Re: [PATCH 1/5] perf tools: Add get_unaligned_leNN()

[Arnaldo Carvalho de Melo <acme@kernel.org>]

Em Thu, Oct 26, 2023 at 07:09:26PM +0300, Adrian Hunter escreveu:
> On 26/10/23 16:44, Arnaldo Carvalho de Melo wrote:
> > Em Thu, Oct 05, 2023 at 04:38:05PM -0300, Arnaldo Carvalho de Melo escreveu:
> >> Em Thu, Oct 05, 2023 at 10:04:47PM +0300, Adrian Hunter escreveu:
> >>> Add get_unaligned_le16(), get_unaligned_le32 and get_unaligned_le64, same
> >>> as include/asm-generic/unaligned.h.
> >>>
> >>> Use diagnostic pragmas to ignore -Wpacked used by perf build.
> >>
> >> Can we get the tools copy of include/asm-generic/unaligned.h closer and
> >> have it in check-headers.sh?
> > 
> > And this is not building when cross building to mips, mips64 and mipsel
> > on debian:experimental:
> > 
> > In file included from util/intel-pt-decoder/intel-pt-pkt-decoder.c:10:
> > /git/perf-6.6.0-rc1/tools/include/asm-generic/unaligned.h: In function 'get_unaligned_le16':
> > /git/perf-6.6.0-rc1/tools/include/asm-generic/unaligned.h:13:29: error: packed attribute causes inefficient alignment for 'x' [-Werror=attributes]
> 
> So I guess another diagnostic pragma is needed, perhaps the following works?
> 
> #pragma GCC diagnostic ignored "-Wattributes"

I'll try it.

- Arnaldo
 
> 
> >    13 |         const struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr);      \
> >       |                             ^
> > /git/perf-6.6.0-rc1/tools/include/asm-generic/unaligned.h:27:28: note: in expansion of macro '__get_unaligned_t'
> >    27 |         return le16_to_cpu(__get_unaligned_t(__le16, p));
> >       |                            ^~~~~~~~~~~~~~~~~
> > /git/perf-6.6.0-rc1/tools/include/asm-generic/unaligned.h: In function 'get_unaligned_le32':
> > /git/perf-6.6.0-rc1/tools/include/asm-generic/unaligned.h:13:29: error: packed attribute causes inefficient alignment for 'x' [-Werror=attributes]
> >    13 |         const struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr);      \
> >       |                             ^
> > /git/perf-6.6.0-rc1/tools/include/asm-generic/unaligned.h:32:28: note: in expansion of macro '__get_unaligned_t'
> >    32 |         return le32_to_cpu(__get_unaligned_t(__le32, p));
> >       |                            ^~~~~~~~~~~~~~~~~
> > 
> > 
> > Ditto for some other distros when cross building on ubuntu:18.04
> > 
> >   MKDIR   /tmp/build/perf/util/perf-regs-arch/
> > In file included from /usr/sparc64-linux-gnu/include/bits/byteswap.h:34:0,
> >                  from /usr/sparc64-linux-gnu/include/endian.h:60,
> >                  from util/intel-pt-decoder/intel-pt-pkt-decoder.c:9:
> > /git/perf-6.6.0-rc1/tools/include/asm-generic/unaligned.h: In function 'get_unaligned_le16':
> > /git/perf-6.6.0-rc1/tools/include/asm-generic/unaligned.h:13:22: error: packed attribute causes inefficient alignment for 'x' [-Werror=attributes]
> >   const struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr); \
> >                       ^
> > /git/perf-6.6.0-rc1/tools/include/asm-generic/unaligned.h:27:21: note: in expansion of macro '__get_unaligned_t'
> >   return le16_to_cpu(__get_unaligned_t(__le16, p));
> >                      ^~~~~~~~~~~~~~~~~
> > 
> >   37    14.17 ubuntu:18.04-x-arm            : FAIL gcc version 7.5.0 (Ubuntu/Linaro 7.5.0-3ubuntu1~18.04)
> >   38    13.56 ubuntu:18.04-x-arm64          : FAIL gcc version 7.5.0 (Ubuntu/Linaro 7.5.0-3ubuntu1~18.04)
> >   42    12.70 ubuntu:18.04-x-riscv64        : FAIL gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04)
> >   44    13.95 ubuntu:18.04-x-sh4            : FAIL gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04)
> >   45    13.08 ubuntu:18.04-x-sparc64        : FAIL gcc version 7.5.0 (Ubuntu 7.5.0-3ubuntu1~18.04)
> >  
> >> - Arnaldo
> >>  
> >>> Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
> >>> ---
> >>>  tools/include/asm-generic/unaligned.h | 20 ++++++++++++++++++++
> >>>  1 file changed, 20 insertions(+)
> >>>
> >>> diff --git a/tools/include/asm-generic/unaligned.h b/tools/include/asm-generic/unaligned.h
> >>> index 47387c607035..9140bb4e16c6 100644
> >>> --- a/tools/include/asm-generic/unaligned.h
> >>> +++ b/tools/include/asm-generic/unaligned.h
> >>> @@ -6,6 +6,9 @@
> >>>  #ifndef __TOOLS_LINUX_ASM_GENERIC_UNALIGNED_H
> >>>  #define __TOOLS_LINUX_ASM_GENERIC_UNALIGNED_H
> >>>  
> >>> +#pragma GCC diagnostic push
> >>> +#pragma GCC diagnostic ignored "-Wpacked"
> >>> +
> >>>  #define __get_unaligned_t(type, ptr) ({						\
> >>>  	const struct { type x; } __packed *__pptr = (typeof(__pptr))(ptr);	\
> >>>  	__pptr->x;								\
> >>> @@ -19,5 +22,22 @@
> >>>  #define get_unaligned(ptr)	__get_unaligned_t(typeof(*(ptr)), (ptr))
> >>>  #define put_unaligned(val, ptr) __put_unaligned_t(typeof(*(ptr)), (val), (ptr))
> >>>  
> >>> +static inline u16 get_unaligned_le16(const void *p)
> >>> +{
> >>> +	return le16_to_cpu(__get_unaligned_t(__le16, p));
> >>> +}
> >>> +
> >>> +static inline u32 get_unaligned_le32(const void *p)
> >>> +{
> >>> +	return le32_to_cpu(__get_unaligned_t(__le32, p));
> >>> +}
> >>> +
> >>> +static inline u64 get_unaligned_le64(const void *p)
> >>> +{
> >>> +	return le64_to_cpu(__get_unaligned_t(__le64, p));
> >>> +}
> >>> +
> >>> +#pragma GCC diagnostic pop
> >>> +
> >>>  #endif /* __TOOLS_LINUX_ASM_GENERIC_UNALIGNED_H */
> >>>  
> >>> -- 
> >>> 2.34.1
> >>>
> >>
> >> -- 
> >>
> >> - Arnaldo
> > 
> 

-- 

- Arnaldo