From mboxrd@z Thu Jan 1 00:00:00 1970 From: nicstange@gmail.com (Nicolai Stange) Date: Tue, 23 Feb 2016 14:56:32 +0100 Subject: [Cocci] [PATCH v4 4/8] debugfs, coccinelle: check for obsolete DEFINE_SIMPLE_ATTRIBUTE() usage In-Reply-To: <8737sjo7qa.fsf@gmail.com> (Nicolai Stange's message of "Tue, 23 Feb 2016 14:51:25 +0100") References: <8737sjo7qa.fsf@gmail.com> Message-ID: <87io1fmsxb.fsf@gmail.com> To: cocci@systeme.lip6.fr List-Id: cocci@systeme.lip6.fr In order to protect against file removal races, debugfs files created via debugfs_create_file() now get wrapped by a struct file_operations at their opening. If the original struct file_operations are known to be safe against removal races by themselves already, the proxy creation may be bypassed by creating the files through debugfs_create_file_unsafe(). In order to help debugfs users who use the common DEFINE_SIMPLE_ATTRIBUTE() + debugfs_create_file() idiom to transition to removal safe struct file_operations, the helper macro DEFINE_DEBUGFS_ATTRIBUTE() has been introduced. Thus, the preferred strategy is to use DEFINE_DEBUGFS_ATTRIBUTE() + debugfs_create_file_unsafe() now. Introduce a Coccinelle script that searches for DEFINE_SIMPLE_ATTRIBUTE()-defined struct file_operations handed into debugfs_create_file(). Suggest to turn these usages into the DEFINE_DEBUGFS_ATTRIBUTE() + debugfs_create_file_unsafe() pattern. Signed-off-by: Nicolai Stange --- .../api/debugfs/debugfs_simple_attr.cocci | 67 ++++++++++++++++++++++ 1 file changed, 67 insertions(+) create mode 100644 scripts/coccinelle/api/debugfs/debugfs_simple_attr.cocci diff --git a/scripts/coccinelle/api/debugfs/debugfs_simple_attr.cocci b/scripts/coccinelle/api/debugfs/debugfs_simple_attr.cocci new file mode 100644 index 0000000..85cf540 --- /dev/null +++ b/scripts/coccinelle/api/debugfs/debugfs_simple_attr.cocci @@ -0,0 +1,67 @@ +/// Use DEFINE_DEBUGFS_ATTRIBUTE rather than DEFINE_SIMPLE_ATTRIBUTE +/// for debugfs files. +/// +//# Rationale: DEFINE_SIMPLE_ATTRIBUTE + debugfs_create_file() +//# imposes some significant overhead as compared to +//# DEFINE_DEBUGFS_ATTRIBUTE + debugfs_create_file_unsafe(). +// +// Copyright (C): 2016 Nicolai Stange +// Options: --no-includes +// + +virtual context +virtual patch +virtual org +virtual report + + at dsa@ +declarer name DEFINE_SIMPLE_ATTRIBUTE; +identifier dsa_fops; +expression dsa_get, dsa_set, dsa_fmt; +position p; +@@ +DEFINE_SIMPLE_ATTRIBUTE at p(dsa_fops, dsa_get, dsa_set, dsa_fmt); + + at dcf@ +expression name, mode, parent, data; +identifier dsa.dsa_fops; +@@ +debugfs_create_file(name, mode, parent, data, &dsa_fops) + + + at context_dsa depends on context && dcf@ +declarer name DEFINE_DEBUGFS_ATTRIBUTE; +identifier dsa.dsa_fops; +expression dsa.dsa_get, dsa.dsa_set, dsa.dsa_fmt; +@@ +* DEFINE_SIMPLE_ATTRIBUTE(dsa_fops, dsa_get, dsa_set, dsa_fmt); + + + at patch_dcf depends on patch expression@ +expression name, mode, parent, data; +identifier dsa.dsa_fops; +@@ +- debugfs_create_file(name, mode, parent, data, &dsa_fops) ++ debugfs_create_file_unsafe(name, mode, parent, data, &dsa_fops) + + at patch_dsa depends on patch_dcf && patch@ +identifier dsa.dsa_fops; +expression dsa.dsa_get, dsa.dsa_set, dsa.dsa_fmt; +@@ +- DEFINE_SIMPLE_ATTRIBUTE(dsa_fops, dsa_get, dsa_set, dsa_fmt); ++ DEFINE_DEBUGFS_ATTRIBUTE(dsa_fops, dsa_get, dsa_set, dsa_fmt); + + + at script:python depends on org && dcf@ +fops << dsa.dsa_fops; +p << dsa.p; +@@ +msg="%s should be defined with DEFINE_DEBUGFS_ATTRIBUTE" % (fops) +coccilib.org.print_todo(p[0], msg) + +@script:python depends on report && dcf@ +fops << dsa.dsa_fops; +p << dsa.p; +@@ +msg="WARNING: %s should be defined with DEFINE_DEBUGFS_ATTRIBUTE" % (fops) +coccilib.report.print_report(p[0], msg) -- 2.7.1