[linux-2.6-block.git] / tools / testing / selftests / bpf / progs / test_get_stack_rawtp.c

// SPDX-License-Identifier: GPL-2.0

#include <linux/bpf.h>
#include "bpf_helpers.h"

/* Permit pretty deep stack traces */
#define MAX_STACK_RAWTP 100
struct stack_trace_t {
	int pid;
	int kern_stack_size;
	int user_stack_size;
	int user_stack_buildid_size;
	__u64 kern_stack[MAX_STACK_RAWTP];
	__u64 user_stack[MAX_STACK_RAWTP];
	struct bpf_stack_build_id user_stack_buildid[MAX_STACK_RAWTP];
};

struct {
	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
	__uint(max_entries, 2);
	__uint(key_size, sizeof(int));
	__uint(value_size, sizeof(__u32));
} perfmap SEC(".maps");

struct {
	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
	__uint(max_entries, 1);
	__type(key, __u32);
	__type(value, struct stack_trace_t);
} stackdata_map SEC(".maps");

/* Allocate per-cpu space twice the needed. For the code below
 *   usize = bpf_get_stack(ctx, raw_data, max_len, BPF_F_USER_STACK);
 *   if (usize < 0)
 *     return 0;
 *   ksize = bpf_get_stack(ctx, raw_data + usize, max_len - usize, 0);
 *
 * If we have value_size = MAX_STACK_RAWTP * sizeof(__u64),
 * verifier will complain that access "raw_data + usize"
 * with size "max_len - usize" may be out of bound.
 * The maximum "raw_data + usize" is "raw_data + max_len"
 * and the maximum "max_len - usize" is "max_len", verifier
 * concludes that the maximum buffer access range is
 * "raw_data[0...max_len * 2 - 1]" and hence reject the program.
 *
 * Doubling the to-be-used max buffer size can fix this verifier
 * issue and avoid complicated C programming massaging.
 * This is an acceptable workaround since there is one entry here.
 */
struct {
	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
	__uint(max_entries, 1);
	__type(key, __u32);
	__type(value, __u64[2 * MAX_STACK_RAWTP]);
} rawdata_map SEC(".maps");

SEC("raw_tracepoint/sys_enter")
int bpf_prog1(void *ctx)
{
	int max_len, max_buildid_len, usize, ksize, total_size;
	struct stack_trace_t *data;
	void *raw_data;
	__u32 key = 0;

	data = bpf_map_lookup_elem(&stackdata_map, &key);
	if (!data)
		return 0;

	max_len = MAX_STACK_RAWTP * sizeof(__u64);
	max_buildid_len = MAX_STACK_RAWTP * sizeof(struct bpf_stack_build_id);
	data->pid = bpf_get_current_pid_tgid();
	data->kern_stack_size = bpf_get_stack(ctx, data->kern_stack,
					      max_len, 0);
	data->user_stack_size = bpf_get_stack(ctx, data->user_stack, max_len,
					    BPF_F_USER_STACK);
	data->user_stack_buildid_size = bpf_get_stack(
		ctx, data->user_stack_buildid, max_buildid_len,
		BPF_F_USER_STACK | BPF_F_USER_BUILD_ID);
	bpf_perf_event_output(ctx, &perfmap, 0, data, sizeof(*data));

	/* write both kernel and user stacks to the same buffer */
	raw_data = bpf_map_lookup_elem(&rawdata_map, &key);
	if (!raw_data)
		return 0;

	usize = bpf_get_stack(ctx, raw_data, max_len, BPF_F_USER_STACK);
	if (usize < 0)
		return 0;

	ksize = bpf_get_stack(ctx, raw_data + usize, max_len - usize, 0);
	if (ksize < 0)
		return 0;

	total_size = usize + ksize;
	if (total_size > 0 && total_size <= max_len)
		bpf_perf_event_output(ctx, &perfmap, 0, raw_data, total_size);

