[PATCH] arm64: efi: Force the use of SetVirtualAddressMap() on Altra Max machines

From: Darren Hart
Date: Wed Feb 08 2023 - 18:14:06 EST


Commit 550b33cfd445 ("arm64: efi: Force the use of SetVirtualAddressMap()
on Altra machines") identifies the Altra family via the family field in
the type#1 SMBIOS record. Altra Max machines are similarly affected but
not detected with the strict strcmp test.

Rather than risk greedy matching with strncmp, add a second test for
Altra Max. Do not refactor to handle multiple tests as these should be
the only two needed.

Fixes: 550b33cfd445 ("arm64: efi: Force the use of SetVirtualAddressMap() on Altra machines")
Cc: <stable@xxxxxxxxxxxxxxx> # 6.1.x
Cc: <linux-efi@xxxxxxxxxxxxxxx>
Cc: Alexandru Elisei <alexandru.elisei@xxxxxxxxx>
Cc: Ard Biesheuvel <ardb@xxxxxxxxxx>
Signed-off-by: Darren Hart <darren@xxxxxxxxxxxxxxxxxxxxxx>
---
drivers/firmware/efi/libstub/arm64.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/firmware/efi/libstub/arm64.c b/drivers/firmware/efi/libstub/arm64.c
index ff2d18c42ee7..97f4423059c7 100644
--- a/drivers/firmware/efi/libstub/arm64.c
+++ b/drivers/firmware/efi/libstub/arm64.c
@@ -19,10 +19,10 @@ static bool system_needs_vamap(void)
const u8 *type1_family = efi_get_smbios_string(1, family);

/*
- * Ampere Altra machines crash in SetTime() if SetVirtualAddressMap()
- * has not been called prior.
+ * Ampere Altra and Altra Max machines crash in SetTime() if
+ * SetVirtualAddressMap() has not been called prior.
*/
- if (!type1_family || strcmp(type1_family, "Altra"))
+ if (!type1_family || (strcmp(type1_family, "Altra") && strcmp(type1_family, "Altra Max")))
return false;

efi_warn("Working around broken SetVirtualAddressMap()\n");
--
2.34.3