From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 62D943128B8 for ; Sun, 6 Sep 2026 02:05:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788660354; cv=none; b=Cq5C75wZY3MXOJDJ+SMc0XWwK3YEf4ABPLnOkm2vhfpEEWKvpxvedoegKvVaeaGi9ofTbyMe1+EVwKdiIB5Qcrj9kZ6OXJWW1udqiIqzT0b8uGBiGX1rRxYPN0TNBzSGPPPWcyzV+2IOwrH3PzCcR5IC0hiajgVGDN4EHDM2LlY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788660354; c=relaxed/simple; bh=u9VhSg4GHHPUviAjeJSij3o5/2Dhnm6UrGdhZW154e8=; h=Date:To:From:Subject:Message-Id; b=HGDI5hUzfSOdEljc3U/srsoc8BvlhWIGKMNjrRPTEEkQ7LV9l8nDb5BtcaeleAF9P/J1EfjYjXg+6gzXXefYB6g8vJQt0nbK1c4PJdJJF0B0jZRMB5DiPSoEgny/HyetXUNzrXMrjECBHVREdvFM3nQrUMznrZAGGmJGUmRliZ4= 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=gc3oEFjK; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="gc3oEFjK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D31901F00A3D; Sun, 6 Sep 2026 02:05:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1788660352; bh=5k3crMXmR2YnFPempFktpPzKaLUbbTTuCGGCvt2msoQ=; h=Date:To:From:Subject; b=gc3oEFjKpyLdWzy+f9HtX5or20pPvHnWAHEHBlRqZaqfwRppG3BIw+N7VadkF1t7O 23kg+1Y6Djadk1RToQJRwZVhiuV3Vgb8GY4wsqDwdk5Z65BS7iyLk6tw5M2KKEmkEe kCW12SSkH6tWkCFSqFo4ij3nzytcViEYF5jruPtw= Date: Sat, 05 Sep 2026 19:05:52 -0700 To: mm-commits@vger.kernel.org,urezki@gmail.com,mcgrof@kernel.org,jikos@kernel.org,bentiss@kernel.org,rppt@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-execmem-handle-potential-allocation-errors-in-the-maple-tree.patch added to mm-new branch Message-Id: <20260906020552.D31901F00A3D@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm/execmem: handle potential allocation errors in the maple tree has been added to the -mm mm-new branch. Its filename is mm-execmem-handle-potential-allocation-errors-in-the-maple-tree.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-execmem-handle-potential-allocation-errors-in-the-maple-tree.patch This patch will later appear in the mm-new branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Note, mm-new is a provisional staging ground for work-in-progress patches, and acceptance into mm-new is a notification for others take notice and to finish up reviews. Please do not hesitate to respond to review feedback and post updated versions to replace or incrementally fixup patches in mm-new. The mm-new branch of mm.git is not included in linux-next If a few days of testing in mm-new is successful, the patch will me moved into mm.git's mm-unstable branch, which is included in linux-next 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 various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: "Mike Rapoport (Microsoft)" Subject: mm/execmem: handle potential allocation errors in the maple tree Date: Thu, 03 Sep 2026 18:49:59 +0300 execmem_cache_clean() and execmem_cache_alloc_locked() ignore potential allocation failures in mas_store_gfp(). While in practice they are unlikely to happen, it's better to handle those errors and ensure the integrity of the ROX cache. Preallocate the maple tree nodes for the stores that must not fail and order the maple tree updates so that there won't be any failures once a tree has been modified. Assisted-by: copilot:claude-opus-5 Link: https://lore.kernel.org/20260903-execmem-rox-cache-pmd-v1-v1-2-11beb2a3d249@kernel.org Signed-off-by: Mike Rapoport (Microsoft) Cc: Benjamin Tissoires