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 --- include/linux/perf_event.h | 6 +++++- include/uapi/asm-generic/bpf_perf_event.h | 9 +++++++++ include/uapi/linux/bpf_perf_event.h | 5 ++--- 3 files changed, 16 insertions(+), 4 deletions(-) create mode 100644 include/uapi/asm-generic/bpf_perf_event.h (limited to 'include') diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 2c9c87d8a0c1..7546822a1d74 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -15,6 +15,7 @@ #define _LINUX_PERF_EVENT_H #include +#include /* * Kernel-internal data types and definitions: @@ -787,7 +788,7 @@ struct perf_output_handle { }; struct bpf_perf_event_data_kern { - struct pt_regs *regs; + bpf_user_pt_regs_t *regs; struct perf_sample_data *data; struct perf_event *event; }; @@ -1177,6 +1178,9 @@ extern void perf_bp_event(struct perf_event *event, void *data); (user_mode(regs) ? PERF_RECORD_MISC_USER : PERF_RECORD_MISC_KERNEL) # define perf_instruction_pointer(regs) instruction_pointer(regs) #endif +#ifndef perf_arch_bpf_user_pt_regs +# define perf_arch_bpf_user_pt_regs(regs) regs +#endif static inline bool has_branch_stack(struct perf_event *event) { diff --git a/include/uapi/asm-generic/bpf_perf_event.h b/include/uapi/asm-generic/bpf_perf_event.h new file mode 100644 index 000000000000..53815d2cd047 --- /dev/null +++ b/include/uapi/asm-generic/bpf_perf_event.h @@ -0,0 +1,9 @@ +#ifndef _UAPI__ASM_GENERIC_BPF_PERF_EVENT_H__ +#define _UAPI__ASM_GENERIC_BPF_PERF_EVENT_H__ + +#include + +/* Export kernel pt_regs structure */ +typedef struct pt_regs bpf_user_pt_regs_t; + +#endif /* _UAPI__ASM_GENERIC_BPF_PERF_EVENT_H__ */ diff --git a/include/uapi/linux/bpf_perf_event.h b/include/uapi/linux/bpf_perf_event.h index af549d4ecf1b..8f95303f9d80 100644 --- a/include/uapi/linux/bpf_perf_event.h +++ b/include/uapi/linux/bpf_perf_event.h @@ -8,11 +8,10 @@ #ifndef _UAPI__LINUX_BPF_PERF_EVENT_H__ #define _UAPI__LINUX_BPF_PERF_EVENT_H__ -#include -#include +#include struct bpf_perf_event_data { - struct pt_regs regs; + bpf_user_pt_regs_t regs; __u64 sample_period; }; -- cgit v1.2.3