[for-linus][PATCH 0/3] tracing: Fixes to 5.16

[for-linus][PATCH 0/3] tracing: Fixes to 5.16

[Steven Rostedt]

Three tracing fixes:

 - Make local osnoise_instances static

 - Copy just actual size of histogram strings

 - Properly check missing operands in histogram expressions

  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
for-next

Head SHA1: 1cab6bce42e62bba2ff2c2370d139618c1828b42


Daniel Bristot de Oliveira (1):
      tracing/osnoise: Make osnoise_instances static

Kalesh Singh (1):
      tracing/histogram: Fix check for missing operands in an expression

Masami Hiramatsu (1):
      tracing/histogram: Do not copy the fixed-size char array field over the field size

----
 kernel/trace/trace_events_hist.c | 12 +++++++-----
 kernel/trace/trace_osnoise.c     |  3 ++-
 2 files changed, 9 insertions(+), 6 deletions(-)

[for-linus][PATCH 1/3] tracing/osnoise: Make osnoise_instances static

[Steven Rostedt]

From: Daniel Bristot de Oliveira <bristot@kernel.org>

Make the struct list_head osnoise_instances definition static.

Link: https://lore.kernel.org/all/202111120052.ZuikQSJi-lkp@intel.com/
Link: https://lkml.kernel.org/r/d001f0eeac66e2b2eeec7d2a15e9e7abede0453a.1636667971.git.bristot@kernel.org

Cc: Ingo Molnar <mingo@redhat.com>
Fixes: dae181349f1e ("tracing/osnoise: Support a list of trace_array *tr")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/trace/trace_osnoise.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index 3e4a1651e329..7520d43aed55 100644
--- a/kernel/trace/trace_osnoise.c
+++ b/kernel/trace/trace_osnoise.c
@@ -55,7 +55,8 @@ struct osnoise_instance {
 	struct list_head	list;
 	struct trace_array	*tr;
 };
-struct list_head osnoise_instances;
+
+static struct list_head osnoise_instances;
 
 static bool osnoise_has_registered_instances(void)
 {
-- 
2.33.0

[for-linus][PATCH 2/3] tracing/histogram: Do not copy the fixed-size char array field over the field size

[Steven Rostedt]

From: Masami Hiramatsu <mhiramat@kernel.org>

Do not copy the fixed-size char array field of the events over
the field size. The histogram treats char array as a string and
there are 2 types of char array in the event, fixed-size and
dynamic string. The dynamic string (__data_loc) field must be
null terminated, but the fixed-size char array field may not
be null terminated (not a string, but just a data).
In that case, histogram can copy the data after the field.
This uses the original field size for fixed-size char array
field to restrict the histogram not to access over the original
field size.

Link: https://lkml.kernel.org/r/163673292822.195747.3696966210526410250.stgit@devnote2

Fixes: 02205a6752f2 (tracing: Add support for 'field variables')
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/trace/trace_events_hist.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 8ff572a31fd3..6a9fa34e2785 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -1953,9 +1953,10 @@ static struct hist_field *create_hist_field(struct hist_trigger_data *hist_data,
 		if (!hist_field->type)
 			goto free;
 
-		if (field->filter_type == FILTER_STATIC_STRING)
+		if (field->filter_type == FILTER_STATIC_STRING) {
 			hist_field->fn = hist_field_string;
-		else if (field->filter_type == FILTER_DYN_STRING)
+			hist_field->size = field->size;
+		} else if (field->filter_type == FILTER_DYN_STRING)
 			hist_field->fn = hist_field_dynstring;
 		else
 			hist_field->fn = hist_field_pstring;
@@ -3025,7 +3026,7 @@ static inline void __update_field_vars(struct tracing_map_elt *elt,
 			char *str = elt_data->field_var_str[j++];
 			char *val_str = (char *)(uintptr_t)var_val;
 
-			strscpy(str, val_str, STR_VAR_LEN_MAX);
+			strscpy(str, val_str, val->size);
 			var_val = (u64)(uintptr_t)str;
 		}
 		tracing_map_set_var(elt, var_idx, var_val);
@@ -4920,7 +4921,7 @@ static void hist_trigger_elt_update(struct hist_trigger_data *hist_data,
 
 				str = elt_data->field_var_str[idx];
 				val_str = (char *)(uintptr_t)hist_val;
-				strscpy(str, val_str, STR_VAR_LEN_MAX);
+				strscpy(str, val_str, hist_field->size);
 
 				hist_val = (u64)(uintptr_t)str;
 			}
-- 
2.33.0

[for-linus][PATCH 3/3] tracing/histogram: Fix check for missing operands in an expression

[Steven Rostedt]

From: Kalesh Singh <kaleshsingh@google.com>

If a binary operation is detected while parsing an expression string,
the operand strings are deduced by splitting the experssion string at
the position of the detected binary operator. Both operand strings are
sub-strings (can be empty string) of the expression string but will
never be NULL.

Currently a NULL check is used for missing operands, fix this by
checking for empty strings instead.

Link: https://lkml.kernel.org/r/20211112191324.1302505-1-kaleshsingh@google.com

Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Fixes: 9710b2f341a0 ("tracing: Fix operator precedence for hist triggers expression")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
 kernel/trace/trace_events_hist.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 6a9fa34e2785..1475d7347fe0 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -2581,7 +2581,8 @@ static struct hist_field *parse_expr(struct hist_trigger_data *hist_data,
 	operand1_str = str;
 	str = sep+1;
 
-	if (!operand1_str || !str)
+	/* Binary operator requires both operands */
+	if (*operand1_str == '\0' || *str == '\0')
 		goto free;
 
 	operand_flags = 0;
-- 
2.33.0