From: Tom Zanussi <zanussi@kernel.org>
Date: Sun, 4 Oct 2020 17:14:03 -0500
Subject: tracing: Change STR_VAR_MAX_LEN
Git-commit: 4a4a56b4e76bbe3211c4f93d99c0c1543f5f3230
Patch-mainline: v5.10-rc1
References: git-fixes

32 is too small for this value, and anyway it makes more sense to use
MAX_FILTER_STR_VAL, as this is also the value used for variable-length
__strings.

Link: https://lkml.kernel.org/r/6adfd1668ac1fd8670bd58206944a762061a5559.1601848695.git.zanussi@kernel.org

Tested-by: Axel Rasmussen <axelrasmussen@google.com>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Miroslav Benes <mbenes@suse.cz>
---
 kernel/trace/trace_events_hist.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -20,7 +20,7 @@
 #define SYNTH_SYSTEM		"synthetic"
 #define SYNTH_FIELDS_MAX	16
 
-#define STR_VAR_LEN_MAX		32 /* must be multiple of sizeof(u64) */
+#define STR_VAR_LEN_MAX		MAX_FILTER_STR_VAL /* must be multiple of sizeof(u64) */
 
 #define ERRORS								\
 	C(NONE,			"No error"),				\
@@ -2259,6 +2259,8 @@ static int hist_trigger_elt_data_alloc(s
 
 	n_str = hist_data->n_field_var_str + hist_data->n_save_var_str;
 
+	BUILD_BUG_ON(STR_VAR_LEN_MAX & (sizeof(u64) - 1));
+
 	size = STR_VAR_LEN_MAX;
 
 	for (i = 0; i < n_str; i++) {