Chris Webb <chris@xxxxxxxxxxxx> writes:
> With the following applied, VNC connections and disconnections still work
> correctly, so it doesn't horribly break anything, but I can't immediately
> confirm whether it will cure the rare segfaults as I haven't yet found a
> rapid way of reproducing the crashes other than by waiting for one.
Just to follow up on this: the backported patch has cured the vast majority of
VNC crashes we've been seeing on 0.10.6, although I've still seen this earlier
today:
Core was generated by `qemu-kvm -m 512 -smp 1 -uuid d6f2cb13-7421-4baa-a978-eda9bec9d075 -pidfile /var'.
Program terminated with signal 11, Segmentation fault.
[New process 16847]
[New process 16855]
(gdb) bt
#0 0x00007fe42e9c6cb1 in memcpy () from /lib/libc.so.6
#1 0x00000000004917e4 in vnc_write (vs=0x31a7f50, data=0x7fffe3a19230, len=2) at vnc.c:323
#2 0x00000000004919bf in vnc_write_u16 (vs=0x7fe2f8cae023, value=<value optimized out>) at vnc.c:1035
#3 0x0000000000491bf3 in vnc_framebuffer_update (vs=0x7fe2f8cae023, x=-475950544, y=2, w=16385, h=1, encoding=6)
at vnc.c:286
#4 0x0000000000496660 in send_framebuffer_update (vs=0x7fe2f8cae023, x=-475950544, y=196, w=208, h=1) at vnc.c:598
#5 0x0000000000496f65 in vnc_update_client (opaque=<value optimized out>) at vnc.c:754
#6 0x000000000040822a in main_loop_wait (timeout=<value optimized out>)
at /packages/qemu-kvm+vncfix/src-nUlCId/vl.c:1240
#7 0x000000000051753a in kvm_main_loop () at /packages/qemu-kvm+vncfix/src-nUlCId/qemu-kvm.c:596
#8 0x000000000040c8a5 in main (argc=<value optimized out>, argv=<value optimized out>, envp=<value optimized out>)
at /packages/qemu-kvm+vncfix/src-nUlCId/vl.c:3850
(gdb) f 1
#1 0x00000000004917e4 in vnc_write (vs=0x31a7f50, data=0x7fffe3a19230, len=2) at vnc.c:323
323 memcpy(buffer->buffer + buffer->offset, data, len);
(gdb) f 1
#1 0x00000000004917e4 in vnc_write (vs=0x31a7f50, data=0x7fffe3a19230, len=2) at vnc.c:323
323 memcpy(buffer->buffer + buffer->offset, data, len);
(gdb) p *vs
$1 = {timer = 0x2b90b20, csock = 18, ds = 0x28a1a20, vd = 0x28b0fc0, need_update = 1, dirty_row = {{0, 0, 0,
0} <repeats 197 times>, {65535, 262128, 0, 0}, {4294967295, 1, 0, 0}, {4294967288, 262143, 0, 0}, {4294443008,
262143, 0, 0}, {131071, 262128, 0, 0}, {4294967295, 1, 0, 0}, {4294967292, 262143, 0, 0}, {4294443008, 262143,
0, 0}, {131071, 262136, 0, 0}, {4294967295, 1, 0, 0}, {4294967292, 262143, 0, 0}, {4294443008, 262143, 0, 0}, {
131071, 262136, 0, 0}, {4294967295, 1, 0, 0}, {4294967292, 262143, 0, 0}, {4294705152, 262143, 0, 0}, {131071,
262136, 0, 0}, {4294967295, 1, 0, 0}, {4294967294, 262143, 0, 0}, {4294705152, 262143, 0, 0}, {131071, 262140,
0, 0}, {4294967295, 1, 0, 0}, {4294967294, 262143, 0, 0}, {4294836224, 262143, 0, 0}, {131071, 262140, 0, 0}, {
4294967295, 1, 0, 0}, {4294967294, 262143, 0, 0}, {4294836224, 262143, 0, 0}, {131071, 262140, 0, 0}, {
4294967295, 1, 0, 0}, {4294967295, 262143, 0, 0}, {4294836224, 262143, 0, 0}, {131071, 262142, 0, 0}, {
4294967295, 1, 0, 0}, {4294967295, 262143, 0, 0}, {4294901760, 262143, 0, 0}, {131071, 262142, 0, 0}, {
4294967295, 1, 0, 0}, {4294967295, 262143, 0, 0}, {4294901760, 262143, 0, 0}, {131071, 262142, 0, 0}, {
4294967295, 131073, 0, 0}, {4294967295, 262143, 0, 0}, {4294901760, 262143, 0, 0}, {131071, 262143, 0, 0}, {
4294967295, 131073, 0, 0}, {4294967295, 262143, 0, 0}, {4294934528, 262143, 0, 0}, {131071, 262143, 0, 0}, {
