Merge tag 'trace-v6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull more tracing updates from Steven Rostedt:

 - Make buffer_percent read/write.

   The buffer_percent file is how users can state how long to block on
   the tracing buffer depending on how much is in the buffer. When it
   hits the "buffer_percent" it will wake the task waiting on the
   buffer. For some reason it was set to read-only.

   This was not noticed because testing was done as root without
   SELinux, but with SELinux it will prevent even root to write to it
   without having CAP_DAC_OVERRIDE.

 - The "touched_functions" was added this merge window, but one of the
   reasons for adding it was not implemented.

   That was to show what functions were not only touched, but had either
   a direct trampoline attached to it, or a kprobe or live kernel
   patching that can "hijack" the function to run a different function.
   The point is to know if there's functions in the kernel that may not
   be behaving as the kernel code shows. This can be used for debugging.

   TODO: Add this information to kernel oops too.

* tag 'trace-v6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ftrace: Add MODIFIED flag to show if IPMODIFY or direct was attached
  tracing: Fix permissions for the buffer_percent file

1 files changed, 3 insertions, 1 deletions

diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h
index 6954e4ed5bbf..b23bdd414394 100644
--- a/include/linux/ftrace.h
+++ b/include/linux/ftrace.h
@@ -549,6 +549,7 @@ bool is_ftrace_trampoline(unsigned long addr);
  *  CALL_OPS - the record can use callsite-specific ops
  *  CALL_OPS_EN - the function is set up to use callsite-specific ops
  *  TOUCHED  - A callback was added since boot up
+ *  MODIFIED - The function had IPMODIFY or DIRECT attached to it
  *
  * When a new ftrace_ops is registered and wants a function to save
  * pt_regs, the rec->flags REGS is set. When the function has been
@@ -569,9 +570,10 @@ enum {
 	FTRACE_FL_CALL_OPS	= (1UL << 22),
 	FTRACE_FL_CALL_OPS_EN	= (1UL << 21),
 	FTRACE_FL_TOUCHED	= (1UL << 20),
+	FTRACE_FL_MODIFIED	= (1UL << 19),
 };
 
-#define FTRACE_REF_MAX_SHIFT	20
+#define FTRACE_REF_MAX_SHIFT	19
 #define FTRACE_REF_MAX		((1UL << FTRACE_REF_MAX_SHIFT) - 1)
 
 #define ftrace_rec_count(rec)	((rec)->flags & FTRACE_REF_MAX)