| Message ID | 1444888618-4506-76-git-send-email-mikko.rapeli@iki.fi (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Mikko,
[auto build test ERROR on drm/drm-next -- if it's inappropriate base, please suggest rules for selecting the more suitable base]
url: https://github.com/0day-ci/linux/commits/Mikko-Rapeli/Userspace-compile-test-and-fixes-for-exported-uapi-header-files/20151015-150653
config: arm64-allmodconfig (attached as .config)
reproduce:
wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# save the attached .config to linux build tree
make.cross ARCH=arm64
All errors (new ones prefixed by >>):
In file included from drivers/xen/privcmd.c:33:0:
>> include/uapi/xen/privcmd.h:48:23: error: conflicting types for 'xen_pfn_t'
typedef unsigned long xen_pfn_t;
^
In file included from arch/arm64/include/asm/xen/interface.h:1:0,
from include/xen/interface/xen.h:30,
from include/xen/xen.h:23,
from arch/arm64/include/asm/io.h:35,
from include/linux/bio.h:30,
from include/linux/writeback.h:192,
from include/linux/memcontrol.h:30,
from include/linux/swap.h:8,
from drivers/xen/privcmd.c:20:
arch/arm64/include/../../arm/include/asm/xen/interface.h:39:15: note: previous declaration of 'xen_pfn_t' was here
typedef __u64 xen_pfn_t;
^
vim +/xen_pfn_t +48 include/uapi/xen/privcmd.h
42 #endif /* domid_t */
43
44 #ifndef xen_pfn_t
45 #if (defined __ARMEL__ || defined __ARMEB__)
46 typedef __u64 xen_pfn_t;
47 #else
> 48 typedef unsigned long xen_pfn_t;
49 #endif /* (defined __ARMEL__ || defined __ARMEB__) */
50 #endif /* xen_pfn_t */
51
---
0-DAY kernel test infrastructure Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all Intel Corporation
On 15/10/15 06:56, Mikko Rapeli wrote: > xen/interface/xen.h is not exported from kernel headers so remove the > dependency and provide needed defines for domid_t and xen_pfn_t if they > are not already defined by some other e.g. Xen specific headers. > > Suggested by Andrew Cooper <andrew.cooper3@citrix.com> on lkml message > <5569F9C9.8000607@citrix.com>. > > The ifdef for ARM is ugly but did not find better solutions for it. > > Fixes userspace compilation error: > > xen/privcmd.h:38:31: fatal error: xen/interface/xen.h: No such file or directory [...] > --- a/include/uapi/xen/privcmd.h > +++ b/include/uapi/xen/privcmd.h > @@ -35,7 +35,19 @@ > > #include <linux/types.h> > #include <linux/compiler.h> > -#include <xen/interface/xen.h> > + > +/* Might be defined by Xen specific headers, but if not */ > +#ifndef domid_t > +typedef __u16 domid_t; > +#endif /* domid_t */ As the kbuild bot points out, this does not work since the existence of a typedef cannot be checked with #ifdef. I'm not really sure what problem you're trying to solve. A user space program making use of this interface gets the domid_t and xen_pfn_t etc typedefs from the headers provided as part of the libxenctrl library. David
On Thu, Oct 15, 2015 at 11:29:12AM +0100, David Vrabel wrote: > On 15/10/15 06:56, Mikko Rapeli wrote: > > xen/interface/xen.h is not exported from kernel headers so remove the > > dependency and provide needed defines for domid_t and xen_pfn_t if they > > are not already defined by some other e.g. Xen specific headers. > > > > Suggested by Andrew Cooper <andrew.cooper3@citrix.com> on lkml message > > <5569F9C9.8000607@citrix.com>. > > > > The ifdef for ARM is ugly but did not find better solutions for it. > > > > Fixes userspace compilation error: > > > > xen/privcmd.h:38:31: fatal error: xen/interface/xen.h: No such file or directory > [...] > > --- a/include/uapi/xen/privcmd.h > > +++ b/include/uapi/xen/privcmd.h > > @@ -35,7 +35,19 @@ > > > > #include <linux/types.h> > > #include <linux/compiler.h> > > -#include <xen/interface/xen.h> > > + > > +/* Might be defined by Xen specific headers, but if not */ > > +#ifndef domid_t > > +typedef __u16 domid_t; > > +#endif /* domid_t */ > > As the kbuild bot points out, this does not work since the existence of > a typedef cannot be checked with #ifdef. Yeah, this hack doesn't cut it. Sorry. Tried to implement these changes: http://www.spinics.net/lists/linux-api/msg11048.html > I'm not really sure what problem you're trying to solve. A user space > program making use of this interface gets the domid_t and xen_pfn_t etc > typedefs from the headers provided as part of the libxenctrl