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

[Paolo Bonzini]

On 01/02/2018 19:00, Alex Williamson wrote:
> 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,

Yeah, I have a fix queued.  Unfortunately, I don't have the usual setup
to do pre-pull-request sets here so it will have to wait for next Monday.

Paolo