From ebfdc40969f24fc0cdd1349835d36e8ebae05374 Mon Sep 17 00:00:00 2001 From: Joe Perches Date: Wed, 6 Aug 2014 16:10:27 -0700 Subject: [PATCH] checkpatch: attempt to find unnecessary 'out of memory' messages Logging messages that show some type of "out of memory" error are generally unnecessary as there is a generic message and a stack dump done by the memory subsystem. These messages generally increase kernel size without much added value. Emit a warning on these types of messages. This test looks for any inserted message function, then looks at the previous line for an "if (!foo)" or "if (foo == NULL)" test and then looks at the preceding statement for an allocation function like "foo = kmalloc()" ie: this code matches: foo = kmalloc(); if (foo == NULL) { printk("Out of memory\n"); return -ENOMEM; } This test is very crude and incomplete. This test can miss quite a lot of of OOM messages that do not have this specific form. ie: this code does not match: foo = kmalloc(); if (!foo) { rtn = -ENOMEM; printk("Out of memory!\n"); goto out; } This test could also be a false positive when the logging message itself does not specify anything about memory, but I did not find any false positives in my limited testing. spatch could be a better solution but correctness seems non-trivial for that tool too. Signed-off-by: Joe Perches Acked-by: Dan Carpenter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-format-patch failed