initramfs: avoid static buffer for error message

The dynamic error message printed if CONFIG_RD_$ALG compression support
is missing needn't be propagated up to the caller via a static buffer.
Print it immediately via pr_err() and set @message to a const string to
flag error.

Before:
   text    data     bss     dec     hex filename
   8006    1118       8    9132    23ac init/initramfs.o

After:
   text    data     bss     dec     hex filename
   7938    1022       8    8968    2308 init/initramfs.o

Signed-off-by: David Disseldorp <ddiss@suse.de>
Link: https://lore.kernel.org/r/20250304061020.9815-9-ddiss@suse.de
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/init/initramfs.c b/init/initramfs.c
index e0b11f8d6f3d67887ba225a70c575b4050db0d81..72bad44a1d4187dddfa0ab2a61ff579ad5fcd54b 100644 (file)
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -511,7 +511,6 @@ char * __init unpack_to_rootfs(char *buf, unsigned long len)
        long written;
        decompress_fn decompress;
        const char *compress_name;
-       static __initdata char msg_buf[64];
        struct {
                char header[CPIO_HDRLEN];
                char symlink[PATH_MAX + N_ALIGN(PATH_MAX) + 1];
@@ -552,12 +551,9 @@ char * __init unpack_to_rootfs(char *buf, unsigned long len)
                        if (res)
                                error("decompressor failed");
                } else if (compress_name) {
-                       if (!message) {
-                               snprintf(msg_buf, sizeof msg_buf,
-                                        "compression method %s not configured",
-                                        compress_name);
-                               message = msg_buf;
-                       }
+                       pr_err("compression method %s not configured\n",
+                              compress_name);
+                       error("decompressor failed");
                } else
                        error("invalid magic at start of compressed archive");
                if (state != Reset)