Update Linux to v5.4.148
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.4.148.tar.gz
Change-Id: Ib3d26c5ba9b022e2e03533005c4fed4d7c30b61b
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index 73956ea..5d87b21 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -53,6 +53,12 @@
struct tracepoint_func probes[0];
};
+/* Called in removal of a func but failed to allocate a new tp_funcs */
+static void tp_stub_func(void)
+{
+ return;
+}
+
static inline void *allocate_probes(int count)
{
struct tp_probes *p = kmalloc(struct_size(p, probes, count),
@@ -131,6 +137,7 @@
{
struct tracepoint_func *old, *new;
int nr_probes = 0;
+ int stub_funcs = 0;
int pos = -1;
if (WARN_ON(!tp_func->func))
@@ -147,14 +154,34 @@
if (old[nr_probes].func == tp_func->func &&
old[nr_probes].data == tp_func->data)
return ERR_PTR(-EEXIST);
+ if (old[nr_probes].func == tp_stub_func)
+ stub_funcs++;
}
}
- /* + 2 : one for new probe, one for NULL func */
- new = allocate_probes(nr_probes + 2);
+ /* + 2 : one for new probe, one for NULL func - stub functions */
+ new = allocate_probes(nr_probes + 2 - stub_funcs);
if (new == NULL)
return ERR_PTR(-ENOMEM);
if (old) {
- if (pos < 0) {
+ if (stub_funcs) {
+ /* Need to copy one at a time to remove stubs */
+ int probes = 0;
+
+ pos = -1;
+ for (nr_probes = 0; old[nr_probes].func; nr_probes++) {
+ if (old[nr_probes].func == tp_stub_func)
+ continue;
+ if (pos < 0 && old[nr_probes].prio < prio)
+ pos = probes++;
+ new[probes++] = old[nr_probes];
+ }
+ nr_probes = probes;
+ if (pos < 0)
+ pos = probes;
+ else
+ nr_probes--; /* Account for insertion */
+
+ } else if (pos < 0) {
pos = nr_probes;
memcpy(new, old, nr_probes * sizeof(struct tracepoint_func));
} else {
@@ -188,8 +215,9 @@
/* (N -> M), (N > 1, M >= 0) probes */
if (tp_func->func) {
for (nr_probes = 0; old[nr_probes].func; nr_probes++) {
- if (old[nr_probes].func == tp_func->func &&
- old[nr_probes].data == tp_func->data)
+ if ((old[nr_probes].func == tp_func->func &&
+ old[nr_probes].data == tp_func->data) ||
+ old[nr_probes].func == tp_stub_func)
nr_del++;
}
}
@@ -208,14 +236,32 @@
/* N -> M, (N > 1, M > 0) */
/* + 1 for NULL */
new = allocate_probes(nr_probes - nr_del + 1);
- if (new == NULL)
- return ERR_PTR(-ENOMEM);
- for (i = 0; old[i].func; i++)
- if (old[i].func != tp_func->func
- || old[i].data != tp_func->data)
- new[j++] = old[i];
- new[nr_probes - nr_del].func = NULL;
- *funcs = new;
+ if (new) {
+ for (i = 0; old[i].func; i++)
+ if ((old[i].func != tp_func->func
+ || old[i].data != tp_func->data)
+ && old[i].func != tp_stub_func)
+ new[j++] = old[i];
+ new[nr_probes - nr_del].func = NULL;
+ *funcs = new;
+ } else {
+ /*
+ * Failed to allocate, replace the old function
+ * with calls to tp_stub_func.
+ */
+ for (i = 0; old[i].func; i++)
+ if (old[i].func == tp_func->func &&
+ old[i].data == tp_func->data) {
+ old[i].func = tp_stub_func;
+ /* Set the prio to the next event. */
+ if (old[i + 1].func)
+ old[i].prio =
+ old[i + 1].prio;
+ else
+ old[i].prio = -1;
+ }
+ *funcs = old;
+ }
}
debug_print_probes(*funcs);
return old;
@@ -225,7 +271,8 @@
* Add the probe function to a tracepoint.
*/
static int tracepoint_add_func(struct tracepoint *tp,
- struct tracepoint_func *func, int prio)
+ struct tracepoint_func *func, int prio,
+ bool warn)
{
struct tracepoint_func *old, *tp_funcs;
int ret;
@@ -240,7 +287,7 @@
lockdep_is_held(&tracepoints_mutex));
old = func_add(&tp_funcs, func, prio);
if (IS_ERR(old)) {
- WARN_ON_ONCE(PTR_ERR(old) != -ENOMEM);
+ WARN_ON_ONCE(warn && PTR_ERR(old) != -ENOMEM);
return PTR_ERR(old);
}
@@ -271,10 +318,12 @@
tp_funcs = rcu_dereference_protected(tp->funcs,
lockdep_is_held(&tracepoints_mutex));
old = func_remove(&tp_funcs, func);
- if (IS_ERR(old)) {
- WARN_ON_ONCE(PTR_ERR(old) != -ENOMEM);
+ if (WARN_ON_ONCE(IS_ERR(old)))
return PTR_ERR(old);
- }
+
+ if (tp_funcs == old)
+ /* Failed allocating new tp_funcs, replaced func with stub */
+ return 0;
if (!tp_funcs) {
/* Removed last function */
@@ -290,6 +339,32 @@
}
/**
+ * tracepoint_probe_register_prio_may_exist - Connect a probe to a tracepoint with priority
+ * @tp: tracepoint
+ * @probe: probe handler
+ * @data: tracepoint data
+ * @prio: priority of this function over other registered functions
+ *
+ * Same as tracepoint_probe_register_prio() except that it will not warn
+ * if the tracepoint is already registered.
+ */
+int tracepoint_probe_register_prio_may_exist(struct tracepoint *tp, void *probe,
+ void *data, int prio)
+{
+ struct tracepoint_func tp_func;
+ int ret;
+
+ mutex_lock(&tracepoints_mutex);
+ tp_func.func = probe;
+ tp_func.data = data;
+ tp_func.prio = prio;
+ ret = tracepoint_add_func(tp, &tp_func, prio, false);
+ mutex_unlock(&tracepoints_mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(tracepoint_probe_register_prio_may_exist);
+
+/**
* tracepoint_probe_register_prio - Connect a probe to a tracepoint with priority
* @tp: tracepoint
* @probe: probe handler
@@ -312,7 +387,7 @@
tp_func.func = probe;
tp_func.data = data;
tp_func.prio = prio;
- ret = tracepoint_add_func(tp, &tp_func, prio);
+ ret = tracepoint_add_func(tp, &tp_func, prio, true);
mutex_unlock(&tracepoints_mutex);
return ret;
}