kernel.git/drivers/firmware/efi/libstub, branch linux-6.3.y

efi/libstub: Disable PCI DMA before grabbing the EFI memory map

2023-07-11T17:39:51Z

[ Upstream commit 2e28a798c3092ea42b968fa16ac835969d124898 ] Currently, the EFI stub will disable PCI DMA as the very last thing it does before calling ExitBootServices(), to avoid interfering with the firmware's normal operation as much as possible. However, the stub will invoke DisconnectController() on all endpoints downstream of the PCI bridges it disables, and this may affect the layout of the EFI memory map, making it substantially more likely that ExitBootServices() will fail the first time around, and that the EFI memory map needs to be reloaded. This, in turn, increases the likelihood that the slack space we allocated is insufficient (and we can no longer allocate memory via boot services after having called ExitBootServices() once), causing the second call to GetMemoryMap (and therefore the boot) to fail. This makes the PCI DMA disable feature a bit more fragile than it already is, so let's make it more robust, by allocating the space for the EFI memory map after disabling PCI DMA. Fixes: 4444f8541dad16fe ("efi: Allow disabling PCI busmastering on bridges during boot") Reported-by: Glenn Washburn Acked-by: Matthew Garrett Signed-off-by: Ard Biesheuvel Signed-off-by: Sasha Levin

efi/libstub: randomalloc: Return EFI_OUT_OF_RESOURCES on failure

2023-03-23T14:15:45Z

The logic in efi_random_alloc() will iterate over the memory map twice, once to count the number of candidate slots, and another time to locate the chosen slot after randomization. If there is insufficient memory to do the allocation, the second loop will run to completion without actually having located a slot, but we currently return EFI_SUCCESS in this case, as we fail to initialize status to the appropriate error value of EFI_OUT_OF_RESOURCES. Signed-off-by: Ard Biesheuvel

efi/libstub: Use relocated version of kernel's struct screen_info

2023-03-23T11:27:18Z

In some cases, we expose the kernel's struct screen_info to the EFI stub directly, so it gets populated before even entering the kernel. This means the early console is available as soon as the early param parsing happens, which is nice. It also means we need two different ways to pass this information, as this trick only works if the EFI stub is baked into the core kernel image, which is not always the case. Huacai reports that the preparatory refactoring that was needed to implement this alternative method for zboot resulted in a non-functional efifb earlycon for other cases as well, due to the reordering of the kernel image relocation with the population of the screen_info struct, and the latter now takes place after copying the image to its new location, which means we copy the old, uninitialized state. So let's ensure that the same-image version of alloc_screen_info() produces the correct screen_info pointer, by taking the displacement of the loaded image into account. Reported-by: Huacai Chen Tested-by: Huacai Chen Link: https://lore.kernel.org/linux-efi/20230310021749.921041-1-chenhuacai@loongson.cn/ Fixes: 42c8ea3dca094ab8 ("efi: libstub: Factor out EFI stub entrypoint into separate file") Signed-off-by: Ard Biesheuvel

efi/libstub: zboot: Add compressed image to make targets

2023-03-21T14:20:56Z

Avoid needlessly rebuilding the compressed image by adding the file 'vmlinuz' to the 'targets' Kbuild make variable. Signed-off-by: Ard Biesheuvel

efi/libstub: smbios: Drop unused 'recsize' parameter

2023-03-18T10:44:57Z

We no longer use the recsize argument for locating the string table in an SMBIOS record, so we can drop it from the internal API. Signed-off-by: Ard Biesheuvel

arm64: efi: Use SMBIOS processor version to key off Ampere quirk

2023-03-18T10:44:56Z

Instead of using the SMBIOS type 1 record 'family' field, which is often modified by OEMs, use the type 4 'processor ID' and 'processor version' fields, which are set to a small set of probe-able values on all known Ampere EFI systems in the field. Fixes: 550b33cfd4452968 ("arm64: efi: Force the use of ...") Tested-by: Andrea Righi Signed-off-by: Ard Biesheuvel

efi/libstub: smbios: Use length member instead of record struct size

2023-03-18T10:37:56Z

The type 1 SMBIOS record happens to always be the same size, but there are other record types which have been augmented over time, and so we should really use the length field in the header to decide where the string table starts. Fixes: 550b33cfd4452968 ("arm64: efi: Force the use of ...") Signed-off-by: Ard Biesheuvel

efi/libstub: arm64: Remap relocated image with strict permissions

2023-03-10T13:11:39Z

After relocating the executable image, use the EFI memory attributes protocol to remap the code and data regions with the appropriate permissions. Signed-off-by: Ard Biesheuvel

efi/libstub: zboot: Mark zboot EFI application as NX compatible

2023-03-10T13:11:39Z

Now that the zboot loader will invoke the EFI memory attributes protocol to remap the decompressed code and rodata as read-only/executable, we can set the PE/COFF header flag that indicates to the firmware that the application does not rely on writable memory being executable at the same time. Cc: # v6.2+ Signed-off-by: Ard Biesheuvel

Merge tag 'efi-next-for-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi

2023-02-23T22:41:48Z

Pull EFI updates from Ard Biesheuvel: "A healthy mix of EFI contributions this time: - Performance tweaks for efifb earlycon (Andy) - Preparatory refactoring and cleanup work in the efivar layer, which is needed to accommodate the Snapdragon arm64 laptops that expose their EFI variable store via a TEE secure world API (Johan) - Enhancements to the EFI memory map handling so that Xen dom0 can safely access EFI configuration tables (Demi Marie) - Wire up the newly introduced IBT/BTI flag in the EFI memory attributes table, so that firmware that is generated with ENDBR/BTI landing pads will be mapped with enforcement enabled - Clean up how we check and print the EFI revision exposed by the firmware - Incorporate EFI memory attributes protocol definition and wire it up in the EFI zboot code (Evgeniy) This ensures that these images can execute under new and stricter rules regarding the default memory permissions for EFI page allocations (More work is in progress here) - CPER header cleanup (Dan Williams) - Use a raw spinlock to protect the EFI runtime services stack on arm64 to ensure the correct semantics under -rt (Pierre) - EFI framebuffer quirk for Lenovo Ideapad (Darrell)" * tag 'efi-next-for-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi: (24 commits) firmware/efi sysfb_efi: Add quirk for Lenovo IdeaPad Duet 3 arm64: efi: Make efi_rt_lock a raw_spinlock efi: Add mixed-mode thunk recipe for GetMemoryAttributes efi: x86: Wire up IBT annotation in memory attributes table efi: arm64: Wire up BTI annotation in memory attributes table efi: Discover BTI support in runtime services regions efi/cper, cxl: Remove cxl_err.h efi: Use standard format for printing the EFI revision efi: Drop minimum EFI version check at boot efi: zboot: Use EFI protocol to remap code/data with the right attributes efi/libstub: Add memory attribute protocol definitions efi: efivars: prevent double registration efi: verify that variable services are supported efivarfs: always register filesystem efi: efivars: add efivars printk prefix efi: Warn if trying to reserve memory under Xen efi: Actually enable the ESRT under Xen efi: Apply allowlist to EFI configuration tables when running under Xen efi: xen: Implement memory descriptor lookup based on hypercall efi: memmap: Disregard bogus entries instead of returning them ...