Commit 50cff898 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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
parents 84d69848 c8990359
#!/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.
......
......@@ -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
......
......@@ -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)
...
......
///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)")
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