5.15-stable review patch. If anyone has any objections, please let me know.
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From: Dan Carpenter dan.carpenter@linaro.org
commit 3d1c651272cf1df8aac7d9b6d92d836d27bed50f upstream.
Clang 19 prints a warning when we pass &th->guid to efi_pa_va_lookup():
drivers/acpi/prmt.c:156:29: error: passing 1-byte aligned argument to 4-byte aligned parameter 1 of 'efi_pa_va_lookup' may result in an unaligned pointer access [-Werror,-Walign-mismatch] 156 | (void *)efi_pa_va_lookup(&th->guid, handler_info->handler_address); | ^
The problem is that efi_pa_va_lookup() takes a efi_guid_t and &th->guid is a regular guid_t. The difference between the two types is the alignment. efi_guid_t is a typedef.
typedef guid_t efi_guid_t __aligned(__alignof__(u32));
It's possible that this a bug in Clang 19. Even though the alignment of &th->guid is not explicitly specified, it will still end up being aligned at 4 or 8 bytes.
Anyway, as Ard points out, it's cleaner to change guid to efi_guid_t type and that also makes the warning go away.
Fixes: 088984c8d54c ("ACPI: PRM: Find EFI_MEMORY_RUNTIME block for PRM handler and context") Reported-by: Linux Kernel Functional Testing lkft@linaro.org Suggested-by: Ard Biesheuvel ardb@kernel.org Signed-off-by: Dan Carpenter dan.carpenter@linaro.org Tested-by: Paul E. McKenney paulmck@kernel.org Acked-by: Ard Biesheuvel ardb@kernel.org Link: https://patch.msgid.link/3777d71b-9e19-45f4-be4e-17bf4fa7a834@stanley.mounta... [ rjw: Subject edit ] Signed-off-by: Rafael J. Wysocki rafael.j.wysocki@intel.com [nathan: Fix conflicts due to lack of e38abdab441c] Signed-off-by: Nathan Chancellor nathan@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/acpi/prmt.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/acpi/prmt.c +++ b/drivers/acpi/prmt.c @@ -52,7 +52,7 @@ struct prm_context_buffer { static LIST_HEAD(prm_module_list);
struct prm_handler_info { - guid_t guid; + efi_guid_t guid; void *handler_addr; u64 static_data_buffer_addr; u64 acpi_param_buffer_addr;