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authorKalesh Singh <kaleshsingh@google.com>2021-11-12 11:13:24 -0800
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2021-11-12 15:55:59 -0500
commit1cab6bce42e62bba2ff2c2370d139618c1828b42 (patch)
tree11476bdb7fd62f116e55dd67f92ea9c92bd9100e
parent63f84ae6b82bb4dff672f76f30c6fd7b9d3766bc (diff)
downloadwireless-drivers-1cab6bce42e62bba2ff2c2370d139618c1828b42.tar.gz
tracing/histogram: Fix check for missing operands in an expression
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>
-rw-r--r--kernel/trace/trace_events_hist.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 6a9fa34e2785cc..1475d7347fe0c1 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;