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 f45812cc23fb ("efivarfs:
Request at most 512 bytes for variable names"), but the second copy of
the variable iteration implementation was overlooked.
Signed-off-by: Tim Schumacher <[email protected]>
---
Changes from v1:
- None, resubmitted as a part of a chain.
---
drivers/firmware/efi/efi-pstore.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/firmware/efi/efi-pstore.c
b/drivers/firmware/efi/efi-pstore.c
index 833cbb995dd3f..5b9dc26e6bcb9 100644
--- a/drivers/firmware/efi/efi-pstore.c
+++ b/drivers/firmware/efi/efi-pstore.c
@@ -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,
--
2.44.0
