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2023-01-31container_of: Update header inclusionsAndy Shevchenko1-1/+1
The commit 848dba781f19 ("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>
2022-12-06container_of: add container_of_const() that preserves const-ness of the pointerGreg Kroah-Hartman1-0/+13
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>
2022-10-25linux/container_of.h: Warn about loss of constnessSakari Ailus1-0/+1
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>
2022-10-25container_of: remove container_of_safe()Greg Kroah-Hartman1-16/+0
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>
2021-11-09linux/container_of.h: switch to static_assertRasmus Villemoes1-6/+6
_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>
2021-11-09kernel.h: split out container_of() and typeof_member() macrosAndy Shevchenko1-0/+40
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>