header_buf is only used in FSM states up to GotHeader, while name_buf is only used in states following GotHeader (Collect is shared, but the collect pointer tracks each buffer). These buffers can therefore be combined into a single cpio_buf, which can be used for both header and file name storage.
Signed-off-by: David Disseldorp ddiss@suse.de --- init/initramfs.c | 26 +++++++++++++++----------- 1 file changed, 15 insertions(+), 11 deletions(-)
diff --git a/init/initramfs.c b/init/initramfs.c index 59b4a43fa491b..4e2506a4bc76f 100644 --- a/init/initramfs.c +++ b/init/initramfs.c @@ -250,11 +250,11 @@ static void __init read_into(char *buf, unsigned size, enum state next) } }
-static __initdata char *header_buf, *name_buf; +static __initdata char *cpio_buf;
static int __init do_start(void) { - read_into(header_buf, CPIO_HDRLEN, GotHeader); + read_into(cpio_buf, CPIO_HDRLEN, GotHeader); return 0; }
@@ -294,14 +294,14 @@ static int __init do_header(void) if (S_ISLNK(mode)) { if (body_len > PATH_MAX) return 0; - collect = collected = name_buf; + collect = collected = cpio_buf; remains = N_ALIGN(name_len) + body_len; next_state = GotSymlink; state = Collect; return 0; } if (S_ISREG(mode) || !body_len) - read_into(name_buf, N_ALIGN(name_len), GotName); + read_into(cpio_buf, N_ALIGN(name_len), GotName); return 0; }
@@ -511,11 +511,16 @@ char * __init unpack_to_rootfs(char *buf, unsigned long len) const char *compress_name; static __initdata char msg_buf[64];
- header_buf = kmalloc(CPIO_HDRLEN, GFP_KERNEL); - /* 2x PATH_MAX as @name_buf is also used for staging symlink targets */ - name_buf = kmalloc(N_ALIGN(PATH_MAX) + PATH_MAX + 1, GFP_KERNEL); - if (!header_buf || !name_buf) - panic_show_mem("can't allocate buffers"); + /* + * @cpio_buf can be used for staging the 110 byte newc/crc cpio header, + * after which parse_header() converts and stashes fields into + * corresponding types. The same buffer can then be reused for file + * path staging. 2 x PATH_MAX covers any possible symlink target. + */ + BUILD_BUG_ON(CPIO_HDRLEN > N_ALIGN(PATH_MAX) + PATH_MAX + 1); + cpio_buf = kmalloc(N_ALIGN(PATH_MAX) + PATH_MAX + 1, GFP_KERNEL); + if (!cpio_buf) + panic_show_mem("can't allocate buffer");
state = Start; this_header = 0; @@ -559,8 +564,7 @@ char * __init unpack_to_rootfs(char *buf, unsigned long len) len -= my_inptr; } dir_utime(); - kfree(name_buf); - kfree(header_buf); + kfree(cpio_buf); return message; }