configuring copy_file_range: linking check instead of compiling

[fda77]

For me compiling works but later linking not

• refs Freetz-NG/freetz-ng@1dd4b9c

[petk]

Thanks for the PR. This is really weird. Usually, it's the other way around. Compilation works, but link step fails. 🤔 I'll check.

Does @devnexen perhaps know, why this happens?

[petk]

@fda77 can you also please mention on which Linux distribution, this happens. Thanks.

From what I understand is, you mean, that the PHP build "works" with the linking test, which fails at the configure step. That would make more sense to me then.

[devnexen]

for reference I had a look into the uclibc-ng repository. so copy_file_range is not guarded declaration-wise however the implementation is guarded by its syscall id presence.

[devnexen]

it seems it misses a proper condition here. But we do need a workaround one way or another.

[fda77]

PHP is used in https://github.com/Freetz-NG/freetz-ng/ , a firmware modification for Fritz!Box routers. It adds programs like PHP to the firmware. Kernel versions are 2.6 - 5, uclib 0.9 - latest uclibg-ng, gcc v4 - v13. These depend on what the device firmware uses. There are closed source kernelmodules and daemons, so kernel version etc could not changed.

I've run here a github action to test compile php on all devices, before that i deleted again the make/pkgs/php/patches/8.5/200-copy_file_range-check.patch which was the same like this PR: https://github.com/fda77/freetz-ng/actions/runs/30579727267

Problems only with some: arm + aarch64 + intel x86,
but not mips + mipsel +armeb
See action logs of

• 5690: aarch64_gcc-13.4.0_uClibc-1.0.58-nptl_kernel-5.4
• 7690: arm_gcc-13.4.0_uClibc-1.0.58-nptl_kernel-5.4
• 6670: i686_gcc-13.4.0_uClibc-1.0.58-nptl_kernel-5.15

/__w/freetz-ng/freetz-ng/toolchain/build/aarch64_gcc-13.4.0_uClibc-1.0.58-nptl_kernel-5.4/aarch64-linux-uclibc/bin-ccache/../lib/gcc/aarch64-linux-uclibc/13.4.0/../../../../aarch64-linux-uclibc/bin/ld: main/streams/streams.o: in function `_php_stream_copy_to_stream_ex':
streams.c:(.text._php_stream_copy_to_stream_ex+0x2d4): undefined reference to `copy_file_range'

There is a newer action run with configure visible soon: https://github.com/fda77/freetz-ng/actions/runs/30581522530

2026-07-30T21:08:56.3680648Z checking for copy_filerange... yes

[devnexen]

ah that reframes everything, I mistakenly looked at master but in your versions copy_file_range implementation did not exist yet..The split we see is not really arm versus mips but kernel headers ? Your PR them seems the right thing to do, wdyt @petk ?

[fda77]

Yes, on my fork i remove the path / this pr again to get the error messages.
If there is a better way to fix copy_file_range problem do it, i'm not advanced with configure!

[petk]

To not delay this PR for too long, then let's do this.

I'll recheck everything after it. Because, why I'm asking this... What I'm suspecting here is something else - that uclibc-ng is linked differently and that's why this issue. At the compile step (AC_COMPILE_IFELSE) the issue isn't present - header is available but the linking step isn't yet performed. And, from my current understanding is that there are more related issues then to this where Autoconf does only AC_COMPILE_IFELSE checks and similar without doing the linking step.

Nothing to worry for now. I'll get to this at some point once I set up this environment in my virtual machine or something. And I might have also misunderstood the issue in the first place and there are no other issues related to this.

When merging, let's merge this to PHP-8.4 and up then.

[fda77]

In Freetz-NG the user could select the desired PHP version: 5.6, 8.2, 8.3 8.4 or 8.5
The patch "200-copy_file_range-check.patch" which is like this PR is used for 8.2-8.5 to be able to compile with uclibc-ng, see subdir of https://github.com/Freetz-NG/freetz-ng/tree/master/make/pkgs/php/patches
I dont know how PHP versions are still supported, but you could also backport it back to 8.2 if you like