Arch Linux User Repository

Use this forum thread for discussion: https://bbs.archlinux.org/viewtopic.php?pid=1946926

Please don't flag this package out-of-date unless a new version has been released by NVIDIA.

The DKMS package guidelines are explicit that linux-headers should not be a dependency of any DKMS package.

As a concrete example of why including that as a hard dependency is a bad idea, what happens when linux is not an installed kernel?

I just used the patch gcc-15.patch of bufferunderrun here and upgrading to kernel 6.14.5-arch1-1 and gcc-15 was successful.

I could be missing something obvious,

Of course I'd forgotten to the patch entry to prepare(). Thanks @bufferunderrun.

And sorry to everyone else for the spam. Incredible work with the patches, investigations and brainstorming.

I assume you added it with a relative path and it's not adding the patch. This should work:

patch -Np1 -i "${srcdir}/gcc-15.patch" -d "${srcdir}/${_pkg}"

No issues with linux 6.14.5

EDIT: I used makepkg -sifc

I could be missing something obvious, since I normally use paru and haven't done this manually recently.

1. Downloaded the content of gcc-15.patch from @bufferunderrun, with and without the addition from @drankinatty.

2. Modified PKGBUILD

3. updpkgsums

4. makepkg -sic

pacman "succeeded", but dkms install --no-depmod nvidia/390.157 -k 6.14.4-arch1-2 exited 10. In the make.log, there were a lot of issues with conftest.sh. A snippet from ~600 lines is given below:

In file included from ././common/inc/conftest.h:5,
                 from ././common/inc/nv_stdarg.h:29,
                 from ././common/inc/os-interface.h:27,
                 from nvidia/nv-frontend.c:12:
././conftest/functions.h:15:2: error: #error kmem_cache_create() conftest failed!
   15 | #error kmem_cache_create() conftest failed!
      |  ^~~~~
././conftest/functions.h:16:2: error: #error on_each_cpu() conftest failed!
   16 | #error on_each_cpu() conftest failed!
      |  ^~~~~
././conftest/functions.h:17:2: error: #error smp_call_function() conftest failed!
   17 | #error smp_call_function() conftest failed!
      |  ^~~~~
././conftest/functions.h:22:2: error: #error acpi_walk_namespace() conftest failed!
   22 | #error acpi_walk_namespace() conftest failed!
      |  ^~~~~
././conftest/functions.h:24:2: error: #error dma_mapping_error() conftest failed!
   24 | #error dma_mapping_error() conftest failed!
      |  ^~~~~
././conftest/functions.h:71:2: error: #error wait_on_bit_lock() conftest failed!
   71 | #error wait_on_bit_lock() conftest failed!
      |  ^~~~~
././conftest/functions.h:76:2: error: #error radix_tree_replace_slot() conftest failed!
   76 | #error radix_tree_replace_slot() conftest failed!
      |  ^~~~~

Does anyone know what could be wrong?

I have put a write-up on The bbs.archlinux.org discussion page outlining where I think the 6.15 kernel problem will be. If you can take a look and add any thoughts you have on the differences with the 390 driver common/inc/nv-mm.h and how to backport the patch from the 470 driver to that file -- that is where I'm stuck.

I should add that kernel 6.15 will drop EXTRA_CFLAGS backward compatibility, so one would need to switch to ccflags-y when it's out. But judging from drankinatty's comments 6.15 will break quite a few other things, so people should prepare for a bumpy ride.

The 6.15 and gcc-15 was a mix-up. @bufferunderrun probably has the better location for adding the -std=gnu17 option. I stumbled on it at Nvidia building with gcc-15 fails. I also added the -Wno-int-conversion option from the Fedora make.log error and combined both in conftest.sh, e.g.