library. I'm trying to make sure that kernel headers in userspace compile with minimal dependencies which are gcc and libc. For me it is clear by now that many Linux API's and ABI's like Xen parts do not live in the uapi header files and instead there's a separate userspace library with needed headers and defines which have embedded copies of the needed API and ABI definitions, like header files. So how could this file be changed so that it compiles in userspace without definitions from libxenctrl? I guess I could copy the needed definitions for domid_t and xen_pfn_t from xen/interface/xen.h of libxenctrl. That I should have done to begin with instead of trying to hack something on my own. -Mikko
On 15/10/15 12:18, Mikko Rapeli wrote: > On Thu, Oct 15, 2015 at 11:29:12AM +0100, David Vrabel wrote: >> On 15/10/15 06:56, Mikko Rapeli wrote: >>> xen/interface/xen.h is not exported from kernel headers so remove the >>> dependency and provide needed defines for domid_t and xen_pfn_t if they >>> are not already defined by some other e.g. Xen specific headers. >>> >>> Suggested by Andrew Cooper <andrew.cooper3@citrix.com> on lkml message >>> <5569F9C9.8000607@citrix.com>. >>> >>> The ifdef for ARM is ugly but did not find better solutions for it. >>> >>> Fixes userspace compilation error: >>> >>> xen/privcmd.h:38:31: fatal error: xen/interface/xen.h: No such file or directory >> [...] >>> --- a/include/uapi/xen/privcmd.h >>> +++ b/include/uapi/xen/privcmd.h >>> @@ -35,7 +35,19 @@ >>> >>> #include <linux/types.h> >>> #include <linux/compiler.h> >>> -#include <xen/interface/xen.h> >>> + >>> +/* Might be defined by Xen specific headers, but if not */ >>> +#ifndef domid_t >>> +typedef __u16 domid_t; >>> +#endif /* domid_t */ >> >> As the kbuild bot points out, this does not work since the existence of >> a typedef cannot be checked with #ifdef. > > Yeah, this hack doesn't cut it. Sorry. Tried to implement these changes: > http://www.spinics.net/lists/linux-api/msg11048.html > >> I'm not really sure what problem you're trying to solve. A user space >> program making use of this interface gets the domid_t and xen_pfn_t etc >> typedefs from the headers provided as part of the libxenctrl library. > > I'm trying to make sure that kernel headers in userspace compile with minimal > dependencies which are gcc and libc. > > For me it is clear by now that many Linux API's and ABI's like Xen parts do > not live in the uapi header files and instead there's a separate userspace > library with needed headers and defines which have embedded copies of > the needed API and ABI definitions, like header files. > > So how could this file be changed so that it compiles in userspace without > definitions from libxenctrl? I don't think anything needs to be changed. Instead I would make your compilation check of this header dependent on the existence of the xen/interface/xen.h header. Or you may exclude the check of this header entirely. > I guess I could copy the needed definitions for domid_t and xen_pfn_t from > xen/interface/xen.h of libxenctrl. That I should have done to begin with > instead of trying to hack something on my own. I do not want definitions duplicated/copied from the hypervisor ABI headers. This causes problems when support for new architectures is added (for example). David
On Thu, Oct 15, 2015 at 12:24:39PM +0100, David Vrabel wrote: > On 15/10/15 12:18, Mikko Rapeli wrote: > > On Thu, Oct 15, 2015 at 11:29:12AM +0100, David Vrabel wrote: > >> On 15/10/15 06:56, Mikko Rapeli wrote: > >>> xen/interface/xen.h is not exported from kernel headers so remove the > >>> dependency and provide needed defines for domid_t and xen_pfn_t if they > >>> are not already defined by some other e.g. Xen specific headers. > >>> > >>> Suggested by Andrew Cooper <andrew.cooper3@citrix.com> on lkml message > >>> <5569F9C9.8000607@citrix.com>. > >>> > >>> The ifdef for ARM is ugly but did not find better solutions for it. > >>> > >>> Fixes userspace compilation error: > >>> > >>> xen/privcmd.h:38:31: fatal error: xen/interface/xen.h: No such file or directory > >> [...] > >>> --- a/include/uapi/xen/privcmd.h > >>> +++ b/include/uapi/xen/privcmd.h > >>> @@ -35,7 +35,19 @@ > >>> > >>> #include <linux/types.h> > >>> #include <linux/compiler.h> > >>> -#include <xen/interface/xen.h> > >>> + > >>> +/* Might be defined by Xen specific headers, but if not */ > >>> +#ifndef domid_t > >>> +typedef __u16 domid_t; > >>> +#endif /* domid_t */ > >> > >> As the kbuild bot points out, this does not work since the existence of > >> a typedef cannot be checked with #ifdef. > > > > Yeah, this hack doesn't cut it. Sorry. Tried to implement these changes: > > http://www.spinics.net/lists/linux-api/msg11048.html > > > >> I'm not really sure what problem you're trying to solve. A user space > >> program making use of this interface gets the domid_t and xen_pfn_t etc > >> typedefs from the headers provided as part of the libxenctrl library. > > > > I'm trying to make sure that kernel headers in userspace compile with minimal > > dependencies which are gcc and libc. > > > > For me it is clear by now that many Linux API's and ABI's like Xen parts do > > not live in the uapi header files and instead there's a separate userspace > > library with needed headers and defines which have embedded copies of > > the needed API and ABI definitions, like header files. > > > > So how could this file be changed so that it compiles in userspace without > > definitions from libxenctrl? > > I don't think anything needs to be changed. > > Instead I would make your compilation check of this header dependent on > the existence of the xen/interface/xen.h header. Or you may exclude the > check of this header entirely. There are not many headers in uapi which require additional userspace headers to compile (I'm not saying that uapi headers represent the full API's/ABI's, it's clear they don't). If there are ~700 headers and just a single one needs an exception and additional dependencies, I would try to make it work without the dependency. I just need some advice and guidance from maintainers how to do this. Or we should start tracking these userspace library dependencies too, at least at linux-headers package levels in distributions. This might be a good idea anyway, but then we might as well move headers like this directly to the userspace library and out of include/uapi. Both would solve the non-compiling uapi header problem. > > I guess I could copy the needed definitions for domid_t and xen_pfn_t from > > xen/interface/xen.h of libxenctrl. That I should have done to begin with > > instead of trying to hack something on my own. > > I do not want definitions duplicated/copied from the hypervisor ABI > headers. This causes problems when support for new architectures is > added (for example). Understood. -Mikko > David
diff --git a/arch/arm/include/asm/xen/interface.h b/arch/arm/include/asm/xen/interface.h index 5006600..68a9d99 100644 --- a/arch/arm/include/asm/xen/interface.h +++ b/arch/arm/include/asm/xen/interface.h @@ -36,7 +36,7 @@ * fine since it simply wouldn't be able to create any sure pfns in * the first place. */ -typedef uint64_t xen_pfn_t; +typedef __u64 xen_pfn_t; #define PRI_xen_pfn "llx" typedef uint64_t xen_ulong_t; #define PRI_xen_ulong "llx" diff --git a/include/uapi/xen/privcmd.h b/include/uapi/xen/privcmd.h index 7ddeeda..95b73a9 100644 --- a/include/uapi/xen/privcmd.h +++ b/include/uapi/xen/privcmd.h @@ -35,7 +35,19 @@ #include <linux/types.h> #include <linux/compiler.h> -#include <xen/interface/xen.h> + +/* Might be defined by Xen specific headers, but if not */ +#ifndef domid_t +typedef __u16 domid_t; +#endif /* domid_t */ + +#ifndef xen_pfn_t +#if (defined __ARMEL__ || defined __ARMEB__) +typedef __u64 xen_pfn_t; +#else +typedef unsigned long xen_pfn_t; +#endif /* (defined __ARMEL__ || defined __ARMEB__) */ +#endif /* xen_pfn_t */ struct privcmd_hypercall { __u64 op;
xen/interface/xen.h is not exported from kernel headers so remove the dependency and provide needed defines for domid_t and xen_pfn_t if they are not already defined by some other e.g. Xen specific headers. Suggested by Andrew Cooper <andrew.cooper3@citrix.com> on lkml message <5569F9C9.8000607@citrix.com>. The ifdef for ARM is ugly but did not find better solutions for it. Fixes userspace compilation error: xen/privcmd.h:38:31: fatal error: xen/interface/xen.h: No such file or directory Signed-off-by: Mikko Rapeli <mikko.rapeli@iki.fi> --- arch/arm/include/asm/xen/interface.h | 2 +- include/uapi/xen/privcmd.h | 14 +++++++++++++- 2 files changed, 14 insertions(+), 2 deletions(-)