[lkml]   [2011]   [Jun]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: {PATCH] fix __packed in exported kernel headers
On Fri, Jun 24, 2011 at 12:33, Arnd Bergmann wrote:
> On Friday 24 June 2011, Markus Trippelsdorf wrote:
>> warns about using __attribute__((packed)) in kernel
>> headers: "__packed is preferred over __attribute__((packed))". If one
>> follows that advice it could cause problems in the exported header
>> files, because the outside world doesn't know about this shortcut.
>> For example busybox will fail to compile:
>>  CC      miscutils/ubi_attach_detach.o
>>  In file included from miscutils/ubi_attach_detach.c:27:0:
>>  /usr/include/mtd/ubi-user.h:330:3: error: conflicting types for ‘__packed’
>>  /usr/include/mtd/ubi-user.h:314:3: note: previous declaration of ‘__packed’ was here
>> ...
>> Fix the problem by substituting __packed with __attribute__((packed)) in
>> the script.
> No objections to the patch, but it should probably be noted that user
> visible data structures should ideally not have any attributes, because
> that requires building all applictions using that interface with gcc.
> We generally try to add no such requirements on user applications.

the only real solution there is to export the compiler.h headers too

plus, many compilers nowadays (like icc/llvm) tend to include support
for common gcc attributes ...
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
More majordomo info at
Please read the FAQ at

 \ /
  Last update: 2011-06-24 19:03    [W:0.053 / U:0.736 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site