Re: claws-mail deadlocking in iconv

On Wed, 9 Oct 2013 18:34:46 +0200
Fabian Keil <freebsd-listen_at_fabiankeil.de> wrote:

> After the iconv import claws-mail started to deadlock in iconv every
> now and then on my system, which prevented claws-mail from rendering
> windows or reacting to input.
> 
> So far I haven't been able to reproduce this intentionally and various
> rebuilds of ports, kernel and userland (mainly for other reasons) had
> no effect.
> 
> When the problem occurs, trying to attach to the process causes
> gdb and gdb76 to crash which also crashes claws-mail, but sending
> SIGABRT causes a proper core dump that can be analysed with gdb.
> 
> The backtraces always show that there is only one thread running and
> it's trying to lock cm_lock in _citrus_mapper_close(), which
> apparently is already locked due to a _citrus_mapper_close()
> recursion. Examples:
> 
> #0  _umtx_op_err ()
> at /usr/src/lib/libthr/arch/amd64/amd64/_umtx_op_err.S:37 37
> RSYSCALL_ERR(_umtx_op) [New Thread 80a806400 (LWP 100487/claws-mail)]
> (gdb) where
> #0  _umtx_op_err ()
> at /usr/src/lib/libthr/arch/amd64/amd64/_umtx_op_err.S:37 #1
> 0x00000008084861a6 in __thr_rwlock_wrlock (rwlock=0x80a8a47c0,
> tsp=<value optimized out>)
> at /usr/src/lib/libthr/thread/thr_umtx.c:296 #2  0x0000000808489b1d
> in rwlock_wrlock_common (rwlock=<value optimized out>, abstime=0x0)
> at /usr/src/lib/libthr/thread/thr_rwlock.c:267 #3  0x0000000808489a8b
> in _pthread_rwlock_wrlock (rwlock=0x80a8a47c0)
> at /usr/src/lib/libthr/thread/thr_rwlock.c:289 #4  0x000000080911e848
> in _citrus_mapper_close (cm=0x80b5a2d80)
> at /usr/src/lib/libc/iconv/citrus_mapper.c:375 #5  0x000000080d205d18
> in _citrus_mapper_serial_mapper_uninit (cm=0x80b5a2d40)
> at /usr/src/lib/libiconv_modules/mapper_parallel/../mapper_serial/citrus_mapper_serial.c:110
> #6  0x000000080911e8d7 in mapper_close (cm=0x80b5a2d40)
> at /usr/src/lib/libc/iconv/citrus_mapper.c:188 #7  0x000000080911e88c
> in _citrus_mapper_close (cm=<value optimized out>)
> at /usr/src/lib/libc/iconv/citrus_mapper.c:384 #8  0x000000080c4e83f3
> in close_srcs (sl=0x80b591140)
> at /usr/src/lib/libiconv_modules/iconv_std/citrus_iconv_std.c:206 #9
> 0x000000080c4e7dc9 in _citrus_iconv_std_iconv_uninit_shared
> (ci=<value optimized out>)
> at /usr/src/lib/libiconv_modules/iconv_std/citrus_iconv_std.c:415 #10
> 0x00000008090f3f95 in release_shared (ci=0x80a8ee630)
> at /usr/src/lib/libc/iconv/citrus_iconv.c:99 #11 0x00000008090f4002
> in _citrus_iconv_close (cv=0x80d88d5d0)
> at /usr/src/lib/libc/iconv/citrus_iconv.c:335 #12 0x00000008090f1ca6
> in iconv_close (handle=0x80a8a47c0)
> at /usr/src/lib/libc/iconv/iconv.c:131 #13 0x000000000046376d in
> conv_iconv_strdup (inbuf=0x7fffffff58b0 "\n", src_code=0x80b5b4db0
> "Windows-1252", dest_code=0x6f03d0 "UTF-8") at codeconv.c:895 #14
> 0x0000000000463d13 in conv_convert (conv=0x80b5a4e80,
> outbuf=0x7fffffff3720 "", outlen=8192, inbuf=0x7fffffff58b0 "\n") at
> codeconv.c:734 #15 0x00000000005e22ac in textview_write_line
> (textview=0x80a959cc0, str=0x7fffffff58b0 "\n", conv=0x80b5a4e80,
