From c1f3e770eec26d6f96dd6d2ea30555ba7c09a244 Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Tue, 23 Jun 2026 13:23:46 -0700 Subject: fortify: Disable -Wstringop-overread in tests clang recently added support for -Wstringop-overread [1], which is on by default like -Wfortify-source. This breaks the usage of -Werror in the fortify tests, resulting in the following false positive warnings in the kernel build: warning: unsafe memcmp() usage lacked '__read_overflow2' warning in lib/test_fortify/read_overflow2-memcmp.c warning: unsafe memcmp() usage lacked '__read_overflow' warning in lib/test_fortify/read_overflow-memcmp.c warning: unsafe memchr() usage lacked '__read_overflow' warning in lib/test_fortify/read_overflow-memchr.c Examining the fortify test logs shows a warning like the following in each of the failed logs: In file included from lib/test_fortify/read_overflow2-memcmp.c:5: lib/test_fortify/test_fortify.h:34:2: error: 'memcmp' reading 17 bytes from a region of size 16 [-Werror,-Wstringop-overread] 34 | TEST; | ^ lib/test_fortify/read_overflow2-memcmp.c:3:2: note: expanded from macro 'TEST' 3 | memcmp(large, small, sizeof(small) + 1) | ^ 1 error generated. Disable -Wstringop-overread for the fortify tests, as it defeats the purpose of testing the Linux specific implementation of fortify, like -Wfortify-source. Cc: stable@vger.kernel.org Closes: https://github.com/ClangBuiltLinux/linux/issues/2168 Link: https://github.com/llvm/llvm-project/commit/86f2e71cb8d165b59ad31a442b2391e23826133e [1] Signed-off-by: Nathan Chancellor Link: https://patch.msgid.link/20260623-fix-test_fortify-for-clang-stringop-overread-v1-1-15ee8342a953@kernel.org Signed-off-by: Kees Cook --- lib/test_fortify/Makefile | 1 + 1 file changed, 1 insertion(+) (limited to 'lib') diff --git a/lib/test_fortify/Makefile b/lib/test_fortify/Makefile index 399cae880e1d..44cd5df41a81 100644 --- a/lib/test_fortify/Makefile +++ b/lib/test_fortify/Makefile @@ -1,6 +1,7 @@ # SPDX-License-Identifier: GPL-2.0 ccflags-y := $(call cc-disable-warning,fortify-source) +ccflags-y += $(call cc-disable-warning,stringop-overread) quiet_cmd_test_fortify = TEST $@ cmd_test_fortify = $(CONFIG_SHELL) $(src)/test_fortify.sh \ -- cgit v1.2.3 From 4fc089235378d1f9ddb6bcbe67c192ffdcaae0ed Mon Sep 17 00:00:00 2001 From: Stanislav Kinsburskii Date: Mon, 29 Jun 2026 16:30:14 -0700 Subject: lib: test_hmm: use device devt for coherent device range selection Commit af69016dab96 ("lib: test_hmm: implement a device release method") moved the initial dmirror_allocate_chunk() call before cdev_device_add(). That means the struct cdev has not been added yet, so cdev_add() has not initialized mdevice->cdevice.dev. The coherent-device range selection uses the device minor to choose between spm_addr_dev0 and spm_addr_dev1. Reading MINOR(mdevice->cdevice.dev) before cdev_add() therefore always sees an uninitialized dev_t. As a result, both coherent devices select the same physical range, and adding the second device fails due to the overlapping dev_pagemap range. Use mdevice->device.devt instead. It is initialized in dmirror_device_init() before dmirror_allocate_chunk() is called and is the same dev_t later passed to cdev_device_add(). Link: https://lore.kernel.org/178277581197.172200.16265155329935822153.stgit@skinsburskii Fixes: af69016dab96 ("lib: