Re: [RFC PATCH net-next] bpf: fix potential percpu map overcopy to user.
From: Alexei Starovoitov <hidden>
Date: 2016-10-20 16:58:15
On Thu, Oct 20, 2016 at 06:04:38PM +0200, Daniel Borkmann wrote:
quoted hunk ↗ jump to hunk
diff --git a/tools/testing/selftests/bpf/test_maps.c b/tools/testing/selftests/bpf/test_maps.c index ee384f0..d4832e8 100644 --- a/tools/testing/selftests/bpf/test_maps.c +++ b/tools/testing/selftests/bpf/test_maps.c@@ -25,6 +25,33 @@ static int map_flags; +static unsigned int num_possible_cpus(void) +{ + static const char *fcpu = "/sys/devices/system/cpu/possible"; + unsigned int val, possible_cpus = 0; + char buff[128]; + FILE *fp; + + fp = fopen(fcpu, "r"); + if (!fp) { + printf("Failed to open %s: '%s'!\n", fcpu, strerror(errno)); + exit(1); + } + + while (fgets(buff, sizeof(buff), fp)) { + if (sscanf(buff, "%*u-%u", &val) == 1) + possible_cpus = val; + }
looks great to me. Could you move it into bpf_sys.h or somehow make it common in libbpf and reuse it in samples/bpf/ ? Since quite a few samples need this fix as well. Thanks!