From c895f6f703ad7dd2f99e751d9884b0aa5d0eea25 Mon Sep 17 00:00:00 2001 From: Hendrik Brueckner Date: Mon, 4 Dec 2017 10:56:44 +0100 Subject: bpf: correct broken uapi for BPF_PROG_TYPE_PERF_EVENT program type Commit 0515e5999a466dfe ("bpf: introduce BPF_PROG_TYPE_PERF_EVENT program type") introduced the bpf_perf_event_data structure which exports the pt_regs structure. This is OK for multiple architectures but fail for s390 and arm64 which do not export pt_regs. Programs using them, for example, the bpf selftest fail to compile on these architectures. For s390, exporting the pt_regs is not an option because s390 wants to allow changes to it. For arm64, there is a user_pt_regs structure that covers parts of the pt_regs structure for use by user space. To solve the broken uapi for s390 and arm64, introduce an abstract type for pt_regs and add an asm/bpf_perf_event.h file that concretes the type. An asm-generic header file covers the architectures that export pt_regs today. The arch-specific enablement for s390 and arm64 follows in separate commits. Reported-by: Thomas Richter Fixes: 0515e5999a466dfe ("bpf: introduce BPF_PROG_TYPE_PERF_EVENT program type") Signed-off-by: Hendrik Brueckner Reviewed-and-tested-by: Thomas Richter Acked-by: Alexei Starovoitov Cc: Arnaldo Carvalho de Melo Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Namhyung Kim Cc: Arnd Bergmann Cc: Daniel Borkmann Signed-off-by: Daniel Borkmann --- kernel/events/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel/events') diff --git a/kernel/events/core.c b/kernel/events/core.c index 16beab4767e1..ba957b9812b3 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7987,11 +7987,11 @@ static void bpf_overflow_handler(struct perf_event *event, { struct bpf_perf_event_data_kern ctx = { .data = data, - .regs = regs, .event = event, }; int ret = 0; + ctx.regs = perf_arch_bpf_user_pt_regs(regs); preempt_disable(); if (unlikely(__this_cpu_inc_return(bpf_prog_active) != 1)) goto out; -- cgit v1.2.3