bpf: Improve verifier log for resource leak on exit

The verifier log when leaking resources on BPF_EXIT may be a bit
confusing, as it's a problem only when finally existing from the main
prog, not from any of the subprogs. Hence, update the verifier error
string and the corresponding selftests matching on it.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Suggested-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20241204030400.208005-6-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index b23f6fddf3afa1c8a5d6442843b642770f3bf14a..31e0d33498acfda519723fded5a6df463ffcebd2 100644 (file)
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -19102,7 +19102,7 @@ process_bpf_exit_full:
                                 * match caller reference state when it exits.
                                 */
                                err = check_resource_leak(env, exception_exit, !env->cur_state->curframe,
-                                                         "BPF_EXIT instruction");
+                                                         "BPF_EXIT instruction in main prog");
                                if (err)
                                        return err;
 

diff --git a/tools/testing/selftests/bpf/progs/exceptions_fail.c b/tools/testing/selftests/bpf/progs/exceptions_fail.c
index fe0f3fa5aab6892447bb7403c77fef53e2c66d3e..8a0fdff899271d615a0c0e2875702b29c5c9df77 100644 (file)
--- a/tools/testing/selftests/bpf/progs/exceptions_fail.c
+++ b/tools/testing/selftests/bpf/progs/exceptions_fail.c
@@ -131,7 +131,7 @@ int reject_subprog_with_lock(void *ctx)
 }
 
 SEC("?tc")
-__failure __msg("BPF_EXIT instruction cannot be used inside bpf_rcu_read_lock-ed region")
+__failure __msg("BPF_EXIT instruction in main prog cannot be used inside bpf_rcu_read_lock-ed region")
 int reject_with_rcu_read_lock(void *ctx)
 {
        bpf_rcu_read_lock();
@@ -147,7 +147,7 @@ __noinline static int throwing_subprog(struct __sk_buff *ctx)
 }
 
 SEC("?tc")
-__failure __msg("BPF_EXIT instruction cannot be used inside bpf_rcu_read_lock-ed region")
+__failure __msg("BPF_EXIT instruction in main prog cannot be used inside bpf_rcu_read_lock-ed region")
 int reject_subprog_with_rcu_read_lock(void *ctx)
 {
        bpf_rcu_read_lock();

diff --git a/tools/testing/selftests/bpf/progs/preempt_lock.c b/tools/testing/selftests/bpf/progs/preempt_lock.c
index 885377e83607754478b2c61bde83d2ce6cf23edb..5269571cf7b57d5dd0c5ea9e927072876d44a1a8 100644 (file)
--- a/tools/testing/selftests/bpf/progs/preempt_lock.c
+++ b/tools/testing/selftests/bpf/progs/preempt_lock.c
@@ -6,7 +6,7 @@
 #include "bpf_experimental.h"
 
 SEC("?tc")
-__failure __msg("BPF_EXIT instruction cannot be used inside bpf_preempt_disable-ed region")
+__failure __msg("BPF_EXIT instruction in main prog cannot be used inside bpf_preempt_disable-ed region")
 int preempt_lock_missing_1(struct __sk_buff *ctx)
 {
        bpf_preempt_disable();
@@ -14,7 +14,7 @@ int preempt_lock_missing_1(struct __sk_buff *ctx)
 }
 
 SEC("?tc")
-__failure __msg("BPF_EXIT instruction cannot be used inside bpf_preempt_disable-ed region")
+__failure __msg("BPF_EXIT instruction in main prog cannot be used inside bpf_preempt_disable-ed region")
 int preempt_lock_missing_2(struct __sk_buff *ctx)
 {
        bpf_preempt_disable();
@@ -23,7 +23,7 @@ int preempt_lock_missing_2(struct __sk_buff *ctx)
 }
 
 SEC("?tc")
-__failure __msg("BPF_EXIT instruction cannot be used inside bpf_preempt_disable-ed region")
+__failure __msg("BPF_EXIT instruction in main prog cannot be used inside bpf_preempt_disable-ed region")
 int preempt_lock_missing_3(struct __sk_buff *ctx)
 {
        bpf_preempt_disable();
@@ -33,7 +33,7 @@ int preempt_lock_missing_3(struct __sk_buff *ctx)
 }
 
 SEC("?tc")
-__failure __msg("BPF_EXIT instruction cannot be used inside bpf_preempt_disable-ed region")
+__failure __msg("BPF_EXIT instruction in main prog cannot be used inside bpf_preempt_disable-ed region")
 int preempt_lock_missing_3_minus_2(struct __sk_buff *ctx)
 {
        bpf_preempt_disable();
@@ -55,7 +55,7 @@ static __noinline void preempt_enable(void)
 }
 
 SEC("?tc")
-__failure __msg("BPF_EXIT instruction cannot be used inside bpf_preempt_disable-ed region")
+__failure __msg("BPF_EXIT instruction in main prog cannot be used inside bpf_preempt_disable-ed region")
 int preempt_lock_missing_1_subprog(struct __sk_buff *ctx)
 {
        preempt_disable();
@@ -63,7 +63,7 @@ int preempt_lock_missing_1_subprog(struct __sk_buff *ctx)
 }
 
 SEC("?tc")
-__failure __msg("BPF_EXIT instruction cannot be used inside bpf_preempt_disable-ed region")
+__failure __msg("BPF_EXIT instruction in main prog cannot be used inside bpf_preempt_disable-ed region")
 int preempt_lock_missing_2_subprog(struct __sk_buff *ctx)
 {
        preempt_disable();
@@ -72,7 +72,7 @@ int preempt_lock_missing_2_subprog(struct __sk_buff *ctx)
 }
 
 SEC("?tc")
-__failure __msg("BPF_EXIT instruction cannot be used inside bpf_preempt_disable-ed region")
+__failure __msg("BPF_EXIT instruction in main prog cannot be used inside bpf_preempt_disable-ed region")
 int preempt_lock_missing_2_minus_1_subprog(struct __sk_buff *ctx)
 {
        preempt_disable();

diff --git a/tools/testing/selftests/bpf/progs/verifier_spin_lock.c b/tools/testing/selftests/bpf/progs/verifier_spin_lock.c
index 3f679de73229f301c69f3b785ef4d267ce5408d5..25599eac9a7029fcce2df4a8e43f037482b56d6a 100644 (file)
--- a/tools/testing/selftests/bpf/progs/verifier_spin_lock.c
+++ b/tools/testing/selftests/bpf/progs/verifier_spin_lock.c
@@ -187,7 +187,7 @@ l0_%=:      r6 = r0;                                        \
 
 SEC("cgroup/skb")
 __description("spin_lock: test6 missing unlock")
-__failure __msg("BPF_EXIT instruction cannot be used inside bpf_spin_lock-ed region")
+__failure __msg("BPF_EXIT instruction in main prog cannot be used inside bpf_spin_lock-ed region")
 __failure_unpriv __msg_unpriv("")
 __naked void spin_lock_test6_missing_unlock(void)
 {