Cc: Jiri Kosina Cc: Luis Chamberalin Cc: "Uladzislau Rezki (Sony)" Signed-off-by: Andrew Morton --- mm/execmem.c | 32 ++++++++++++++++++++++---------- 1 file changed, 22 insertions(+), 10 deletions(-) --- a/mm/execmem.c~mm-execmem-handle-potential-allocation-errors-in-the-maple-tree +++ a/mm/execmem.c @@ -149,7 +149,15 @@ static void execmem_cache_clean(struct w if (vm && get_vm_area_size(vm) == size && IS_ALIGNED(size, PMD_SIZE) && IS_ALIGNED(mas.index, PMD_SIZE)) { - mas_store_gfp(&mas, NULL, GFP_KERNEL); + /* + * Preallocate to ensure mas_store does not fail + * If there is no memory for the tree update, bail out, + * next execmem_free() might be more lucky + */ + if (mas_preallocate(&mas, NULL, GFP_KERNEL)) + break; + + mas_store_prealloc(&mas, NULL); vfree(area); } } @@ -219,30 +227,34 @@ static void *execmem_cache_alloc_locked( addr = mas_free.index; last = mas_free.last; + mas_set_range(&mas_free, addr, addr + size - 1); + if (mas_preallocate(&mas_free, NULL, GFP_KERNEL)) + return NULL; + /* insert allocated size to busy_areas at range [addr, addr + size) */ mas_set_range(&mas_busy, addr, addr + size - 1); err = mas_store_gfp(&mas_busy, (void *)addr, GFP_KERNEL); if (err) - return NULL; + goto err_destroy_mas_free; - mas_store_gfp(&mas_free, NULL, GFP_KERNEL); + mas_store_prealloc(&mas_free, NULL); if (area_size > size) { - void *ptr = (void *)(addr + size); - /* * re-insert remaining free size to free_areas at range * [addr + size, last] + * the range matches an existing entry, so this cannot allocate */ + ptr = (void *)(addr + size); mas_set_range(&mas_free, addr + size, last); - err = mas_store_gfp(&mas_free, ptr, GFP_KERNEL); - if (err) { - mas_store_gfp(&mas_busy, NULL, GFP_KERNEL); - return NULL; - } + mas_store_gfp(&mas_free, ptr, GFP_KERNEL); } ptr = (void *)addr; return ptr; + +err_destroy_mas_free: + mas_destroy(&mas_free); + return NULL; } static void *__execmem_cache_alloc(struct execmem_range *range, size_t size) _ Patches currently in -mm which might be from rppt@kernel.org are set_memory-add-number-of-pages-parameter-to-set_direct_map-apis.patch mm-vmalloc-set-areas-page_order-after-allocation-succeeds.patch mm-vmalloc-constify-vm-parameter-of-get_vm_area_page_order.patch mm-vmalloc-make-set_area_direct_map-huge_vmap-friendly.patch mm-execmem-use-vm_flush_reset_perms-for-rox-cache-allocations.patch revert-arch-introduce-set_direct_map_valid_noflush.patch docs-core-api-memory-allocation-add-kalloc_obj-and-clarify-kmalloc.patch maintainers-add-memory-related-docs-in-core-mm-to-mm-misc-section.patch mm-execmem-free-rox-cache-chunks-only-when-they-span-an-entire-vm-area.patch mm-execmem-handle-potential-allocation-errors-in-the-maple-tree.patch mm-execmem-make-sure-rox-cache-always-contains-multiples-of-pmd_size.patch mm-vmalloc-add-define_free-for-vfree.patch mm-execmem-use-cleanup-infrastructure-in-rox-cache-functions.patch sh-remove-config_numa-and-realted-configuration-options.patch sh-mm-remove-numac.patch sh-mm-drop-allocate_pgdat.patch sh-remove-setup_bootmem_node-and-plat_mem_setup.patch sh-drop-dead-code-guarded-by-ifdef-config_numa.patch sh-drop-include-asm-mmzoneh.patch init-kconfig-drop-arch_want_numa_variable_locality.patch sh-init-remove-call-the-memblock_set_node.patch sh-remove-sparsemem-related-entries-from-kconfig.patch sh-drop-include-asm-sparsememh.patch