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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
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#include <stdio.h>
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#include <unistd.h>
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#include <bpf/libbpf.h>
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int main(int argc, char **argv)
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{
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struct bpf_link *link = NULL;
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struct bpf_program *prog;
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struct bpf_object *obj;
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char filename[256];
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char command[256];
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int ret = 0;
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FILE *f;
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if (!argv[1]) {
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fprintf(stderr, "ERROR: Run with the btrfs device argument!\n");
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return 0;
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}
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snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
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obj = bpf_object__open_file(filename, NULL);
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if (libbpf_get_error(obj)) {
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fprintf(stderr, "ERROR: opening BPF object file failed\n");
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return 0;
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}
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prog = bpf_object__find_program_by_name(obj, "bpf_prog1");
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if (!prog) {
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fprintf(stderr, "ERROR: finding a prog in obj file failed\n");
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goto cleanup;
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}
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/* load BPF program */
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if (bpf_object__load(obj)) {
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fprintf(stderr, "ERROR: loading BPF object file failed\n");
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goto cleanup;
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}
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link = bpf_program__attach(prog);
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if (libbpf_get_error(link)) {
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fprintf(stderr, "ERROR: bpf_program__attach failed\n");
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link = NULL;
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goto cleanup;
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}
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snprintf(command, 256, "mount %s tmpmnt/", argv[1]);
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f = popen(command, "r");
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ret = pclose(f);
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cleanup:
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bpf_link__destroy(link);
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bpf_object__close(obj);
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return ret ? 0 : 1;
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}
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