| Message ID | 20211007154407.29746-3-andriy.shevchenko@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | kernel.h further split | expand |
On Thu, Oct 7, 2021 at 5:44 PM Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote: > > +#define typeof_member(T, m) typeof(((T*)0)->m) Is the patch missing the removal from the other place? Cheers, Miguel
On Thu, Oct 07, 2021 at 05:54:32PM +0200, Miguel Ojeda wrote: > On Thu, Oct 7, 2021 at 5:44 PM Andy Shevchenko > <andriy.shevchenko@linux.intel.com> wrote: > > > > +#define typeof_member(T, m) typeof(((T*)0)->m) > > Is the patch missing the removal from the other place? Possibly, but I leave it for now for builders to place with the series and people having chance to comment. Thanks for review! Maybe Andrew can fix this when applying?
On Thu, 2021-10-07 at 18:44 +0300, Andy Shevchenko wrote: > 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. IMO: this new file is missing 2 #include directives. > diff --git a/include/linux/container_of.h b/include/linux/container_of.h [] > @@ -0,0 +1,37 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ And trivially: I'd prefer GPL-2.0-only > +#ifndef _LINUX_CONTAINER_OF_H > +#define _LINUX_CONTAINER_OF_H > + > +#define typeof_member(T, m) typeof(((T*)0)->m) > + > +/** > + * container_of - cast a member of a structure out to the containing structure > + * @ptr: the pointer to the member. > + * @type: the type of the container struct this is embedded in. > + * @member: the name of the member within the struct. > + * > + */ > +#define container_of(ptr, type, member) ({ \ > + void *__mptr = (void *)(ptr); \ > + BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \ > + !__same_type(*(ptr), void), \ > + "pointer type mismatch in container_of()"); \ This is not a self-contained header as it requires #include <linux/build_bug.h> which should be at the top of this file. > + ((type *)(__mptr - offsetof(type, member))); }) > + > +/** > + * container_of_safe - cast a member of a structure out to the containing structure > + * @ptr: the pointer to the member. > + * @type: the type of the container struct this is embedded in. > + * @member: the name of the member within the struct. > + * > + * If IS_ERR_OR_NULL(ptr), ptr is returned unchanged. > + */ > +#define container_of_safe(ptr, type, member) ({ \ > + void *__mptr = (void *)(ptr); \ > + BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \ > + !__same_type(*(ptr), void), \ > + "pointer type mismatch in container_of()"); \ > + IS_ERR_OR_NULL(__mptr) ? ERR_CAST(__mptr) : \ > + ((type *)(__mptr - offsetof(type, member))); }) And this requires #include <linux/err.h> > + > +#endif /* _LINUX_CONTAINER_OF_H */
On Thu, Oct 07, 2021 at 09:27:38AM -0700, Joe Perches wrote: > On Thu, 2021-10-07 at 18:44 +0300, Andy Shevchenko wrote: > > 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. > > IMO: this new file is missing 2 #include directives. Thanks, Joe, I'll address this in v5.
From: Joe Perches > Sent: 07 October 2021 17:28 ... > IMO: this new file is missing 2 #include directives. ... > This is not a self-contained header as it requires > #include <linux/build_bug.h> > which should be at the top of this file. ... > And this requires > > #include <linux/err.h> And I bet the biggest problem is the time spent by the compiler searching down the -I path for headers. If you count system calls during a build I suspect that failed opens of .h files dominate. To see how much this really costs try running a build with a (traditional) NFS mounted source tree - where every directory name in a filename requires an NFS file handle lookup. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
diff --git a/include/linux/container_of.h b/include/linux/container_of.h new file mode 100644 index 000000000000..f6ee1be0e784 --- /dev/null +++ b/include/linux/container_of.h @@ -0,0 +1,37 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _LINUX_CONTAINER_OF_H +#define _LINUX_CONTAINER_OF_H + +#define typeof_member(T, m) typeof(((T*)0)->m) + +/** + * container_of - cast a member of a structure out to the containing structure + * @ptr: the pointer to the member. + * @type: the type of the container struct this is embedded in. + * @member: the name of the member within the struct. + * + */ +#define container_of(ptr, type, member) ({ \ + void *__mptr = (void *)(ptr); \ + BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \ + !__same_type(*(ptr), void), \ + "pointer type mismatch in container_of()"); \ + ((type *)(__mptr - offsetof(type, member))); }) + +/** + * container_of_safe - cast a member of a structure out to the containing structure + * @ptr: the pointer to the member. + * @type: the type of the container struct this is embedded in. + * @member: the name of the member within the struct. + * + * If IS_ERR_OR_NULL(ptr), ptr is returned unchanged. + */ +#define container_of_safe(ptr, type, member) ({ \ + void *__mptr = (void *)(ptr); \ + BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \ + !__same_type(*(ptr), void), \ + "pointer type mismatch in container_of()"); \ + IS_ERR_OR_NULL(__mptr) ? ERR_CAST(__mptr) : \ + ((type *)(__mptr - offsetof(type, member))); }) + +#endif /* _LINUX_CONTAINER_OF_H */ diff --git a/include/linux/kernel.h b/include/linux/kernel.h index d416fe3165cb..ad9fdcce9dcf 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -9,6 +9,7 @@ #include <linux/stddef.h> #include <linux/types.h> #include <linux/compiler.h> +#include <linux/container_of.h> #include <linux/bitops.h> #include <linux/kstrtox.h> #include <linux/log2.h> @@ -482,36 +483,6 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } #define __CONCAT(a, b) a ## b #define CONCATENATE(a, b) __CONCAT(a, b) -/** - * container_of - cast a member of a structure out to the containing structure - * @ptr: the pointer to the member. - * @type: the type of the container struct this is embedded in. - * @member: the name of the member within the struct. - * - */ -#define container_of(ptr, type, member) ({ \ - void *__mptr = (void *)(ptr); \ - BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \ - !__same_type(*(ptr), void), \ - "pointer type mismatch in container_of()"); \ - ((type *)(__mptr - offsetof(type, member))); }) - -/** - * container_of_safe - cast a member of a structure out to the containing structure - * @ptr: the pointer to the member. - * @type: the type of the container struct this is embedded in. - * @member: the name of the member within the struct. - * - * If IS_ERR_OR_NULL(ptr), ptr is returned unchanged. - */ -#define container_of_safe(ptr, type, member) ({ \ - void *__mptr = (void *)(ptr); \ - BUILD_BUG_ON_MSG(!__same_type(*(ptr), ((type *)0)->member) && \ - !__same_type(*(ptr), void), \ - "pointer type mismatch in container_of()"); \ - IS_ERR_OR_NULL(__mptr) ? ERR_CAST(__mptr) : \ - ((type *)(__mptr - offsetof(type, member))); }) - /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */ #ifdef CONFIG_FTRACE_MCOUNT_RECORD # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
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. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> --- include/linux/container_of.h | 37 ++++++++++++++++++++++++++++++++++++ include/linux/kernel.h | 31 +----------------------------- 2 files changed, 38 insertions(+), 30 deletions(-) create mode 100644 include/linux/container_of.h