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

[Greg Kurz <groug@kaod.org>]

On Thu, 1 Feb 2018 19:10:06 -0500
Paolo Bonzini <pbonzini@redhat.com> wrote:

> On 01/02/2018 19:00, Alex Williamson wrote:
> > On Tue, 16 Jan 2018 15:16:59 +0100
> > Paolo Bonzini <pbonzini@redhat.com> wrote:
> >   
> >> From: Marc-André Lureau <marcandre.lureau@redhat.com>
> >>
> >> 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 <marcandre.lureau@redhat.com>
> >> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> >> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> >> Message-Id: <20180104160523.22995-11-marcandre.lureau@redhat.com>
> >> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> >> ---  
> > 
> > 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, path=path@entry=0x55e5ac2fa0f8 "/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
> 

The queued fix is:

http://patchwork.ozlabs.org/patch/862816/