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bpf: Consolidate sleepable checks in check_func_call()

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The sleepable context check for global function calls in
check_func_call() open-codes the same checks that in_sleepable_context()
already performs. Replace the open-coded check with a call to
in_sleepable_context() and use non_sleepable_context_description() for
the error message, consistent with check_helper_call() and
check_kfunc_call().

Note that in_sleepable_context() also checks active_locks, which
overlaps with the existing active_locks check above it. However, the two
checks serve different purposes: the active_locks check rejects all
global function calls while holding a lock (not just sleepable ones), so
it must remain as a separate guard.

Update the expected error messages in the irq and preempt_lock selftests
to match.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20260318174327.3151925-4-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Puranjay Mohan 2026-03-18 10:43:26 -07:00 committed by Alexei Starovoitov
parent cd9840c413
commit a2542a91aa
3 changed files with 10 additions and 11 deletions
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11
kernel/bpf/verifier.c
View File

@ -210,6 +210,8 @@ static bool in_rbtree_lock_required_cb(struct bpf_verifier_env *env);
static int ref_set_non_owning(struct bpf_verifier_env *env,
struct bpf_reg_state *reg);
static bool is_trusted_reg(const struct bpf_reg_state *reg);
static inline bool in_sleepable_context(struct bpf_verifier_env *env);
static const char *non_sleepable_context_description(struct bpf_verifier_env *env);
static bool bpf_map_ptr_poisoned(const struct bpf_insn_aux_data *aux)
{
@ -10948,12 +10950,9 @@ static int check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
return -EINVAL;
}
if (env->subprog_info[subprog].might_sleep &&
(env->cur_state->active_rcu_locks || env->cur_state->active_preempt_locks ||
env->cur_state->active_irq_id || !in_sleepable(env))) {
verbose(env, "global functions that may sleep are not allowed in non-sleepable context,\n"
"i.e., in a RCU/IRQ/preempt-disabled section, or in\n"
"a non-sleepable BPF program context\n");
if (env->subprog_info[subprog].might_sleep && !in_sleepable_context(env)) {
verbose(env, "sleepable global function %s() called in %s\n",
sub_name, non_sleepable_context_description(env));
return -EINVAL;
}

4
tools/testing/selftests/bpf/progs/irq.c
View File

@ -490,7 +490,7 @@ int irq_non_sleepable_global_subprog(void *ctx)
}
SEC("?syscall")
__failure __msg("global functions that may sleep are not allowed in non-sleepable context")
__failure __msg("sleepable global function")
int irq_sleepable_helper_global_subprog(void *ctx)
{
unsigned long flags;
@ -502,7 +502,7 @@ int irq_sleepable_helper_global_subprog(void *ctx)
}
SEC("?syscall")
__failure __msg("global functions that may sleep are not allowed in non-sleepable context")
__failure __msg("sleepable global function")
int irq_sleepable_global_subprog_indirect(void *ctx)
{
unsigned long flags;

6
tools/testing/selftests/bpf/progs/preempt_lock.c
View File

@ -177,7 +177,7 @@ global_subprog_calling_sleepable_global(int i)
}
SEC("?syscall")
__failure __msg("global functions that may sleep are not allowed in non-sleepable context")
__failure __msg("sleepable global function")
int preempt_global_sleepable_helper_subprog(struct __sk_buff *ctx)
{
preempt_disable();
@ -188,7 +188,7 @@ int preempt_global_sleepable_helper_subprog(struct __sk_buff *ctx)
}
SEC("?syscall")
__failure __msg("global functions that may sleep are not allowed in non-sleepable context")
__failure __msg("sleepable global function")
int preempt_global_sleepable_kfunc_subprog(struct __sk_buff *ctx)
{
preempt_disable();
@ -199,7 +199,7 @@ int preempt_global_sleepable_kfunc_subprog(struct __sk_buff *ctx)
}
SEC("?syscall")
__failure __msg("global functions that may sleep are not allowed in non-sleepable context")
__failure __msg("sleepable global function")
int preempt_global_sleepable_subprog_indirect(struct __sk_buff *ctx)
{
preempt_disable();