efi_loader: Convert runtime reset from switch to if statements

We currently handle the UEFI runtime reset / power off case handling via
a switch statement. Compilers (gcc in my case) may opt to handle these via
jump tables which they may conveniently put into .rodata which is not part
of the runtime section, so it will be unreachable when executed.

Fix this by just converting the switch statement into an if/else statement.
It produces smaller code that is faster and also correct because we no
longer refer .rodata from efi runtime code.

Reported-by: Andreas Färber <aferber@suse.de>
Signed-off-by: Alexander Graf <agraf@suse.de>

1 files changed, 4 insertions, 7 deletions

diff --git a/arch/arm/cpu/armv8/fwcall.c b/arch/arm/cpu/armv8/fwcall.c
index c5aa41a0e6..0ba3dad8cc 100644
--- a/arch/arm/cpu/armv8/fwcall.c
+++ b/arch/arm/cpu/armv8/fwcall.c
@@ -143,15 +143,12 @@ void __efi_runtime EFIAPI efi_reset_system(
 			efi_status_t reset_status,
 			unsigned long data_size, void *reset_data)
 {
-	switch (reset_type) {
-	case EFI_RESET_COLD:
-	case EFI_RESET_WARM:
-	case EFI_RESET_PLATFORM_SPECIFIC:
+	if (reset_type == EFI_RESET_COLD ||
+	    reset_type == EFI_RESET_WARM ||
+	    reset_type == EFI_RESET_PLATFORM_SPECIFIC) {
 		psci_system_reset();
-		break;
-	case EFI_RESET_SHUTDOWN:
+	} else if (reset_type == EFI_RESET_SHUTDOWN) {
 		psci_system_off();
-		break;
 	}
 
 	while (1) { }