[PATCH RFC bpf-next 1/2] selftests/bpf: Add riscv support for get_preempt_count()

[Pu Lehui]

On 2026/4/20 19:15, Tiezhu Yang wrote:
> There is no riscv support for get_preempt_count() currently and its
> fallback path always returns 0, just add it so that bpf_in_interrupt(),
> bpf_in_nmi(), bpf_in_hardirq(), bpf_in_serving_softirq(), bpf_in_task()
> works for riscv as well. With this patch, "./test_progs -t exe_ctx"
> should pass on riscv.
> 
> Signed-off-by: Tiezhu Yang <yangtiezhu at loongson.cn>
> ---
>   tools/testing/selftests/bpf/bpf_experimental.h | 7 +++++++
>   1 file changed, 7 insertions(+)
> 
> diff --git a/tools/testing/selftests/bpf/bpf_experimental.h b/tools/testing/selftests/bpf/bpf_experimental.h
> index 2234bd6bc9d3..e5c039bc44cb 100644
> --- a/tools/testing/selftests/bpf/bpf_experimental.h
> +++ b/tools/testing/selftests/bpf/bpf_experimental.h
> @@ -505,6 +505,8 @@ static inline int get_preempt_count(void)
>   	return bpf_get_current_task_btf()->thread_info.preempt_count;
>   #elif defined(bpf_target_s390)
>   	return bpf_get_lowcore()->preempt_count;
> +#elif defined(bpf_target_riscv)
> +	return bpf_get_current_task_btf()->thread_info.preempt_count;
>   #endif
>   	return 0;
>   }
> @@ -515,6 +517,7 @@ static inline int get_preempt_count(void)
>    *	* arm64
>    *	* powerpc64
>    *	* s390x
> + *	* riscv
>    */
>   static inline int bpf_in_interrupt(void)
>   {
> @@ -536,6 +539,7 @@ static inline int bpf_in_interrupt(void)
>    *	* arm64
>    *	* powerpc64
>    *	* s390x
> + *	* riscv
>    */
>   static inline int bpf_in_nmi(void)
>   {
> @@ -548,6 +552,7 @@ static inline int bpf_in_nmi(void)
>    *	* arm64
>    *	* powerpc64
>    *	* s390x
> + *	* riscv
>    */
>   static inline int bpf_in_hardirq(void)
>   {
> @@ -560,6 +565,7 @@ static inline int bpf_in_hardirq(void)
>    *	* arm64
>    *	* powerpc64
>    *	* s390x
> + *	* riscv
>    */
>   static inline int bpf_in_serving_softirq(void)
>   {
> @@ -580,6 +586,7 @@ static inline int bpf_in_serving_softirq(void)
>    *	* arm64
>    *	* powerpc64
>    *	* s390x
> + *	* riscv
>    */
>   static inline int bpf_in_task(void)
>   {

Hi Tiezhu,

Thanks for doing this, feel free to add:

Tested-by: Pu Lehui <pulehui at huawei.com>
Reviewed-by: Pu Lehui <pulehui at huawei.com>