[PATCH v4 17/61] arm64: idreg-override: avoid strlen() to check for empty strings

[Ard Biesheuvel]

From: Ard Biesheuvel <ardb at kernel.org>

strlen() is a costly way to decide whether a string is empty, as in that
case, the first character will be NUL so we can check for that directly.

Signed-off-by: Ard Biesheuvel <ardb at kernel.org>
---
 arch/arm64/kernel/idreg-override.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kernel/idreg-override.c b/arch/arm64/kernel/idreg-override.c
index cb4de31071d4..96fec5b7a65e 100644
--- a/arch/arm64/kernel/idreg-override.c
+++ b/arch/arm64/kernel/idreg-override.c
@@ -241,7 +241,7 @@ static void __init match_options(const char *cmdline)
 
 		override = prel64_to_pointer(&reg->override_prel);
 
-		for (f = 0; strlen(reg->fields[f].name); f++) {
+		for (f = 0; reg->fields[f].name[0] != '\0'; f++) {
 			u64 shift = reg->fields[f].shift;
 			u64 width = reg->fields[f].width ?: 4;
 			u64 mask = GENMASK_ULL(shift + width - 1, shift);
-- 
2.42.0.283.g2d96d420d3-goog