Re: [Qemu-devel] [PULL 17/51] readline: add a free function

[Alex Williamson]

On Tue, 16 Jan 2018 15:16:59 +0100
Paolo Bonzini <address@hidden> wrote:

> From: Marc-André Lureau <address@hidden>
> 
> Fixes leaks such as:
> 
> Direct leak of 2 byte(s) in 1 object(s) allocated from:
>     #0 0x7eff58beb850 in malloc (/lib64/libasan.so.4+0xde850)
>     #1 0x7eff57942f0c in g_malloc ../glib/gmem.c:94
>     #2 0x7eff579431cf in g_malloc_n ../glib/gmem.c:331
>     #3 0x7eff5795f6eb in g_strdup ../glib/gstrfuncs.c:363
>     #4 0x55db720f1d46 in readline_hist_add 
> /home/elmarco/src/qq/util/readline.c:258
>     #5 0x55db720f2d34 in readline_handle_byte 
> /home/elmarco/src/qq/util/readline.c:387
>     #6 0x55db71539d00 in monitor_read /home/elmarco/src/qq/monitor.c:3896
>     #7 0x55db71f9be35 in qemu_chr_be_write_impl 
> /home/elmarco/src/qq/chardev/char.c:167
>     #8 0x55db71f9bed3 in qemu_chr_be_write 
> /home/elmarco/src/qq/chardev/char.c:179
>     #9 0x55db71fa013c in fd_chr_read /home/elmarco/src/qq/chardev/char-fd.c:66
>     #10 0x55db71fe18a8 in qio_channel_fd_source_dispatch 
> /home/elmarco/src/qq/io/channel-watch.c:84
>     #11 0x7eff5793a90b in g_main_dispatch ../glib/gmain.c:3182
>     #12 0x7eff5793b7ac in g_main_context_dispatch ../glib/gmain.c:3847
>     #13 0x55db720af3bd in glib_pollfds_poll 
> /home/elmarco/src/qq/util/main-loop.c:214
>     #14 0x55db720af505 in os_host_main_loop_wait 
> /home/elmarco/src/qq/util/main-loop.c:261
>     #15 0x55db720af6d6 in main_loop_wait 
> /home/elmarco/src/qq/util/main-loop.c:515
>     #16 0x55db7184e0de in main_loop /home/elmarco/src/qq/vl.c:1995
>     #17 0x55db7185e956 in main /home/elmarco/src/qq/vl.c:4914
>     #18 0x7eff4ea17039 in __libc_start_main (/lib64/libc.so.6+0x21039)
> 
> (while at it, use g_new0(ReadLineState), it's a bit easier to read)
> 
> Signed-off-by: Marc-André Lureau <address@hidden>
> Reviewed-by: Dr. David Alan Gilbert <address@hidden>
> Reviewed-by: Philippe Mathieu-Daudé <address@hidden>
> Message-Id: <address@hidden>
> Signed-off-by: Paolo Bonzini <address@hidden>
> ---

I'm having some trouble with this patch, using b05631954d6d:

# /usr/local/bin/qemu-system-x86_64 -m 1G -nodefaults -net none -monitor stdio 
-serial none -parallel none -nographic 
QEMU 2.11.50 monitor - type 'help' for more information
(qemu) sys<tab>
system_powerdown  system_reset      system_wakeup     
(qemu) system_p<tab>    # resulting in system_powerdown
(qemu) quit
Segmentation fault (core dumped)

gdb shows:

Thread 1 "qemu-system-x86" received signal SIGSEGV, Segmentation fault.
0x00007f7d64d82927 in malloc () from /lib64/libc.so.6
(gdb) bt
#0  0x00007f7d64d82927 in malloc () at /lib64/libc.so.6
#1  0x00007f7d6ef68359 in g_malloc () at /lib64/libglib-2.0.so.0
#2  0x00007f7d6ef83004 in g_strsplit () at /lib64/libglib-2.0.so.0
#3  0x000055e5ac0d549d in container_get (root=0x55e5ad570ee0, address@hidden 
"/chardevs") at qom/container.c:34
#4  0x000055e5ac14d102 in get_chardevs_root () at chardev/char.c:43
#5  0x000055e5ac14ec4d in qemu_chr_cleanup () at chardev/char.c:1107
#6  0x000055e5abeff1c4 in main (argc=<optimized out>, argv=<optimized out>, 
envp=<optimized out>) at vl.c:4780

Reverting this patch, commit e5dc1a6c6c435, I don't see the issue.
Thanks,

Alex