lwn.git/drivers/firmware/efi/efibc.c, branch docs-mw

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

efi: efibc: change kmalloc(size * count, ...) to kmalloc_array()

2025-03-10T17:22:47+00:00

Open coded arithmetic in allocator arguments is discouraged. Helper functions like kcalloc or, in this case, kmalloc_array are preferred. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments Signed-off-by: Ethan Carter Edwards Signed-off-by: Ard Biesheuvel

efi: efibc: Guard against allocation failure

2022-09-20T16:42:55+00:00

There is a single kmalloc in this driver, and it's not currently guarded against allocation failure. Do it here by just bailing-out the reboot handler, in case this tentative allocation fails. Fixes: 416581e48679 ("efi: efibc: avoid efivar API for setting variables") Signed-off-by: Guilherme G. Piccoli Signed-off-by: Ard Biesheuvel

efi: efibc: avoid efivar API for setting variables

2022-06-20T10:43:25+00:00

Avoid abusing the efivar API by passing locally instantiated efivar_entry structs into efivar_set_entry_safe(), rather than using the API as intended. Instead, just call efi.set_variable() directly. Signed-off-by: Ard Biesheuvel

efi: efibc: check for efivars write capability

2020-09-15T15:22:47+00:00

Branden reports that commit f88814cc2578c1 ("efi/efivars: Expose RT service availability via efivars abstraction") regresses UEFI platforms that implement GetVariable but not SetVariable when booting kernels that have EFIBC (bootloader control) enabled. The reason is that EFIBC is a user of the efivars abstraction, which was updated to permit users that rely only on the read capability, but not on the write capability. EFIBC is in the latter category, so it has to check explicitly whether efivars supports writes. Fixes: f88814cc2578c1 ("efi/efivars: Expose RT service availability via efivars abstraction") Tested-by: Branden Sherrell Link: https://lore.kernel.org/linux-efi/AE217103-C96F-4AFC-8417-83EC11962004@gmail.com/ Signed-off-by: Ard Biesheuvel

efibc: Replace variable set function in notifier call

2019-06-22T08:24:57+00:00

Replace the variable set function from "efivar_entry_set" to "efivar_entry_set_safe" in efibc panic notifier. In safe function parameter "block" will set to false and will call "efivar_entry_set_nonblocking"to set efi variables. efivar_entry_set_nonblocking is guaranteed to not block and is suitable for calling from crash/panic handlers. In UEFI android platform, when warm reset happens, with this change, efibc will not block the reboot process. Otherwise, set variable will call queue work and send to other offlined cpus then cause another panic, finally will cause reboot failure. Signed-off-by: Tian Baofeng Signed-off-by: Luo XinanX Signed-off-by: Ard Biesheuvel

efi: Replace GPL license boilerplate with SPDX headers

2019-02-04T07:27:25+00:00

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

efibc: Report more information in the error messages

2016-06-27T11:06:54+00:00

Report the name of the EFI variable if the value size is too large, or if efibc_set_variable() fails to allocate the 'struct efivar_entry' object. If efibc_set_variable() fails because the 'size' value is too large, it also reports this value in the error message. Reported-by: Robert Elliott Signed-off-by: Jeremy Compostella Signed-off-by: Matt Fleming Cc: Ard Biesheuvel Cc: Arnd Bergmann Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1466839230-12781-2-git-send-email-matt@codeblueprint.co.uk [ Minor readability edits. ] Signed-off-by: Ingo Molnar

efibc: Fix excessive stack footprint warning

2016-05-07T05:06:13+00:00

GCC complains about a newly added file for the EFI Bootloader Control: drivers/firmware/efi/efibc.c: In function 'efibc_set_variable': drivers/firmware/efi/efibc.c:53:1: error: the frame size of 2272 bytes is larger than 1024 bytes [-Werror=frame-larger-than=] The problem is the declaration of a local variable of type struct efivar_entry, which is by itself larger than the warning limit of 1024 bytes. Use dynamic memory allocation instead of stack memory for the entry object. This patch also fixes a potential buffer overflow. Reported-by: Ingo Molnar Reported-by: Arnd Bergmann Signed-off-by: Jeremy Compostella [ Updated changelog to include GCC error ] Signed-off-by: Matt Fleming Cc: Andy Lutomirski Cc: Ard Biesheuvel Cc: Borislav Petkov Cc: Brian Gerst Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/1462570771-13324-3-git-send-email-matt@codeblueprint.co.uk Signed-off-by: Ingo Molnar