Checkpatch.pl doesn't have a check for excluding while (...) {...} blocks
from MULTISTATEMENT_MACRO_USE_DO_WHILE error.
For example, running checkpatch.pl on the file mm/maccess.c in the kernel
generates the following error:
ERROR: Macros with complex values should be enclosed in parentheses
+#define copy_from_kernel_nofault_loop(dst, src, len, type, err_label) \
+ while (len >= sizeof(type)) { \
+ __get_kernel_nofault(dst, src, type, err_label); \
+ dst += sizeof(type); \
+ src += sizeof(type); \
+ len -= sizeof(type); \
+ }
The error is misleading for this case. Enclosing it in parentheses
doesn't make any sense.
Checkpatch already has an exception list for such common macro types.
Added a new exception for while (...) {...} style blocks to the same.
In addition, the brace flatten logic was modified by changing the
substitution characters from "1" to "1u". This was done to ensure that
macros in the form "#define foo(bar) while(bar){bar--;}" were also
correctly procecssed.
Link: https://lore.kernel.org/linux-kernel-mentees/dc985938aa3986702815a0bd68dfca8a03c85447.camel@perches.com/
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/20201001171903.312021-1-dwaipayanray1@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Embedding the complete filename path inside the file isn't particularly
useful as often the path is moved around and becomes incorrect.
Emit a warning when the source contains the filename.
[akpm@linux-foundation.org: remove stray " di"]
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/1fd5f9188a14acdca703ca00301ee323de672a8d.camel@perches.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Checkpatch did not handle cases where the author From: header was split
into multiple lines. The author identity could not be resolved and
checkpatch generated a false NO_AUTHOR_SIGN_OFF warning.
A typical example is commit e33bcbab16 ("tee: add support for session's
client UUID generation"). When checkpatch was run on this commit, it
displayed:
"WARNING:NO_AUTHOR_SIGN_OFF: Missing Signed-off-by: line by nominal
patch author ''"
This was due to split header lines not being handled properly and the
author himself wrote in commit cd2614967d ("checkpatch: warn if missing
author Signed-off-by"):
"Split From: headers are not fully handled: only the first part
is compared."
Support split From: headers by correctly parsing the header extension
lines. RFC 5322, Section-2.2.3 stated that each extended line must start
with a WSP character (a space or htab). The solution was therefore to
concatenate the lines which start with a WSP to get the correct long
header.
Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Dwaipayan Ray <dwaipayanray1@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Reviewed-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Link: https://lore.kernel.org/linux-kernel-mentees/f5d8124e54a50480b0a9fa638787bc29b6e09854.camel@perches.com/
Link: https://lkml.kernel.org/r/20200921085436.63003-1-dwaipayanray1@gmail.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The uninitialized_var() macro was removed recently via commit 63a0895d96
("compiler: Remove uninitialized_var() macro") as it's not a particularly
useful warning and its use can "paper over real bugs".
Add a checkpatch test to warn on self-assignments as a means to avoid
compiler warnings and as a back-door mechanism to reproduce the old
uninitialized_var macro behavior.
[akpm@linux-foundation.org: coding style fixes]
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Gustavo A. R. Silva <gustavoars@kernel.org>
Cc: Denis Efremov <efremov@linux.com>
Cc: Julia Lawall <julia.lawall@inria.fr>
Link: https://lkml.kernel.org/r/afc2cffdd315d3e4394af149278df9e8af7f49f4.camel@perches.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
trace_printk is meant as a debugging tool, and should not be compiled into
production code without specific debug Kconfig options enabled, or source
code changes, as indicated by the warning that shows up on boot if any
trace_printk is called:
** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **
** **
** trace_printk() being used. Allocating extra memory. **
** **
** This means that this is a DEBUG kernel and it is **
** unsafe for production use. **
Let's warn developers when they try to submit such a change.
