here is backtrace of gdb for "./mount /dev/sda1 /mnt"

Program received signal SIGSEGV, Segmentation fault.

0x00007ffff7dd58fb in strlen () from /lib/ld-musl-x86_64.so.1

(gdb) at

#0 0x00007ffff7dd58fb in strlen () from /lib/ld-musl-x86_64.so.1

#1 0x00007ffff79614b6 in unmangle_string (s=0x6164732f7665642f <Address 0x616732f7665642 out of bounds>) at ./include/mangle.h:17

#2 mnt_parse_table_line (s=0x7fffffffe640 "/dev/sda1 /mnt ext4 rw 0 0", fs=0x608f00) at libmount/src/tab_parse.c:78

#3 mnt_table_parse_next (tb=tb@entry=0x7ffff7ffb360, f=f@entry=0x608a00, fs=fs@entry=0x608f00, filename=filename@entry=0x7ffff7973e78 "/etc/mtab", nlines=nlines@entry=0x7fffffffeab4) at at libmount/src/tab_parse.c:396

#4 0x00007ffff79618e7 in mnt_table_parse_stream (tb=tb@entry=0x7ffff7ffb360, f=f@entry=0x608a00, filename=<optimzed out>, filename@entry=0x7ffff7973e78 "/etc/mtab") at libmount/src/tab_parse.c:529

#5 0x00007ffff7961e26 in mnt_table_parse_file (tb=0x7ffff7ffb360, filename=0x7ffff7973e78 "/etc/mtab") at libmount/src/tab_parse.c:584
#6 0x00007ffff796246f in mnt_table_parse_mtab (tb=0x7ffff7ffb360, filename=0x7ffff7973e78 "/etc/mtab") at libmount/src/tab_parse.c:968

#7 0x00007ffff794fbf5 in mnt_context_get_mtab (cxt=cxt@entry=0x7ffff7ffb260, tb=tb@entry=0x7fffffffec90) at libmount/src/context.c:958

#8 0x0000000000403c7d in print_all (show_label=0, pattern=0x0, cxt=0x7ffff7ffb260) at sys-utils/mount.c:130

#9 main (argc=0, argv=0x7fffffffed40) at sys-utils/mount.c:1004

(gdb)

On Thu, May 30, 2013 at 7:17 AM, plan9assembler <plan9assembler@gmail.com> wrote:

correction:

#if 1
#define _IO(a,b) _IOC(0U,(a),(b),0)                 //?

#define _IOW(a,b,c) _IOC(1U,(a),(b),sizeof(c)) //?
#else
#define _IO(a,b) _IOC(0,(a),(b),0)                   //ok
#define _IOW(a,b,c) _IOC(1,(a),(b),sizeof(c))   //ok
#endif

#define _IOR(a,b,c) _IOC(2U,(a),(b),sizeof(c)) //ok
- #define _IOW(a,b,c) _IOC(3U,(a),(b),sizeof(c)) //ok
+ #define _IOWR(a,b,c) _IOC(3U,(a),(b),sizeof(c)) //ok
On Thu, May 30, 2013 at 7:07 AM, plan9assembler <plan9assembler@gmail.com> wrote:
could you send me the patch? i will test it.

BTW, in latest musl-git version, i found something wrong with ioctl.h

#if 1
#define _IO(a,b) _IOC(0U,(a),(b),0)                 //?

#define _IOW(a,b,c) _IOC(1U,(a),(b),sizeof(c)) //?
#else
#define _IO(a,b) _IOC(0,(a),(b),0)                   //ok
#define _IOW(a,b,c) _IOC(1,(a),(b),sizeof(c))   //ok
#endif

#define _IOR(a,b,c) _IOC(2U,(a),(b),sizeof(c)) //ok
#define _IOW(a,b,c) _IOC(3U,(a),(b),sizeof(c)) //ok

if i set 0, it works fine run as "./mount", but set 1 then,
# ./mount /dev/sda1 /mnt
EXT4-fs (sda1): mounted filesystem with ordered data mode. Opts: (null)

< 30 - 40  seconds waiting without return to shell>

mount: /mnt: filesystem mounted, but mount(8) failedOperation timed out
// <-- this is weird.
#
On Thu, May 30, 2013 at 5:04 AM, Szabolcs Nagy <nsz@port70.net> wrote:

* plan9assembler <plan9assembler@gmail.com> [2013-05-29 23:41:13 +0900]:

> util-linux umount gets segfaults randomly..(X)
> util-linux umount gets segfaults always..(O)
>
> # ./umount /mnt
> traps: umount[9444] general protection ip:7f9c48e618fb sp:7fff72447b88
> error:0 in libc.so[7f9c48e16000+72000]
> Segmentation fault.

it seems util-linux uses sscanf with %ms to parse mtab
in libmount in tab_parse.c

after i fixed that mount and umount does not segfault here
(used fixed size malloc and %s instead)