From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Lieven Subject: Re: [Qemu-devel] segmentation fault in qemu-kvm-0.14.0 Date: Tue, 15 Mar 2011 13:53:20 +0100 Message-ID: <4D7F6140.8060605@dlh.net> References: <2640D58E-2101-47FA-99B6-28815666651E@dlh.net> <4D772BBC.4040603@mail.berlios.de> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: qemu-devel , kvm@vger.kernel.org, anthony@codemonkey.ws, Corentin Chary To: Stefan Weil Return-path: Received: from ssl.dlh.net ([91.198.192.8]:39650 "EHLO ssl.dlh.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757561Ab1COMxY (ORCPT ); Tue, 15 Mar 2011 08:53:24 -0400 In-Reply-To: <4D772BBC.4040603@mail.berlios.de> Sender: kvm-owner@vger.kernel.org List-ID: On 09.03.2011 08:26, Stefan Weil wrote: > Am 08.03.2011 23:53, schrieb Peter Lieven: >> Hi, >> >> during testing of qemu-kvm-0.14.0 i can reproduce the following >> segfault. i have seen similar crash already in 0.13.0, but had no >> time to debug. >> my guess is that this segfault is related to the threaded vnc server >> which was introduced in qemu 0.13.0. the bug is only triggerable if a >> vnc >> client is attached. it might also be connected to a resolution change >> in the guest. i have a backtrace attached. the debugger is still >> running if someone >> needs more output >> >> Reading symbols from /usr/local/bin/qemu-system-x86_64...done. >> (gdb) r -net tap,vlan=141,script=no,downscript=no,ifname=tap0 -net >> nic,vlan=141,model=rtl8139,macaddr=52:54:00:ff:00:93 -drive >> format=host_device,file=/dev/mapper/iqn.2001-05.co >> m.equallogic:0-8a0906-e6b70e107-e87000e7acf4d4e5-lieven-winxp-r17453,if=ide,boot=on,cache=none,aio=native >> -m 1024 -monitor tcp:0:4001,server,nowait -vnc :1 -name 'lieven-winxp-te >> st' -boot order=c,menu=on -k de -pidfile /var/run/qemu/vm-265.pid >> -mem-path /hugepages -mem-prealloc -cpu qemu64,model_id='Intel(R) >> Xeon(R) CPU E5640 @ 2.67GHz',-n >> x -rtc base=localtime,clock=vm -vga cirrus -usb -usbdevice tablet >> Starting program: /usr/local/bin/qemu-system-x86_64 -net >> tap,vlan=141,script=no,downscript=no,ifname=tap0 -net >> nic,vlan=141,model=rtl8139,macaddr=52:54:00:ff:00:93 -drive format >> =host_device,file=/dev/mapper/iqn.2001-05.com.equallogic:0-8a0906-e6b70e107-e87000e7acf4d4e5-lieven-winxp-r17453,if=ide,boot=on,cache=none,aio=native >> -m 1024 -monitor tcp:0:4001, >> server,nowait -vnc :1 -name 'lieven-winxp-test' -boot order=c,menu=on >> -k de -pidfile /var/run/qemu/vm-265.pid -mem-path /hugepages >> -mem-prealloc -cpu qemu64,model_id='Intel(R >> ) Xeon(R) CPU E5640 @ 2.67GHz',-nx -rtc base=localtime,clock=vm -vga >> cirrus -usb -usbdevice tablet >> [Thread debugging using libthread_db enabled] >> >> [New Thread 0x7ffff694e700 (LWP 29042)] >> [New Thread 0x7ffff6020700 (LWP 29043)] >> [New Thread 0x7ffff581f700 (LWP 29074)] >> [Thread 0x7ffff581f700 (LWP 29074) exited] >> [New Thread 0x7ffff581f700 (LWP 29124)] >> [Thread 0x7ffff581f700 (LWP 29124) exited] >> [New Thread 0x7ffff581f700 (LWP 29170)] >> [Thread 0x7ffff581f700 (LWP 29170) exited] >> [New Thread 0x7ffff581f700 (LWP 29246)] >> [Thread 0x7ffff581f700 (LWP 29246) exited] >> [New Thread 