Bug 728385
| Summary: | attempting to take a screenshot of a VM with no graphics crashes qemu | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 6 | Reporter: | Dave Allan <dallan> |
| Component: | qemu-kvm | Assignee: | Gerd Hoffmann <kraxel> |
| Status: | CLOSED ERRATA | QA Contact: | Virtualization Bugs <virt-bugs> |
| Severity: | medium | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | 6.2 | CC: | chayang, juzhang, minovotn, mkenneth, tburke, virt-maint, wdai |
| Target Milestone: | rc | ||
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | qemu-kvm-0.12.1.2-2.211.el6 | Doc Type: | Bug Fix |
| Doc Text: |
Cause:
Run qemu-kvm without graphics by passing -nographic argument and then try to do screendump.
Consequence:
Guest is destroyed as qemu-kvm crashes with segmentation fault.
Fix:
Check for valid screendump function pointer has been implemented prior to calling it.
Result:
qemu-kvm doesn't crash and continues running
|
Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | 2012-06-20 11:33:46 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
|
Description
Dave Allan
2011-08-04 21:55:36 UTC
Reproducer: /usr/libexec/qemu-kvm -nographic -vga none Type 'Ctrl-A c' to get the monitor prompt, then try screendump. Upstream at least doesn't crash. Doesn't report an error though. Will look into this. Reproduced this issue with steps and environment as follows: # uname -r;rpm -q qemu-kvm 2.6.32-220.el6.x86_64 qemu-kvm-0.12.1.2-2.209.el6.x86_64 1. configure qemu without a graphics device, say: /usr/libexec/qemu-kvm -nographic -vga none -nographic -vga none 2. Type 'Ctrl-A c' to get the monitor and issue screendump /path/to/file Actual Result: (qemu) screendump /home/screen-file Program received signal SIGSEGV, Segmentation fault. vga_hw_screen_dump (filename=0xf4a9e0 "/home/screen-file") at console.c:181 181 if (consoles[0]->hw_screen_dump) (gdb) bt #0 vga_hw_screen_dump (filename=0xf4a9e0 "/home/screen-file") at console.c:181 #1 0x0000000000412289 in do_screen_dump (mon=<value optimized out>, qdict=<value optimized out>, ret_data=<value optimized out>) at /usr/src/debug/qemu-kvm-0.12.1.2/monitor.c:1309 #2 0x0000000000412920 in monitor_call_handler (mon=<value optimized out>, cmd=0x591c58, params=<value optimized out>) at /usr/src/debug/qemu-kvm-0.12.1.2/monitor.c:4105 #3 0x00000000004176f0 in handle_user_command (mon=0xf07870, cmdline=<value optimized out>) at /usr/src/debug/qemu-kvm-0.12.1.2/monitor.c:4142 #4 0x000000000041781a in monitor_command_cb (mon=0xf07870, cmdline=<value optimized out>, opaque=<value optimized out>) at /usr/src/debug/qemu-kvm-0.12.1.2/monitor.c:4697 #5 0x00000000004aba2b in readline_handle_byte (rs=0xf07ce0, ch=<value optimized out>) at readline.c:369 #6 0x0000000000417a3c in monitor_read (opaque=<value optimized out>, buf=0x7fffffffcf1f "\r", size=1) at /usr/src/debug/qemu-kvm-0.12.1.2/monitor.c:4683 #7 0x00000000004bf79b in mux_chr_read (opaque=0xf07600, buf=0x7fffffffcf1f "\r", size=1) at qemu-char.c:442 #8 0x00000000004be1ff in qemu_chr_read (opaque=0xf07450) at qemu-char.c:170 #9 stdio_read (opaque=0xf07450) at qemu-char.c:794 #10 0x000000000040c43f in main_loop_wait (timeout=1000) at /usr/src/debug/qemu-kvm-0.12.1.2/vl.c:4024 #11 0x000000000042aefa in kvm_main_loop () at /usr/src/debug/qemu-kvm-0.12.1.2/qemu-kvm.c:2225 #12 0x000000000040de85 in main_loop (argc=<value optimized out>, argv=<value optimized out>, envp=<value optimized out>) at /usr/src/debug/qemu-kvm-0.12.1.2/vl.c:4234 #13 main (argc=<value optimized out>, argv=<value optimized out>, envp=<value optimized out>) at /usr/src/debug/qemu-kvm-0.12.1.2/vl.c:6470 Marking qa_ack+ according to above info. Reproduced this issue with steps and environment as follows:
# uname -r;rpm -q qemu-kvm
2.6.32-220.el6.x86_64
qemu-kvm-0.12.1.2-2.207.el6.x86_64
1. configure qemu without a graphics device:
/usr/libexec/qemu-kvm -nographic -vga none
2. Type 'Ctrl-A c' to get the monitor and issue screendump /path/to/file
Actual Result:
(qemu) screendump /tmp/screen-file1
Program received signal SIGSEGV, Segmentation fault.
