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| author |   Andy Lutomirski <luto@kernel.org> | 2021-02-09 18:33:46 -0800 |
|---|---|---|
| committer |   Borislav Petkov <bp@suse.de> | 2021-02-10 18:39:23 +0100 |
| commit | c46f52231e79af025e2c89e889d69ec20a4c024f (patch) | |
| tree | edd2bdcce0593d181156fa6fb744e1ddc3fe5610 /arch/x86/mm/fault.c | |
| parent | x86/fault: Don't run fixups for SMAP violations (diff) | |
| download | linux-dev-c46f52231e79af025e2c89e889d69ec20a4c024f.tar.xz linux-dev-c46f52231e79af025e2c89e889d69ec20a4c024f.zip | |
x86/{fault,efi}: Fix and rename efi_recover_from_page_fault()
efi_recover_from_page_fault() doesn't recover -- it does a special EFI
mini-oops. Rename it to make it clear that it crashes.
While renaming it, I noticed a blatant bug: a page fault oops in a
different thread happening concurrently with an EFI runtime service call
would be misinterpreted as an EFI page fault. Fix that.
This isn't quite exact. The situation could be improved by using a
special CS for calls into EFI.
[ bp: Massage commit message and simplify in interrupt check. ]
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/f43b1e80830dc78ed60ed8b0826f4f189254570c.1612924255.git.luto@kernel.org
Diffstat (limited to 'arch/x86/mm/fault.c')
| -rw-r--r-- | arch/x86/mm/fault.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 1c3054bb4a5b..7b3a125e1e98 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -16,7 +16,7 @@ #include <linux/prefetch.h> /* prefetchw */ #include <linux/context_tracking.h> /* exception_enter(), ... */ #include <linux/uaccess.h> /* faulthandler_disabled() */ -#include <linux/efi.h> /* efi_recover_from_page_fault()*/ +#include <linux/efi.h> /* efi_crash_gracefully_on_page_fault()*/ #include <linux/mm_types.h> #include <asm/cpufeature.h> /* boot_cpu_has, ... */ @@ -25,7 +25,7 @@ #include <asm/vsyscall.h> /* emulate_vsyscall */ #include <asm/vm86.h> /* struct vm86 */ #include <asm/mmu_context.h> /* vma_pkey() */ -#include <asm/efi.h> /* efi_recover_from_page_fault()*/ +#include <asm/efi.h> /* efi_crash_gracefully_on_page_fault()*/ #include <asm/desc.h> /* store_idt(), ... */ #include <asm/cpu_entry_area.h> /* exception stack */ #include <asm/pgtable_areas.h> /* VMALLOC_START, ... */ @@ -701,11 +701,12 @@ page_fault_oops(struct pt_regs *regs, unsigned long error_code, #endif /* - * Buggy firmware could access regions which might page fault, try to - * recover from such faults. + * Buggy firmware could access regions which might page fault. If + * this happens, EFI has a special OOPS path that will try to + * avoid hanging the system. */ if (IS_ENABLED(CONFIG_EFI)) - efi_recover_from_page_fault(address); + efi_crash_gracefully_on_page_fault(address); oops: /* |