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Joe Perches <joe@perches.com>
Link: https://lkml.kernel.org/r/20200825193600.v2.1.I723c43c155f02f726c97501be77984f1e6bb740a@changeid
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There are commas used as statement terminations that should typically have
used semicolons instead. Only direct assignments or use of a single
function or value on a single line are detected by this test.
e.g.:
foo = bar(), /* typical use is semicolon not comma */
bar = baz();
Add an imperfect test to detect these comma uses.
No false positives were found in testing, but many types of false
negatives are possible.
e.g.:
foo = bar() + 1, /* comma use, but not direct assignment */
bar = baz();
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.kernel.org/r/3bf27caf462007dfa75647b040ab3191374a59de.camel@perches.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Kconfig allows to customize the CONFIG_ prefix via the $CONFIG_
environment variable. Out-of-tree projects may therefore use Kconfig with
a different prefix, or they may use a custom configuration tool which does
not use the CONFIG_ prefix at all. Such projects may still want to adhere
to the Linux kernel coding style and run checkpatch.pl.
One example is OP-TEE [1] which does not use Kconfig but does have
configuration options prefixed with CFG_. It also mostly follows the
kernel coding style and therefore being able to use checkpatch is quite
valuable.
To make this possible, add the --kconfig-prefix command line option.
[1] https://github.com/OP-TEE/optee_os
Signed-off-by: Jerome Forissier <jerome@forissier.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Joe Perches <joe@perches.com>
Link: http://lkml.kernel.org/r/20200818081732.800449-1-jerome@forissier.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
list_for_each_entry_safe() guarantees that we will never stumble over the
list head; "&page->lru != list" will always evaluate to true. Let's
simplify.
[david@redhat.com: Changelog refinements]
Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Link: http://lkml.kernel.org/r/20200818084448.33969-1-richard.weiyang@linux.alibaba.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If we fail to decompress in zram it's a pretty serious problem. We were
entrusted to be able to decompress the old data but we failed. Either
we've got some crazy bug in the compression code or we've got memory
corruption.
At the moment, when this happens the log looks like this:
ERR kernel: [ 1833.099861] zram: Decompression failed! err=-22, page=336112
ERR kernel: [ 1833.099881] zram: Decompression failed! err=-22, page=336112
ALERT kernel: [ 1833.099886] Read-error on swap-device (253:0:2688896)
It is true that we have an "ALERT" level log in there, but (at least to
me) it feels like even this isn't enough to impart the seriousness of this
error. Let's convert to a WARN_ON. Note that WARN_ON is automatically
"unlikely" so we can simply replace the old annotation with the new one.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Sonny Rao <sonnyrao@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Link: https://lkml.kernel.org/r/20200917174059.1.If09c882545dbe432268f7a67a4d4cfcb6caace4f@changeid
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__free_pages_core() is used when exposing fresh memory to the buddy during
system boot and when onlining memory in generic_online_page().
generic_online_page() is used in two cases:
1. Direct memory onlining in online_pages().
2. Deferred memory onlining in memory-ballooning-like mechanisms (HyperV
balloon and virtio-mem), when parts of a section are kept
fake-offline to be fake-onlined later on.
In 1, we already place pages to the tail of the freelist. Pages will be
freed to MIGRATE_ISOLATE lists first and moved to the tail of the
freelists via undo_isolate_page_range().
In 2, we currently don't implement a proper rule. In case of virtio-mem,
where we currently always online MAX_ORDER - 1 pages, the pages will be
placed to the HEAD of the freelist - undesireable. While the hyper-v
balloon calls generic_online_page() with single pages, usually it will
call it on successive single pages in a larger block.
The pages are fresh, so place them to the tail of the freelist and avoid
the PCP. In __free_pages_core(), remove the now superflouos call to
set_page_refcounted() and add a comment regarding page initialization and
the refcount.
Note: In 2. we currently don't shuffle. If ever relevant (page shuffling
is usually of limited use in virtualized environments), we might want to
shuffle after a sequence of generic_online_page() calls in the relevant
callers.
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Scott Cheloha <cheloha@linux.ibm.com>
Link: https://lkml.kernel.org/r/20201005121534.15649-5-david@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
