dkms build fails on kernel version >6.8.0

jschwender commented 4 months ago

build fails with error on strlcpy() function.

gcc (Ubuntu 13.2.0-4ubuntu3) 13.2.0

v4l2loopback version: 0.12.7
Distribution (+version): _____ lsb_release -a No LSB modules are available. Distributor ID: Ubuntu Description: Ubuntu 23.10 Release: 23.10 Codename: mantic

Steps to reproduce:

build vanilla kernel 6.8.0 run dkms build on installation the kernel

Observed Results:

build fails

Suggested fix: --- v4l2loopback.c.sav 2023-07-05 14:05:05.000000000 +0200 +++ v4l2loopback.c 2024-03-12 08:36:48.736536585 +0100 @@ -739,7 +739,11 @@ ->devicenr; __u32 capabilities = V4L2_CAP_STREAMING | V4L2_CAP_READWRITE;

+#if LINUX_VERSION_CODE < KERNEL_VERSION(6, 8, 0) strlcpy(cap->driver, "v4l2 loopback", sizeof(cap->driver)); +#else

strscpy(cap->driver, "v4l2 loopback", sizeof(cap->driver)); +#endif vidioc_fill_name(cap->card, sizeof(cap->card), devnr); snprintf(cap->bus_info, sizeof(cap->bus_info), "platform:v4l2loopback-%03d", devnr); @@ -1247,7 +1251,11 @@ if (!cnf) BUG();

+#if LINUX_VERSION_CODE < KERNEL_VERSION(6, 8, 0) strlcpy(q->name, cnf->name, sizeof(q->name)); +#else

strscpy(q->name, cnf->name, sizeof(q->name)); +#endif q->default_value = cnf->def; q->type = cnf->type; q->minimum = cnf->min; @@ -1352,7 +1360,11 @@ memset(outp, 0, sizeof(*outp));

outp->index = index; +#if LINUX_VERSION_CODE < KERNEL_VERSION(6, 8, 0) strlcpy(outp->name, "loopback in", sizeof(outp->name)); +#else
strscpy(outp->name, "loopback in", sizeof(outp->name)); +#endif outp->type = V4L2_OUTPUT_TYPE_ANALOG; outp->audioset = 0; outp->modulator = 0; @@ -1411,7 +1423,11 @@ memset(inp, 0, sizeof(*inp));

inp->index = index; +#if LINUX_VERSION_CODE < KERNEL_VERSION(6, 8, 0) strlcpy(inp->name, "loopback", sizeof(inp->name)); +#else
strscpy(inp->name, "loopback", sizeof(inp->name)); +#endif inp->type = V4L2_INPUT_TYPE_CAMERA; inp->audioset = 0; inp->tuner = 0;

replacing the function for kernels > 6.8 works for me, but i don't feel involved enough with the code, so i want you to look over it and decide if that is a good idea or not. Hope it helps.

cbricart commented 4 months ago

@jschwender fix is already in (yet unreleased) code: first with commit ee177b680f68f7862e349c2d97230c785620e94f and refined by commit b261f19bc74862abb3ad1999bd8e8ba69052b105

edmundlaugasson commented 4 months ago

I can confirm with EndeavourOS: kernel 6.8.1-arch1-1 v4l2loopback-dkms 0.12.7-2 v4l-utils 1.26.1-1

DKMS make.log for v4l2loopback-0.12.7 for kernel 6.8.1-arch1-1 (x86_64)
Sunday, March 17 2024 10:33:34 EET
Building v4l2-loopback driver...
make -C /usr/lib/modules/6.8.1-arch1-1/build M=/var/lib/dkms/v4l2loopback/0.12.7/build modules
make[1]: Entering directory '/usr/lib/modules/6.8.1-arch1-1/build'
  CC [M]  /var/lib/dkms/v4l2loopback/0.12.7/build/v4l2loopback.o
/var/lib/dkms/v4l2loopback/0.12.7/build/v4l2loopback.c: In function ‘vidioc_querycap’:
/var/lib/dkms/v4l2loopback/0.12.7/build/v4l2loopback.c:717:9: error: implicit declaration of function ‘strlcpy’; did you mean ‘strscpy’? [-Werror=implicit-function-declaration]
  717 |         strlcpy(cap->driver, "v4l2 loopback", sizeof(cap->driver));
      |         ^~~~~~~
      |         strscpy
cc1: some warnings being treated as errors
make[3]: *** [scripts/Makefile.build:243: /var/lib/dkms/v4l2loopback/0.12.7/build/v4l2loopback.o] Error 1
make[2]: *** [/usr/lib/modules/6.8.1-arch1-1/build/Makefile:1921: /var/lib/dkms/v4l2loopback/0.12.7/build] Error 2
make[1]: *** [Makefile:240: __sub-make] Error 2
make[1]: Leaving directory '/usr/lib/modules/6.8.1-arch1-1/build'
make: *** [Makefile:43: v4l2loopback.ko] Error 2

command-z-z commented 4 months ago

I can confirm with EndeavourOS: kernel 6.8.1-arch1-1 v4l2loopback-dkms 0.12.7-2 v4l-utils 1.26.1-1