0x7ffff581f700 (LWP 29303)] >> [Thread 0x7ffff581f700 (LWP 29303) exited] >> [New Thread 0x7ffff581f700 (LWP 29349)] >> [Thread 0x7ffff581f700 (LWP 29349) exited] >> [New Thread 0x7ffff581f700 (LWP 29399)] >> [Thread 0x7ffff581f700 (LWP 29399) exited] >> [New Thread 0x7ffff581f700 (LWP 29471)] >> [Thread 0x7ffff581f700 (LWP 29471) exited] >> [New Thread 0x7ffff581f700 (LWP 29521)] >> [Thread 0x7ffff581f700 (LWP 29521) exited] >> [New Thread 0x7ffff581f700 (LWP 29593)] >> [Thread 0x7ffff581f700 (LWP 29593) exited] >> [New Thread 0x7ffff581f700 (LWP 29703)] >> [Thread 0x7ffff581f700 (LWP 29703) exited] >> >> Program received signal SIGSEGV, Segmentation fault. >> 0x0000000000000000 in ?? () >> (gdb) >> >> (gdb) thread apply all bt full >> >> Thread 3 (Thread 0x7ffff6020700 (LWP 29043)): >> #0 0x00007ffff79c385c in pthread_cond_wait@@GLIBC_2.3.2 () >> from /lib/libpthread.so.0 >> No symbol table info available. >> #1 0x00000000004d3ae1 in qemu_cond_wait (cond=0x1612d50, >> mutex=0x1612d80) >> at qemu-thread.c:133 >> err = 0 >> __func__ = "qemu_cond_wait" >> #2 0x00000000004d2b39 in vnc_worker_thread_loop (queue=0x1612d50) >> at ui/vnc-jobs-async.c:198 >> job = 0x7ffff058cd20 >> entry = 0x0 >> tmp = 0x0 >> vs = {csock = -1, ds = 0x15cb380, dirty = {{0, 0, 0, 0, >> 0} }, vd = 0x1607ff0, need_update = 0, >> force_update = 0, features = 243, absolute = 0, last_x = 0, >> last_y = 0, client_width = 0, client_height = 0, vnc_encoding = 7, >> major = 0, minor = 0, challenge = '\000' , >> info = 0x0, output = {capacity = 3194, offset = 2723, >> buffer = 0x1fbbfd0 ""}, input = {capacity = 0, offset = 0, >> buffer = 0x0}, write_pixels = 0x4c4bc9 , >> clientds = {flags = 0 '\000', width = 720, height = 400, >> linesize = 2880, >> data = 0x7ffff6021010
, >> 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 '\000', >> 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 = 0, nchannels = 0, fmt = AUD_FMT_U8, >> endianness = 0}, read_handler = 0, read_handler_expect = 0, >> modifiers_state = '\000' , led = 0x0, >> abort = false, output_mutex = {lock = {__data = {__lock = 0, >> __count = 0, __owner = 0, __nusers = 0, __kind = 0, >> __spins = 0, __list = {__prev = 0x0, __next = 0x0}}, >> __size = '\000' , __align = 0}}, tight = { >> type = 7, quality = 255 '\377', compression = 9 '\t', >> pixel24 = 1 '\001', tight = {capacity = 3146708, offset = 1376, >> buffer = 0x7ffff4684010 ""}, tmp = {capacity = 3194, >> offset = 2672, buffer = 0x1fbbfd0 ""}, zlib = { >> capacity = 141451, offset = 0, >> buffer = 0x1805da0 >> "B--G\317\253\031=\257f\364\274\232\321\363jF\317\253\241\326y5"}, >> gradient = {capacity = 0, offset = 0, buffer = 0x0}, >> levels = {9, 9, 9, 0}, stream = {{ >> next_in = 0x7ffff4684460 >> "\002\003\002\003\002\002\002\002\002\002\002\002\002", avail_in = 0, >> total_in = 9048240, >> next_out = 0x1805df6 >> "d\276\345c\363\216\237\212\377\314\003\236\246\\$\361\025~\032\311\232\067q&_$\231\251y\262*!