4294967295, 131075, 0, 0}, {4294967295, 262143, 0, 0}, {4294934528, 262143, 0, 0}, {131071, 262143, 0, 0}, {
4294967295, 196611, 0, 0}, {4294967295, 262143, 0, 0}, {4294934528, 262143, 0, 0}, {2147614719, 262143, 0, 0}, {
4294967295, 196611, 0, 0}, {4294967295, 262143, 0, 0}, {4294950912, 262143, 0, 0}, {2147614719, 262143, 0, 0}, {
4294967295, 196611, 0, 0}, {4294967295, 262143, 0, 0}, {4294950912, 262143, 0, 0}, {2147614719, 262143, 0, 0}, {
4294967295, 229379, 0, 0}, {4294967295, 262143, 0, 0}, {4294950912, 262143, 0, 0}, {3221356543, 262143, 0, 0}, {
4294967295, 229379, 0, 0}, {4294967295, 262143, 0, 0}, {4294950912, 262143, 0, 0}, {3221356543, 262143, 0, 0}, {
4294967295, 229377, 0, 0}, {4294967295, 262143, 0, 0}, {4294959104, 262143, 0, 0}, {3221356543, 262143, 0, 0}, {
4294967295, 245761, 0, 0}, {4294967295, 262143, 0, 0}, {4294959104, 262143, 0, 0}, {3758227455, 262143, 0, 0}, {
4294967295, 245761, 0, 0}, {4294967295, 262143, 0, 0}, {4294959104, 262143, 0, 0}, {3758227455, 262143, 0, 0}, {
4294967295, 245761, 0, 0}, {4294967295, 262143, 0, 0}, {4294963200, 262143, 0, 0}, {3758227455, 262143, 0, 0}, {
4294967295, 253953, 0, 0}, {4294967295, 262143, 0, 0}, {4294963200, 262143, 0, 0}, {4026662911, 262143, 0, 0}, {
4294967295, 253953, 0, 0}, {4294967295, 262143, 0, 0}, {4294963200, 262143, 0, 0}, {4026662911, 262143, 0, 0}, {
4294967295, 253953, 0, 0}, {4294967295, 262143, 0, 0}, {4294965248, 262143, 0, 0}, {4026662911, 262143, 0, 0}, {
4294967295, 258049, 0, 0}, {4294967295, 262143, 0, 0}, {4294965248, 262143, 0, 0}, {4026662911, 262143, 0, 0}, {
4294967295, 258049, 0, 0}, {4294967295, 262143, 0, 0}, {4294965248, 262143, 0, 0}, {4160815103, 262143, 0, 0}, {
4294967295, 258049, 0, 0}, {4294967295, 262143, 0, 0}, {4294966272, 262143, 0, 0}, {4160815103, 262143, 0, 0}, {
4294967295, 258049, 0, 0}, {4294967295, 262143, 0, 0}, {4294966272, 262143, 0, 0}, {4160815103, 262143, 0, 0}, {
4294967295, 260097, 0, 0}, {4294967295, 262143, 0, 0}, {4294966272, 262143, 0, 0}, {4227923967, 262143, 0, 0}, {
4294967295, 260097, 0, 0}, {4294967295, 131071, 0, 0}, {4294966272, 262143, 0, 0}, {4227923967, 262143, 0, 0}, {
4294967295, 260097, 0, 0}, {4294967295, 131071, 0, 0}, {4294966784, 262143, 0, 0}, {4227923967, 262143, 0, 0}, {
4294967295, 261121, 0, 0}, {4294967295, 131071, 0, 0}, {4294966784, 262143, 0, 0}, {4227923967, 262143, 0, 0}, {
4294967295, 261120, 0, 0}, {4294967295, 131071, 0, 0}, {4294966784, 262143, 0, 0}, {4261478399, 262143, 0, 0}, {
4294967295, 261120, 0, 0}, {4294967295, 131071, 0, 0}, {4294967040, 262143, 0, 0}, {4261478399, 262143, 0, 0}, {
4294967295, 261120, 0, 0}, {4294967295, 131071, 0, 0}, {4294967040, 262143, 0, 0}, {4261478399, 262143, 0, 0}, {
4294967295, 261632, 0, 0}, {4294967295, 131071, 0, 0}, {4294967040, 262143, 0, 0}, {4278222847, 262143, 0, 0}, {
4294967295, 261632, 0, 0}, {4294967295, 131071, 0, 0}, {4294967040, 262143, 0, 0}, {4278222847, 262143, 0, 0}, {
4294967295, 261632, 0, 0}, {4294967295, 131071, 0, 0}, {4294967168, 262143, 0, 0}, {4278222847, 262143, 0, 0}, {
4294967295, 261888, 0, 0}, {4294967295, 131071, 0, 0}, {4294967168, 262143, 0, 0}, {4278222847, 262143, 0, 0}, {
4294967295, 261888, 0, 0}, {4294967295, 65535, 0, 0}, {4294967168, 262143, 0, 0}, {4286611455, 262143, 0, 0}, {
4294967295, 261888, 0, 0}, {4294967295, 65535, 0, 0}, {4294967232, 262143, 0, 0}, {4286611455, 262143, 0, 0}, {
