kernel/drivers/firmware/efi/esrt.c, branch linux-6.5.y

efi/esrt: Allow ESRT access without CAP_SYS_ADMIN

2023-06-06T13:33:59Z

Access to the files in /sys/firmware/efi/esrt has been restricted to CAP_SYS_ADMIN since support for ESRT was added, but this seems overly restrictive given that the files are read-only and just provide information about UEFI firmware updates. Remove the CAP_SYS_ADMIN restriction so that a non-root process can read the files, provided a suitably-privileged process changes the file ownership first. The files are still read-only and still owned by root by default. Signed-off-by: Nicholas Bishop Signed-off-by: Ard Biesheuvel

efi: make kobj_type structure constant

2023-05-10T17:00:52Z

Since commit ee6d3dd4ed48 ("driver core: make kobj_type constant.") the driver core allows the usage of const struct kobj_type. Take advantage of this to constify the structure definition to prevent modification at runtime. Signed-off-by: Thomas Weißschuh Signed-off-by: Ard Biesheuvel

efi: Actually enable the ESRT under Xen

2023-01-23T10:33:24Z

The ESRT can be parsed if EFI_PARAVIRT is enabled, even if EFI_MEMMAP is not. Also allow the ESRT to be in reclaimable memory, as that is where future Xen versions will put it. Reported-by: Marek Marczykowski-Górecki Signed-off-by: Demi Marie Obenour Tested-by: Marek Marczykowski-Górecki Signed-off-by: Ard Biesheuvel

efi: memmap: Disregard bogus entries instead of returning them

2023-01-22T09:14:15Z

The ESRT code currently contains two consistency checks on the memory descriptor it obtains, but one of them is both incomplete and can only trigger on invalid descriptors. So let's drop these checks, and instead disregard descriptors entirely if the start address is misaligned, or if the number of pages reaches to or beyond the end of the address space. Note that the memory map as a whole could still be inconsistent: multiple entries might cover the same area, or the address could be outside of the addressable PA space, but validating that goes beyond the scope of these helpers. Also note that since the physical address space is never 64-bits wide, a descriptor that includes the last page of memory is not valid. This is fortunate, since it means that a valid physical address will never be an error pointer and that the length of a memory descriptor in bytes will fit in a 64-bit unsigned integer. Co-developed-by: Ard Biesheuvel Signed-off-by: Ard Biesheuvel Signed-off-by: Demi Marie Obenour Tested-by: Marek Marczykowski-Górecki Signed-off-by: Ard Biesheuvel

efi: use default_groups in kobj_type

2022-01-06T20:19:05Z

There are currently 2 ways to create a set of sysfs files for a kobj_type, through the default_attrs field, and the default_groups field. Move the firmware efi sysfs code to use default_groups field which has been the preferred way since aa30f47cf666 ("kobject: Add support for default attribute groups to kobj_type") so that we can soon get rid of the obsolete default_attrs field. Cc: Ard Biesheuvel Cc: linux-efi@vger.kernel.org Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ard Biesheuvel

efi/esrt: Fix reference count leak in esre_create_sysfs_entry.

2020-06-15T12:38:56Z

kobject_init_and_add() takes reference even when it fails. If this function returns an error, kobject_put() must be called to properly clean up the memory associated with the object. Previous commit "b8eb718348b8" fixed a similar problem. Fixes: 0bb549052d33 ("efi: Add esrt support") Signed-off-by: Qiushi Wu Link: https://lore.kernel.org/r/20200528183804.4497-1-wu000273@umn.edu Signed-off-by: Ard Biesheuvel

efi/esrt: Clean up efi_esrt_init

2020-02-23T20:57:59Z

Remove an unused variable in __init efi_esrt_init(). Simplify a logical constraint. Signed-off-by: Heinrich Schuchardt Link: https://lore.kernel.org/r/20200223204557.114634-1-xypron.glpk@gmx.de Signed-off-by: Ard Biesheuvel

x86/efi: Push EFI_MEMMAP check into leaf routines

2019-11-07T14:44:04Z

In preparation for adding another EFI_MEMMAP dependent call that needs to occur before e820__memblock_setup() fixup the existing efi calls to check for EFI_MEMMAP internally. This ends up being cleaner than the alternative of checking EFI_MEMMAP multiple times in setup_arch(). Reviewed-by: Dave Hansen Reviewed-by: Ard Biesheuvel Signed-off-by: Dan Williams Acked-by: Thomas Gleixner Signed-off-by: Rafael J. Wysocki

efi: Replace GPL license boilerplate with SPDX headers

2019-02-04T07:27:25Z

Replace all GPL license blurbs with an equivalent SPDX header (most files are GPLv2, some are GPLv2+). While at it, drop some outdated header changelogs as well. Signed-off-by: Ard Biesheuvel Cc: AKASHI Takahiro Cc: Alexander Graf Cc: Bjorn Andersson Cc: Borislav Petkov Cc: Heinrich Schuchardt Cc: Jeffrey Hugo Cc: Lee Jones Cc: Leif Lindholm Cc: Linus Torvalds Cc: Matt Fleming Cc: Peter Jones Cc: Peter Zijlstra Cc: Sai Praneeth Prakhya Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20190202094119.13230-7-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar

efi/esrt: Only call efi_mem_reserve() for boot services memory

2018-07-17T07:15:05Z

The following commit: 7e1550b8f208 ("efi: Drop type and attribute checks in efi_mem_desc_lookup()") refactored the implementation of efi_mem_desc_lookup() so that the type check is moved to the callers, one of which is the x86 version of efi_arch_mem_reserve(), where we added a modified check that only takes EFI_BOOT_SERVICES_DATA regions into account. This is reasonable, since it is the only memory type that requires this, but doing so uncovered some unexpected behavior in the ESRT code, which permits the ESRT table to reside in other types of memory than what the UEFI spec mandates (i.e., EFI_BOOT_SERVICES_DATA), and unconditionally calls efi_mem_reserve() on the region in question. This may result in errors such as esrt: Reserving ESRT space from 0x000000009c810318 to 0x000000009c810350. efi: Failed to lookup EFI memory descriptor for 0x000000009c810318 when the ESRT table is not in EFI_BOOT_SERVICES_DATA memory, but we try to reserve it nonetheless. So make the call to efi_mem_reserve() conditional on the memory type. Signed-off-by: Ard Biesheuvel Cc: Linus Torvalds Cc: Peter Jones Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar