net: remove newlines in NL_SET_ERR_MSG_MOD

The NL_SET_ERR_MSG_MOD macro is used to report a string describing an
error message to userspace via the netlink extended ACK structure. It
should not have a trailing newline.

Add a cocci script which catches cases where the newline marker is
present. Using this script, fix the handful of cases which accidentally
included a trailing new line.

I couldn't figure out a way to get a patch mode working, so this script
only implements context, report, and org.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 75 insertions, 0 deletions

diff --git a/scripts/coccinelle/misc/newline_in_nl_msg.cocci b/scripts/coccinelle/misc/newline_in_nl_msg.cocci
new file mode 100644
index 000000000000..c175886e4015
--- /dev/null
+++ b/scripts/coccinelle/misc/newline_in_nl_msg.cocci
@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: GPL-2.0-only
+///
+/// Catch strings ending in newline with GENL_SET_ERR_MSG, NL_SET_ERR_MSG,
+/// NL_SET_ERR_MSG_MOD.
+///
+// Confidence: Very High
+// Copyright: (C) 2020 Intel Corporation
+// URL: http://coccinelle.lip6.fr/
+// Options: --no-includes --include-headers
+
+virtual context
+virtual org
+virtual report
+
+@r depends on context || org || report@
+expression e;
+constant m;
+position p;
+@@
+  \(GENL_SET_ERR_MSG\|NL_SET_ERR_MSG\|NL_SET_ERR_MSG_MOD\)(e,m@p)
+
+@script:python@
+m << r.m;
+@@
+
+if not m.endswith("\\n\""):
+	cocci.include_match(False)
+
+@r1 depends on r@
+identifier fname;
+expression r.e;
+constant r.m;
+position r.p;
+@@
+  fname(e,m@p)
+
+//----------------------------------------------------------
+//  For context mode
+//----------------------------------------------------------
+
+@depends on context && r@
+identifier r1.fname;
+expression r.e;
+constant r.m;
+@@
+* fname(e,m)
+
+//----------------------------------------------------------
+//  For org mode
+//----------------------------------------------------------
+
+@script:python depends on org@
+fname << r1.fname;
+m << r.m;
+p << r.p;
+@@
+
+if m.endswith("\\n\""):
+	msg="WARNING avoid newline at end of message in %s" % (fname)
+	msg_safe=msg.replace("[","@(").replace("]",")")
+	coccilib.org.print_todo(p[0], msg_safe)
+
+//----------------------------------------------------------
+//  For report mode
+//----------------------------------------------------------
+
+@script:python depends on report@
+fname << r1.fname;
+m << r.m;
+p << r.p;
+@@
+
+if m.endswith("\\n\""):
+	msg="WARNING avoid newline at end of message in %s" % (fname)
+	coccilib.report.print_report(p[0], msg)