diff mbox series

[1/3] initramfs: move unnecessary memcmp from hot path

Message ID 20210610214525.13891-1-ddiss@suse.de (mailing list archive)
State New
Headers show
Series [1/3] initramfs: move unnecessary memcmp from hot path | expand

Commit Message

David Disseldorp June 10, 2021, 9:45 p.m. UTC
do_header() is called for each cpio entry and first checks for "newc"
magic before parsing further. The magic check includes a special case
error message if POSIX.1 ASCII (cpio -H odc) magic is detected. This
special case POSIX.1 check needn't be done in the hot path, so move it
under the non-newc-magic error path.

Signed-off-by: David Disseldorp <ddiss@suse.de>
---
 init/initramfs.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/init/initramfs.c b/init/initramfs.c
index af27abc59643..f01590cefa2d 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -256,12 +256,11 @@  static int __init do_collect(void)
 
 static int __init do_header(void)
 {
-	if (memcmp(collected, "070707", 6)==0) {
-		error("incorrect cpio method used: use -H newc option");
-		return 1;
-	}
 	if (memcmp(collected, "070701", 6)) {
-		error("no cpio magic");
+		if (memcmp(collected, "070707", 6) == 0)
+			error("incorrect cpio method used: use -H newc option");
+		else
+			error("no cpio magic");
 		return 1;
 	}
 	parse_header(collected);