2024-06-05 18:09:23

by Steven Rostedt

Subject: [PATCH v2 4/5] ftrace: Convert "inc" parameter to bool in ftrace_hash_rec_update_modify()

From: "Steven Rostedt (Google)" <[email protected]>

The parameter "inc" in the function ftrace_hash_rec_update_modify() is
boolean. Change it to be such.

Also add documentation to what the function does.

Signed-off-by: Steven Rostedt (Google) <[email protected]>
---
kernel/trace/ftrace.c | 23 ++++++++++++++++++++---
1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 1a2444199740..83f23f8fc26d 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -1882,7 +1882,24 @@ static bool ftrace_hash_rec_enable(struct ftrace_ops *ops)
return __ftrace_hash_rec_update(ops, true);
}

-static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops, int inc)
+/*
+ * This function will update what functions @ops traces when its filter
+ * changes.
+ *
+ * The @inc states if the @ops callbacks are going to be added or removed.
+ * When one of the @ops hashes are updated to a "new_hash" the dyn_ftrace
+ * records are update via:
+ *
+ * ftrace_hash_rec_disable_modify(ops);
+ * ops->hash = new_hash
+ * ftrace_hash_rec_enable_modify(ops);
+ *
+ * Where the @ops is removed from all the records it is tracing using
+ * its old hash. The @ops hash is updated to the new hash, and then
+ * the @ops is added back to the records so that it is tracing all
+ * the new functions.
+ */
+static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops, bool inc)
{
struct ftrace_ops *op;

@@ -1906,12 +1923,12 @@ static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops, int inc)

static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops)
{
- ftrace_hash_rec_update_modify(ops, 0);
+ ftrace_hash_rec_update_modify(ops, false);
}

static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops)
{
- ftrace_hash_rec_update_modify(ops, 1);
+ ftrace_hash_rec_update_modify(ops, true);
}

/*
--
2.43.0

2024-06-06 17:56:03

by Mark Rutland

Subject: Re: [PATCH v2 4/5] ftrace: Convert "inc" parameter to bool in ftrace_hash_rec_update_modify()

On Wed, Jun 05, 2024 at 02:03:38PM -0400, Steven Rostedt wrote:
> From: "Steven Rostedt (Google)" <[email protected]>
>
> The parameter "inc" in the function ftrace_hash_rec_update_modify() is
> boolean. Change it to be such.
>
> Also add documentation to what the function does.
>
> Signed-off-by: Steven Rostedt (Google) <[email protected]>

Acked-by: Mark Rutland <[email protected]>

Mark.

> ---
> kernel/trace/ftrace.c | 23 ++++++++++++++++++++---
> 1 file changed, 20 insertions(+), 3 deletions(-)
>
> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> index 1a2444199740..83f23f8fc26d 100644
> --- a/kernel/trace/ftrace.c
> +++ b/kernel/trace/ftrace.c
> @@ -1882,7 +1882,24 @@ static bool ftrace_hash_rec_enable(struct ftrace_ops *ops)
> return __ftrace_hash_rec_update(ops, true);
> }
>
> -static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops, int inc)
> +/*
> + * This function will update what functions @ops traces when its filter
> + * changes.
> + *
> + * The @inc states if the @ops callbacks are going to be added or removed.
> + * When one of the @ops hashes are updated to a "new_hash" the dyn_ftrace
> + * records are update via:
> + *
> + * ftrace_hash_rec_disable_modify(ops);
> + * ops->hash = new_hash
> + * ftrace_hash_rec_enable_modify(ops);
> + *
> + * Where the @ops is removed from all the records it is tracing using
> + * its old hash. The @ops hash is updated to the new hash, and then
> + * the @ops is added back to the records so that it is tracing all
> + * the new functions.
> + */
> +static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops, bool inc)
> {
> struct ftrace_ops *op;
>
> @@ -1906,12 +1923,12 @@ static void ftrace_hash_rec_update_modify(struct ftrace_ops *ops, int inc)
>
> static void ftrace_hash_rec_disable_modify(struct ftrace_ops *ops)
> {
> - ftrace_hash_rec_update_modify(ops, 0);
> + ftrace_hash_rec_update_modify(ops, false);
> }
>
> static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops)
> {
> - ftrace_hash_rec_update_modify(ops, 1);
> + ftrace_hash_rec_update_modify(ops, true);
> }
>
> /*
> --
> 2.43.0
>
>