diff options
| -rw-r--r-- | usr/gen_init_cpio.c | 49 |
1 files changed, 38 insertions, 11 deletions
diff --git a/usr/gen_init_cpio.c b/usr/gen_init_cpio.c index 729585342e16..75e9561ba313 100644 --- a/usr/gen_init_cpio.c +++ b/usr/gen_init_cpio.c @@ -28,13 +28,15 @@ #define CPIO_TRAILER "TRAILER!!!" #define padlen(_off, _align) (((_align) - ((_off) & ((_align) - 1))) % (_align)) -static char padding[512]; +/* zero-padding the filename field for data alignment is limited by PATH_MAX */ +static char padding[PATH_MAX]; static unsigned int offset; static unsigned int ino = 721; static time_t default_mtime; static bool do_file_mtime; static bool do_csum = false; static int outfd = STDOUT_FILENO; +static unsigned int dalign; struct file_handler { const char *type; @@ -359,7 +361,7 @@ static int cpio_mkfile(const char *name, const char *location, int file, retval, len; int rc = -1; time_t mtime; - int namesize; + int namesize, namepadlen; unsigned int i; uint32_t csum = 0; ssize_t this_read; @@ -407,14 +409,27 @@ static int cpio_mkfile(const char *name, const char *location, } size = 0; + namepadlen = 0; for (i = 1; i <= nlinks; i++) { - /* data goes on last link */ - if (i == nlinks) - size = buf.st_size; - if (name[0] == '/') name++; namesize = strlen(name) + 1; + + /* data goes on last link, after any alignment padding */ + if (i == nlinks) + size = buf.st_size; + + if (dalign && size > dalign) { + namepadlen = padlen(offset + CPIO_HDR_LEN + namesize, + dalign); + if (namesize + namepadlen > PATH_MAX) { + fprintf(stderr, + "%s: best-effort alignment %u missed\n", + name, dalign); + namepadlen = 0; + } + } + len = dprintf(outfd, "%s%08X%08X%08lX%08lX%08X%08lX" "%08lX%08X%08X%08X%08X%08X%08X", do_csum ? "070702" : "070701", /* magic */ @@ -429,13 +444,13 @@ static int cpio_mkfile(const char *name, const char *location, 1, /* minor */ 0, /* rmajor */ 0, /* rminor */ - namesize, /* namesize */ + namesize + namepadlen, /* namesize */ size ? csum : 0); /* chksum */ offset += len; if (len != CPIO_HDR_LEN || push_buf(name, namesize) < 0 || - push_pad(padlen(offset, 4)) < 0) + push_pad(namepadlen ? namepadlen : padlen(offset, 4)) < 0) goto error; if (size) { @@ -552,7 +567,7 @@ static int cpio_mkfile_line(const char *line) static void usage(const char *prog) { fprintf(stderr, "Usage:\n" - "\t%s [-t <timestamp>] [-c] [-o <output_file>] <cpio_list>\n" + "\t%s [-t <timestamp>] [-c] [-o <output_file>] [-a <data_align>] <cpio_list>\n" "\n" "<cpio_list> is a file containing newline separated entries that\n" "describe the files to be included in the initramfs archive:\n" @@ -590,7 +605,10 @@ static void usage(const char *prog) "The default is to use the current time for all files, but\n" "preserve modification time for regular files.\n" "-c: calculate and store 32-bit checksums for file data.\n" - "<output_file>: write cpio to this file instead of stdout\n", + "<output_file>: write cpio to this file instead of stdout\n" + "<data_align>: attempt to align file data by zero-padding the\n" + "filename field up to data_align. Must be a multiple of 4.\n" + "Alignment is best-effort; PATH_MAX limits filename padding.\n", prog); } @@ -632,7 +650,7 @@ int main (int argc, char *argv[]) default_mtime = time(NULL); while (1) { - int opt = getopt(argc, argv, "t:cho:"); + int opt = getopt(argc, argv, "t:cho:a:"); char *invalid; if (opt == -1) @@ -661,6 +679,15 @@ int main (int argc, char *argv[]) exit(1); } break; + case 'a': + dalign = strtoul(optarg, &invalid, 10); + if (!*optarg || *invalid || (dalign & 3)) { + fprintf(stderr, "Invalid data_align: %s\n", + optarg); + usage(argv[0]); + exit(1); + } + break; case 'h': case '?': usage(argv[0]); |