Merge tag 'probes-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes updates from Masami Hiramatsu:
 "x86 kprobes:

   - Use boolean for some function return instead of 0 and 1

   - Prohibit probing on INT/UD. This prevents user to put kprobe on
     INTn/INT1/INT3/INTO and UD0/UD1/UD2 because these are used for a
     special purpose in the kernel

   - Boost Grp instructions. Because a few percent of kernel
     instructions are Grp 2/3/4/5 and those are safe to be executed
     without ip register fixup, allow those to be boosted (direct
     execution on the trampoline buffer with a JMP)

  tracing:

   - Add function argument access from return events (kretprobe and
     fprobe). This allows user to compare how a data structure field is
     changed after executing a function. With BTF, return event also
     accepts function argument access by name.

   - Fix a wrong comment (using "Kretprobe" in fprobe)

   - Cleanup a big probe argument parser function into three parts, type
     parser, post-processing function, and main parser

   - Cleanup to set nr_args field when initializing trace_probe instead
     of counting up it while parsing

   - Cleanup a redundant #else block from tracefs/README source code

   - Update selftests to check entry argument access from return probes

   - Documentation update about entry argument access from return
     probes"

* tag 'probes-v6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  Documentation: tracing: Add entry argument access at function exit
  selftests/ftrace: Add test cases for entry args at function exit
  tracing/probes: Support $argN in return probe (kprobe and fprobe)
  tracing: Remove redundant #else block for BTF args from README
  tracing/probes: cleanup: Set trace_probe::nr_args at trace_probe_init
  tracing/probes: Cleanup probe argument parser
  tracing/fprobe-event: cleanup: Fix a wrong comment in fprobe event
  x86/kprobes: Boost more instructions from grp2/3/4/5
  x86/kprobes: Prohibit kprobing on INT and UD
  x86/kprobes: Refactor can_{probe,boost} return type to bool

4 files changed, 42 insertions, 0 deletions

diff --git a/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_entry_arg.tc b/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_entry_arg.tc
new file mode 100644
index 000000000000..d183b8a8ecf8
--- /dev/null
+++ b/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_entry_arg.tc
@@ -0,0 +1,18 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# description: Function return probe entry argument access
+# requires: dynamic_events 'f[:[<group>/][<event>]] <func-name>':README 'kernel return probes support:':README
+
+echo 'f:tests/myevent1 vfs_open arg=$arg1' >> dynamic_events
+echo 'f:tests/myevent2 vfs_open%return arg=$arg1' >> dynamic_events
+
+echo 1 > events/tests/enable
+
+echo > trace
+cat trace > /dev/null
+
+function streq() {
+	test $1 = $2
+}
+
+streq `grep -A 1 -m 1 myevent1 trace | sed -r 's/^.*(arg=.*)/\1/' `
diff --git a/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_syntax_errors.tc b/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_syntax_errors.tc
index 20e42c030095..61877d166451 100644
--- a/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_syntax_errors.tc
+++ b/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_syntax_errors.tc
@@ -34,7 +34,9 @@ check_error 'f vfs_read ^$stack10000'	# BAD_STACK_NUM
 
 check_error 'f vfs_read ^$arg10000'	# BAD_ARG_NUM
 
+if !grep -q 'kernel return probes support:' README; then
 check_error 'f vfs_read $retval ^$arg1' # BAD_VAR
+fi
 check_error 'f vfs_read ^$none_var'	# BAD_VAR
 check_error 'f vfs_read ^'$REG		# BAD_VAR
 
@@ -99,7 +101,9 @@ if grep -q "<argname>" README; then
 check_error 'f vfs_read args=^$arg*'		# BAD_VAR_ARGS
 check_error 'f vfs_read +0(^$arg*)'		# BAD_VAR_ARGS
 check_error 'f vfs_read $arg* ^$arg*'		# DOUBLE_ARGS
+if !grep -q 'kernel return probes support:' README; then
 check_error 'f vfs_read%return ^$arg*'		# NOFENTRY_ARGS
+fi
 check_error 'f vfs_read ^hoge'			# NO_BTFARG
 check_error 'f kfree ^$arg10'			# NO_BTFARG (exceed the number of parameters)
 check_error 'f kfree%return ^$retval'		# NO_RETVAL
diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_syntax_errors.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_syntax_errors.tc
index 65fbb26fd58c..a16c6a6f6055 100644
--- a/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_syntax_errors.tc
+++ b/tools/testing/selftests/ftrace/test.d/kprobe/kprobe_syntax_errors.tc
@@ -108,7 +108,9 @@ if grep -q "<argname>" README; then
 check_error 'p vfs_read args=^$arg*'		# BAD_VAR_ARGS
 check_error 'p vfs_read +0(^$arg*)'		# BAD_VAR_ARGS
 check_error 'p vfs_read $arg* ^$arg*'		# DOUBLE_ARGS
+if !grep -q 'kernel return probes support:' README; then
 check_error 'r vfs_read ^$arg*'			# NOFENTRY_ARGS
+fi
 check_error 'p vfs_read+8 ^$arg*'		# NOFENTRY_ARGS
 check_error 'p vfs_read ^hoge'			# NO_BTFARG
 check_error 'p kfree ^$arg10'			# NO_BTFARG (exceed the number of parameters)
diff --git a/tools/testing/selftests/ftrace/test.d/kprobe/kretprobe_entry_arg.tc b/tools/testing/selftests/ftrace/test.d/kprobe/kretprobe_entry_arg.tc
new file mode 100644
index 000000000000..53b82f36a1d0
--- /dev/null
+++ b/tools/testing/selftests/ftrace/test.d/kprobe/kretprobe_entry_arg.tc
@@ -0,0 +1,18 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+# description: Kretprobe entry argument access
+# requires: kprobe_events 'kernel return probes support:':README
+
+echo 'p:myevent1 vfs_open arg=$arg1' >> kprobe_events
+echo 'r:myevent2 vfs_open arg=$arg1' >> kprobe_events
+
+echo 1 > events/kprobes/enable
+
+echo > trace
+cat trace > /dev/null
+
+function streq() {
+	test $1 = $2
+}
+
+streq `grep -A 1 -m 1 myevent1 trace | sed -r 's/^.*(arg=.*)/\1/' `