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Diffstat (limited to 'kernel/bpf/trampoline.c')
-rw-r--r--kernel/bpf/trampoline.c84
1 files changed, 60 insertions, 24 deletions
diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c
index d382f5ebe06c..c4b1a98ff726 100644
--- a/kernel/bpf/trampoline.c
+++ b/kernel/bpf/trampoline.c
@@ -115,10 +115,14 @@ bool bpf_prog_has_trampoline(const struct bpf_prog *prog)
(ptype == BPF_PROG_TYPE_LSM && eatype == BPF_LSM_MAC);
}
-void bpf_image_ksym_add(void *data, unsigned int size, struct bpf_ksym *ksym)
+void bpf_image_ksym_init(void *data, unsigned int size, struct bpf_ksym *ksym)
{
ksym->start = (unsigned long) data;
ksym->end = ksym->start + size;
+}
+
+void bpf_image_ksym_add(struct bpf_ksym *ksym)
+{
bpf_ksym_add(ksym);
perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_BPF, ksym->start,
PAGE_SIZE, false, ksym->name);
@@ -333,7 +337,7 @@ static void bpf_tramp_image_put(struct bpf_tramp_image *im)
int err = bpf_arch_text_poke(im->ip_after_call, BPF_MOD_JUMP,
NULL, im->ip_epilogue);
WARN_ON(err);
- if (IS_ENABLED(CONFIG_PREEMPTION))
+ if (IS_ENABLED(CONFIG_TASKS_RCU))
call_rcu_tasks(&im->rcu, __bpf_tramp_image_put_rcu_tasks);
else
percpu_ref_kill(&im->pcref);
@@ -377,7 +381,8 @@ static struct bpf_tramp_image *bpf_tramp_image_alloc(u64 key, int size)
ksym = &im->ksym;
INIT_LIST_HEAD_RCU(&ksym->lnode);
snprintf(ksym->name, KSYM_NAME_LEN, "bpf_trampoline_%llu", key);
- bpf_image_ksym_add(image, size, ksym);
+ bpf_image_ksym_init(image, size, ksym);
+ bpf_image_ksym_add(ksym);
return im;
out_free_image:
@@ -456,7 +461,9 @@ again:
if (err < 0)
goto out_free;
- arch_protect_bpf_trampoline(im->image, im->size);
+ err = arch_protect_bpf_trampoline(im->image, im->size);
+ if (err)
+ goto out_free;
WARN_ON(tr->cur_image && total == 0);
if (tr->cur_image)
@@ -521,7 +528,27 @@ static enum bpf_tramp_prog_type bpf_attach_type_to_tramp(struct bpf_prog *prog)
}
}
-static int __bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr)
+static int bpf_freplace_check_tgt_prog(struct bpf_prog *tgt_prog)
+{
+ struct bpf_prog_aux *aux = tgt_prog->aux;
+
+ guard(mutex)(&aux->ext_mutex);
+ if (aux->prog_array_member_cnt)
+ /* Program extensions can not extend target prog when the target
+ * prog has been updated to any prog_array map as tail callee.
+ * It's to prevent a potential infinite loop like:
+ * tgt prog entry -> tgt prog subprog -> freplace prog entry
+ * --tailcall-> tgt prog entry.
+ */
+ return -EBUSY;
+
+ aux->is_extended = true;
+ return 0;
+}
+
+static int __bpf_trampoline_link_prog(struct bpf_tramp_link *link,
+ struct bpf_trampoline *tr,
+ struct bpf_prog *tgt_prog)
{
enum bpf_tramp_prog_type kind;
struct bpf_tramp_link *link_exiting;
@@ -542,6 +569,9 @@ static int __bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_tr
/* Cannot attach extension if fentry/fexit are in use. */
if (cnt)
return -EBUSY;
+ err = bpf_freplace_check_tgt_prog(tgt_prog);
+ if (err)
+ return err;
tr->extension_prog = link->link.prog;
return bpf_arch_text_poke(tr->func.addr, BPF_MOD_JUMP, NULL,
link->link.prog->bpf_func);
@@ -568,17 +598,21 @@ static int __bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_tr
return err;
}
-int bpf_trampoline_link_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr)
+int bpf_trampoline_link_prog(struct bpf_tramp_link *link,
+ struct bpf_trampoline *tr,
+ struct bpf_prog *tgt_prog)
{
int err;
mutex_lock(&tr->mutex);
- err = __bpf_trampoline_link_prog(link, tr);
+ err = __bpf_trampoline_link_prog(link, tr, tgt_prog);
mutex_unlock(&tr->mutex);
return err;
}
-static int __bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr)
+static int __bpf_trampoline_unlink_prog(struct bpf_tramp_link *link,
+ struct bpf_trampoline *tr,
+ struct bpf_prog *tgt_prog)
{
enum bpf_tramp_prog_type kind;
int err;
