diff options
authorArd Biesheuvel <ard.biesheuvel@linaro.org>2018-06-23 23:19:03 +0200
committerIngo Molnar <mingo@kernel.org>2018-06-24 09:05:58 +0200
commit2e6eb40ca5eb53836d18f3b9ac61ff2e0b417038 (patch)
parent52e1cf2d19c2e62e6a81b8de3f7320d033917dd5 (diff)
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@lebenslange-mailadresse.de> Tested-by: Wilfried Klaebe <linux-kernel@lebenslange-mailadresse.de> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: hdegoede@redhat.com Cc: linux-efi@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
1 files changed, 1 insertions, 1 deletions
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,
if (status != EFI_SUCCESS)
return status;