> do_quote_folding=1) at textview.c:1573 #16 0x00000000005df8e4 in
> textview_write_body (textview=0x80a959cc0, mimeinfo=0x80aad2d00) at
> textview.c:1177 #17 0x00000000005e5363 in textview_add_part
> (textview=0x80a959cc0, mimeinfo=0x80aad2d00) at textview.c:826 #18
> 0x00000000005e4053 in recursive_add_parts (textview=0x80a959cc0,
> node=0x80a826190) at textview.c:839 #19 0x00000000005e4302 in
> recursive_add_parts (textview=0x80a959cc0, node=0x80aa81d20) at
> textview.c:888 #20 0x00000000005e4302 in recursive_add_parts
> (textview=0x80a959cc0, node=0x80a828890) at textview.c:888 #21
> 0x00000000005defa1 in textview_add_parts (textview=0x80a959cc0,
> mimeinfo=0x80b610700) at textview.c:898 #22 0x00000000005deb85 in
> textview_show_part (textview=0x80a959cc0, mimeinfo=0x80b610700,
> fp=0x8094319a0) at textview.c:645 [...]
> 
> #0  0x0000000808491b9c in __error () from /lib/libthr.so.3
> #1  0x000000080848bb1d in rwlock_wrlock_common (rwlock=<value
> optimized out>, abstime=0x0)
> at /usr/src/lib/libthr/thread/thr_rwlock.c:267 #2  0x000000080848ba8b
> in _pthread_rwlock_wrlock (rwlock=0x80a8ede20)
> at /usr/src/lib/libthr/thread/thr_rwlock.c:289 #3  0x000000080911f848
> in _citrus_mapper_close (cm=0x80a8bfc40)
> at /usr/src/lib/libc/iconv/citrus_mapper.c:375 #4  0x000000080ce02d18
> in _citrus_mapper_serial_mapper_uninit (cm=0x80a8bfc00)
> at /usr/src/lib/libiconv_modules/mapper_parallel/../mapper_serial/citrus_mapper_serial.c:110
> #5  0x000000080911f8d7 in mapper_close (cm=0x80a8bfc00)
> at /usr/src/lib/libc/iconv/citrus_mapper.c:188 #6  0x000000080911f88c
> in _citrus_mapper_close (cm=<value optimized out>)
> at /usr/src/lib/libc/iconv/citrus_mapper.c:384 #7  0x000000080c5893f3
> in close_srcs (sl=0x80a8edda0)
> at /usr/src/lib/libiconv_modules/iconv_std/citrus_iconv_std.c:206 #8
> 0x000000080c588dc9 in _citrus_iconv_std_iconv_uninit_shared
> (ci=<value optimized out>)
> at /usr/src/lib/libiconv_modules/iconv_std/citrus_iconv_std.c:415 #9
> 0x00000008090f4f95 in release_shared (ci=0x80b408890)
> at /usr/src/lib/libc/iconv/citrus_iconv.c:99 #10 0x00000008090f5002
> in _citrus_iconv_close (cv=0x80b782630)
> at /usr/src/lib/libc/iconv/citrus_iconv.c:335 #11 0x00000008090f2ca6
> in iconv_close (handle=0x80a8ede20)
> at /usr/src/lib/libc/iconv/iconv.c:131 #12 0x000000000046376d in
> conv_iconv_strdup ( inbuf=0x80b600e00 "[...]"...,
> src_code=0x80b782640 "ISO-8859-15", dest_code=0x80c07ab24 "UTF-8") at
> codeconv.c:895 #13 0x0000000000463f2f in conv_codeset_strdup
> ( inbuf=0x80b600e00 "[...]"..., src_code=0x80b782640 "ISO-8859-15",
> dest_code=0x80c07ab24 "UTF-8") at codeconv.c:774 #14
> 0x000000080c07a1a7 in get_part_as_string (mimeinfo=0x80aad2d80) at
> pgpinline.c:153 #15 0x000000080c078333 in pgpinline_is_encrypted
> (mimeinfo=0x80aad2d80) at pgpinline.c:375 [...]
> 
> #0  _umtx_op_err ()
> at /usr/src/lib/libthr/arch/amd64/amd64/_umtx_op_err.S:37 #1
> 0x00000008084861a6 in __thr_rwlock_wrlock (rwlock=0x80bf93f40,
> tsp=<value optimized out>)
> at /usr/src/lib/libthr/thread/thr_umtx.c:296 #2  0x0000000808489b1d
> in rwlock_wrlock_common (rwlock=<value optimized out>, abstime=0x0)
