On Thu, Feb 09, 2023 at 12:16:46AM +0100, Ard Biesheuvel wrote:
Hello Darren,
On Thu, 9 Feb 2023 at 00:14, Darren Hart darren@os.amperecomputing.com wrote:
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.
Famous last words ...
Indeed, I nearly included that myself...
Unfortunately, I just had a report the other day that 'eMAG' and 'Server' (!) are also being used.
https://lore.kernel.org/all/20230131040355.3116-1-justin.he@arm.com/
OK, so in order to workaround this in the kernel, we need a better way to match. Unfortunately, this is specific to the oem platform, and the oem controls those strings.
Thanks for the pointer, will go mull this over and see if I can come up with something better.
In the meantime, would you consider matching on: Altra Altra Max eMAG
to capture the bulk of the systems until we have a better solution?
Thanks,
Darren
Fixes: 550b33cfd445 ("arm64: efi: Force the use of SetVirtualAddressMap() on Altra machines") Cc: stable@vger.kernel.org # 6.1.x Cc: linux-efi@vger.kernel.org Cc: Alexandru Elisei alexandru.elisei@gmail.com Cc: Ard Biesheuvel ardb@kernel.org Signed-off-by: Darren Hart darren@os.amperecomputing.com
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