=; h=Date:To:From:Subject:From; b=PuiKoXbw+SngoVTRbxpUJn0daC8AvXR9QgaZwao6QN4qtSl4WY+XSJtbX+Ks8QuPv hLbomONsO4iWYru6Ky86MCNWDoWIpBSq6fVm5I94Af0DpDNlBvanzuDqDXTlyXlKV0 eNWecmxAzLUgtXW3LZ4uX+/8JCK/Pcjop2hlWJiM= Date: Wed, 19 Jun 2024 17:58:49 -0700 To: mm-commits@vger.kernel.org,vbabka@suse.cz,svens@linux.ibm.com,rostedt@goodmis.org,roman.gushchin@linux.dev,rientjes@google.com,penberg@kernel.org,mhiramat@kernel.org,mark.rutland@arm.com,kasan-dev@googlegroups.com,iamjoonsoo.kim@lge.com,hca@linux.ibm.com,gor@linux.ibm.com,glider@google.com,elver@google.com,dvyukov@google.com,cl@linux.com,borntraeger@linux.ibm.com,agordeev@linux.ibm.com,42.hyeyoo@gmail.com,iii@linux.ibm.com,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-kfence-disable-kmsan-when-checking-the-canary.patch added to mm-unstable branch Message-Id: <20240620005850.52650C2BBFC@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm: kfence: disable KMSAN when checking the canary has been added to the -mm mm-unstable branch. Its filename is mm-kfence-disable-kmsan-when-checking-the-canary.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-kfence-disable-kmsan-when-checking-the-canary.patch This patch will later appear in the mm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Ilya Leoshkevich Subject: mm: kfence: disable KMSAN when checking the canary Date: Wed, 19 Jun 2024 17:43:53 +0200 KMSAN warns about check_canary() accessing the canary. The reason is that, even though set_canary() is properly instrumented and sets shadow, slub explicitly poisons the canary's address range afterwards. Unpoisoning the canary is not the right thing to do: only check_canary() is supposed to ever touch it. Instead, disable KMSAN checks around canary read accesses. Link: https://lkml.kernel.org/r/20240619154530.163232-19-iii@linux.ibm.com Signed-off-by: Ilya Leoshkevich Reviewed-by: Alexander Potapenko Tested-by: Alexander Potapenko Cc: Alexander Gordeev Cc: Christian Borntraeger Cc: Christoph Lameter Cc: David Rientjes Cc: Dmitry Vyukov Cc: Heiko Carstens Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Joonsoo Kim Cc: Cc: Marco Elver Cc: Mark Rutland Cc: Masami Hiramatsu (Google) Cc: Pekka Enberg Cc: Roman Gushchin Cc: Steven Rostedt (Google) Cc: Sven Schnelle Cc: Vasily Gorbik Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- mm/kfence/core.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) --- a/mm/kfence/core.c~mm-kfence-disable-kmsan-when-checking-the-canary +++ a/mm/kfence/core.c @@ -305,8 +305,14 @@ metadata_update_state(struct kfence_meta WRITE_ONCE(meta->state, next); } +#ifdef CONFIG_KMSAN +#define check_canary_attributes noinline __no_kmsan_checks +#else +#define check_canary_attributes inline +#endif + /* Check canary byte at @addr. */ -static inline bool check_canary_byte(u8 *addr) +static check_canary_attributes bool check_canary_byte(u8 *addr) { struct kfence_metadata *meta; unsigned long flags; @@ -341,7 +347,8 @@ static inline void set_canary(const stru *((u64 *)addr) = KFENCE_CANARY_PATTERN_U64; } -static inline void check_canary(const struct kfence_metadata *meta) +static check_canary_attributes void +check_canary(const struct kfence_metadata *meta) { const unsigned long pageaddr = ALIGN_DOWN(meta->addr, PAGE_SIZE); unsigned long addr = pageaddr; _ Patches currently in -mm which might be from iii@linux.ibm.com are ftrace-unpoison-ftrace_regs-in-ftrace_ops_list_func.patch kmsan-make-the-tests-compatible-with-kmsanpanic=1.patch kmsan-disable-kmsan-when-deferred_struct_page_init-is-enabled.patch kmsan-increase-the-maximum-store-size-to-4096.patch kmsan-fix-is_bad_asm_addr-on-arches-with-overlapping-address-spaces.patch kmsan-fix-kmsan_copy_to_user-on-arches-with-overlapping-address-spaces.patch kmsan-remove-a-useless-assignment-from-kmsan_vmap_pages_range_noflush.patch kmsan-remove-an-x86-specific-include-from-kmsanh.patch kmsan-expose-kmsan_get_metadata.patch kmsan-export-panic_on_kmsan.patch kmsan-allow-disabling-kmsan-checks-for-the-current-task.patch kmsan-introduce-memset_no_sanitize_memory.patch kmsan-support-slab_poison.patch kmsan-use-align_down-in-kmsan_get_metadata.patch kmsan-do-not-round-up-pg_data_t-size.patch mm-slub-let-kmsan-access-metadata.patch mm-slub-disable-kmsan-when-checking-the-padding-bytes.patch mm-kfence-disable-kmsan-when-checking-the-canary.patch lib-zlib-unpoison-dfltcc-output-buffers.patch kmsan-accept-ranges-starting-with-0-on-s390.patch s390-boot-turn-off-kmsan.patch s390-use-a-larger-stack-for-kmsan.patch s390-boot-add-the-kmsan-runtime-stub.patch s390-checksum-add-a-kmsan-check.patch s390-cpacf-unpoison-the-results-of-cpacf_trng.patch s390-cpumf-unpoison-stcctm-output-buffer.patch s390-diag-unpoison-diag224-output-buffer.patch s390-ftrace-unpoison-ftrace_regs-in-kprobe_ftrace_handler.patch s390-irqflags-do-not-instrument-arch_local_irq_-with-kmsan.patch s390-mm-define-kmsan-metadata-for-vmalloc-and-modules.patch s390-string-add-kmsan-support.patch s390-traps-unpoison-the-kernel_stack_overflows-pt_regs.patch s390-uaccess-add-kmsan-support-to-put_user-and-get_user.patch s390-uaccess-add-the-missing-linux-instrumentedh-include.patch s390-unwind-disable-kmsan-checks.patch s390-kmsan-implement-the-architecture-specific-functions.patch kmsan-enable-on-s390.patch