6.6-stable review patch. If anyone has any objections, please let me know.
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From: Kees Cook kees@kernel.org
[ Upstream commit 40696426b8c8c4f13cf6ac52f0470eed144be4b2 ]
The only reason nvme_pci_npages_prp() could be used as a compile-time known result in BUILD_BUG_ON() is because the compiler was always choosing to inline the function. Under special circumstances (sanitizer coverage functions disabled for __init functions on ARCH=um), the compiler decided to stop inlining it:
drivers/nvme/host/pci.c: In function 'nvme_init': include/linux/compiler_types.h:557:45: error: call to '__compiletime_assert_678' declared with attribute error: BUILD_BUG_ON failed: nvme_pci_npages_prp() > NVME_MAX_NR_ALLOCATIONS 557 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) | ^ include/linux/compiler_types.h:538:25: note: in definition of macro '__compiletime_assert' 538 | prefix ## suffix(); \ | ^~~~~~ include/linux/compiler_types.h:557:9: note: in expansion of macro '_compiletime_assert' 557 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__) | ^~~~~~~~~~~~~~~~~~~ include/linux/build_bug.h:39:37: note: in expansion of macro 'compiletime_assert' 39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg) | ^~~~~~~~~~~~~~~~~~ include/linux/build_bug.h:50:9: note: in expansion of macro 'BUILD_BUG_ON_MSG' 50 | BUILD_BUG_ON_MSG(condition, "BUILD_BUG_ON failed: " #condition) | ^~~~~~~~~~~~~~~~ drivers/nvme/host/pci.c:3804:9: note: in expansion of macro 'BUILD_BUG_ON' 3804 | BUILD_BUG_ON(nvme_pci_npages_prp() > NVME_MAX_NR_ALLOCATIONS); | ^~~~~~~~~~~~
Force it to be __always_inline to make sure it is always available for use with BUILD_BUG_ON().
Reported-by: kernel test robot lkp@intel.com Closes: https://lore.kernel.org/oe-kbuild-all/202505061846.12FMyRjj-lkp@intel.com/ Fixes: c372cdd1efdf ("nvme-pci: iod npages fits in s8") Signed-off-by: Kees Cook kees@kernel.org Signed-off-by: Christoph Hellwig hch@lst.de Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/nvme/host/pci.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index fdde38903ebcd..08280bd65d03d 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -386,7 +386,7 @@ static bool nvme_dbbuf_update_and_check_event(u16 value, __le32 *dbbuf_db, * as it only leads to a small amount of wasted memory for the lifetime of * the I/O. */ -static int nvme_pci_npages_prp(void) +static __always_inline int nvme_pci_npages_prp(void) { unsigned max_bytes = (NVME_MAX_KB_SZ * 1024) + NVME_CTRL_PAGE_SIZE; unsigned nprps = DIV_ROUND_UP(max_bytes, NVME_CTRL_PAGE_SIZE);