diff options
| -rw-r--r-- | util-linux/blockdev.c | 56 |
1 files changed, 34 insertions, 22 deletions
diff --git a/util-linux/blockdev.c b/util-linux/blockdev.c index a780d2238..29c288a15 100644 --- a/util-linux/blockdev.c +++ b/util-linux/blockdev.c @@ -3,7 +3,7 @@ * * Copyright (C) 2010 Sergey Naumov <sknaumov@gmail.com> * - * Licensed under GPLv2, see file LICENSE in this source tree. + * Licensed under GPLv2, see file License in this tarball for details. */ //applet:IF_BLOCKDEV(APPLET(blockdev, _BB_DIR_SBIN, _BB_SUID_DROP)) @@ -39,7 +39,8 @@ enum { ARG_NONE = 0, ARG_INT = 1, ARG_ULONG = 2, - ARG_ULLONG = 3, + /* Yes, BLKGETSIZE64 takes pointer to uint64_t, not ullong! */ + ARG_U64 = 3, ARG_MASK = 3, FL_USRARG = 4, /* argument is provided by user */ @@ -92,7 +93,7 @@ static const struct bdc bdcommands[] = { },{ .ioc = BLKGETSIZE64, .name = "getsize64", - .flags = ARG_ULLONG, + .flags = ARG_U64, .argval = -1, },{ .ioc = BLKFLSBUF, @@ -125,55 +126,66 @@ int blockdev_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int blockdev_main(int argc, char **argv) { const struct bdc *bdcmd; - void *ioctl_ptr; int fd; - int iarg; - unsigned long lu; - unsigned long long llu; + uint64_t u64; + union { + int i; + unsigned long lu; + uint64_t u64; + } ioctl_val_on_stack; if ((unsigned)(argc - 3) > 1) /* must have 2 or 3 args */ bb_show_usage(); bdcmd = find_cmd(*++argv); - llu = (int)bdcmd->argval; + u64 = (int)bdcmd->argval; if (bdcmd->flags & FL_USRARG) - llu = xatoi_positive(*++argv); - lu = llu; - iarg = llu; + u64 = xatoi_positive(*++argv); if (!*++argv || argv[1]) bb_show_usage(); fd = xopen(*argv, O_RDONLY); - ioctl_ptr = NULL; + ioctl_val_on_stack.u64 = u64; +#if BB_BIG_ENDIAN + /* Store data properly wrt data size. + * (1) It's no-op for little-endian. + * (2) it's no-op for 0 and -1. Only --setro uses arg != 0 and != -1, + * and it is ARG_INT. --setbsz USER_VAL is also ARG_INT. + * Thus, we don't need to handle ARG_ULONG. + */ switch (bdcmd->flags & ARG_MASK) { case ARG_INT: - ioctl_ptr = &iarg; + ioctl_val_on_stack.i = (int)u64; break; +# if 0 /* unused */ case ARG_ULONG: - ioctl_ptr = &lu; - break; - case ARG_ULLONG: - ioctl_ptr = &llu; + ioctl_val_on_stack.lu = (unsigned long)u64; break; +# endif } +#endif - if (ioctl(fd, bdcmd->ioc, ioctl_ptr) == -1) + if (ioctl(fd, bdcmd->ioc, &ioctl_val_on_stack.u64) == -1) bb_simple_perror_msg_and_die(*argv); + /* Fetch it into register(s) */ + u64 = ioctl_val_on_stack.u64; + + /* Zero- or one-extend the value if needed, then print */ switch (bdcmd->flags & (ARG_MASK+FL_NORESULT)) { case ARG_INT: /* Smaller code when we use long long * (gcc tail-merges printf call) */ - printf("%lld\n", (long long)iarg); + printf("%lld\n", (long long)(int)u64); break; case ARG_ULONG: - llu = lu; + u64 = (unsigned long)u64; /* FALLTHROUGH */ - case ARG_ULLONG: - printf("%llu\n", llu); + case ARG_U64: + printf("%llu\n", (unsigned long long)u64); break; } |