> at /usr/src/lib/libthr/thread/thr_rwlock.c:267 #3  0x0000000808489a8b
> in _pthread_rwlock_wrlock (rwlock=0x80bf93f40)
> at /usr/src/lib/libthr/thread/thr_rwlock.c:289 #4  0x000000080911e848
> in _citrus_mapper_close (cm=0x80bfa0b40)
> at /usr/src/lib/libc/iconv/citrus_mapper.c:375 #5  0x000000080d08ad18
> in _citrus_mapper_serial_mapper_uninit (cm=0x80bfa0b00)
> at /usr/src/lib/libiconv_modules/mapper_parallel/../mapper_serial/citrus_mapper_serial.c:110
> #6  0x000000080911e8d7 in mapper_close (cm=0x80bfa0b00)
> at /usr/src/lib/libc/iconv/citrus_mapper.c:188 #7  0x000000080911e88c
> in _citrus_mapper_close (cm=<value optimized out>)
> at /usr/src/lib/libc/iconv/citrus_mapper.c:384 #8  0x000000080ae2c3f3
> in close_srcs (sl=0x80bf9fbc0)
> at /usr/src/lib/libiconv_modules/iconv_std/citrus_iconv_std.c:206 #9
> 0x000000080ae2bdc9 in _citrus_iconv_std_iconv_uninit_shared
> (ci=<value optimized out>)
> at /usr/src/lib/libiconv_modules/iconv_std/citrus_iconv_std.c:415 #10
> 0x00000008090f3f95 in release_shared (ci=0x80bd59ac0)
> at /usr/src/lib/libc/iconv/citrus_iconv.c:99 #11 0x00000008090f4002
> in _citrus_iconv_close (cv=0x80dc1a3d0)
> at /usr/src/lib/libc/iconv/citrus_iconv.c:335 #12 0x00000008090f1ca6
> in iconv_close (handle=0x80bf93f40)
> at /usr/src/lib/libc/iconv/iconv.c:131 #13 0x000000000046376d in
> conv_iconv_strdup (inbuf=0x80bd570c0 "[...]", src_code=0x7fffffff5d60
> "ISO-8859-2", dest_code=0x6f03d0 "UTF-8") at codeconv.c:895 #14
> 0x0000000000463f2f in conv_codeset_strdup (inbuf=0x80bd570c0 "[...]",
> src_code=0x7fffffff5d60 "ISO-8859-2", dest_code=0x0) at
> codeconv.c:774 #15 0x00000000005f63f0 in unmime_header
> (encoded_str=0x7fffffff7e94 "[...]", addr_field=1) at unmime.c:144
> #16 0x0000000000464a56 in conv_unmime_header (str=0x7fffffff7e94
> "[...]", default_encoding=0x0, addr_field=1) at codeconv.c:1516 #17
> 0x000000000059588a in parse_stream (data=0x8094319a0, isstring=0,
> flags={perm_flags = 3, tmp_flags = 0}, full=0, decrypted=0) at
> procheader.c:558 #18 0x0000000000595234 in procheader_parse_stream
> (fp=0x8094319a0, flags={perm_flags = 3, tmp_flags = 0}, full=0,
> decrypted=0) at procheader.c:461 #19 0x0000000000595195 in
> procheader_parse_file (file=0x80d4202b0
> "/home/fk/.claws-mail/tempfolder/processing/18", flags={perm_flags =
> 3, tmp_flags = 0}, full=0, decrypted=0) at procheader.c:354 [...]
> 
> This patch:
> http://www.fabiankeil.de/sourcecode/freebsd/iconv-Let-_citrus_mapper_close-unlock-cm_lock-before-calli.diff
> seems to prevent the deadlock, but I'm not 100% sure that it's
> correct and I'm also a bit surprised by the lack of reports from
> other claws-mail users.
> 
> Did anyone else run into this or can comment on the patch or
> the backtraces?
> 
> Fabian

Hello Fabian,

I can not go that sophisticated deep into the details like you. But I'm
running claws-mail on a cutting-edge 10.0-CURRENT and I can confirm,
that claws-mail starts locking up from time to time in the way you
described. The frequency of such a non-rendering locked up window of
claws-mail correlates with the frequency I use the client.

I'll try the patch.

Oliver