vga_hw_screen_dump (filename=0xea69e0 "/tmp/screen-file1") at console.c:181
181 if (consoles[0]->hw_screen_dump)
(gdb) bt
#0 vga_hw_screen_dump (filename=0xea69e0 "/tmp/screen-file1") at console.c:181
#1 0x0000000000412239 in do_screen_dump (mon=<value optimized out>, qdict=<value optimized out>, ret_data=<value optimized out>)
at /usr/src/debug/qemu-kvm-0.12.1.2/monitor.c:1309
#2 0x00000000004128d0 in monitor_call_handler (mon=<value optimized out>, cmd=0x591b18, params=<value optimized out>)
at /usr/src/debug/qemu-kvm-0.12.1.2/monitor.c:4105
#3 0x00000000004176a0 in handle_user_command (mon=0xe5e570, cmdline=<value optimized out>) at /usr/src/debug/qemu-kvm-0.12.1.2/monitor.c:4142
#4 0x00000000004177ca in monitor_command_cb (mon=0xe5e570, cmdline=<value optimized out>, opaque=<value optimized out>)
at /usr/src/debug/qemu-kvm-0.12.1.2/monitor.c:4697
#5 0x00000000004ab98b in readline_handle_byte (rs=0xe5e9e0, ch=<value optimized out>) at readline.c:369
#6 0x00000000004179ec in monitor_read (opaque=<value optimized out>, buf=0x7fffffffcb8f "\r", size=1)
at /usr/src/debug/qemu-kvm-0.12.1.2/monitor.c:4683
#7 0x00000000004bf6fb in mux_chr_read (opaque=0xd6a650, buf=0x7fffffffcb8f "\r", size=1) at qemu-char.c:442
#8 0x00000000004be15f in qemu_chr_read (opaque=0xd5a490) at qemu-char.c:170
#9 stdio_read (opaque=0xd5a490) at qemu-char.c:794
#10 0x000000000040c3ef in main_loop_wait (timeout=1000) at /usr/src/debug/qemu-kvm-0.12.1.2/vl.c:4024
#11 0x000000000042aeaa in kvm_main_loop () at /usr/src/debug/qemu-kvm-0.12.1.2/qemu-kvm.c:2225
#12 0x000000000040de35 in main_loop (argc=<value optimized out>, argv=<value optimized out>, envp=<value optimized out>)
at /usr/src/debug/qemu-kvm-0.12.1.2/vl.c:4234
#13 main (argc=<value optimized out>, argv=<value optimized out>, envp=<value optimized out>) at /usr/src/debug/qemu-kvm-0.12.1.2/vl.c:6470
Verified this issue with steps and environment as follows:
# uname -r;rpm -q qemu-kvm
2.6.32-220.el6.x86_64
qemu-kvm-0.12.1.2-2.213.el6.x86_64
1. configure qemu without a graphics device:
/usr/libexec/qemu-kvm -nographic -vga none
2. Type 'Ctrl-A c' to get the monitor and issue screendump /path/to/file
Actual Result:
(qemu) screendump /tmp/screen-file2
(qemu) info status
VM status: running
3.check the result in host
# ls /tmp/screen-file2
ls: cannot access /tmp/screen-file2: No such file or directory
qemu neither crash nor report an error.According to Comment 2 ,this bug had been fixed.
Technical note added. If any revisions are required, please edit the "Technical Notes" field
accordingly. All revisions will be proofread by the Engineering Content Services team.
New Contents:
Cause:
Run qemu-kvm without graphics by passing -nographic argument and then try to do screendump.
Consequence:
Guest is destroyed as qemu-kvm crashes with segmentation fault.
Fix:
Check for valid screendump function pointer has been implemented prior to calling it.
Result:
qemu-kvm doesn't crash and continues running
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. http://rhn.redhat.com/errata/RHBA-2012-0746.html |