> On 12-Jan-2022, at 3:44 PM, Ard Biesheuvel <ardb@xxxxxxxxxx> wrote: > > Aditya reports [0] that his recent MacbookPro crashes in the firmware > when using the variable services at runtime. The culprit appears to be a > call to QueryVariableInfo(), which we did not use to call on Apple x86 > machines in the past as they only upgraded from EFI v1.10 to EFI v2.40 > firmware fairly recently, and QueryVariableInfo() (along with > UpdateCapsule() et al) was added in EFI v2.00. > > The only runtime service introduced in EFI v2.00 that we actually use in > Linux is QueryVariableInfo(), as the capsule based ones are optional, > generally not used at runtime (all the LVFS/fwupd firmware update > infrastructure uses helper EFI programs that invoke capsule update at > boot time, not runtime), and not implemented by Apple machines in the > first place. QueryVariableInfo() is used to 'safely' set variables, > i.e., only when there is enough space. This prevents machines with buggy > firmwares from corrupting their NVRAMs when they run out of space. > > Given that Apple machines have been using EFI v1.10 services only for > the longest time (the EFI v2.0 spec was released in 2006, and Linux > support for the newly introduced runtime services was added in 2011, but > the MacbookPro12,1 released in 2015 still claims to be EFI v1.10 only), > let's avoid the EFI v2.0 ones on all Apple x86 machines. > > [0] https://lore.kernel.org/all/6D757C75-65B1-468B-842D-10410081A8E4@xxxxxxxx/ > > Cc: <stable@xxxxxxxxxxxxxxx> > Cc: Jeremy Kerr <jk@xxxxxxxxxx> > Cc: Matthew Garrett <mjg59@xxxxxxxxxxxxx> > Reported-by: Aditya Garg <gargaditya08@xxxxxxxx> > Tested-by: Orlando Chamberlain <redecorating@xxxxxxxxxxxxxx> > Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx> > --- > drivers/firmware/efi/efi.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c > index ae79c3300129..7de3f5b6e8d0 100644 > --- a/drivers/firmware/efi/efi.c > +++ b/drivers/firmware/efi/efi.c > @@ -722,6 +722,13 @@ void __init efi_systab_report_header(const efi_table_hdr_t *systab_hdr, > systab_hdr->revision >> 16, > systab_hdr->revision & 0xffff, > vendor); > + > + if (IS_ENABLED(CONFIG_X86_64) && > + systab_hdr->revision > EFI_1_10_SYSTEM_TABLE_REVISION && > + !strcmp(vendor, "Apple")) { > + pr_info("Apple Mac detected, using EFI v1.10 runtime services only\n"); > + efi.runtime_version = EFI_1_10_SYSTEM_TABLE_REVISION; > + } > } > > static __initdata char memory_type_name[][13] = { > -- > 2.30.2 > Hi Ard Patch works for me. Thanks for investing time to fix the issue :) Tested-by: Aditya Garg <gargaditya08@xxxxxxxx> You may also add the link of the Bug report Link: https://bugzilla.kernel.org/show_bug.cgi?id=215277 Regards Aditya
