On 12/21/2017 10:49 AM, Prashant Bhole wrote:
> The default memlock rlimit is 64KB, which causes failure in
> creating a map
>
> For example:
> test@test# ./sampleip
> failed to create a map: 1 Operation not permitted
> ERROR: loading BPF program (errno 1):
> Try: ulimit -l unlimited
>
> Signed-off-by: Prashant Bhole <bhole_prashant...@lab.ntt.co.jp>
> ---
> samples/bpf/sampleip_user.c | 17 ++++++++++-------
> 1 file changed, 10 insertions(+), 7 deletions(-)
>
> diff --git a/samples/bpf/sampleip_user.c b/samples/bpf/sampleip_user.c
> index 4ed690b907ff..f240a7db7c0a 100644
> --- a/samples/bpf/sampleip_user.c
> +++ b/samples/bpf/sampleip_user.c
> @@ -19,6 +19,7 @@
> #include <linux/ptrace.h>
> #include <linux/bpf.h>
> #include <sys/ioctl.h>
> +#include <sys/resource.h>
> #include "libbpf.h"
> #include "bpf_load.h"
> #include "perf-sys.h"
> @@ -132,8 +133,9 @@ static void int_exit(int sig)
>
> int main(int argc, char **argv)
> {
> - char filename[256];
> int *pmu_fd, opt, freq = DEFAULT_FREQ, secs = DEFAULT_SECS;
> + struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
> + char filename[256];
>
> /* process arguments */
> while ((opt = getopt(argc, argv, "F:h")) != -1) {
> @@ -154,6 +156,11 @@ int main(int argc, char **argv)
> return 1;
> }
>
> + if (setrlimit(RLIMIT_MEMLOCK, &r)) {
> + perror("Failed to set memlock rlimit");
> + return 1;
> + }
> +
> /* initialize kernel symbol translation */
> if (load_kallsyms()) {
> fprintf(stderr, "ERROR: loading /proc/kallsyms\n");
> @@ -171,12 +178,8 @@ int main(int argc, char **argv)
> /* load BPF program */
> snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
> if (load_bpf_file(filename)) {
> - fprintf(stderr, "ERROR: loading BPF program (errno %d):\n",
> - errno);
> - if (strcmp(bpf_log_buf, "") == 0)
> - fprintf(stderr, "Try: ulimit -l unlimited\n");
Given the author of that sample code clearly gave this as a hint to make
the decision up to the user to tweak ulimit, I don't think we should
then do it unconditionally in the sample program here. Therefore, I'm
not taking this, sorry.
> - else
> - fprintf(stderr, "%s", bpf_log_buf);
> + fprintf(stderr, "ERROR: loading BPF program (errno %d): %s\n",
> + errno, bpf_log_buf);
> return 1;
> }
> signal(SIGINT, int_exit);
>
