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| author | Ard Biesheuvel <ardb@kernel.org> | 2022-10-28 17:39:14 +0300 |
|---|---|---|
| committer | Ard Biesheuvel <ardb@kernel.org> | 2023-01-16 17:27:31 +0300 |
| commit | 8a9a1a18731eb123e35f48176380a18b9782845e (patch) | |
| tree | f575285adbe808f8a4b9b7346a6e88a266d4b304 /arch/arm64/kernel/efi.c | |
| parent | d3f450533bbcb6dd4d7d59cadc9b61b7321e4ac1 (diff) | |
| download | linux-8a9a1a18731eb123e35f48176380a18b9782845e.tar.xz | |
arm64: efi: Avoid workqueue to check whether EFI runtime is live
Comparing current_work() against efi_rts_work.work is sufficient to
decide whether current is currently running EFI runtime services code at
any level in its call stack.
However, there are other potential users of the EFI runtime stack, such
as the ACPI subsystem, which may invoke efi_call_virt_pointer()
directly, and so any sync exceptions occurring in firmware during those
calls are currently misidentified.
So instead, let's check whether the stashed value of the thread stack
pointer points into current's thread stack. This can only be the case if
current was interrupted while running EFI runtime code. Note that this
implies that we should clear the stashed value after switching back, to
avoid false positives.
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Diffstat (limited to 'arch/arm64/kernel/efi.c')
| -rw-r--r-- | arch/arm64/kernel/efi.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c index fab05de2e12d..b273900f4566 100644 --- a/arch/arm64/kernel/efi.c +++ b/arch/arm64/kernel/efi.c @@ -11,6 +11,7 @@ #include <linux/init.h> #include <asm/efi.h> +#include <asm/stacktrace.h> static bool region_is_misaligned(const efi_memory_desc_t *md) { @@ -154,7 +155,7 @@ asmlinkage efi_status_t __efi_rt_asm_recover(void); bool efi_runtime_fixup_exception(struct pt_regs *regs, const char *msg) { /* Check whether the exception occurred while running the firmware */ - if (current_work() != &efi_rts_work.work || regs->pc >= TASK_SIZE_64) + if (!current_in_efi() || regs->pc >= TASK_SIZE_64) return false; pr_err(FW_BUG "Unable to handle %s in EFI runtime service\n", msg); |