@@ -589,6 +623,8 @@ static int __bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, struct bpf_
err = bpf_arch_text_poke(tr->func.addr, BPF_MOD_JUMP,
tr->extension_prog->bpf_func, NULL);
tr->extension_prog = NULL;
+ guard(mutex)(&tgt_prog->aux->ext_mutex);
+ tgt_prog->aux->is_extended = false;
return err;
}
hlist_del_init(&link->tramp_hlist);
@@ -597,12 +633,14 @@ static int __bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, struct bpf_
}
/* bpf_trampoline_unlink_prog() should never fail. */
-int bpf_trampoline_unlink_prog(struct bpf_tramp_link *link, struct bpf_trampoline *tr)
+int bpf_trampoline_unlink_prog(struct bpf_tramp_link *link,
+ struct bpf_trampoline *tr,
+ struct bpf_prog *tgt_prog)
{
int err;
mutex_lock(&tr->mutex);
- err = __bpf_trampoline_unlink_prog(link, tr);
+ err = __bpf_trampoline_unlink_prog(link, tr, tgt_prog);
mutex_unlock(&tr->mutex);
return err;
}
@@ -617,7 +655,7 @@ static void bpf_shim_tramp_link_release(struct bpf_link *link)
if (!shim_link->trampoline)
return;
- WARN_ON_ONCE(bpf_trampoline_unlink_prog(&shim_link->link, shim_link->trampoline));
+ WARN_ON_ONCE(bpf_trampoline_unlink_prog(&shim_link->link, shim_link->trampoline, NULL));
bpf_trampoline_put(shim_link->trampoline);
}
@@ -731,7 +769,7 @@ int bpf_trampoline_link_cgroup_shim(struct bpf_prog *prog,
goto err;
}
- err = __bpf_trampoline_link_prog(&shim_link->link, tr);
+ err = __bpf_trampoline_link_prog(&shim_link->link, tr, NULL);
if (err)
goto err;
@@ -866,6 +904,8 @@ static u64 notrace __bpf_prog_enter_recur(struct bpf_prog *prog, struct bpf_tram
if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) {
bpf_prog_inc_misses_counter(prog);
+ if (prog->aux->recursion_detected)
+ prog->aux->recursion_detected(prog);
return 0;
}
return bpf_prog_start_time();
@@ -883,12 +923,13 @@ static void notrace update_prog_stats(struct bpf_prog *prog,
* Hence check that 'start' is valid.
*/
start > NO_START_TIME) {
+ u64 duration = sched_clock() - start;
unsigned long flags;
stats = this_cpu_ptr(prog->stats);
flags = u64_stats_update_begin_irqsave(&stats->syncp);
u64_stats_inc(&stats->cnt);
- u64_stats_add(&stats->nsecs, sched_clock() - start);
+ u64_stats_add(&stats->nsecs, duration);
u64_stats_update_end_irqrestore(&stats->syncp, flags);
}
}
@@ -941,6 +982,8 @@ u64 notrace __bpf_prog_enter_sleepable_recur(struct bpf_prog *prog,
if (unlikely(this_cpu_inc_return(*(prog->active)) != 1)) {
bpf_prog_inc_misses_counter(prog);
+ if (prog->aux->recursion_detected)
+ prog->aux->recursion_detected(prog);
return 0;
}
return bpf_prog_start_time();
@@ -1014,7 +1057,7 @@ void notrace __bpf_tramp_exit(struct bpf_tramp_image *tr)
bpf_trampoline_enter_t bpf_trampoline_enter(const struct bpf_prog *prog)
{
- bool sleepable = prog->aux->sleepable;
+ bool sleepable = prog->sleepable;
if (bpf_prog_check_recur(prog))
return sleepable ? __bpf_prog_enter_sleepable_recur :
@@ -1029,7 +1072,7 @@ bpf_trampoline_enter_t bpf_trampoline_enter(const struct bpf_prog *prog)
bpf_trampoline_exit_t bpf_trampoline_exit(const struct bpf_prog *prog)
{
- bool sleepable = prog->aux->sleepable;
+ bool sleepable = prog->sleepable;
if (bpf_prog_check_recur(prog))
return sleepable ? __bpf_prog_exit_sleepable_recur :
@@ -1072,17 +1115,10 @@ void __weak arch_free_bpf_trampoline(void *image, unsigned int size)
bpf_jit_free_exec(image);
}
-void __weak arch_protect_bpf_trampoline(void *image, unsigned int size)
-{
- WARN_ON_ONCE(size > PAGE_SIZE);
- set_memory_rox((long)image, 1);
-}
-
-void __weak arch_unprotect_bpf_trampoline(void *image, unsigned int size)
+int __weak arch_protect_bpf_trampoline(void *image, unsigned int size)
{
WARN_ON_ONCE(size > PAGE_SIZE);
- set_memory_nx((long)image, 1);
- set_memory_rw((long)image, 1);
+ return set_memory_rox((long)image, 1);
}
int __weak arch_bpf_trampoline_size(const struct btf_func_model *m, u32 flags,
generated by cgit (git 2.34.1) at 2025-07-25 18:28:10 +0000