4294967295, 261888, 0, 0}, {4294967295, 65535, 0, 0}, {4294967232, 262143, 0, 0}, {4286611455, 262143, 0, 0}, {
2147483647, 262016, 0, 0}, {4294967295, 65535, 0, 0}, {4294967232, 262143, 0, 0}, {4286611455, 262143, 0, 0}, {
2147483647, 262016, 0, 0}, {4294967295, 65535, 0, 0}, {4294967232, 262143, 0, 0}, {4290805759, 262143, 0, 0}, {
2147483647, 262016, 0, 0}, {4294967295, 65535, 0, 0}, {4294967264, 262143, 0, 0}, {4290805759, 262143, 0, 0}, {
2147483647, 262016, 0, 0}, {4294967295, 65535, 0, 0}, {4294967264, 262143, 0, 0}, {4290789375, 262143, 0, 0}, {
2147483647, 262080, 0, 0}...}, old_data = 0x2bbd1d0 "", features = 99, absolute = 1, last_x = -1, last_y = -1,
vnc_encoding = 6, tight_quality = 6 '\006', tight_compression = 9 '\t', major = 3, minor = 8,
challenge = "\314\351\243\267G\207\002\v\313\363\226\301ZQ\310m", output = {capacity = 2147485644,
offset = 18446744071562067987,
buffer = 0x7fe378cae010 "H\247BE\311\251\237\305j\200|\344\372\331\232\001\302t`"}, input = {capacity = 5120,
offset = 0, buffer = 0x31b0390 "\003\001"}, write_pixels = 0x491830 <vnc_write_pixels_generic>,
send_hextile_tile = 0x492db0 <send_hextile_tile_generic_32>, clientds = {flags = 0 '\0', width = 800, height = 600,
linesize = 3200, data = 0x7fe40c2ad010 "", pf = {bits_per_pixel = 32 ' ', bytes_per_pixel = 4 '\004',
depth = 24 '\030', rmask = 0, gmask = 0, bmask = 0, amask = 0, rshift = 16 '\020', gshift = 8 '\b',
bshift = 0 '\0', ashift = 24 '\030', rmax = 255 '\377', gmax = 255 '\377', bmax = 255 '\377',
amax = 255 '\377', rbits = 8 '\b', gbits = 8 '\b', bbits = 8 '\b', abits = 8 '\b'}}, serverds = {
flags = 2 '\002', width = 800, height = 600, linesize = 3200, data = 0x7fe40c2ad010 "", pf = {
bits_per_pixel = 32 ' ', bytes_per_pixel = 4 '\004', depth = 24 '\030', rmask = 16711680, gmask = 65280,
bmask = 255, amask = 0, rshift = 16 '\020', gshift = 8 '\b', bshift = 0 '\0', ashift = 24 '\030',
rmax = 255 '\377', gmax = 255 '\377', bmax = 255 '\377', amax = 255 '\377', rbits = 8 '\b', gbits = 8 '\b',
bbits = 8 '\b', abits = 8 '\b'}}, audio_cap = 0x0, as = {freq = 44100, nchannels = 2, fmt = AUD_FMT_S16,
endianness = 0}, read_handler = 0x495a10 <protocol_client_msg>, read_handler_expect = 1,
modifiers_state = '\0' <repeats 255 times>, zlib = {capacity = 1920304, offset = 2176,
buffer = 0x3680680 "A\271\237"}, zlib_tmp = {capacity = 2147485644, offset = 2147483353,
buffer = 0x7fe378cae010 "H\247BE\311\251\237\305j\200|\344\372\331\232\001\302t`"}, zlib_stream = {{
next_in = 0x3680f00 ":\244\215", avail_in = 0, total_in = 15141151424, next_out = 0x7fe3f8cae023 "",
avail_out = 1977, total_out = 2112923344, msg = 0x0, state = 0x31b2ed0, zalloc = 0x7fe42f528b90 <zcalloc>,
zfree = 0x7fe42f528b80 <zcfree>, opaque = 0x31a7f50, data_type = 0, adler = 1623013286, reserved = 0}, {
next_in = 0x0, avail_in = 0, total_in = 0, next_out = 0x0, avail_out = 0, total_out = 0, msg = 0x0,
state = 0x0, zalloc = 0, zfree = 0, opaque = 0x0, data_type = 0, adler = 0, reserved = 0}, {next_in = 0x0,
avail_in = 0, total_in = 0, next_out = 0x0, avail_out = 0, total_out = 0, msg = 0x0, state = 0x0, zalloc = 0,
zfree = 0, opaque = 0x0, data_type = 0, adler = 0, reserved = 0}, {next_in = 0x0, avail_in = 0, total_in = 0,
next_out = 0x0, avail_out = 0, total_out = 0, msg = 0x0, state = 0x0, zalloc = 0, zfree = 0, opaque = 0x0,
data_type = 0, adler = 0, reserved = 0}}, next = 0x0}
Best wishes,
Chris.
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