From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
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@xxxxxxxxxx>
Suggested-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Tested-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
Acked-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
Link: https://patch.msgid.link/3777d71b-9e19-45f4-be4e-17bf4fa7a834@stanley.mountain
[ rjw: Subject edit ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
[nathan: Fix conflicts due to lack of e38abdab441c]
Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
---
This resolves the warning that Naresh reported, which breaks the build
with CONFIG_WERROR=y:
https://lore.kernel.org/CA+G9fYtgOA-5y73G1YEixQ+OjmG=awBQjdKjK+b0qLNYvAAVpQ@xxxxxxxxxxxxxx/
https://storage.tuxsuite.com/public/clangbuiltlinux/continuous-integration2/builds/2ogNnyGv40aCb0Jqybv8RlPt3S7/build.log
---
drivers/acpi/prmt.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/acpi/prmt.c b/drivers/acpi/prmt.c
index 63ead3f1d294..890c74c52beb 100644
--- 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;
base-commit: 3c17fc4839052076b9f27f22551d0d0bd8557822
--
2.47.0
