Dan Carpenter 2c3766fac9 ACPI: PRM: Clean up guid type in struct prm_handler_info
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.mountain
[ rjw: Subject edit ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-01 01:56:07 +01:00
2022-09-28 09:02:20 +02:00
2024-10-22 15:56:52 +02:00

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