From e67b2c715415b121339049b630f0b4e1ede888dc Mon Sep 17 00:00:00 2001 From: "Daniel T. Lee" Date: Thu, 4 Apr 2019 07:17:56 +0900 Subject: samples, selftests/bpf: add NULL check for ksym_search Since, ksym_search added with verification logic for symbols existence, it could return NULL when the kernel symbols are not loaded. This commit will add NULL check logic after ksym_search. Signed-off-by: Daniel T. Lee Signed-off-by: Daniel Borkmann --- samples/bpf/offwaketime_user.c | 5 +++++ samples/bpf/sampleip_user.c | 5 +++++ samples/bpf/spintest_user.c | 7 ++++++- samples/bpf/trace_event_user.c | 5 +++++ 4 files changed, 21 insertions(+), 1 deletion(-) (limited to 'samples/bpf') diff --git a/samples/bpf/offwaketime_user.c b/samples/bpf/offwaketime_user.c index f06063af9fcb..bb315ce1b866 100644 --- a/samples/bpf/offwaketime_user.c +++ b/samples/bpf/offwaketime_user.c @@ -28,6 +28,11 @@ static void print_ksym(__u64 addr) if (!addr) return; sym = ksym_search(addr); + if (!sym) { + printf("ksym not found. Is kallsyms loaded?\n"); + return; + } + if (PRINT_RAW_ADDR) printf("%s/%llx;", sym->name, addr); else diff --git a/samples/bpf/sampleip_user.c b/samples/bpf/sampleip_user.c index 216c7ecbbbe9..23b90a45c802 100644 --- a/samples/bpf/sampleip_user.c +++ b/samples/bpf/sampleip_user.c @@ -109,6 +109,11 @@ static void print_ip_map(int fd) for (i = 0; i < max; i++) { if (counts[i].ip > PAGE_OFFSET) { sym = ksym_search(counts[i].ip); + if (!sym) { + printf("ksym not found. Is kallsyms loaded?\n"); + continue; + } + printf("0x%-17llx %-32s %u\n", counts[i].ip, sym->name, counts[i].count); } else { diff --git a/samples/bpf/spintest_user.c b/samples/bpf/spintest_user.c index 8d3e9cfa1909..2556af2d9b3e 100644 --- a/samples/bpf/spintest_user.c +++ b/samples/bpf/spintest_user.c @@ -37,8 +37,13 @@ int main(int ac, char **argv) bpf_map_lookup_elem(map_fd[0], &next_key, &value); assert(next_key == value); sym = ksym_search(value); - printf(" %s", sym->name); key = next_key; + if (!sym) { + printf("ksym not found. Is kallsyms loaded?\n"); + continue; + } + + printf(" %s", sym->name); } if (key) printf("\n"); diff --git a/samples/bpf/trace_event_user.c b/samples/bpf/trace_event_user.c index d08046ab81f0..d4178f60e075 100644 --- a/samples/bpf/trace_event_user.c +++ b/samples/bpf/trace_event_user.c @@ -34,6 +34,11 @@ static void print_ksym(__u64 addr) if (!addr) return; sym = ksym_search(addr); + if (!sym) { + printf("ksym not found. Is kallsyms loaded?\n"); + return; + } + printf("%s;", sym->name); if (!strcmp(sym->name, "sys_read")) sys_read_seen = true; -- cgit v1.2.3