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authorLinus Torvalds <torvalds@linux-foundation.org>2016-10-14 15:03:08 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-10-14 15:03:08 -0700
commit50cff89837a43a7c62ac080de9742a298d6418b3 (patch)
tree28e12a9565ec81ac7bac6d433de0e2d05e6dade5
parent84d69848c97faab0c25aa2667b273404d2e2a64a (diff)
parentc8990359d4b12f14656386526ddf904635076902 (diff)
downloadlinux-sh-50cff89837a43a7c62ac080de9742a298d6418b3.tar.gz
Merge branch 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull misc kbuild changes from Michal Marek: "Just a few patches on the kbuild.git#misc branch this time: - New Coccinelle patch by Nicholas Mc Guire - Existing patch fixes by Julia Lawall - Minor comment fix by Markus Elfring" * 'misc' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: Coccinelle: flag conditions with no effect scripts/coccicheck: Update reference for the corresponding documentation Coccinelle: pm_runtime: ensure relevance of pm_runtime reports Coccinelle: limit memdup_user transformation to GFP_KERNEL case
-rwxr-xr-xscripts/coccicheck2
-rw-r--r--scripts/coccinelle/api/memdup_user.cocci8
-rw-r--r--scripts/coccinelle/api/pm_runtime.cocci18
-rw-r--r--scripts/coccinelle/misc/cond_no_effect.cocci64
4 files changed, 80 insertions, 12 deletions
diff --git a/scripts/coccicheck b/scripts/coccicheck
index c92c1528a54d..ec487b8e7051 100755
--- a/scripts/coccicheck
+++ b/scripts/coccicheck
@@ -1,7 +1,7 @@
#!/bin/bash
# Linux kernel coccicheck
#
-# Read Documentation/coccinelle.txt
+# Read Documentation/dev-tools/coccinelle.rst
#
# This script requires at least spatch
# version 1.0.0-rc11.
diff --git a/scripts/coccinelle/api/memdup_user.cocci b/scripts/coccinelle/api/memdup_user.cocci
index c606231b0e46..2a5aea8e8487 100644
--- a/scripts/coccinelle/api/memdup_user.cocci
+++ b/scripts/coccinelle/api/memdup_user.cocci
@@ -15,11 +15,11 @@ virtual org
virtual report
@depends on patch@
-expression from,to,size,flag;
+expression from,to,size;
identifier l1,l2;
@@
-- to = \(kmalloc\|kzalloc\)(size,flag);
+- to = \(kmalloc\|kzalloc\)(size,GFP_KERNEL);
+ to = memdup_user(from,size);
if (
- to==NULL
@@ -37,12 +37,12 @@ identifier l1,l2;
- }
@r depends on !patch@
-expression from,to,size,flag;
+expression from,to,size;
position p;
statement S1,S2;
@@
-* to = \(kmalloc@p\|kzalloc@p\)(size,flag);
+* to = \(kmalloc@p\|kzalloc@p\)(size,GFP_KERNEL);
if (to==NULL || ...) S1
if (copy_from_user(to, from, size) != 0)
S2
diff --git a/scripts/coccinelle/api/pm_runtime.cocci b/scripts/coccinelle/api/pm_runtime.cocci
index 89b98a2f7a6f..d67ccf5f8227 100644
--- a/scripts/coccinelle/api/pm_runtime.cocci
+++ b/scripts/coccinelle/api/pm_runtime.cocci
@@ -17,9 +17,10 @@ virtual report
@runtime_bad_err_handle exists@
expression ret;
+position p;
@@
(
-ret = \(pm_runtime_idle\|
+ret@p = \(pm_runtime_idle\|
pm_runtime_suspend\|
pm_runtime_autosuspend\|
pm_runtime_resume\|
@@ -47,12 +48,13 @@ IS_ERR_VALUE(ret)
// For context mode
//----------------------------------------------------------
-@depends on runtime_bad_err_handle && context@
+@depends on context@
identifier pm_runtime_api;
expression ret;
+position runtime_bad_err_handle.p;
@@
(
-ret = pm_runtime_api(...);
+ret@p = pm_runtime_api(...);
...
* IS_ERR_VALUE(ret)
...
@@ -62,12 +64,13 @@ ret = pm_runtime_api(...);
// For patch mode
//----------------------------------------------------------
-@depends on runtime_bad_err_handle && patch@
+@depends on patch@
identifier pm_runtime_api;
expression ret;
+position runtime_bad_err_handle.p;
@@
(
-ret = pm_runtime_api(...);
+ret@p = pm_runtime_api(...);
...
- IS_ERR_VALUE(ret)
+ ret < 0
@@ -78,13 +81,14 @@ ret = pm_runtime_api(...);
// For org and report mode
//----------------------------------------------------------
-@r depends on runtime_bad_err_handle && (org || report) exists@
+@r depends on (org || report) exists@
position p1, p2;
identifier pm_runtime_api;
expression ret;
+position runtime_bad_err_handle.p;
@@
(
-ret = pm_runtime_api@p1(...);
+ret@p = pm_runtime_api@p1(...);
...
IS_ERR_VALUE@p2(ret)
...
diff --git a/scripts/coccinelle/misc/cond_no_effect.cocci b/scripts/coccinelle/misc/cond_no_effect.cocci
new file mode 100644
index 000000000000..8467dbd1c465
--- /dev/null
+++ b/scripts/coccinelle/misc/cond_no_effect.cocci
@@ -0,0 +1,64 @@
+///Find conditions where if and else branch are functionally
+// identical.
+//
+// There can be false positives in cases where the positional
+// information is used (as with lockdep) or where the identity
+// is a placeholder for not yet handled cases.
+// Unfortunately there also seems to be a tendency to use
+// the last if else/else as a "default behavior" - which some
+// might consider a legitimate coding pattern. From discussion
+// on kernelnewbies though it seems that this is not really an
+// accepted pattern and if at all it would need to be commented
+//
+// In the Linux kernel it does not seem to actually report
+// false positives except for those that were documented as
+// being intentional.
+// the two known cases are:
+// arch/sh/kernel/traps_64.c:read_opcode()
+// } else if ((pc & 1) == 0) {
+// /* SHcompact */
+// /* TODO : provide handling for this. We don't really support
+// user-mode SHcompact yet, and for a kernel fault, this would
+// have to come from a module built for SHcompact. */
+// return -EFAULT;
+// } else {
+// /* misaligned */
+// return -EFAULT;
+// }
+// fs/kernfs/file.c:kernfs_fop_open()
+// * Both paths of the branch look the same. They're supposed to
+// * look that way and give @of->mutex different static lockdep keys.
+// */
+// if (has_mmap)
+// mutex_init(&of->mutex);
+// else
+// mutex_init(&of->mutex);
+//
+// All other cases look like bugs or at least lack of documentation
+//
+// Confidence: Moderate
+// Copyright: (C) 2016 Nicholas Mc Guire, OSADL. GPLv2.
+// Comments:
+// Options: --no-includes --include-headers
+
+virtual org
+virtual report
+
+@cond@
+statement S1;
+position p;
+@@
+
+* if@p (...) S1 else S1
+
+@script:python depends on org@
+p << cond.p;
+@@
+
+cocci.print_main("WARNING: possible condition with no effect (if == else)",p)
+
+@script:python depends on report@
+p << cond.p;
+@@
+
+coccilib.report.print_report(p[0],"WARNING: possible condition with no effect (if == else)")