FAILED: patch "[PATCH] tracing: Add the bucket size to expr_field_str()" failed to apply to 6.6-stable tree

FAILED: patch "[PATCH] tracing: Add the bucket size to expr_field_str()" failed to apply to 6.6-stable tree

[gregkh]

The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x c027ed03bc03a0e82fc368eaad657584a4480c7a
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026102834-proximity-conjoined-4fdf@gregkh' --subject-prefix 'PATCH 6.6.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From c027ed03bc03a0e82fc368eaad657584a4480c7a Mon Sep 17 00:00:00 2001
From: Donggeun Yoo <donggeunyoo.kernel@gmail.com>
Date: Mon, 14 Sep 2026 14:34:41 +0900
Subject: [PATCH] tracing: Add the bucket size to expr_field_str()

expr_field_str() renders a HIST_FIELD_FL_BUCKET field as "pid.buckets",
dropping the count, and parse_field() rejects that spelling.

get_hist_field_flags() returns the bare string "buckets" and keeps the
count in hist_field->buckets. hist_field_print() appends it,
expr_field_str() never did. Nothing reaches it today, since .buckets is
refused on a value and no expression can carry one, but the next patch
renders histogram keys with expr_field_str(), where a .buckets key is
legal.

Append the count, as hist_field_print() does.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260914053443.981201-3-donggeunyoo.kernel@gmail.com
Fixes: de9a48a360b7 ("tracing: Add linear buckets to histogram logic")
Signed-off-by: Donggeun Yoo <donggeunyoo.kernel@gmail.com>
Assisted-by: Claude:claude-fable-5
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index a3eae5c1344a..91a550411e8a 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -1754,6 +1754,9 @@ static bool expr_field_str(struct hist_field *field, struct seq_buf *s)
 			seq_buf_printf(s, ".%s", flags_str);
 	}
 
+	if (field->buckets)
+		seq_buf_printf(s, "=%lu", field->buckets);
+
 	return !seq_buf_has_overflowed(s);
 }