arm: Add return value argument to longjmp

The normal longjmp command allows for a caller to pass the return value
of the setjmp() invocation. This patch adds that semantic to the arm
implementation of it and adjusts the efi_loader call respectively.

Signed-off-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Simon Glass <sjg@chromium.org>

arch/arm/include/asm/setjmp.h

@@ -11,29 +11,26 @@
 struct jmp_buf_data {
 	ulong target;
 	ulong regs[5];
+	int ret;
 };
 
 typedef struct jmp_buf_data jmp_buf[1];
 
 static inline int setjmp(jmp_buf jmp)
 {
-	long r = 0;
+	jmp->ret = 0;
 
 #ifdef CONFIG_ARM64
 	asm volatile(
 		"adr x1, jmp_target\n"
-		"str x1, %1\n"
-		"stp x26, x27, %2\n"
-		"stp x28, x29, %3\n"
+		"str x1, %0\n"
+		"stp x26, x27, %1\n"
+		"stp x28, x29, %2\n"
 		"mov x1, sp\n"
-		"str x1, %4\n"
-		"b 2f\n"
+		"str x1, %3\n"
 		"jmp_target: "
-		"mov %0, #1\n"
-		"2:\n"
-		: "+r" (r), "=m" (jmp->target),
-		  "=m" (jmp->regs[0]), "=m" (jmp->regs[2]),
-		  "=m" (jmp->regs[4])
+		: "=m" (jmp->target), "=m" (jmp->regs[0]),
+		  "=m" (jmp->regs[2]), "=m" (jmp->regs[4])
 		:
 		: "x0", "x1", "x2", "x3", "x4", "x5", "x6", "x7",
 		  "x8", "x9", "x10", "x11", "x12", "x13", "x14", "x15",
@@ -49,26 +46,25 @@ static inline int setjmp(jmp_buf jmp)
 #else
 		"adr r0, jmp_target\n"
 #endif
-		"mov r1, %1\n"
+		"mov r1, %0\n"
 		"mov r2, sp\n"
 		"stm r1!, {r0, r2, r4, r5, r6, r7}\n"
-		"b 2f\n"
 		".align 2\n"
 		"jmp_target: \n"
-		"mov %0, #1\n"
-		"2:\n"
-		: "+l" (r)
+		:
 		: "l" (&jmp->target)
 		: "r0", "r1", "r2", "r3", /* "r4", "r5", "r6", "r7", */
 		  "r8", "r9", "r10", "r11", /* sp, */ "ip", "lr",
 		  "cc", "memory");
 #endif
 
-	return r;
+	return jmp->ret;
 }
 
-static inline __noreturn void longjmp(jmp_buf jmp)
+static inline __noreturn void longjmp(jmp_buf jmp, int ret)
 {
+	jmp->ret = ret;
+
 #ifdef CONFIG_ARM64
 	asm volatile(
 		"ldr x0, %0\n"

lib/efi_loader/efi_boottime.c

@@ -475,7 +475,7 @@ static efi_status_t EFIAPI efi_exit(efi_handle_t image_handle,
 		  exit_data_size, exit_data);
 
 	loaded_image_info->exit_status = exit_status;
-	longjmp(&loaded_image_info->exit_jmp);
+	longjmp(&loaded_image_info->exit_jmp, 1);
 
 	panic("EFI application exited");
 }