	return 0;
}

char _license[] SEC("license") = "GPL";
Commit	Line	Data
173965fb YS	1	// SPDX-License-Identifier: GPL-2.0
	2
	3	#include <linux/bpf.h>
	4	#include "bpf_helpers.h"
	5
	6	/* Permit pretty deep stack traces */
	7	#define MAX_STACK_RAWTP 100
	8	struct stack_trace_t {
	9	int pid;
	10	int kern_stack_size;
	11	int user_stack_size;
	12	int user_stack_buildid_size;
	13	__u64 kern_stack[MAX_STACK_RAWTP];
	14	__u64 user_stack[MAX_STACK_RAWTP];
	15	struct bpf_stack_build_id user_stack_buildid[MAX_STACK_RAWTP];
	16	};
	17
df0b7792	18	struct {
bc7430cc AN	19	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
	20	__uint(max_entries, 2);
	21	__uint(key_size, sizeof(int));
	22	__uint(value_size, sizeof(__u32));
	23	} perfmap SEC(".maps");
173965fb	24
df0b7792	25	struct {
bc7430cc AN	26	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
	27	__uint(max_entries, 1);
	28	__type(key, __u32);
	29	__type(value, struct stack_trace_t);
	30	} stackdata_map SEC(".maps");
173965fb YS	31
	32	/* Allocate per-cpu space twice the needed. For the code below
	33	* usize = bpf_get_stack(ctx, raw_data, max_len, BPF_F_USER_STACK);
	34	* if (usize < 0)
	35	* return 0;
	36	* ksize = bpf_get_stack(ctx, raw_data + usize, max_len - usize, 0);
	37	*
	38	* If we have value_size = MAX_STACK_RAWTP * sizeof(__u64),
	39	* verifier will complain that access "raw_data + usize"
	40	* with size "max_len - usize" may be out of bound.
	41	* The maximum "raw_data + usize" is "raw_data + max_len"
	42	* and the maximum "max_len - usize" is "max_len", verifier
	43	* concludes that the maximum buffer access range is
	44	* "raw_data[0...max_len * 2 - 1]" and hence reject the program.
	45	*
	46	* Doubling the to-be-used max buffer size can fix this verifier
	47	* issue and avoid complicated C programming massaging.
	48	* This is an acceptable workaround since there is one entry here.
	49	*/
df0b7792	50	struct {
bc7430cc AN	51	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
	52	__uint(max_entries, 1);
	53	__type(key, __u32);
a53ba15d	54	__type(value, __u64[2 * MAX_STACK_RAWTP]);
bc7430cc	55	} rawdata_map SEC(".maps");
173965fb	56
58b80815	57	SEC("raw_tracepoint/sys_enter")
173965fb YS	58	int bpf_prog1(void *ctx)
	59	{
	60	int max_len, max_buildid_len, usize, ksize, total_size;
	61	struct stack_trace_t *data;
	62	void *raw_data;
	63	__u32 key = 0;
	64
	65	data = bpf_map_lookup_elem(&stackdata_map, &key);
	66	if (!data)
	67	return 0;
	68
	69	max_len = MAX_STACK_RAWTP * sizeof(__u64);
	70	max_buildid_len = MAX_STACK_RAWTP * sizeof(struct bpf_stack_build_id);
	71	data->pid = bpf_get_current_pid_tgid();
	72	data->kern_stack_size = bpf_get_stack(ctx, data->kern_stack,
	73	max_len, 0);
	74	data->user_stack_size = bpf_get_stack(ctx, data->user_stack, max_len,
	75	BPF_F_USER_STACK);
	76	data->user_stack_buildid_size = bpf_get_stack(
	77	ctx, data->user_stack_buildid, max_buildid_len,
	78	BPF_F_USER_STACK \| BPF_F_USER_BUILD_ID);
	79	bpf_perf_event_output(ctx, &perfmap, 0, data, sizeof(*data));
	80
	81	/* write both kernel and user stacks to the same buffer */
	82	raw_data = bpf_map_lookup_elem(&rawdata_map, &key);
	83	if (!raw_data)
	84	return 0;
	85
	86	usize = bpf_get_stack(ctx, raw_data, max_len, BPF_F_USER_STACK);
	87	if (usize < 0)
	88	return 0;
	89
	90	ksize = bpf_get_stack(ctx, raw_data + usize, max_len - usize, 0);
	91	if (ksize < 0)
	92	return 0;
	93
	94	total_size = usize + ksize;
	95	if (total_size > 0 && total_size <= max_len)
	96	bpf_perf_event_output(ctx, &perfmap, 0, raw_data, total_size);
	97
	98	return 0;
	99	}
	100
	101	char _license[] SEC("license") = "GPL";