diff options
| author | Steven Rostedt (Google) <rostedt@goodmis.org> | 2023-05-02 21:32:33 -0400 |
|---|---|---|
| committer | Steven Rostedt (Google) <rostedt@goodmis.org> | 2023-05-05 11:09:25 -0400 |
| commit | 6ce2c04fcbcaa5eb086e5142ab359be306cbc3e1 (patch) | |
| tree | e404fa564374277c40bff95682f3477de87fbae9 /include | |
| parent | 4f94559f40ad06d627c0fdfc3319cec778a2845b (diff) | |
ftrace: Add MODIFIED flag to show if IPMODIFY or direct was attached
If a function had ever had IPMODIFY or DIRECT attached to it, where this
is how live kernel patching and BPF overrides work, mark them and display
an "M" in the enabled_functions and touched_functions files. This can be
used for debugging. If a function had been modified and later there's a bug
in the code related to that function, this can be used to know if the cause
is possibly from a live kernel patch or a BPF program that changed the
behavior of the code.
Also update the documentation on the enabled_functions and
touched_functions output, as it was missing direct callers and CALL_OPS.
And include this new modify attribute.
Link: https://lore.kernel.org/linux-trace-kernel/20230502213233.004e3ae4@gandalf.local.home
Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/ftrace.h | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 327046f1278d..7dffd740e784 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) |