Merge tag 'probes-v6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes updates from Masami Hiramatsu:
 "fprobe performance enhancement using rhltable:
   - use rhltable for fprobe_ip_table. The fprobe IP table has been
     converted to use an rhltable for improved performance when dealing
     with a large number of probed functions
   - Fix a suspicious RCU usage warning of the above change in the
     fprobe entry handler
   - Remove an unused local variable of the above change
   - Fix to initialize fprobe_ip_table in core_initcall()

  Performance optimization of fprobe by ftrace:
   - Use ftrace instead of fgraph for entry only probes. This avoids the
     unneeded overhead of fgraph stack setup
   - Also update fprobe selftest for entry-only probe
   - fprobe: Use ftrace only if CONFIG_DYNAMIC_FTRACE_WITH_ARGS or
     WITH_REGS is defined

  Cleanup probe event subsystems:
   - Allocate traceprobe_parse_context per probe instead of each probe
     argument parsing. This reduce memory allocation/free of temporary
     working memory
   - Cleanup code using __free()
   - Replace strcpy() with memcpy() in __trace_probe_log_err()"

* tag 'probes-v6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: fprobe: use ftrace if CONFIG_DYNAMIC_FTRACE_WITH_ARGS
  lib/test_fprobe: add testcase for mixed fprobe
  tracing: fprobe: optimization for entry only case
  tracing: fprobe: Fix to init fprobe_ip_table earlier
  tracing: fprobe: Remove unused local variable
  tracing: probes: Replace strcpy() with memcpy() in __trace_probe_log_err()
  tracing: fprobe: fix suspicious rcu usage in fprobe_entry
  tracing: uprobe: eprobes: Allocate traceprobe_parse_context per probe
  tracing: uprobes: Cleanup __trace_uprobe_create() with __free()
  tracing: eprobe: Cleanup eprobe event using __free()
  tracing: probes: Use __free() for trace_probe_log
  tracing: fprobe: use rhltable for fprobe_ip_table

1 files changed, 98 insertions, 1 deletions

diff --git a/lib/tests/test_fprobe.c b/lib/tests/test_fprobe.c
index cf92111b5c79..108c7aa33cb4 100644
--- a/lib/tests/test_fprobe.c
+++ b/lib/tests/test_fprobe.c
@@ -12,7 +12,8 @@
 
 static struct kunit *current_test;
 
-static u32 rand1, entry_val, exit_val;
+static u32 rand1, entry_only_val, entry_val, exit_val;
+static u32 entry_only_count, entry_count, exit_count;
 
 /* Use indirect calls to avoid inlining the target functions */
 static u32 (*target)(u32 value);
@@ -190,6 +191,101 @@ static void test_fprobe_skip(struct kunit *test)
 	KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp));
 }
 
+/* Handler for fprobe entry only case */
+static notrace int entry_only_handler(struct fprobe *fp, unsigned long ip,
+				      unsigned long ret_ip,
+				      struct ftrace_regs *fregs, void *data)
+{
+	KUNIT_EXPECT_FALSE(current_test, preemptible());
+	KUNIT_EXPECT_EQ(current_test, ip, target_ip);
+
+	entry_only_count++;
+	entry_only_val = (rand1 / div_factor);
+
+	return 0;
+}
+
+static notrace int fprobe_entry_multi_handler(struct fprobe *fp, unsigned long ip,
+					      unsigned long ret_ip,
+					      struct ftrace_regs *fregs,
+					      void *data)
+{
+	KUNIT_EXPECT_FALSE(current_test, preemptible());
+	KUNIT_EXPECT_EQ(current_test, ip, target_ip);
+
+	entry_count++;
+	entry_val = (rand1 / div_factor);
+
+	return 0;
+}
+
+static notrace void fprobe_exit_multi_handler(struct fprobe *fp, unsigned long ip,
+					      unsigned long ret_ip,
+					      struct ftrace_regs *fregs,
+					      void *data)
+{
+	unsigned long ret = ftrace_regs_get_return_value(fregs);
+
+	KUNIT_EXPECT_FALSE(current_test, preemptible());
+	KUNIT_EXPECT_EQ(current_test, ip, target_ip);
+	KUNIT_EXPECT_EQ(current_test, ret, (rand1 / div_factor));
+
+	exit_count++;
+	exit_val = ret;
+}
+
+static void check_fprobe_multi(struct kunit *test)
+{
+	entry_only_count = entry_count = exit_count = 0;
+	entry_only_val = entry_val = exit_val = 0;
+
+	target(rand1);
+
+	/* Verify all handlers were called */
+	KUNIT_EXPECT_EQ(test, 1, entry_only_count);
+	KUNIT_EXPECT_EQ(test, 1, entry_count);
+	KUNIT_EXPECT_EQ(test, 1, exit_count);
+
+	/* Verify values are correct */
+	KUNIT_EXPECT_EQ(test, (rand1 / div_factor), entry_only_val);
+	KUNIT_EXPECT_EQ(test, (rand1 / div_factor), entry_val);
+	KUNIT_EXPECT_EQ(test, (rand1 / div_factor), exit_val);
+}
+
+/* Test multiple fprobes hooking the same target function */
+static void test_fprobe_multi(struct kunit *test)
+{
+	struct fprobe fp1 = {
+		.entry_handler = fprobe_entry_multi_handler,
+		.exit_handler = fprobe_exit_multi_handler,
+	};
+	struct fprobe fp2 = {
+		.entry_handler = entry_only_handler,
+	};
+
+	current_test = test;
+
+	/* Test Case 1: Register in order 1 -> 2 */
+	KUNIT_EXPECT_EQ(test, 0, register_fprobe(&fp1, "fprobe_selftest_target", NULL));
+	KUNIT_EXPECT_EQ(test, 0, register_fprobe(&fp2, "fprobe_selftest_target", NULL));
+
+	check_fprobe_multi(test);
+
+	/* Unregister all */
+	KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp1));
+	KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp2));
+
+	/* Test Case 2: Register in order 2 -> 1 */
+	KUNIT_EXPECT_EQ(test, 0, register_fprobe(&fp2, "fprobe_selftest_target", NULL));
+	KUNIT_EXPECT_EQ(test, 0, register_fprobe(&fp1, "fprobe_selftest_target", NULL));
+
+	check_fprobe_multi(test);
+
+	/* Unregister all */
+	KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp1));
+	KUNIT_EXPECT_EQ(test, 0, unregister_fprobe(&fp2));
+}
+
 static unsigned long get_ftrace_location(void *func)
 {
 	unsigned long size, addr = (unsigned long)func;
@@ -217,6 +313,7 @@ static struct kunit_case fprobe_testcases[] = {
 	KUNIT_CASE(test_fprobe_syms),
 	KUNIT_CASE(test_fprobe_data),
 	KUNIT_CASE(test_fprobe_skip),
+	KUNIT_CASE(test_fprobe_multi),
 	{}
 };