DKMS make.log for v4l2loopback-0.12.7 for kernel 6.8.1-arch1-1 (x86_64)
Sunday, March 17 2024 10:33:34 EET
Building v4l2-loopback driver...
make -C /usr/lib/modules/6.8.1-arch1-1/build M=/var/lib/dkms/v4l2loopback/0.12.7/build modules
make[1]: Entering directory '/usr/lib/modules/6.8.1-arch1-1/build'
  CC [M]  /var/lib/dkms/v4l2loopback/0.12.7/build/v4l2loopback.o
/var/lib/dkms/v4l2loopback/0.12.7/build/v4l2loopback.c: In function ‘vidioc_querycap’:
/var/lib/dkms/v4l2loopback/0.12.7/build/v4l2loopback.c:717:9: error: implicit declaration of function ‘strlcpy’; did you mean ‘strscpy’? [-Werror=implicit-function-declaration]
  717 |         strlcpy(cap->driver, "v4l2 loopback", sizeof(cap->driver));
      |         ^~~~~~~
      |         strscpy
cc1: some warnings being treated as errors
make[3]: *** [scripts/Makefile.build:243: /var/lib/dkms/v4l2loopback/0.12.7/build/v4l2loopback.o] Error 1
make[2]: *** [/usr/lib/modules/6.8.1-arch1-1/build/Makefile:1921: /var/lib/dkms/v4l2loopback/0.12.7/build] Error 2
make[1]: *** [Makefile:240: __sub-make] Error 2
make[1]: Leaving directory '/usr/lib/modules/6.8.1-arch1-1/build'
make: *** [Makefile:43: v4l2loopback.ko] Error 2

v4l2loopback/0.13.1.r8.gc94a1e8 fix the problem, you can update this package:)

Abdull commented 1 day ago

I now run into this issue with Debian 12 during apt upgrade since the release of the latest linux-image in bookworm-backports, linux-image-6.9.7+bpo-rt-amd64.

The previous linux-image-6.7.12+bpo-amd64 did not have this issue (so Linux 6.7.12 is okay, Linux 6.9.7 makes problem — fitting this issue report's "dkms build fails on kernel").

`sudo apt upgrade` output, containing error log information (click to reveal)

``` $ sudo apt upgrade Reading package lists... Done Building dependency tree... Done Reading state information... Done Calculating upgrade... Done The following packages were automatically installed and are no longer required: linux-headers-6.1.0-22-amd64 linux-headers-6.1.0-22-common linux-image-6.1.0-22-amd64 Use 'sudo apt autoremove' to remove them. 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. 4 not fully installed or removed. After this operation, 0 B of additional disk space will be used. Do you want to continue? [Y/n] Setting up linux-image-6.9.7+bpo-rt-amd64 (6.9.7-1~bpo12+1) ... /etc/kernel/postinst.d/dkms: dkms: running auto installation service for kernel 6.9.7+bpo-rt-amd64. Sign command: /lib/modules/6.9.7+bpo-rt-amd64/build/scripts/sign-file Signing key: /var/lib/dkms/mok.key Public certificate (MOK): /var/lib/dkms/mok.pub Building module: Cleaning build area... make -j12 KERNELRELEASE=6.9.7+bpo-rt-amd64 KERNEL_DIR=/lib/modules/6.9.7+bpo-rt-amd64/build all...(bad exit status: 2) Error! Bad return status for module build on kernel: 6.9.7+bpo-rt-amd64 (x86_64) Consult /var/lib/dkms/v4l2loopback/0.12.7/build/make.log for more information. Error! One or more modules failed to install during autoinstall. Refer to previous errors for more information. dkms: autoinstall for kernel: 6.9.7+bpo-rt-amd64 failed! run-parts: /etc/kernel/postinst.d/dkms exited with return code 11 dpkg: error processing package linux-image-6.9.7+bpo-rt-amd64 (--configure): installed linux-image-6.9.7+bpo-rt-amd64 package post-installation script subprocess returned error exit status 1 dpkg: dependency problems prevent configuration of linux-image-rt-amd64: linux-image-rt-amd64 depends on linux-image-6.9.7+bpo-rt-amd64 (= 6.9.7-1~bpo12+1); however: Package linux-image-6.9.7+bpo-rt-amd64 is not configured yet. dpkg: error processing package linux-image-rt-amd64 (--configure): dependency problems - leaving unconfigured dpkg: dependency problems prevent configuration of linux-headers-6.9.7+bpo-rt-amd64: linux-headers-6.9.7+bpo-rt-amd64 depends on linux-image-6.9.7+bpo-rt-amd64 (= 6.9.7-1~bpo12+1) | linux-image-6.9.7+bpo-rt-amd64-unsigned (= 6.9.7-1~bpo12+1); however: Package linux-image-6.9.7+bpo-rt-amd64 is not configured yet. Package linux-image-6.9.7+bpo-rt-amd64-unsigned is not installed. dpkg: error processing package linux-headers-6.9.7+bpo-rt-amd64 (--configure): dependency problems - leaving unconfigured dpkg: dependency problems prevent configuration of linux-headers-rt-amd64: linux-headers-rt-amd64 depends on linux-headers-6.9.7+bpo-rt-amd64 (= 6.9.7-1~bpo12+1); however: Package linux-headers-6.9.7+bpo-rt-amd64 is not configured yet. dpkg: error processing package linux-headers-rt-amd64 (--configure): dependency problems - leaving unconfigured Errors were encountered while processing: linux-image-6.9.7+bpo-rt-amd64 linux-image-rt-amd64 linux-headers-6.9.7+bpo-rt-amd64 linux-headers-rt-amd64 E: Sub-process /usr/bin/dpkg returned an error code (1) (exit=100) ```

file `/var/lib/dkms/v4l2loopback/0.12.7/build/make.log` contents (click to reveal)

