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Message-Id: <20250507033536.work.088-kees@kernel.org>
Date: Tue, 6 May 2025 20:35:40 -0700
From: Kees Cook <kees@...nel.org>
To: Keith Busch <kbusch@...nel.org>
Cc: Kees Cook <kees@...nel.org>,
kernel test robot <lkp@...el.com>,
Jens Axboe <axboe@...nel.dk>,
Christoph Hellwig <hch@....de>,
Sagi Grimberg <sagi@...mberg.me>,
linux-nvme@...ts.infradead.org,
Chaitanya Kulkarni <kch@...dia.com>,
linux-kernel@...r.kernel.org,
linux-hardening@...r.kernel.org
Subject: [PATCH] nvme-pci: Make nvme_pci_npages_prp() __always_inline
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@...el.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@...nel.org>
---
Cc: Keith Busch <kbusch@...nel.org>
Cc: Jens Axboe <axboe@...nel.dk>
Cc: Christoph Hellwig <hch@....de>
Cc: Sagi Grimberg <sagi@...mberg.me>
Cc: <linux-nvme@...ts.infradead.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 b178d52eac1b..9ab070a9f037 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -390,7 +390,7 @@ 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);
--
2.34.1
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