[PATCH RFC bpf-next 3/4] bpf/selftests: add tests to validate proper arguments alignment on ARM64

[Alexis Lothoré]

On Mon Apr 28, 2025 at 10:41 PM CEST, Alexis Lothoré wrote:
> On Mon Apr 28, 2025 at 6:52 PM CEST, Eduard Zingerman wrote:
>> Alexis Lothoré <alexis.lothore at bootlin.com> writes:

> If things really behaved correctly, f would not have the correct value but
> would still be handled as a 16 bytes value, so the test would not fail with
> "actual 35 != 43", but something like "actual
> 27254487904906932132179118915584 != 43" (43 << 64 | 35) I guess. I still
> need to sort this out.

And so indeed, the broken value is a big one:

(gdb) p skel->bss->t11_f
$4 = 793209995169510719523
(gdb) p/x skel->bss->t11_f
$5 = 0x2b0000000000000023
(gdb)

But we see the 35 (0x23) value in the error log because the formatters used in
ASSERT_EQ truncate the actual value.

Alexis

-- 
Alexis Lothoré, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com