Commit c5ffb263 authored by Daniel T. Lee's avatar Daniel T. Lee Committed by Andrii Nakryiko
Browse files

samples/bpf: Use BPF_KSYSCALL macro in syscall tracing programs 



This commit enhances the syscall tracing programs by using the
BPF_SYSCALL macro to reduce the inconvenience of parsing arguments from
pt_regs. By simplifying argument extraction, bpf program will become
clear to understand.

Signed-off-by: default avatarDaniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221224071527.2292-6-danieltimlee@gmail.com
parent 2e5c4dd7

samples/bpf/map_perf_test.bpf.c

+11 −15
Original line number Diff line number Diff line
@@ -101,7 +101,7 @@ struct { 
} lru_hash_lookup_map SEC(".maps");



SEC("ksyscall/getuid")

int stress_hmap(struct pt_regs *ctx)

int BPF_KSYSCALL(stress_hmap)

{

	u32 key = bpf_get_current_pid_tgid();

	long init_val = 1;
@@ -119,7 +119,7 @@ int stress_hmap(struct pt_regs *ctx) 
}



SEC("ksyscall/geteuid")

int stress_percpu_hmap(struct pt_regs *ctx)

int BPF_KSYSCALL(stress_percpu_hmap)

{

	u32 key = bpf_get_current_pid_tgid();

	long init_val = 1;
@@ -136,7 +136,7 @@ int stress_percpu_hmap(struct pt_regs *ctx) 
}



SEC("ksyscall/getgid")

int stress_hmap_alloc(struct pt_regs *ctx)

int BPF_KSYSCALL(stress_hmap_alloc)

{

	u32 key = bpf_get_current_pid_tgid();

	long init_val = 1;
@@ -153,7 +153,7 @@ int stress_hmap_alloc(struct pt_regs *ctx) 
}



SEC("ksyscall/getegid")

int stress_percpu_hmap_alloc(struct pt_regs *ctx)

int BPF_KSYSCALL(stress_percpu_hmap_alloc)

{

	u32 key = bpf_get_current_pid_tgid();

	long init_val = 1;
@@ -168,11 +168,10 @@ int stress_percpu_hmap_alloc(struct pt_regs *ctx) 
	}

	return 0;

}



SEC("ksyscall/connect")

int stress_lru_hmap_alloc(struct pt_regs *ctx)

int BPF_KSYSCALL(stress_lru_hmap_alloc, int fd, struct sockaddr_in *uservaddr,

		 int addrlen)

{

	struct pt_regs *real_regs = (struct pt_regs *)PT_REGS_PARM1_CORE(ctx);

	char fmt[] = "Failed at stress_lru_hmap_alloc. ret:%dn";

	union {

		u16 dst6[8];
@@ -185,14 +184,11 @@ int stress_lru_hmap_alloc(struct pt_regs *ctx) 
			u32 key;

		};

	} test_params;

	struct sockaddr_in6 *in6;

	struct sockaddr_in6 *in6 = (struct sockaddr_in6 *)uservaddr;

	u16 test_case;

	int addrlen, ret;

	long val = 1;

	u32 key = 0;



	in6 = (struct sockaddr_in6 *)PT_REGS_PARM2_CORE(real_regs);

	addrlen = (int)PT_REGS_PARM3_CORE(real_regs);

	int ret;



	if (addrlen != sizeof(*in6))

		return 0;
@@ -250,7 +246,7 @@ int stress_lru_hmap_alloc(struct pt_regs *ctx) 
}



SEC("ksyscall/gettid")

int stress_lpm_trie_map_alloc(struct pt_regs *ctx)

int BPF_KSYSCALL(stress_lpm_trie_map_alloc)

{

	union {

		u32 b32[2];
@@ -272,7 +268,7 @@ int stress_lpm_trie_map_alloc(struct pt_regs *ctx) 
}



SEC("ksyscall/getpgid")

int stress_hash_map_lookup(struct pt_regs *ctx)

int BPF_KSYSCALL(stress_hash_map_lookup)

{

	u32 key = 1, i;

	long *value;
@@ -285,7 +281,7 @@ int stress_hash_map_lookup(struct pt_regs *ctx) 
}



SEC("ksyscall/getppid")

int stress_array_map_lookup(struct pt_regs *ctx)

int BPF_KSYSCALL(stress_array_map_lookup)

{

	u32 key = 1, i;

	long *value;

samples/bpf/test_current_task_under_cgroup.bpf.c

+3 −1
Original line number Diff line number Diff line
@@ -8,6 +8,8 @@ 
#include "vmlinux.h"

#include <linux/version.h>

#include <bpf/bpf_helpers.h>

#include <bpf/bpf_tracing.h>

#include <bpf/bpf_core_read.h>



struct {

	__uint(type, BPF_MAP_TYPE_CGROUP_ARRAY);
@@ -25,7 +27,7 @@ struct { 


/* Writes the last PID that called sync to a map at index 0 */

SEC("ksyscall/sync")

int bpf_prog1(struct pt_regs *ctx)

int BPF_KSYSCALL(bpf_prog1)

{

	u64 pid = bpf_get_current_pid_tgid();

	int idx = 0;

samples/bpf/test_probe_write_user.bpf.c

+5 −7
Original line number Diff line number Diff line
@@ -27,24 +27,22 @@ struct { 
 * of course, across platforms, and over time, the ABI may change.

 */

SEC("ksyscall/connect")

int bpf_prog1(struct pt_regs *ctx)

int BPF_KSYSCALL(bpf_prog1, int fd, struct sockaddr_in *uservaddr,

		 int addrlen)

{

	struct pt_regs *real_regs = (struct pt_regs *)PT_REGS_PARM1_CORE(ctx);

	void *sockaddr_arg = (void *)PT_REGS_PARM2_CORE(real_regs);

	int sockaddr_len = (int)PT_REGS_PARM3_CORE(real_regs);

	struct sockaddr_in new_addr, orig_addr = {};

	struct sockaddr_in *mapped_addr;



	if (sockaddr_len > sizeof(orig_addr))

	if (addrlen > sizeof(orig_addr))

		return 0;



	if (bpf_probe_read_user(&orig_addr, sizeof(orig_addr), sockaddr_arg) != 0)

	if (bpf_probe_read_user(&orig_addr, sizeof(orig_addr), uservaddr) != 0)

		return 0;



	mapped_addr = bpf_map_lookup_elem(&dnat_map, &orig_addr);

	if (mapped_addr != NULL) {

		memcpy(&new_addr, mapped_addr, sizeof(new_addr));

		bpf_probe_write_user(sockaddr_arg, &new_addr,

		bpf_probe_write_user(uservaddr, &new_addr,

				     sizeof(new_addr));

	}

	return 0;