diff mbox series

[v4,bpf-next,14/14] bpf: Add object leak check.

Message ID 20230706033447.54696-15-alexei.starovoitov@gmail.com (mailing list archive)
State Accepted
Commit 4ed8b5bcfada6687baa478bf8febe891d9107118
Delegated to: BPF
Headers show
Series bpf: Introduce bpf_mem_cache_free_rcu(). | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for bpf-next
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 13 this patch: 13
netdev/cc_maintainers warning 8 maintainers not CCed: yhs@fb.com kpsingh@kernel.org martin.lau@linux.dev john.fastabend@gmail.com song@kernel.org sdf@google.com jolsa@kernel.org haoluo@google.com
netdev/build_clang fail Errors and warnings before: 18 this patch: 18
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 13 this patch: 13
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 43 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0
bpf/vmtest-bpf-next-PR success PR summary
bpf/vmtest-bpf-next-VM_Test-1 success Logs for ShellCheck
bpf/vmtest-bpf-next-VM_Test-6 success Logs for set-matrix
bpf/vmtest-bpf-next-VM_Test-2 success Logs for build for aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-4 success Logs for build for x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-5 success Logs for build for x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-3 success Logs for build for s390x with gcc
bpf/vmtest-bpf-next-VM_Test-7 success Logs for test_maps on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-9 success Logs for test_maps on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-10 success Logs for test_maps on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-19 success Logs for test_progs_no_alu32_parallel on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-20 success Logs for test_progs_no_alu32_parallel on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-21 success Logs for test_progs_no_alu32_parallel on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-22 success Logs for test_progs_parallel on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-23 success Logs for test_progs_parallel on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-24 success Logs for test_progs_parallel on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-25 success Logs for test_verifier on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-26 success Logs for test_verifier on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-27 success Logs for test_verifier on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-28 success Logs for test_verifier on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-29 success Logs for veristat
bpf/vmtest-bpf-next-VM_Test-11 success Logs for test_progs on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-13 success Logs for test_progs on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-14 success Logs for test_progs on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-15 success Logs for test_progs_no_alu32 on aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-17 success Logs for test_progs_no_alu32 on x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-18 success Logs for test_progs_no_alu32 on x86_64 with llvm-16
bpf/vmtest-bpf-next-VM_Test-16 success Logs for test_progs_no_alu32 on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-12 success Logs for test_progs on s390x with gcc
bpf/vmtest-bpf-next-VM_Test-8 success Logs for test_maps on s390x with gcc

Commit Message

Alexei Starovoitov July 6, 2023, 3:34 a.m. UTC 
From: Hou Tao <houtao1@huawei.com>

The object leak check is cheap. Do it unconditionally to spot difficult races
in bpf_mem_alloc.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
---
 kernel/bpf/memalloc.c | 35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)
diff mbox series

Patch

diff --git a/kernel/bpf/memalloc.c b/kernel/bpf/memalloc.c
index 17ef2e9b278a..51d6389e5152 100644
--- a/kernel/bpf/memalloc.c
+++ b/kernel/bpf/memalloc.c
@@ -567,8 +567,43 @@  static void drain_mem_cache(struct bpf_mem_cache *c)
 	free_all(llist_del_all(&c->waiting_for_gp), percpu);
 }
 
+static void check_mem_cache(struct bpf_mem_cache *c)
+{
+	WARN_ON_ONCE(!llist_empty(&c->free_by_rcu_ttrace));
+	WARN_ON_ONCE(!llist_empty(&c->waiting_for_gp_ttrace));
+	WARN_ON_ONCE(!llist_empty(&c->free_llist));
+	WARN_ON_ONCE(!llist_empty(&c->free_llist_extra));
+	WARN_ON_ONCE(!llist_empty(&c->free_by_rcu));
+	WARN_ON_ONCE(!llist_empty(&c->free_llist_extra_rcu));
+	WARN_ON_ONCE(!llist_empty(&c->waiting_for_gp));
+}
+
+static void check_leaked_objs(struct bpf_mem_alloc *ma)
+{
+	struct bpf_mem_caches *cc;
+	struct bpf_mem_cache *c;
+	int cpu, i;
+
+	if (ma->cache) {
+		for_each_possible_cpu(cpu) {
+			c = per_cpu_ptr(ma->cache, cpu);
+			check_mem_cache(c);
+		}
+	}
+	if (ma->caches) {
+		for_each_possible_cpu(cpu) {
+			cc = per_cpu_ptr(ma->caches, cpu);
+			for (i = 0; i < NUM_CACHES; i++) {
+				c = &cc->cache[i];
+				check_mem_cache(c);
+			}
+		}
+	}
+}
+
 static void free_mem_alloc_no_barrier(struct bpf_mem_alloc *ma)
 {
+	check_leaked_objs(ma);
 	free_percpu(ma->cache);
 	free_percpu(ma->caches);
 	ma->cache = NULL;