[linux-dvb] [BUG] usage of undefined macros in dvb header files
js at linuxtv.org
Thu Mar 10 13:52:51 CET 2005
Nico Sabbi wrote:
> on kernels that don't have __iomem and __iouser defined,
> especially distributions with patched kernel headers that have funny
> version names
> like 22.214.171.124-mdkcustom, compilation of dvb drivers (and applications
> that use them)
> _always_ fails because those macros are required by dvb header files.
> I understand that this bug is related to the kernel rather than to dvb,
> and I guess that the check to define these macros as empty for older
> kernels is done badly, still dvb drivers and applications are affected,
> so I hope someone of you developers will find a definitive fix to this
> ending problem.
The problem is actually that the includes that come with glibc
are out of date. On a recent distribution you have DVB includes
in /usr/include/linux/dvb/ and a /usr/include/linux/compiler.h
that defines __user. When you mess with the files in
/usr/include/linux/dvb/, or you use -I.../dvb-kernel/include
then it's your fault if you don't supply a matching __user
I don't know if the policy has changed, but AFAIK Linus does
not like userspace compatibility cruft in kernel includes,
i.e. he does (did?) not accept patches with #ifdef __KERNEL
cruft in it. (There's a separate project to get around that:
Likely I guess he would not like
repeated in all DVB API headers.
But of course I see the problem with backwards compatibility.
The only way to solve it cleanly would be to have a "dvb-dev"
package that installs compatible API headers in /usr/include/dvb/.
(Or you add a cleaned copy of the API headers to your source tree
(like xawtv does it with v4l headers).)
I don't like both ;-/
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