Re: [PATCH bpf-next 5/6] selftests/bpf: Add arena fault test for load-acquire

On 8/6/26 4:39 PM, Daniel Borkmann wrote:
> Add stream_arena_load_acquire_fault, which performs a load-acquire from an
> unmapped arena address, next to the existing read and write fault tests.
> 
> The test covers both halves of the JIT bug that treated a load-acquire as
> a store when populating its exception table entry:
> 
>    - the fault has to be reported as a READ, and at the address held by
>      the source register, which __stderr() and test_address() check, and
>    - the destination register has to be cleared by the fault handler,
>      which the program checks by poisoning it before the load-acquire
>      and returning it, so __retval(0) fails if it is left untouched
> 
>    # LDLIBS=-static PKG_CONFIG='pkg-config --static' ./vmtest.sh -- ./test_progs -t stream_arena_fault_address
>    [...]
>    #462/1   stream_arena_fault_address/read_fault:OK
>    #462/2   stream_arena_fault_address/write_fault:OK
>    #462/3   stream_arena_fault_address/load_acquire_fault:OK
>    #462     stream_arena_fault_address:OK
>    Summary: 1/3 PASSED, 0 SKIPPED, 0 FAILED
> 
> Signed-off-by: Daniel Borkmann <[email protected]>
(will push a v2 given this one fails on s390 due to encoding)