Red Hat Bugzilla – Bug 515038
Kernel General Protection Fault - libgphoto2-2.4.7
Last modified: 2010-06-28 09:57:27 EDT
Created attachment 355870 [details]
dmesg output of libgphoto2-126.96.36.199 kernel oops on FC11
Description of problem:
I am testing a new version of libgphoto2. It is libgphoto2-188.8.131.52 which will become libgphoto2-2.4.7. See https://sourceforge.net/tracker/?func=detail&atid=108874&aid=2794538&group_id=8874 for reference.
After 15 successful remote captures (and 16 in another case) I am getting a kernel general protection fault.
Please see the attached "fc11_libgphoto2-184.108.40.206.4_kernel_opps" for the dmesg output.
Version-Release number of selected component (if applicable):
kernel: 220.127.116.11-213.fc11.i686.PAE #1 SMP
How reproducible: always
Steps to Reproduce:
1. Install FC11 and update the system to make sure it is up to date
2. Install libgphoto2-18.104.22.168:
3. Install gphoto2 v2.4.5
4. Set some parameters on the camera to make sure we can talk to it ok:
gphoto2 --set-config capture=on --set-config zoom=60 --set-config iso=0 --set-config owner=dan --set-config capturetarget=0
5. Capture an image and download it:
gphoto2 --capture-image-and-download --force-overwrite --filename=image.jpg
6. Repeat 20 times and observe the kernel general protection fault.
Actual results: kernel general protection fault
Expected results: successful remote capture and image download time after time
c04a3019: 8b 50 0c mov 0xc(%eax),%edx
c04a301c: 8b 14 93 mov (%ebx,%edx,4),%edx
c04a301f: 89 10 mov %edx,(%eax)
1615 object = c->freelist;
1616 c->freelist = object[c->offset];
Looks like USB code is writing past its allocations? Try the kernel-debug package and see if it finds slab corruption.
I am genuinely confused. Here is what I have done:
1) I upgraded to the latest 22.214.171.124-217.2.3 Kernel (which happened to be out since the previous post) to see if the issue persists and it does.
After 7 remote capture attempts, the same general protection fault occurs.
2) As suggested, I then installed kernel-PAEdebug for the latest Kernel. To my amazement the issue doesn't occur with in the kernel-debug Kernel.
3) Thinking maybe I am crazy, I switched again to the regular Kernel, tried remote gphoto capture, and the issue occurred right away.
4) I switched back to Kernel-debug and did over 500 remote captures without the issue occurring (which statistically seems like good sample data in light of the small number of attempts to generate the fault in the regular Kernel).
This is not what I expected to happen, assuming the only difference in the kernel-debug is extra logging etc'.
I haven't done sufficient kernel debugging to know how common this is.
What gives? Any suggestions?
Any suggestions? Have anyone seen anything like that before?
Can anyone think of a reason why the problem would occur in the regular Kernel but not the debug Kernel?
Created attachment 362574 [details]
dmesg output for kernel 126.96.36.199-43.fc11 opps with libgphoto2-2.4.7
Created attachment 362576 [details]
libgphoto2-2.4.7 debug log for FC11 Kernel oops (188.8.131.52-43 )
1. I updated to the latest Kernel (184.108.40.206-43) and to the latest version of libgphoto2 (2.4.7) and the issue still persists as described above (Kernel General Protection Fault).
2. I installed the corresponding Debug Kernel (220.127.116.11-43) in the hope of gathering more info but similar to the above the issue doesn't manifest itself in the Debug Kernel!?
Attached please find:
1. Dmesg output from the regular kernel oops (dmesg_output_kernel_oops_18.104.22.168-43.fc11)
2. The libgphoto2 debug output (fc11_libgphoto2-2.4.7_kernel_oops.log)
Changed the title from "libgphoto2-22.214.171.124" to "libgphoto2-2.4.7"
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