efibc: Replace variable set function in notifier call

Replace the variable set function from "efivar_entry_set" to
"efivar_entry_set_safe" in efibc panic notifier.
In safe function parameter "block" will set to false
and will call "efivar_entry_set_nonblocking"to set efi variables.
efivar_entry_set_nonblocking is guaranteed to
not block and is suitable for calling from crash/panic handlers.
In UEFI android platform, when warm reset happens,
with this change, efibc will not block the reboot process.
Otherwise, set variable will call queue work and send to other offlined
cpus then cause another panic, finally will cause reboot failure.

Signed-off-by: Tian Baofeng <[email protected]>
Signed-off-by: Luo XinanX <[email protected]>
Signed-off-by: Ard Biesheuvel <[email protected]>

Author: btian1

drivers/firmware/efi/efibc.c

@@ -43,11 +43,13 @@ static int efibc_set_variable(const char *name, const char *value)
 	efibc_str_to_str16(value, (efi_char16_t *)entry->var.Data);
 	memcpy(&entry->var.VendorGuid, &guid, sizeof(guid));
 
-	ret = efivar_entry_set(entry,
-			       EFI_VARIABLE_NON_VOLATILE
-			       | EFI_VARIABLE_BOOTSERVICE_ACCESS
-			       | EFI_VARIABLE_RUNTIME_ACCESS,
-			       size, entry->var.Data, NULL);
+	ret = efivar_entry_set_safe(entry->var.VariableName,
+				    entry->var.VendorGuid,
+				    EFI_VARIABLE_NON_VOLATILE
+				    | EFI_VARIABLE_BOOTSERVICE_ACCESS
+				    | EFI_VARIABLE_RUNTIME_ACCESS,
+				    false, size, entry->var.Data);
+
 	if (ret)
 		pr_err("failed to set %s EFI variable: 0x%x\n",
 		       name, ret);