test_hmm: implement a device release method") Signed-off-by: Stanislav Kinsburskii Reviewed-by: Alistair Popple Cc: Balbir Singh Cc: Zenghui Yu (Huawei) Cc: Jason Gunthorpe Cc: Leon Romanovsky Cc: Signed-off-by: Andrew Morton --- lib/test_hmm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/test_hmm.c b/lib/test_hmm.c index 9c59d1ceb5b5..c4adbf98fac7 100644 --- a/lib/test_hmm.c +++ b/lib/test_hmm.c @@ -581,7 +581,7 @@ static int dmirror_allocate_chunk(struct dmirror_device *mdevice, devmem->pagemap.type = MEMORY_DEVICE_PRIVATE; break; case HMM_DMIRROR_MEMORY_DEVICE_COHERENT: - devmem->pagemap.range.start = (MINOR(mdevice->cdevice.dev) - 2) ? + devmem->pagemap.range.start = (MINOR(mdevice->device.devt) - 2) ? spm_addr_dev0 : spm_addr_dev1; devmem->pagemap.range.end = devmem->pagemap.range.start + -- cgit v1.2.3 From a82c8a05e86f3f84e09698f65b4515b5d04633f6 Mon Sep 17 00:00:00 2001 From: Michael Bommarito Date: Sun, 19 Jul 2026 12:15:05 -0400 Subject: assoc_array: trim the final shortcut word using the current chunk end assoc_array_walk() masks off the bits past shortcut->skip_to_level in the word that contains skip_to_level, gated on round_up(sc_level, ASSOC_ARRAY_KEY_CHUNK_SIZE) > skip_to_level. That guard is wrong in two opposite ways: - When sc_level is word-aligned (every word after the first) round_up() is a no-op, so the guard is sc_level > skip_to_level and never fires for the word that holds skip_to_level. A shortcut that spans more than one word and ends in the middle of its last word leaves that word untrimmed, and its stale high bits leak into the dissimilarity word and can steer the walk down the wrong descendant. - When sc_level is unaligned (the first word) and skip_to_level sits on the next chunk boundary, sc_level + CHUNK would exceed skip_to_level and fire the trim with shift = skip_to_level & CHUNK_MASK == 0, which clears the whole dissimilarity word and makes a differing shortcut compare equal. Use the end of the chunk that contains sc_level instead: skip_to_level < round_down(sc_level, CHUNK) + CHUNK For an aligned sc_level whose word holds skip_to_level this now fires (the first bug); for an unaligned sc_level with skip_to_level on the following boundary it does not, so shift is never 0 when the branch runs and the trim never clears the whole word. Fixes: 3cb989501c26 ("Add a generic associative array implementation.") Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Michael Bommarito Reviewed-by: Jarkko Sakkinen Tested-by: Jarkko Sakkinen Link: https://lore.kernel.org/r/20260719161505.2423935-4-michael.bommarito@gmail.com Signed-off-by: Jarkko Sakkinen --- lib/assoc_array.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/assoc_array.c b/lib/assoc_array.c index bcc6e0a013eb..b6c9723e12ce 100644 --- a/lib/assoc_array.c +++ b/lib/assoc_array.c @@ -255,7 +255,8 @@ follow_shortcut: sc_segments = shortcut->index_key[sc_level >> ASSOC_ARRAY_KEY_CHUNK_SHIFT]; dissimilarity = segments ^ sc_segments; - if (round_up(sc_level, ASSOC_ARRAY_KEY_CHUNK_SIZE) > shortcut->skip_to_level) { + if (shortcut->skip_to_level < round_down(sc_level, + ASSOC_ARRAY_KEY_CHUNK_SIZE) + ASSOC_ARRAY_KEY_CHUNK_SIZE) { /* Trim segments that are beyond the shortcut */ int shift = shortcut->skip_to_level & ASSOC_ARRAY_KEY_CHUNK_MASK; dissimilarity &= ~(ULONG_MAX << shift); -- cgit v1.2.3