``` DKMS make.log for v4l2loopback-0.12.7 for kernel 6.9.7+bpo-rt-amd64 (x86_64) Mon Jul 22 03:48:09 PM CEST 2024 Building v4l2-loopback driver... make -C /lib/modules/6.9.7+bpo-rt-amd64/build M=/var/lib/dkms/v4l2loopback/0.12.7/build modules make[1]: Entering directory '/usr/src/linux-headers-6.9.7+bpo-rt-amd64' CC [M] /var/lib/dkms/v4l2loopback/0.12.7/build/v4l2loopback.o /var/lib/dkms/v4l2loopback/0.12.7/build/v4l2loopback.c: In function ‘vidioc_querycap’: /var/lib/dkms/v4l2loopback/0.12.7/build/v4l2loopback.c:717:9: error: implicit declaration of function ‘strlcpy’; did you mean ‘strncpy’? [-Werror=implicit-function-declaration] 717 | strlcpy(cap->driver, "v4l2 loopback", sizeof(cap->driver)); | ^~~~~~~ | strncpy cc1: some warnings being treated as errors make[3]: *** [/usr/src/linux-headers-6.9.7+bpo-common-rt/scripts/Makefile.build:249: /var/lib/dkms/v4l2loopback/0.12.7/build/v4l2loopback.o] Error 1 make[2]: *** [/usr/src/linux-headers-6.9.7+bpo-common-rt/Makefile:1943: /var/lib/dkms/v4l2loopback/0.12.7/build] Error 2 make[1]: *** [/usr/src/linux-headers-6.9.7+bpo-common-rt/Makefile:252: __sub-make] Error 2 make[1]: Leaving directory '/usr/src/linux-headers-6.9.7+bpo-rt-amd64' make: *** [Makefile:43: v4l2loopback.ko] Error 2 ```

umlaeute commented 1 day ago

Sure. You need v4l2loopback>=0.13, which is not available on Debian 12 (or backports). The Debian12 package of v4l2loopback works nicely with the linux-kernel-headers package of Debian12. But if you install a package from backports, then this is no longer guaranteed (and obviously fails in your case).

Abdull commented 19 hours ago

Sure. You need v4l2loopback>=0.13, which is not available on Debian 12 (or backports). The Debian12 package of v4l2loopback works nicely with the linux-kernel-headers package of Debian12. But if you install a package from backports, then this is no longer guaranteed (and obviously fails in your case).

Thank you for your response.

As I don't know what to do in such situations, I just removed/uninstalled v4l2loopback (i.e., sudo apt remove v4l2loopback-dkms).

Then after running sudo apt upgrade, Debian 12 was able to set up and install [linux-image-6.9.7+bpo-rt-amd64](https://packages.debian.org/bookworm-backports/linux-image-6.9.7+bpo-rt-amd64), albeit without the v4l2loopback-dkms, and also rebuilding all other installed linux-image / kernels without v4l2loopback dynamic kernel module support.

umlaeute / v4l2loopback

dkms build fails on kernel version >6.8.0 #575

Steps to reproduce:

Observed Results: