kernel.git/fs/efivarfs, branch linux-6.5.y

efivarfs: fix statfs() on efivarfs

2023-09-23T09:14:32Z

[ Upstream commit 79b83606abc778aa3cbee535b362ce905d0b9448 ] Some firmware (notably U-Boot) provides GetVariable() and GetNextVariableName() but not QueryVariableInfo(). With commit d86ff3333cb1 ("efivarfs: expose used and total size") the statfs syscall was broken for such firmware. If QueryVariableInfo() does not exist or returns EFI_UNSUPPORTED, just report the file system size as 0 as statfs_simple() previously did. Fixes: d86ff3333cb1 ("efivarfs: expose used and total size") Link: https://lore.kernel.org/all/20230910045445.41632-1-heinrich.schuchardt@canonical.com/ Signed-off-by: Heinrich Schuchardt [ardb: log warning on QueryVariableInfo() failure] Reviewed-by: Ilias Apalodimas Signed-off-by: Ard Biesheuvel Signed-off-by: Sasha Levin

efivarfs: expose used and total size

2023-05-17T16:21:34Z

When writing EFI variables, one might get errors with no other message on why it fails. Being able to see how much is used by EFI variables helps analyzing such issues. Since this is not a conventional filesystem, block size is intentionally set to 1 instead of PAGE_SIZE. x86 quirks of reserved size are taken into account; so that available and free size can be different, further helping debugging space issues. With this patch, one can see the remaining space in EFI variable storage via efivarfs, like this: $ df -h /sys/firmware/efi/efivars/ Filesystem Size Used Avail Use% Mounted on efivarfs 176K 106K 66K 62% /sys/firmware/efi/efivars Signed-off-by: Anisse Astier [ardb: - rename efi_reserved_space() to efivar_reserved_space() - whitespace/coding style tweaks] 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 ...

efivarfs: always register filesystem

2023-01-26T20:32:01Z

The efivar ops are typically registered at subsys init time so that they are available when efivarfs is registered at module init time. Other efivars implementations, such as Google SMI, exist and can currently be built as modules which means that efivar may not be available when efivarfs is initialised. Move the efivar availability check from module init to when the filesystem is mounted to allow late registration of efivars. Signed-off-by: Johan Hovold Signed-off-by: Ard Biesheuvel

fs: port ->fileattr_set() to pass mnt_idmap

2023-01-19T08:24:27Z

Convert to struct mnt_idmap. Last cycle we merged the necessary infrastructure in 256c8aed2b42 ("fs: introduce dedicated idmap type for mounts"). This is just the conversion to struct mnt_idmap. Currently we still pass around the plain namespace that was attached to a mount. This is in general pretty convenient but it makes it easy to conflate namespaces that are relevant on the filesystem with namespaces that are relevent on the mount level. Especially for non-vfs developers without detailed knowledge in this area this can be a potential source for bugs. Once the conversion to struct mnt_idmap is done all helpers down to the really low-level helpers will take a struct mnt_idmap argument instead of two namespace arguments. This way it becomes impossible to conflate the two eliminating the possibility of any bugs. All of the vfs and all filesystems only operate on struct mnt_idmap. Acked-by: Dave Chinner Reviewed-by: Christoph Hellwig Signed-off-by: Christian Brauner (Microsoft)

fs: port ->create() to pass mnt_idmap

2023-01-19T08:24:25Z

efi: efivars: drop kobject from efivars_register()

2023-01-17T15:14:36Z

Since commit 0f5b2c69a4cb ("efi: vars: Remove deprecated 'efivars' sysfs interface") and the removal of the sysfs interface there are no users of the efivars kobject. Drop the kobject argument from efivars_register() and add a new efivar_is_available() helper in favour of the old efivars_kobject(). Note that the new helper uses the prefix 'efivar' (i.e. without an 's') for consistency with efivar_supports_writes() and the rest of the interface (except the registration functions). For the benefit of drivers with optional EFI support, also provide a dummy implementation of efivar_is_available(). Signed-off-by: Johan Hovold Signed-off-by: Ard Biesheuvel

efi: vars: prohibit reading random seed variables

2022-12-01T08:51:21Z

In anticipation of putting random seeds in EFI variables, it's important that the random GUID namespace of variables remains hidden from userspace. We accomplish this by not populating efivarfs with entries from that GUID, as well as denying the creation of new ones in that GUID. Signed-off-by: Jason A. Donenfeld Signed-off-by: Ard Biesheuvel

efi: efivars: Fix variable writes without query_variable_store()

2022-10-21T09:09:40Z

Commit bbc6d2c6ef22 ("efi: vars: Switch to new wrapper layer") refactored the efivars layer so that the 'business logic' related to which UEFI variables affect the boot flow in which way could be moved out of it, and into the efivarfs driver. This inadvertently broke setting variables on firmware implementations that lack the QueryVariableInfo() boot service, because we no longer tolerate a EFI_UNSUPPORTED result from check_var_size() when calling efivar_entry_set_get_size(), which now ends up calling check_var_size() a second time inadvertently. If QueryVariableInfo() is missing, we support writes of up to 64k - let's move that logic into check_var_size(), and drop the redundant call. Cc: # v6.0 Fixes: bbc6d2c6ef22 ("efi: vars: Switch to new wrapper layer") Signed-off-by: Ard Biesheuvel

efi: vars: Move efivar caching layer into efivarfs

2022-06-24T18:40:19Z

Move the fiddly bits of the efivar layer into its only remaining user, efivarfs, and confine its use to that particular module. All other uses of the EFI variable store have no need for this additional layer of complexity, given that they either only read variables, or read and write variables into a separate GUIDed namespace, and cannot be used to manipulate EFI variables that are covered by the EFI spec and/or affect the boot flow. Signed-off-by: Ard Biesheuvel