--- a/kernel/conftest.sh        2025-05-02 22:11:41.841797003 -0500
+++ b/kernel/conftest.sh        2025-05-04 19:32:38.569127659 -0500
@@ -151,10 +151,11 @@
 }

 build_cflags() {
-    BASE_CFLAGS="-O2 -D__KERNEL__ \
+    BASE_CFLAGS="-O2 -D__KERNEL__ -std=gnu17 \
 -DKBUILD_BASENAME=\"#conftest$$\" -DKBUILD_MODNAME=\"#conftest$$\" \
 -nostdinc -isystem $ISYSTEM \
--Wno-implicit-function-declaration -Wno-strict-prototypes -Wno-incompatible-pointer-types"
+-Wno-implicit-function-declaration -Wno-strict-prototypes \
+-Wno-incompatible-pointer-types -Wno-int-conversion"

     if [ "$OUTPUT" != "$SOURCES" ]; then
         OUTPUT_CFLAGS="-I$OUTPUT/include2 -I$OUTPUT/include"

This builds and the dkms modules build fine with gcc-15 and linux-6.14. I'll let the smarter folks decide where the option should go. I tend to like Kbuild as @bufferoverrun did, but we should also look at including -Wno-int-conversion as looks like a future issue as well. But we likely don't need it in both BASE_CFLAGS and EXTRA_CFLAGS. So I guess the deciding factor comes down to whether you consider -std=gnu17 a BASE or EXTRA flag.

But looking at the linux-6.15 requirements kernel/common/inc/nv-mm.h changes appear a bit more involved. It may end up not being as bad as I image. The core issue is the 470 driver uses a nv_vm_flags_xxx naming convention while the 390 driver was never updated from get_user_pages_xxx function names. The 470 linux-6.15 patch uses vm_flags_reset(vma, vma->vm_flags | flags); as part of the nv_vm_flags_set() function to avoid the now prohibited kernel file locks from the driver. vm_flags_reset() is provided by ../linux/mm.h so it is available to the 390 driver, but how/where it must be integrated is unclear given the driver differences and the 390 driver having no nv_vm_flags_set(). We will cross that bridge when we get there.

No idea why kernel 6.15 is brought to this discussion when the issue is with GCC. GCC 15 switched over to C23 by default, so one needs to specify C17 ala https://gitlab.archlinux.org/archlinux/packaging/packages/nvidia-utils/-/blob/main/0002-CFLAGS-Set-std-gnu17-for-all-compilation-flags.patch

gcc-15.patch:

diff --git a/kernel/Kbuild b/kernel/Kbuild
index 85aa267..baa6986 100644
--- a/kernel/Kbuild
+++ b/kernel/Kbuild
@@ -61,6 +61,7 @@ $(foreach _module, $(NV_KERNEL_MODULES), \
 # $(EXTRA_CFLAGS) to ccflags-y for compatibility.
 #

+EXTRA_CFLAGS += -std=gnu17
 EXTRA_CFLAGS += -I$(src)/common/inc
 EXTRA_CFLAGS += -I$(src)
 EXTRA_CFLAGS += -Wall -MD $(DEFINES) $(INCLUDES) -Wsign-compare -Wno-cast-qual -Wno-error
diff --git a/kernel/conftest.sh b/kernel/conftest.sh
index 4da7588..1106ea5 100755
--- a/kernel/conftest.sh
+++ b/kernel/conftest.sh
@@ -151,7 +151,7 @@ test_headers() {
 }

 build_cflags() {
-    BASE_CFLAGS="-O2 -D__KERNEL__ \
+    BASE_CFLAGS="-std=gnu17 -O2 -D__KERNEL__ \
 -DKBUILD_BASENAME=\"#conftest$$\" -DKBUILD_MODNAME=\"#conftest$$\" \
 -nostdinc -isystem $ISYSTEM \
 -Wno-implicit-function-declaration -Wno-strict-prototypes -Wno-incompatible-pointer-types"

I'll let maintainers decide on the rest, gcc-14.patch and so on. I just applied it on top of everything.

https://gist.github.com/joanbm/def2bf57ed7a799c1d84a67606459314 seems to hold patches for gcc15 and linux 6.15, the latter (involving vm_flags_reset) not be relevant to the currently used 6.14 kernel in the non-testin repos.

https://paste.opensuse.org/pastes/5e28f342c461 drops the contradictive "-Wsign-compare -Wnosign-compare", tried to just keep at least -Wnosign-compare ?

but they produce no working driver due to the issues noted above Not working like "how"? Does the module fail to load? Cause errors?

Is the gcc14 patch still applied? Do you have build logs?

I don't understand, JuliusTZM is speaking about GCC 15 and drankinatty is speaking about Linux 6.15 ?