$7 = <optimized out>
(gdb) p newlen
$8 = 30
(gdb) where
#0 0xb7fdbbe8 in __kernel_vsyscall ()
#1 0xb7de9057 in __GI_raise (sig=6) at ../sysdeps/unix/sysv/linux/raise.c:55
#2 0xb7dea699 in __GI_abort () at abort.c:89
#3 0xb7e2c8c1 in __malloc_assert (
assertion=assertion@entry=0xb7f2184c "(old_top == (((mbinptr) (((char *) &((av)->bins[((1) - 1) * 2])) - __builtin_offsetof (struct malloc_chunk, fd)))) && old_size == 0) || ((unsigned long) (old_size) >= (unsigned long)((((__builtin_offs"..., file=file@entry=0xb7f1d50b "malloc.c", line=2373, function=0xb7f1d89c <__func__.10910> "sysmalloc") at malloc.c:297
#4 0xb7e2f1e9 in sysmalloc (av=0xb6a00010, nb=<optimized out>) at malloc.c:2370
#5 _int_malloc (av=av@entry=0xb6a00010, bytes=bytes@entry=33) at malloc.c:3794
#6 0xb7e2f8ec in _int_realloc (av=av@entry=0xb6a00010, oldp=oldp@entry=0xb6a08ea0, oldsize=24, nb=40) at malloc.c:4271
#7 0xb7e30a09 in __GI___libc_realloc (oldmem=0xb6a08ea8, bytes=31) at malloc.c:3023
#8 0x80008e5a in append_line (len=<synthetic pointer>, line=0xb6a08dd8 "rss_huge 0\n", contents=<synthetic pointer>) at cgfs.c:85
#9 read_file (from=<optimized out>) at cgfs.c:106
#10 cgfs_get_value (controller=0x800097b7 "memory", cgroup=0xb6a08e58 "/user.slice/user-1000.slice/session-1.scope/lxcfs_test_proc", file=0x80009934 "memory.stat", value=0xb73fee00) at cgfs.c:667
#11 0x80006202 in proc_meminfo_read (fi=<optimized out>, offset=<optimized out>, size=32768, buf=0xb6a00c70 "") at lxcfs.c:1957
#12 proc_read (path=0xb6a004e0 "/proc/meminfo", fi=0xb73ff1ac, offset=0, size=32768, buf=0xb6a00c70 "") at lxcfs.c:2883
#13 lxcfs_read (path=<optimized out>, buf=0xb6a00c70 "", size=32768, offset=0, fi=0xb73ff1ac) at lxcfs.c:2976
#14 0xb7fa0355 in fuse_fs_read_buf () from /lib/i386-linux-gnu/libfuse.so.2
#15 0xb7fa054e in ?? () from /lib/i386-linux-gnu/libfuse.so.2
#16 0xb7fa9774 in ?? () from /lib/i386-linux-gnu/libfuse.so.2
#17 0xb7faa124 in ?? () from /lib/i386-linux-gnu/libfuse.so.2
#18 0xb7fad81b in fuse_session_process_buf () from /lib/i386-linux-gnu/libfuse.so.2
#19 0xb7fa6783 in ?? () from /lib/i386-linux-gnu/libfuse.so.2
#20 0xb7f7f1aa in start_thread (arg=0xb73ffb40) at pthread_create.c:333
#21 0xb7ea6fde in clone () at ../sysdeps/unix/sysv/linux/i386/clone.S:122
(gdb)