[PATCH v3 20/60] arm64: idreg-override: avoid strlen() to check for empty strings

Ard Biesheuvel
2023-03-07T14:09:21Z

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@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 23bbbc37ac24ba09..476dc3f0e9d90e22 100644
--- a/arch/arm64/kernel/idreg-override.c
+++ b/arch/arm64/kernel/idreg-override.c
@@ -221,7 +221,7 @@ 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);
--
2.39.2