Update Linux to v5.10.109
Sourced from [1]
[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz
Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c
index 888cd00..a58da91 100644
--- a/kernel/trace/fgraph.c
+++ b/kernel/trace/fgraph.c
@@ -96,11 +96,34 @@
return 0;
}
+/*
+ * Not all archs define MCOUNT_INSN_SIZE which is used to look for direct
+ * functions. But those archs currently don't support direct functions
+ * anyway, and ftrace_find_rec_direct() is just a stub for them.
+ * Define MCOUNT_INSN_SIZE to keep those archs compiling.
+ */
+#ifndef MCOUNT_INSN_SIZE
+/* Make sure this only works without direct calls */
+# ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
+# error MCOUNT_INSN_SIZE not defined with direct calls enabled
+# endif
+# define MCOUNT_INSN_SIZE 0
+#endif
+
int function_graph_enter(unsigned long ret, unsigned long func,
unsigned long frame_pointer, unsigned long *retp)
{
struct ftrace_graph_ent trace;
+ /*
+ * Skip graph tracing if the return location is served by direct trampoline,
+ * since call sequence and return addresses is unpredicatable anymore.
+ * Ex: BPF trampoline may call original function and may skip frame
+ * depending on type of BPF programs attached.
+ */
+ if (ftrace_direct_func_count &&
+ ftrace_find_rec_direct(ret - MCOUNT_INSN_SIZE))
+ return -EBUSY;
trace.func = func;
trace.depth = ++current->curr_ret_depth;
@@ -332,9 +355,14 @@
return 0;
}
+/*
+ * Simply points to ftrace_stub, but with the proper protocol.
+ * Defined by the linker script in linux/vmlinux.lds.h
+ */
+extern void ftrace_stub_graph(struct ftrace_graph_ret *);
+
/* The callbacks that hook a function */
-trace_func_graph_ret_t ftrace_graph_return =
- (trace_func_graph_ret_t)ftrace_stub;
+trace_func_graph_ret_t ftrace_graph_return = ftrace_stub_graph;
trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub;
static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub;
@@ -359,8 +387,8 @@
}
}
- read_lock(&tasklist_lock);
- do_each_thread(g, t) {
+ rcu_read_lock();
+ for_each_process_thread(g, t) {
if (start == end) {
ret = -EAGAIN;
goto unlock;
@@ -374,10 +402,10 @@
smp_wmb();
t->ret_stack = ret_stack_list[start++];
}
- } while_each_thread(g, t);
+ }
unlock:
- read_unlock(&tasklist_lock);
+ rcu_read_unlock();
free:
for (i = start; i < end; i++)
kfree(ret_stack_list[i]);
@@ -612,7 +640,7 @@
goto out;
ftrace_graph_active--;
- ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
+ ftrace_graph_return = ftrace_stub_graph;
ftrace_graph_entry = ftrace_graph_entry_stub;
__ftrace_graph_entry = ftrace_graph_entry_stub;
ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET);