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authorTim Schumacher <timschumi@gmx.de>2024-03-28 21:50:33 +0100
committerArd Biesheuvel <ardb@kernel.org>2024-04-13 10:33:02 +0200
commitcda30c6542c8bb445bc84f6616cac8d012547f0a (patch)
treefaced30502e21da512704a6c6e1c79f947ac86f3 /fs/efivarfs
parentefivarfs: Remove unused internal struct members (diff)
downloadlinux-cda30c6542c8bb445bc84f6616cac8d012547f0a.tar.xz
linux-cda30c6542c8bb445bc84f6616cac8d012547f0a.zip
efi: Clear up misconceptions about a maximum variable name size
The UEFI specification does not make any mention of a maximum variable name size, so the headers and implementation shouldn't claim that one exists either. Comments referring to this limit have been removed or rewritten, as this is an implementation detail local to the Linux kernel. Where appropriate, the magic value of 1024 has been replaced with EFI_VAR_NAME_LEN, as this is used for the efi_variable struct definition. This in itself does not change any behavior, but should serve as points of interest when making future changes in the same area. A related build-time check has been added to ensure that the special 512 byte sized buffer will not overflow with a potentially decreased EFI_VAR_NAME_LEN. Signed-off-by: Tim Schumacher <timschumi@gmx.de> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Diffstat (limited to 'fs/efivarfs')
-rw-r--r--fs/efivarfs/vars.c5
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/efivarfs/vars.c b/fs/efivarfs/vars.c
index 4d722af1014f..3cc89bb624f0 100644
--- a/fs/efivarfs/vars.c
+++ b/fs/efivarfs/vars.c
@@ -295,9 +295,9 @@ static bool variable_is_present(efi_char16_t *variable_name, efi_guid_t *vendor,
unsigned long strsize1, strsize2;
bool found = false;
- strsize1 = ucs2_strsize(variable_name, 1024);
+ strsize1 = ucs2_strsize(variable_name, EFI_VAR_NAME_LEN);
list_for_each_entry_safe(entry, n, head, list) {
- strsize2 = ucs2_strsize(entry->var.VariableName, 1024);
+ strsize2 = ucs2_strsize(entry->var.VariableName, EFI_VAR_NAME_LEN);
if (strsize1 == strsize2 &&
!memcmp(variable_name, &(entry->var.VariableName),
strsize2) &&
@@ -396,6 +396,7 @@ int efivar_init(int (*func)(efi_char16_t *, efi_guid_t, unsigned long, void *,
do {
variable_name_size = 512;
+ BUILD_BUG_ON(EFI_VAR_NAME_LEN < 512);
status = efivar_get_next_variable(&variable_name_size,
variable_name,