\231\067\236\067\363\214\347\315\240\361\221,\274T\257\221\314\333\341\251\362R\373\232_\311a\272\002\061sgt\317\030\332\262~\300\063\267]\307\267\343\033", >> avail_out = 141365, >> total_out = 1034664, msg = 0x0, state = 0x16ea550, >> zalloc = 0x4ca2d8 , >> zfree = 0x4ca315 , opaque = 0x7ffff6015920, >> data_type = 0, adler = 1285581469, reserved = 0}, { >> next_in = 0x7ffff4684022 "\002\002", avail_in = 0, >> total_in = 46491, >> next_out = 0x1805da8 "\257f\364\274\232\321\363jF\317\253\241\326y5", >> avail_out = 141443, total_out = 9905, msg = 0x0, state = 0x17a3f00, >> zalloc = 0x4ca2d8 , >> zfree = 0x4ca315 , opaque = 0x7ffff6015920, >> data_type = 0, adler = 2415253306, reserved = 0}, { >> next_in = 0x7ffff4684570 "\017(`", avail_in = 0, >> total_in = 2188024, >> next_out = 0x1805dbd >> "z\222\024#\233O\214g\341\352\211/U\310s\017\361\245\020\262\343\211TO\222\371\304\207\fryK|\251E\222\343\311+\237\351`>\355\312sR\265\320\272~\001", >> avail_out = 141422, total_out = 100512, msg = 0x0, >> state = 0x1682950, zalloc = 0x4ca2d8 , >> zfree = 0x4ca315 , opaque = 0x7ffff6015920, >> data_type = 0, adler = 3999694267, 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}}}, zlib = {zlib = {capacity = 0, offset = 0, >> buffer = 0x0}, tmp = {capacity = 0, offset = 0, buffer = 0x0}, >> stream = {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}, level = 0}, hextile = { >> send_tile = 0x4cd21d }, >> mouse_mode_notifier = {notify = 0x80, node = {tqe_next = 0x1612da8, >> tqe_prev = 0x7ffff6020700}}, next = {tqe_next = 0x7ffff6020700, >> tqe_prev = 0x7ffff7ffe128}} >> n_rectangles = 40 >> saved_offset = 2 >> flush = true >> #3 0x00000000004d302c in vnc_worker_thread (arg=0x1612d50) >> at ui/vnc-jobs-async.c:302 >> queue = 0x1612d50 >> #4 0x00007ffff79be9ca in start_thread () from /lib/libpthread.so.0 >> No symbol table info available. >> #5 0x00007ffff6c3970d in clone () from /lib/libc.so.6 >> No symbol table info available. >> #6 0x0000000000000000 in ?? () >> No symbol table info available. >> >> Thread 2 (Thread 0x7ffff694e700 (LWP 29042)): >> #0 0x00007ffff6c31197 in ioctl () from /lib/libc.so.6 >> No symbol table info available. >> #1 0x0000000000434c12 in kvm_run (env=0x118c2e0) >> at /usr/src/qemu-kvm-0.14.0/qemu-kvm.c:582 >> r = 0 >> kvm = 0x1172538 >> run = 0x7ffff7fc7000 >> fd = 15 >> #2 0x0000000000435ed4 in kvm_cpu_exec (env=0x118c2e0) >> at /usr/src/qemu-kvm-0.14.0/qemu-kvm.c:1233 >> r = 0 >> #3 0x00000000004364f7 in kvm_main_loop_cpu (env=0x118c2e0) >> at /usr/src/qemu-kvm-0.14.0/qemu-kvm.c:1419 >> run_cpu = 1 >> #4 0x0000000000436640 in ap_main_loop (_env=0x118c2e0) >> at /usr/src/qemu-kvm-0.14.0/qemu-kvm.c:1466 >> env = 0x118c2e0 >> signals = {__val = {18446744067267100671, >> 18446744073709551615 }} >> data = 0x0 >> #5 0x00007ffff79be9ca in start_thread () from /lib/libpthread.so.0 >> No symbol table info available. >> #6 0x00007ffff6c3970d in clone () from /lib/libc.so.6 >> No symbol table info available. >> #7 0x0000000000000000 in ?? () >> No symbol table info available. >> >> Thread 1 (Thread 0x7ffff7ff0700 (LWP 29038)): >> #0 0x0000000000000000 in ?? () >> No symbol table info available. >> #1 0x000000000041d669 in main_loop_wait (nonblocking=0) >> at /usr/src/qemu-kvm-0.14.0/vl.c:1388 >> pioh = 0x1652870 >> ioh = 0x1613330 >> rfds = {fds_bits = {0 }} >> wfds = {fds_bits = {1048576, 0 }} >> xfds = {fds_bits = {0 }} >> ret = 1 >> nfds = 21 >> tv = {tv_sec = 0, tv_usec = 999998} >> timeout = 1000 >> #2 0x0000000000436a4a in kvm_main_loop () >> at /usr/src/qemu-kvm-0.14.0/qemu-kvm.c:1589 >> mask = {__val = {268443712, 0 }} >> sigfd = 19 >> #3 0x000000000041d785 in main_loop () at >> /usr/src/qemu-kvm-0.14.0/vl.c:1429 >> r = 0 >> #4 0x000000000042166a in main (argc=33, argv=0x7fffffffe658, >> envp=0x7fffffffe768) at /usr/src/qemu-kvm-0.14.0/vl.c:3201 >> gdbstub_dev = 0x0 >> i = 64 >> snapshot = 0 >> linux_boot = 0 >> icount_option = 0x0 >> initrd_filename = 0x0 >> kernel_filename = 0x0 >> kernel_cmdline = 0x5e57a3 "" >> boot_devices = "c\000d", '\000' >> ds = 0x15cb380 >> dcl = 0x0 >> cyls = 0 >> heads = 0 >> secs = 0 >> translation = 0 >> hda_opts = 0x0 >> opts = 0x1171a80 >> olist = 0x7fffffffe3f0 >> optind = 33 >> optarg = 0x7fffffffebce "tablet" >> loadvm = 0x0 >> machine = 0x962cc0 >> cpu_model = 0x7fffffffeb51 "qemu64,model_id=Intel(R) Xeon(R) CPU", ' >> ' , "E5640 @ 2.67GHz,-nx" >> tb_size = 0 >> pid_file = 0x7fffffffeb10 "/var/run/qemu/vm-265.pid" >> incoming = 0x0 >> show_vnc_port = 0 >> defconfig = 1 >> (gdb) info threads >> 3 Thread 0x7ffff6020700 (LWP 29043) 0x00007ffff79c385c in >> pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0 >> 2 Thread 0x7ffff694e700 (LWP 29042) 0x00007ffff6c31197 in ioctl () >> from /lib/libc.so.6 >> * 1 Thread 0x7ffff7ff0700 (LWP 29038) 0x0000000000000000 in ?? () >> (gdb) >> >> >> Help appreciated! >> >> Thanks, >> Peter > > Hi Peter, > > did you apply this patch which fixes one of the known vnc problems > (but is still missing in qemu git master): > > http://lists.nongnu.org/archive/html/qemu-devel/2011-03/msg00256.html > > Then you can read this thread: > > http://lists.nongnu.org/archive/html/qemu-devel/2011-03/msg00313.html > > And finally the following modifications of ui/vnc.c might help to see > whether you experience the same kind of crash as I get here in > my environment. They add assertions for bad memory access > which occurs sometimes when a vnc client-server connection exists and > the screen is refreshed after a resolution change. > The code line with the //~ comment also includes a fix which > works for me. > > Regards, > Stefan W. > > @@ -2382,6 +2384,10 @@ static int > vnc_refresh_server_surface(VncDisplay *vd) > int y; > uint8_t *guest_row; > uint8_t *server_row; > + > + size_t guest_size = vd->guest.ds->linesize * vd->guest.ds->height; > + size_t server_size = vd->server->linesize * vd->server->height; > + > int cmp_bytes; > VncState *vs; > int has_dirty = 0; > @@ -2399,11 +2405,15 @@ static int > vnc_refresh_server_surface(VncDisplay *vd) > * Update server dirty map. > */ > cmp_bytes = 16 * ds_get_bytes_per_pixel(vd->ds); > + if (cmp_bytes > vd->ds->surface->linesize) { > + //~ fix crash: cmp_bytes = vd->ds->surface->linesize; > + } Stefan, I can confirm that I ran into issues if this is check is missing: qemu-kvm-0.14.0: ui/vnc.c:2292: vnc_refresh_server_surface: Assertion `cmp_bytes <= vd->ds->surface->linesize' failed. Somebody should definetly look into the root cause or at least your proposed check+fix should be added. Peter