7d07006f05
The current behavior of 'tracex7' doesn't consist with other bpf samples
tracex{1..6}. Other samples do not require any argument to run with, but
tracex7 should be run with btrfs device argument. (it should be executed
with test_override_return.sh)
Currently, tracex7 doesn't have any description about how to run this
program and raises an unexpected error. And this result might be
confusing since users might not have a hunch about how to run this
program.
// Current behavior
# ./tracex7
sh: 1: Syntax error: word unexpected (expecting ")")
// Fixed behavior
# ./tracex7
ERROR: Run with the btrfs device argument!
In order to fix this error, this commit adds logic to report a message
and exit when running this program with a missing argument.
Additionally in test_override_return.sh, there is a problem with
multiple directory(tmpmnt) creation. So in this commit adds a line with
removing the directory with every execution.
Signed-off-by: Juhee Kang <claudiajkang@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210727041056.23455-1-claudiajkang@gmail.com
57 lines
1.2 KiB
C
57 lines
1.2 KiB
C
#define _GNU_SOURCE
|
|
|
|
#include <stdio.h>
|
|
#include <unistd.h>
|
|
#include <bpf/libbpf.h>
|
|
|
|
int main(int argc, char **argv)
|
|
{
|
|
struct bpf_link *link = NULL;
|
|
struct bpf_program *prog;
|
|
struct bpf_object *obj;
|
|
char filename[256];
|
|
char command[256];
|
|
int ret = 0;
|
|
FILE *f;
|
|
|
|
if (!argv[1]) {
|
|
fprintf(stderr, "ERROR: Run with the btrfs device argument!\n");
|
|
return 0;
|
|
}
|
|
|
|
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
|
|
obj = bpf_object__open_file(filename, NULL);
|
|
if (libbpf_get_error(obj)) {
|
|
fprintf(stderr, "ERROR: opening BPF object file failed\n");
|
|
return 0;
|
|
}
|
|
|
|
prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
|
|
if (!prog) {
|
|
fprintf(stderr, "ERROR: finding a prog in obj file failed\n");
|
|
goto cleanup;
|
|
}
|
|
|
|
/* load BPF program */
|
|
if (bpf_object__load(obj)) {
|
|
fprintf(stderr, "ERROR: loading BPF object file failed\n");
|
|
goto cleanup;
|
|
}
|
|
|
|
link = bpf_program__attach(prog);
|
|
if (libbpf_get_error(link)) {
|
|
fprintf(stderr, "ERROR: bpf_program__attach failed\n");
|
|
link = NULL;
|
|
goto cleanup;
|
|
}
|
|
|
|
snprintf(command, 256, "mount %s tmpmnt/", argv[1]);
|
|
f = popen(command, "r");
|
|
ret = pclose(f);
|
|
|
|
cleanup:
|
|
bpf_link__destroy(link);
|
|
bpf_object__close(obj);
|
|
return ret ? 0 : 1;
|
|
}
|