alistair23-linux/include/linux/tracepoint-defs.h
Matt Mullins 9df1c28bb7 bpf: add writable context for raw tracepoints
This is an opt-in interface that allows a tracepoint to provide a safe
buffer that can be written from a BPF_PROG_TYPE_RAW_TRACEPOINT program.
The size of the buffer must be a compile-time constant, and is checked
before allowing a BPF program to attach to a tracepoint that uses this
feature.

The pointer to this buffer will be the first argument of tracepoints
that opt in; the pointer is valid and can be bpf_probe_read() by both
BPF_PROG_TYPE_RAW_TRACEPOINT and BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE
programs that attach to such a tracepoint, but the buffer to which it
points may only be written by the latter.

Signed-off-by: Matt Mullins <mmullins@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-04-26 19:04:19 -07:00

52 lines
1 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef TRACEPOINT_DEFS_H
#define TRACEPOINT_DEFS_H 1
/*
* File can be included directly by headers who only want to access
* tracepoint->key to guard out of line trace calls, or the definition of
* trace_print_flags{_u64}. Otherwise linux/tracepoint.h should be used.
*/
#include <linux/atomic.h>
#include <linux/static_key.h>
struct trace_print_flags {
unsigned long mask;
const char *name;
};
struct trace_print_flags_u64 {
unsigned long long mask;
const char *name;
};
struct tracepoint_func {
void *func;
void *data;
int prio;
};
struct tracepoint {
const char *name; /* Tracepoint name */
struct static_key key;
int (*regfunc)(void);
void (*unregfunc)(void);
struct tracepoint_func __rcu *funcs;
};
#ifdef CONFIG_HAVE_ARCH_PREL32_RELOCATIONS
typedef const int tracepoint_ptr_t;
#else
typedef struct tracepoint * const tracepoint_ptr_t;
#endif
struct bpf_raw_event_map {
struct tracepoint *tp;
void *bpf_func;
u32 num_args;
u32 writable_size;
} __aligned(32);
#endif