[PATCH] arm64: perf: fix syscalltbl path base

[Arnd Bergmann]

On Mon, Dec 15, 2025, at 12:28, Leo Yan wrote:
> On Mon, Dec 15, 2025 at 12:52:24PM +0200, James Clark wrote:
>> On 15/12/2025 11:33, Arnd Bergmann wrote:
>> > On Mon, Dec 15, 2025, at 09:47, James Clark wrote:
>> > > The first commit has an older fixes: tag and also fixes some other
>> > > issues so it might be better to take that one rather than this one.
>> > 
>> > I don't understand that other "fix", doesn't that just work around
>> > the arm64 build issue by adding another special case for arm64?
>> > 
>> > If we want the tools directory to have a copy of the generated unistd.h
>> > files instead of generating them, it should at the minimum be done
>> > the same across all architectures.
>> 
>> I don't think it's a special case, the other architectures already have a
>> copy of their syscall headers in tools/ don't they?
>
> Correct.  Most of architectures simply include
>
>     tools/include/uapi/asm-generic/unistd.h
>
> x86 includes their own unistd_32/64.h; only arm64 attempted to generate
> unistd_64.h dynamically, but this is problem for build dependency - when
> build perf, feature tests in tools/build/feature/ run before libperf and
> fail if unistd_64.h has not yet been generated by libperf Makefile.

Ah, I see now that arc/hexagon/loongarch/riscv just use an old
copy of the header based on the and no longer update them. I only
saw that they have the stub version but hadn't realized that they
never updated past the point where we started generating the
ones for the uapi.

Still, I would suggest using the same method across all architectures:
either we figure out how to use the generated headers on all of them
(including x86, which uses yet another method), or we just stick with
the old asm-generic/unistd.h copy and use that on arm64 as well.

     Arnd