checkpatch: add warning on BUG/BUG_ON use

[firefly-linux-kernel-4.4.55.git] / scripts / checkpatch.pl

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index d5c8e9a3a73cfc1450b7c698e10aa9848a01dad2..1629e3513f0d13aec1b510511f1434bb3cfe60d9 100755 (executable)
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2317,9 +2317,11 @@ sub process {
                }
 
 # Check for git id commit length and improperly formed commit descriptions
-               if ($in_commit_log && $line =~ /\b(c)ommit\s+([0-9a-f]{5,})/i) {
-                       my $init_char = $1;
-                       my $orig_commit = lc($2);
+               if ($in_commit_log &&
+                   ($line =~ /\bcommit\s+[0-9a-f]{5,}\b/i ||
+                    $line =~ /\b[0-9a-f]{12,40}\b/i)) {
+                       my $init_char = "c";
+                       my $orig_commit = "";
                        my $short = 1;
                        my $long = 0;
                        my $case = 1;
@@ -2330,6 +2332,13 @@ sub process {
                        my $orig_desc = "commit description";
                        my $description = "";
 
+                       if ($line =~ /\b(c)ommit\s+([0-9a-f]{5,})\b/i) {
+                               $init_char = $1;
+                               $orig_commit = lc($2);
+                       } elsif ($line =~ /\b([0-9a-f]{12,40})\b/i) {
+                               $orig_commit = lc($1);
+                       }
+
                        $short = 0 if ($line =~ /\bcommit\s+[0-9a-f]{12,40}/i);
                        $long = 1 if ($line =~ /\bcommit\s+[0-9a-f]{41,}/i);
                        $space = 0 if ($line =~ /\bcommit [0-9a-f]/i);
@@ -3439,13 +3448,15 @@ sub process {
                        }
                }
 
-# # no BUG() or BUG_ON()
-#              if ($line =~ /\b(BUG|BUG_ON)\b/) {
-#                      print "Try to use WARN_ON & Recovery code rather than BUG() or BUG_ON()\n";
-#                      print "$herecurr";
-#                      $clean = 0;
-#              }
+# avoid BUG() or BUG_ON()
+               if ($line =~ /\b(?:BUG|BUG_ON)\b/) {
+                       my $msg_type = \&WARN;
+                       $msg_type = \&CHK if ($file);
+                       &{$msg_type}("AVOID_BUG",
+                                    "Avoid crashing the kernel - try using WARN_ON & recovery code rather than BUG() or BUG_ON()\n" . $herecurr);
+               }
 
+# avoid LINUX_VERSION_CODE
                if ($line =~ /\bLINUX_VERSION_CODE\b/) {
                        WARN("LINUX_VERSION_CODE",
                             "LINUX_VERSION_CODE should be avoided, code should be for the version to which it is merged\n" . $herecurr);
@@ -5011,6 +5022,7 @@ sub process {
                                     "memory barrier without comment\n" . $herecurr);
                        }
                }
+
 # check for waitqueue_active without a comment.
                if ($line =~ /\bwaitqueue_active\s*\(/) {
                        if (!ctx_has_comment($first_line, $linenr)) {
@@ -5018,6 +5030,24 @@ sub process {
                                     "waitqueue_active without comment\n" . $herecurr);
                        }
                }
+
+# Check for expedited grace periods that interrupt non-idle non-nohz
+# online CPUs.  These expedited can therefore degrade real-time response
+# if used carelessly, and should be avoided where not absolutely
+# needed.  It is always OK to use synchronize_rcu_expedited() and
+# synchronize_sched_expedited() at boot time (before real-time applications
+# start) and in error situations where real-time response is compromised in
+# any case.  Note that synchronize_srcu_expedited() does -not- interrupt
+# other CPUs, so don't warn on uses of synchronize_srcu_expedited().
+# Of course, nothing comes for free, and srcu_read_lock() and
+# srcu_read_unlock() do contain full memory barriers in payment for
+# synchronize_srcu_expedited() non-interruption properties.
+               if ($line =~ /\b(synchronize_rcu_expedited|synchronize_sched_expedited)\(/) {
+                       WARN("EXPEDITED_RCU_GRACE_PERIOD",
+                            "expedited RCU grace periods should be avoided where they can degrade real-time response\n" . $herecurr);
+
+               }
+
 # check of hardware specific defines
                if ($line =~ m@^.\s*\#\s*if.*\b(__i386__|__powerpc64__|__sun__|__s390x__)\b@ && $realfile !~ m@include/asm-@) {
                        CHK("ARCH_DEFINES",