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6 Коммитов

Автор SHA1 Сообщение Дата
Andy Shevchenko 2b8e353376 container_of: Update header inclusions
The commit 848dba781f ("container_of: remove container_of_safe()")
removed the code that uses err.h. Replace the inclusion by stddef.h
which provides offsetof() definition which is still in use.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230130111746.59830-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-31 12:44:20 +01:00
Greg Kroah-Hartman 64f6a5d192 container_of: add container_of_const() that preserves const-ness of the pointer
container_of does not preserve the const-ness of a pointer that is
passed into it, which can cause C code that passes in a const pointer to
get a pointer back that is not const and then scribble all over the data
in it.  To prevent this, container_of_const() will preserve the const
status of the pointer passed into it using the newly available _Generic()
method.

Suggested-by: Jason Gunthorpe <jgg@ziepe.ca>
Suggested-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20221205121206.166576-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-12-06 16:55:18 +01:00
Sakari Ailus 7376e561fd linux/container_of.h: Warn about loss of constness
container_of() casts the original type to another which leads to the loss
of the const qualifier if it is not specified in the caller-provided type.
This easily leads to container_of() returning a non-const pointer to a
const struct which the C compiler does not warn about.

Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Link: https://lore.kernel.org/r/20221024111627.75183-1-sakari.ailus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-25 10:28:15 +02:00
Greg Kroah-Hartman 848dba781f container_of: remove container_of_safe()
It came in from a staging driver that has been long removed from the
tree, and there are no in-kernel users of the macro, and it's very
dubious if anyone should ever use this thing, so just remove it
entirely.

Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20221024123933.3331116-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-10-25 10:27:54 +02:00
Rasmus Villemoes e1edc277e6 linux/container_of.h: switch to static_assert
_Static_assert() is evaluated already in the compiler's frontend, and
gives a somehat more to-the-point error, compared to the BUILD_BUG_ON
macro, which only fires after the optimizer has had a chance to
eliminate calls to functions marked with __attribute__((error)).  In
theory, this might make builds a tiny bit faster.

There's also a little less gunk in the error message emitted:

  lib/sort.c: In function `foo':
  include/linux/build_bug.h:78:41: error: static assertion failed: "pointer type mismatch in container_of()"
     78 | #define __static_assert(expr, msg, ...) _Static_assert(expr, msg)

compared to

  lib/sort.c: In function `foo':
  include/linux/compiler_types.h:322:38: error: call to `__compiletime_assert_2' declared with attribute error: pointer type mismatch in container_of()
    322 |  _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)

While at it, fix the copy-pasto in container_of_safe().

Link: https://lkml.kernel.org/r/20211015090530.2774079-1-linux@rasmusvillemoes.dk
Link: https://lore.kernel.org/lkml/20211014132331.GA4811@kernel.org/T/
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-09 10:02:49 -08:00
Andy Shevchenko d2a8ebbf81 kernel.h: split out container_of() and typeof_member() macros
kernel.h is being used as a dump for all kinds of stuff for a long time.
Here is the attempt cleaning it up by splitting out container_of() and
typeof_member() macros.

For time being include new header back to kernel.h to avoid twisted
indirected includes for existing users.

Note, there are _a lot_ of headers and modules that include kernel.h
solely for one of these macros and this allows to unburden compiler for
the twisted inclusion paths and to make new code cleaner in the future.

Link: https://lkml.kernel.org/r/20211013170417.87909-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Brendan Higgins <brendanhiggins@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Sakari Ailus <sakari.ailus@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thorsten Leemhuis <regressions@leemhuis.info>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-11-09 10:02:49 -08:00