Commit 24427cda authored by Tim Schumacher's avatar Tim Schumacher Committed by Ard Biesheuvel
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efi: pstore: Request at most 512 bytes for variable names 



Work around a quirk in a few old (2011-ish) UEFI implementations, where
a call to `GetNextVariableName` with a buffer size larger than 512 bytes
will always return EFI_INVALID_PARAMETER.

This was already done to efivarfs in commit f45812cc ("efivarfs:
Request at most 512 bytes for variable names"), but the second copy of
the variable iteration implementation was overlooked.

Signed-off-by: default avatarTim Schumacher <timschumi@gmx.de>
Signed-off-by: default avatarArd Biesheuvel <ardb@kernel.org>
parent 4cece764

drivers/firmware/efi/efi-pstore.c

+9 −1
Original line number Diff line number Diff line
@@ -162,7 +162,15 @@ static ssize_t efi_pstore_read(struct pstore_record *record) 
	efi_status_t status;



	for (;;) {

		varname_size = 1024;

		/*

		 * A small set of old UEFI implementations reject sizes

		 * above a certain threshold, the lowest seen in the wild

		 * is 512.

		 *

		 * TODO: Commonize with the iteration implementation in

		 *       fs/efivarfs to keep all the quirks in one place.

		 */

		varname_size = 512;



		/*

		 * If this is the first read() call in the pstore enumeration,