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Commit 973d94d8 authored by Naveen N. Rao's avatar Naveen N. Rao Committed by David S. Miller
Browse files

bpf samples: update tracex5 sample to use __seccomp_filter 



seccomp_phase1() does not exist anymore. Instead, update sample to use
__seccomp_filter(). While at it, set max locked memory to unlimited.

Signed-off-by: default avatarNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2b064fff

samples/bpf/tracex5_kern.c

+7 −9
Original line number Diff line number Diff line
@@ -19,20 +19,18 @@ struct bpf_map_def SEC("maps") progs = { 
	.max_entries = 1024,

};



SEC("kprobe/seccomp_phase1")

SEC("kprobe/__seccomp_filter")

int bpf_prog1(struct pt_regs *ctx)

{

	struct seccomp_data sd;



	bpf_probe_read(&sd, sizeof(sd), (void *)PT_REGS_PARM1(ctx));

	int sc_nr = (int)PT_REGS_PARM1(ctx);



	/* dispatch into next BPF program depending on syscall number */

	bpf_tail_call(ctx, &progs, sd.nr);

	bpf_tail_call(ctx, &progs, sc_nr);



	/* fall through -> unknown syscall */

	if (sd.nr >= __NR_getuid && sd.nr <= __NR_getsid) {

	if (sc_nr >= __NR_getuid && sc_nr <= __NR_getsid) {

		char fmt[] = "syscall=%d (one of get/set uid/pid/gid)\n";

		bpf_trace_printk(fmt, sizeof(fmt), sd.nr);

		bpf_trace_printk(fmt, sizeof(fmt), sc_nr);

	}

	return 0;

}
@@ -42,7 +40,7 @@ PROG(__NR_write)(struct pt_regs *ctx) 
{

	struct seccomp_data sd;



	bpf_probe_read(&sd, sizeof(sd), (void *)PT_REGS_PARM1(ctx));

	bpf_probe_read(&sd, sizeof(sd), (void *)PT_REGS_PARM2(ctx));

	if (sd.args[2] == 512) {

		char fmt[] = "write(fd=%d, buf=%p, size=%d)\n";

		bpf_trace_printk(fmt, sizeof(fmt),
@@ -55,7 +53,7 @@ PROG(__NR_read)(struct pt_regs *ctx) 
{

	struct seccomp_data sd;



	bpf_probe_read(&sd, sizeof(sd), (void *)PT_REGS_PARM1(ctx));

	bpf_probe_read(&sd, sizeof(sd), (void *)PT_REGS_PARM2(ctx));

	if (sd.args[2] > 128 && sd.args[2] <= 1024) {

		char fmt[] = "read(fd=%d, buf=%p, size=%d)\n";

		bpf_trace_printk(fmt, sizeof(fmt),

samples/bpf/tracex5_user.c

+3 −0
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ 
#include <sys/prctl.h>

#include "libbpf.h"

#include "bpf_load.h"

#include <sys/resource.h>



/* install fake seccomp program to enable seccomp code path inside the kernel,

 * so that our kprobe attached to seccomp_phase1() can be triggered
@@ -27,8 +28,10 @@ int main(int ac, char **argv) 
{

	FILE *f;

	char filename[256];

	struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};



	snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);

	setrlimit(RLIMIT_MEMLOCK, &r);



	if (load_bpf_file(filename)) {

		printf("%s", bpf_log_buf);