efi/x86: Use non-blocking SetVariable() for efi_delete_dummy_variable()

Sai Praneeth · Ingo Molnar · commit 5a58bc1b1edc · 2018-07-16T00:43:12.000+02:00
Presently, efi_delete_dummy_variable() uses set_variable() which might block, which the scheduler is rightfully upset about when used from the idle thread, producing this splat: "bad: scheduling from the idle thread!" So, make efi_delete_dummy_variable() use set_variable_nonblocking(), which, as the name suggests, doesn't block. Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20180711094040.12506-3-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
@@ -105,12 +105,11 @@ early_param("efi_no_storage_paranoia", setup_storage_paranoia);
 */
 void efi_delete_dummy_variable(void)
 {
-	efi.set_variable((efi_char16_t *)efi_dummy_name,
-			 &EFI_DUMMY_GUID,
-			 EFI_VARIABLE_NON_VOLATILE |
-			 EFI_VARIABLE_BOOTSERVICE_ACCESS |
-			 EFI_VARIABLE_RUNTIME_ACCESS,
-			 0, NULL);
+	efi.set_variable_nonblocking((efi_char16_t *)efi_dummy_name,
+				     &EFI_DUMMY_GUID,
+				     EFI_VARIABLE_NON_VOLATILE |
+				     EFI_VARIABLE_BOOTSERVICE_ACCESS |
+				     EFI_VARIABLE_RUNTIME_ACCESS, 0, NULL);
 }
 
 /*
