bpf: Unify resource leak checks

There are similar checks for covering locks, references, RCU read
sections and preempt_disable sections in 3 places in the verifer, i.e.
for tail calls, bpf_ld_[abs, ind], and exit path (for BPF_EXIT and
bpf_throw). Unify all of these into a common check_resource_leak
function to avoid code duplication.

Also update the error strings in selftests to the new ones in the same
change to ensure clean bisection.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20241103225940.1408302-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

4 files changed, 12 insertions, 12 deletions

diff --git a/tools/testing/selftests/bpf/progs/exceptions_fail.c b/tools/testing/selftests/bpf/progs/exceptions_fail.c
index 9cceb6521143..fe0f3fa5aab6 100644
--- 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_rcu_read_unlock is missing")
+__failure __msg("BPF_EXIT instruction 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_rcu_read_unlock is missing")
+__failure __msg("BPF_EXIT instruction 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 672fc368d9c4..885377e83607 100644
--- 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("1 bpf_preempt_enable is missing")
+__failure __msg("BPF_EXIT instruction 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("2 bpf_preempt_enable(s) are missing")
+__failure __msg("BPF_EXIT instruction 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("3 bpf_preempt_enable(s) are missing")
+__failure __msg("BPF_EXIT instruction 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("1 bpf_preempt_enable is missing")
+__failure __msg("BPF_EXIT instruction 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("1 bpf_preempt_enable is missing")
+__failure __msg("BPF_EXIT instruction 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("2 bpf_preempt_enable(s) are missing")
+__failure __msg("BPF_EXIT instruction 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("1 bpf_preempt_enable is missing")
+__failure __msg("BPF_EXIT instruction 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_ref_tracking.c b/tools/testing/selftests/bpf/progs/verifier_ref_tracking.c
index c4c6da21265e..683a882b3e6d 100644
--- a/tools/testing/selftests/bpf/progs/verifier_ref_tracking.c
+++ b/tools/testing/selftests/bpf/progs/verifier_ref_tracking.c
@@ -791,7 +791,7 @@ l0_%=:	r0 = *(u8*)skb[0];				\
 
 SEC("tc")
 __description("reference tracking: forbid LD_ABS while holding reference")
-__failure __msg("BPF_LD_[ABS|IND] cannot be mixed with socket references")
+__failure __msg("BPF_LD_[ABS|IND] would lead to reference leak")
 __naked void ld_abs_while_holding_reference(void)
 {
 	asm volatile ("					\
@@ -836,7 +836,7 @@ l0_%=:	r7 = 1;						\
 
 SEC("tc")
 __description("reference tracking: forbid LD_IND while holding reference")
-__failure __msg("BPF_LD_[ABS|IND] cannot be mixed with socket references")
+__failure __msg("BPF_LD_[ABS|IND] would lead to reference leak")
 __naked void ld_ind_while_holding_reference(void)
 {
 	asm volatile ("					\
diff --git a/tools/testing/selftests/bpf/progs/verifier_spin_lock.c b/tools/testing/selftests/bpf/progs/verifier_spin_lock.c
index fb316c080c84..3f679de73229 100644
--- 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("unlock is missing")
+__failure __msg("BPF_EXIT instruction cannot be used inside bpf_spin_lock-ed region")
 __failure_unpriv __msg_unpriv("")
 __naked void spin_lock_test6_missing_unlock(void)
 {