Re: [PATCH] nios2, openrisc, xtensa: Fix definitions of bpf_user_pt_regs_t

[Stafford Horne <shorne@gmail.com>]

On Fri, Aug 22, 2025 at 03:58:48PM +0200, Ben Hutchings wrote:
> The UAPI <asm/bpf_perf_event.h> header is required to define the type
> alias bpf_user_pt_regs_t.  The generic version includes
> <linux/ptrace.h> and defines it as an alias for struct pt_regs.
> 
> For these 3 architectures, struct pt_regs is not defined in the UAPI.
> They need to override the generic version with an architecture-
> specific definition of bpf_user_pt_regs_t.
> 
> References: https://autobuild.buildroot.org/results/bf2/bf21079facd21d684e8656e7ac44b4218a8fcb9d/build-end.log
> Fixes: c895f6f703ad ("bpf: correct broken uapi for BPF_PROG_TYPE_PERF_EVENT program type")
> Signed-off-by: Ben Hutchings <ben.hutchings@mind.be>
> ---
> I understand that perf_events is not yet supported on nios2 and
> openrisc, so this isn't obviously useful.  However, libbpf has generic
> handling for BPF_PROG_TYPE_PERF_EVENT that includes
> <linux/bpf_perf_event.h> and it now fails to build on openrisc.

Understood.

> I verified that:
> - This fixes building libbpf with Buildroot for openrisc
> - This makes "#include <linux/bpf_perf_event.h>" work on xtensa
> 
> I wasn't able to test nios2 at all.
> 
> Ben.
> 
>  arch/nios2/include/uapi/asm/bpf_perf_event.h    | 9 +++++++++
>  arch/openrisc/include/uapi/asm/bpf_perf_event.h | 9 +++++++++
>  arch/xtensa/include/uapi/asm/bpf_perf_event.h   | 9 +++++++++
>  3 files changed, 27 insertions(+)
>  create mode 100644 arch/nios2/include/uapi/asm/bpf_perf_event.h
>  create mode 100644 arch/openrisc/include/uapi/asm/bpf_perf_event.h
>  create mode 100644 arch/xtensa/include/uapi/asm/bpf_perf_event.h
> 
> diff --git a/arch/nios2/include/uapi/asm/bpf_perf_event.h b/arch/nios2/include/uapi/asm/bpf_perf_event.h
> new file mode 100644
> index 000000000000..5e1e648aeec4
> --- /dev/null
> +++ b/arch/nios2/include/uapi/asm/bpf_perf_event.h
> @@ -0,0 +1,9 @@
> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> +#ifndef _UAPI__ASM_BPF_PERF_EVENT_H__
> +#define _UAPI__ASM_BPF_PERF_EVENT_H__
> +
> +#include <asm/ptrace.h>
> +
> +typedef struct user_pt_regs bpf_user_pt_regs_t;
> +
> +#endif /* _UAPI__ASM_BPF_PERF_EVENT_H__ */
> diff --git a/arch/openrisc/include/uapi/asm/bpf_perf_event.h b/arch/openrisc/include/uapi/asm/bpf_perf_event.h
> new file mode 100644
> index 000000000000..6cb1c2823288
> --- /dev/null
> +++ b/arch/openrisc/include/uapi/asm/bpf_perf_event.h
> @@ -0,0 +1,9 @@
> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> +#ifndef _UAPI__ASM_BPF_PERF_EVENT_H__
> +#define _UAPI__ASM_BPF_PERF_EVENT_H__
> +
> +#include <asm/ptrace.h>
> +
> +typedef struct user_regs_struct bpf_user_pt_regs_t;
> +
> +#endif /* _UAPI__ASM_BPF_PERF_EVENT_H__ */

This bit,

Acked-by: Stafford Horne <shorne@gmail.com>

Who do you plan on having take this patch for upstream?  Will you?

-Stafford

> diff --git a/arch/xtensa/include/uapi/asm/bpf_perf_event.h b/arch/xtensa/include/uapi/asm/bpf_perf_event.h
> new file mode 100644
> index 000000000000..5e1e648aeec4
> --- /dev/null
> +++ b/arch/xtensa/include/uapi/asm/bpf_perf_event.h
> @@ -0,0 +1,9 @@
> +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
> +#ifndef _UAPI__ASM_BPF_PERF_EVENT_H__
> +#define _UAPI__ASM_BPF_PERF_EVENT_H__
> +
> +#include <asm/ptrace.h>
> +
> +typedef struct user_pt_regs bpf_user_pt_regs_t;
> +
> +#endif /* _UAPI__ASM_BPF_PERF_EVENT_H__ */
> -- 
> 2.39.5
> 
>