header_buf, symlink_buf and name_buf all share the same lifecycle so needn't be allocated / freed separately. This change leads to a minor reduction in .text size:
before: text data bss dec hex filename 7914 1110 8 9032 2348 init/initramfs.o
after: text data bss dec hex filename 7854 1110 8 8972 230c init/initramfs.o
A previous iteration of this patch reused a single buffer instead of three, given that buffer use is state-sequential (GotHeader, GotName, GotSymlink). However, the slight decrease in heap use during early boot isn't really worth the extra review complexity.
Link: https://lore.kernel.org/all/20241107002044.16477-7-ddiss@suse.de/ Signed-off-by: David Disseldorp ddiss@suse.de --- init/initramfs.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-)
diff --git a/init/initramfs.c b/init/initramfs.c index 6dd3b02c15d7e..df75624cdefbf 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -510,14 +510,19 @@ char * __init unpack_to_rootfs(char *buf, unsigned long len) 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]; + char name[N_ALIGN(PATH_MAX)]; + } *bufs = kmalloc(sizeof(*bufs), GFP_KERNEL);
- header_buf = kmalloc(CPIO_HDRLEN, GFP_KERNEL); - symlink_buf = kmalloc(PATH_MAX + N_ALIGN(PATH_MAX) + 1, GFP_KERNEL); - name_buf = kmalloc(N_ALIGN(PATH_MAX), GFP_KERNEL); - - if (!header_buf || !symlink_buf || !name_buf) + if (!bufs) panic_show_mem("can't allocate buffers");
+ header_buf = bufs->header; + symlink_buf = bufs->symlink; + name_buf = bufs->name; + state = Start; this_header = 0; message = NULL; @@ -560,9 +565,7 @@ char * __init unpack_to_rootfs(char *buf, unsigned long len) len -= my_inptr; } dir_utime(); - kfree(name_buf); - kfree(symlink_buf); - kfree(header_buf); + kfree(bufs); return message; }