s390/bpf: correct broken uapi for BPF_PROG_TYPE_PERF_EVENT program type (466698e6) · Commits · 戴 / test

To mitigate and correct the broken uapi for the BPF_PROG_TYPE_PERF_EVENT program type, introduce a user_pt_regs structure (similar to arm64) that exports parts from the beginnig of the pt_regs structure. The export must start with the beginning of the pt_regs structure because to correctly calculate BPF prologues for perf (regs_query_register_offset()). For BPF_PROG_TYPE_PERF_EVENT program types, the BPF program is then passed a user_pt_regs structure. Note: Depending on future changes to the s390 pt_regs structure, consider the user_pt_regs structure to be stable for a particular kernel version only. (Of course, s390 tries to ensure keep it stable as much as possible.) Signed-off-by:

Hendrik Brueckner <brueckner@linux.vnet.ibm.com> Reviewed-and-tested-by:

Thomas Richter <tmricht@linux.vnet.ibm.com> Acked-by:

Alexei Starovoitov <ast@kernel.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by:

Daniel Borkmann <daniel@iogearbox.net>

arch/s390/include/asm/perf_event.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -40,6 +40,7 @@ struct pt_regs;
		extern unsigned long perf_instruction_pointer(struct pt_regs *regs);
		extern unsigned long perf_misc_flags(struct pt_regs *regs);
		#define perf_misc_flags(regs) perf_misc_flags(regs)
		#define perf_arch_bpf_user_pt_regs(regs) &regs->user_regs

		/* Perf pt_regs extension for sample-data-entry indicators */
		struct perf_sf_sde_regs {

arch/s390/include/asm/ptrace.h

+8 −3

Original line number	Diff line number	Diff line
		@@ -74,9 +74,14 @@ enum {
		*/
		struct pt_regs
		{
		union {
		user_pt_regs user_regs;
		struct {
		unsigned long args[1];
		psw_t psw;
		unsigned long gprs[NUM_GPRS];
		};
		};
		unsigned long orig_gpr2;
		unsigned int int_code;
		unsigned int int_parm;

arch/s390/include/uapi/asm/bpf_perf_event.h

0 → 100644

+9 −0

Original line number	Diff line number	Diff line
		/* SPDX-License-Identifier: GPL-2.0 */
		#ifndef _UAPI__ASM_BPF_PERF_EVENT_H__
		#define _UAPI__ASM_BPF_PERF_EVENT_H__

		#include <asm/ptrace.h>

		typedef user_pt_regs bpf_user_pt_regs_t;

		#endif /* _UAPI__ASM_BPF_PERF_EVENT_H__ */

arch/s390/include/uapi/asm/ptrace.h

+11 −0

Original line number	Diff line number	Diff line
		@@ -290,6 +290,17 @@ typedef struct
		unsigned long orig_gpr2;
		} s390_regs;

		/*
		* The user_pt_regs structure exports the beginning of
		* the in-kernel pt_regs structure to user space.
		*/
		typedef struct
		{
		unsigned long args[1];
		psw_t psw;
		unsigned long gprs[NUM_GPRS];
		} user_pt_regs;

		/*
		* Now for the user space program event recording (trace) definitions.
		* The following structures are used only for the ptrace interface, don't

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