diff options
| -rw-r--r-- | util-linux/mkswap.c | 31 |
1 files changed, 28 insertions, 3 deletions
diff --git a/util-linux/mkswap.c b/util-linux/mkswap.c index 11c411b6a..167b9ee03 100644 --- a/util-linux/mkswap.c +++ b/util-linux/mkswap.c @@ -5,7 +5,6 @@ * * Licensed under GPL version 2, see file LICENSE in this tarball for details. */ - #include "libbb.h" #if ENABLE_SELINUX @@ -48,7 +47,33 @@ static void mkswap_selinux_setcontext(int fd, const char *path) bb_perror_msg_and_die("SELinux relabeling failed"); } #else -#define mkswap_selinux_setcontext(fd, path) ((void)0) +# define mkswap_selinux_setcontext(fd, path) ((void)0) +#endif + +#if ENABLE_DESKTOP +static void mkswap_generate_uuid(uint8_t *buf) +{ + unsigned i; + char uuid_string[32]; + + /* rand() is guaranteed to generate at least [0, 2^15) range, + * but lowest bits in some libc are not so "random". */ + srand((unsigned)monotonic_us() + getpid()); + for (i = 0; i < 16; i++) + buf[i] = rand() >> 5; + + bin2hex(uuid_string, (void*) buf, 16); + /* f.e. UUID=dfd9c173-be52-4d27-99a5-c34c6c2ff55f */ + printf("UUID=%.8s" "-%.4s-%.4s-%.4s-%.12s\n", + uuid_string, + uuid_string+8, + uuid_string+8+4, + uuid_string+8+4+4, + uuid_string+8+4+4+4 + ); +} +#else +# define mkswap_generate_uuid(buf) ((void)0) #endif #if 0 /* from Linux 2.6.23 */ @@ -113,10 +138,10 @@ int mkswap_main(int argc, char **argv) // Make a header. hdr is zero-filled so far... hdr[0] = 1; hdr[1] = (len / pagesize) - 1; + mkswap_generate_uuid((void*) &hdr[3]); // Write the header. Sync to disk because some kernel versions check // signature on disk (not in cache) during swapon. - xlseek(fd, 1024, SEEK_SET); xwrite(fd, hdr, NWORDS * 4); xlseek(fd, pagesize - 10, SEEK_SET); |