[tip:efi/urgent] efi/x86: Fix incorrect invocation of PciIo->Attributes()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Commit-ID:  2e6eb40ca5eb53836d18f3b9ac61ff2e0b417038
Gitweb:     https://git.kernel.org/tip/2e6eb40ca5eb53836d18f3b9ac61ff2e0b417038
Author:     Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
AuthorDate: Sat, 23 Jun 2018 23:19:03 +0200
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Sun, 24 Jun 2018 09:05:58 +0200

efi/x86: Fix incorrect invocation of PciIo->Attributes()

The following commit:

  2c3625cb9fa2 ("efi/x86: Fold __setup_efi_pci32() and __setup_efi_pci64() into one function")

... merged the two versions of __setup_efi_pciXX(), without taking into
account that the 32-bit version used a rather dodgy trick to pass an
immediate 0 constant as argument for a uint64_t parameter.

The issue is caused by the fact that on x86, UEFI protocol method calls
are redirected via struct efi_config::call(), which is a variadic function,
and so the compiler has to infer the types of the parameters from the
arguments rather than from the prototype.

As the 32-bit x86 calling convention passes arguments via the stack,
passing the unqualified constant 0 twice is the same as passing 0ULL,
which is why the 32-bit code in __setup_efi_pci32() contained the
following call:

  status = efi_early->call(pci->attributes, pci,
                           EfiPciIoAttributeOperationGet, 0, 0,
                           &attributes);

to invoke this UEFI protocol method:

  typedef
  EFI_STATUS
  (EFIAPI *EFI_PCI_IO_PROTOCOL_ATTRIBUTES) (
    IN  EFI_PCI_IO_PROTOCOL                     *This,
    IN  EFI_PCI_IO_PROTOCOL_ATTRIBUTE_OPERATION Operation,
    IN  UINT64                                  Attributes,
    OUT UINT64                                  *Result OPTIONAL
    );

After the merge, we inadvertently ended up with this version for both
32-bit and 64-bit builds, breaking the latter.

So replace the two zeroes with the explicitly typed constant 0ULL,
which works as expected on both 32-bit and 64-bit builds.

Wilfried tested the 64-bit build, and I checked the generated assembly
of a 32-bit build with and without this patch, and they are identical.

Reported-by: Wilfried Klaebe <linux-kernel@xxxxxxxxxxxxxxxxxxxxxxxxxx>
Tested-by: Wilfried Klaebe <linux-kernel@xxxxxxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: hdegoede@xxxxxxxxxx
Cc: linux-efi@xxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 arch/x86/boot/compressed/eboot.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/boot/compressed/eboot.c b/arch/x86/boot/compressed/eboot.c
index a8a8642d2b0b..e57665b4ba1c 100644
--- a/arch/x86/boot/compressed/eboot.c
+++ b/arch/x86/boot/compressed/eboot.c
@@ -118,7 +118,7 @@ __setup_efi_pci(efi_pci_io_protocol_t *pci, struct pci_setup_rom **__rom)
 	void *romimage;
 
 	status = efi_call_proto(efi_pci_io_protocol, attributes, pci,
-				EfiPciIoAttributeOperationGet, 0, 0,
+				EfiPciIoAttributeOperationGet, 0ULL,
 				&attributes);
 	if (status != EFI_SUCCESS)
 		return status;
--
To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux Stable Commits]     [Linux Stable Kernel]     [Linux Kernel]     [Linux USB Devel]     [Linux Video &Media]     [Linux Audio Users]     [Yosemite News]     [Linux SCSI]

  Powered by Linux