Bug#747151: Explanation for the error, other patch available for ppc64/ppc64el.

[Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>]

Package: src:linux-tools
Version: 3.14-1
User: debian-powerpc@lists.debian.org
Usertags: ppc64el


Hi,

I looked at this for a while, in order to fix for ppc64el. A patch for
fixing this was submitted as part of #754213.

In short:
Using 'int-ll64.h' (which defines u32/u64/et al) in userspace on ppc64
requires defining "__SANE_USERSPACE_TYPES__", introduced in commit [4].

Rationale:
---------

This build failure

	make[6]: Entering directory `/«PKGBUILDDIR»/debian/build/scripts/mod'

	gcc -include real-lsb-32/types.h -I/«PKGBUILDDIR»/include -S -o 
real-lsb-32/devicetable-offsets.s 
/«PKGBUILDDIR»/scripts/mod/devicetable-offsets.c
	In file included from ./real-lsb-32/types.h:1:0,
		         from <command-line>:0:
	/«PKGBUILDDIR»/include/linux/types.h:148:1: error: unknown type name 'u32'
	 typedef u32 dma_addr_t;
	 ^

occurs because of a change in the "asm/int-{l,ll}64.h" logic between 
3.13 and 3.14.

	(ppc64 build on with linux-libc-dev 3.13 succeeds [1] but 3.14 fails [2])

The file 'int-l64.h' which defined non-double-underscore u32/u64 was
removed in commit [3] ('asm/types.h: Remove include/asm-generic
/int-l64.h') for *kernelspace*.

For *userspace*, the commits mentions this:

	"""
	For backwards compatibility, alpha, ia64, mips64, and
	powerpc64 still use int-l64.h in userspace.
	"""

but 'include/*uapi*/asm-generic/int-l64.h' defines double-underscore
__u32/__u64 (for userspace data type exportation, double-underscore)

The non-double-underscore definition u32/u64 is in 'int-*ll*64.h'.


Now, for ppc64, there a flag just for that (__SANE_USERSPACE_TYPES__),
which was introduced in [4] ('powerpc: Add__SANE_USERSPACE_TYPES__ to
asm/types.h for LL64'):

	"""
	[...] Some user programs (e.g. kvmtool) may actually
	want LL64, so this patch adds a check for 		
	__SANE_USERSPACE_TYPES__ so
	that, if defined, int-ll64.h is included instead.

	[...]
	
	#if !defined(__SANE_USERSPACE_TYPES__)
				[line breaks added for clarity]
	 &&  defined(__powerpc64__)
	 && !defined(__KERNEL__)
	# include <asm-generic/int-l64.h>
	#else
	# include <asm-generic/int-ll64.h>
	#endif
	"""


It is used by perf (for example) [4] ('perf tools, powerpc: Fix compile
warnings in tests/attr.c').


I didn't find anything similar for alpha, unfortunately.


Links:
-----

[1] ppc64 build log: linux-tools with linux-libc-dev_3.13.5-1 (successful)

http://buildd.debian-ports.org/status/fetch.php?pkg=linux-tools&arch=ppc64&ver=3.13.6-1&stamp=1395302858
[2] ppc64 build log: linux-tools with linux-libc-dev_3.14.2-1 (failure)

http://buildd.debian-ports.org/status/fetch.php?pkg=linux-tools&arch=ppc64&ver=3.14-1&stamp=1399098596
[3] asm/types.h: Remove include/asm-generic/int-l64.h

https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/commit/include/asm-generic/int-l64.h?id=0c79a8e29b5fcbcbfd611daf9d500cfad8370fcf
[4] powerpc: Add __SANE_USERSPACE_TYPES__ to asm/types.h for LL64

https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/commit/arch/powerpc/include/asm/types.h?id=2c9c6ce0199a4d252e20c531cfdc9d24e39235c0
[5] perf tools, powerpc: Fix compile warnings in tests/attr.c

https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/commit/?id=e3541ec75219819d3235f80125a1a75d798ff6e1



--
Mauricio Faria de Oliveira
IBM Linux Technology Center