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FS#79603 - [cctag] CCTAG_ENABLE_SIMD_AVX2 breaks baseline

Attached to Project: Arch Linux
Opened by Xeonacid (Xeonacid) - Thursday, 07 September 2023, 13:30 GMT
Last edited by Buggy McBugFace (bugbot) - Saturday, 25 November 2023, 20:19 GMT
Task Type Bug Report
Category Packages: Extra
Status Closed
Assigned To Sven-Hendrik Haase (Svenstaro)
Architecture All
Severity Medium
Priority Normal
Reported Version
Due in Version Undecided
Due Date Undecided
Percent Complete 100%
Votes 1
Private No



This includes avx2 instruction at compile time without runtime detection.
An older cpu without avx2 will refuse to work.

Steps to reproduce:

$ qemu-x86_64 -cpu Broadwell-v4 /usr/bin/detection
Program for detecting CCTags in one image, in a directory or in a video
For each image or video frame it detects the markers and it shows the image with a graphical overlayshowing the center of the tag, its ID and the outer ellipse:

Required input parameters:
-i [ --input ] arg Path to an image (JPG, PNG) or video (avi,
mov) or camera index for live capture (0,
1...) or to a directory containing the images
to process
-n [ --nbrings ] arg Number of rings of the CCTags to detect

Optional parameters:
-b [ --bank ] arg Path to a bank parameter file, e.g.
-p [ --params ] arg Path to configuration XML file
-o [ --output ] arg Output folder name
-s [ --save-detected-image ] Save an image with the graphical overlay of
the detected tags. For single images the saved
images will have a '_detected' suffix and it
will be placed either in the current directory
or in the directory given by --output. For
videos a file named #####.png will be saved
instead with the #s representing the
zero-padded frame number, either in the
current directory or in the directory given by
-u [ --show-unreliable ] Show the unreliable tags (marker id = -1)

$ qemu-x86_64 -cpu core2duo-v1 /usr/bin/detection
qemu: uncaught target signal 4 (Illegal instruction) - core dumped
fish: Job 1, 'qemu-x86_64 -cpu core2duo-v1 /u…' terminated by signal SIGILL (Illegal instruction)
This task depends upon

Closed by  Buggy McBugFace (bugbot)
Saturday, 25 November 2023, 20:19 GMT
Reason for closing:  Moved
Additional comments about closing: ackaging/packages/cctag/issues/1
Comment by Toolybird (Toolybird) - Thursday, 07 September 2023, 21:05 GMT
> without runtime detection

Yeah, appears to be missing from upstream implementation.
Comment by Caham Everan (olcammy) - Tuesday, 26 September 2023, 17:08 GMT
Think I've also been bit by this bug. Getting SIGILL in on instruction vmovdqa which seems to be an AVX instruction. My old i5 cpus don't support AVX (cat /proc/cpuinfo | grep avx -- shows nothing). Tried downgrading libgcc (which owns this library) from 13 to 12 to 11 to no avail. A number of applications including Firefox and Gimp now are unusable following some recent upgrade as a result of this Illegal Instruction. Sorry m8s. Thanks for looking into it.
Comment by loqs (loqs) - Tuesday, 26 September 2023, 17:22 GMT
@olcammy is the system you experienced the issue on using linux-hardened?
Comment by Caham Everan (olcammy) - Tuesday, 26 September 2023, 17:29 GMT
Oh right, forgot to mention: 6.5.4-hardened1-1-hardened
Comment by loqs (loqs) - Tuesday, 26 September 2023, 17:42 GMT
@olcammy see  FS#79444 .
Comment by Caham Everan (olcammy) - Tuesday, 26 September 2023, 18:12 GMT
With hardened kernel:

__builtin_cpu_supports ("avx"):0
__builtin_cpu_supports ("avx2"):0

Attempting to add 'gather_data_sampling=off' to grub config just now nearly bricked my system...
grub was rebooting the machine before I'd even had a chance to edit the options!
Had to boot a rescue CD and reinstall grub to get back to here.
Plain vanilla kernel avoids the issue, and the test.c gives:

__builtin_cpu_supports ("avx"):512
__builtin_cpu_supports ("avx2"):1024

Not really sure where to go from here.

Comment by Sven-Hendrik Haase (Svenstaro) - Wednesday, 27 September 2023, 00:27 GMT
Please check package rel-13.