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Re: PING: PATCH: Automatically test IFUNC implementations
On Thu, Oct 4, 2012 at 6:02 AM, Andreas Jaeger <aj@suse.com> wrote:
> On Wednesday, October 03, 2012 08:11:42 H.J. Lu wrote:
>> On Sat, Sep 29, 2012 at 10:31 AM, H.J. Lu <hjl.tools@gmail.com> wrote:
>> > On Fri, Sep 28, 2012 at 7:25 AM, H.J. Lu <hjl.tools@gmail.com>
> wrote:
>> >> On Thu, Sep 27, 2012 at 5:16 PM, H.J. Lu <hjl.tools@gmail.com>
> wrote:
>> >>> On Thu, Sep 27, 2012 at 3:31 PM, Roland McGrath
> <roland@hack.frob.com> wrote:
>> >>>>> I thought we'd discussed returning a count from __libc_func,
>> >>>>> and the (static) array provided by the test program.
>> >>>>>
>> >>>>> Certainly that's going to be less dead bss space in libc.so.
>> >>>>
>> >>>> IMHO this feature must be done in a way that adds zero data space
>> >>>> (including zero relro const data), zero bss space, and zero
>> >>>> relocs
>> >>>> to the library.
>> >>>
>> >>> I updated hjl/ifunc/test branch. __libc_func is now specified as:
>> >>>
>> >>> /* Fill ARRAY of MAX elements with IFUNC implementations for
>> >>> function
>> >>>
>> >>> NAME supported on target machine and return the number of valid
>> >>> entries. */
>> >>>
>> >>> extern int __libc_func (const char *name, struct libc_func_test
>> >>> *array,>>>
>> >>> int max);
>> >>>
>> >>> arch-specific __libc_func can issue a run-time error if array is
>> >>> too
>> >
>> >>> small. There are no .bss nor .data spaces:
>> > Here are comparisons of master branch vs. hjl/ifunc/test branch:
>> >
>> > x86-64 master branch:
>> >
>> > [hjl@gnu-tools-1 build-x86_64-linux]$ readelf -r libc.so|wc -l
>> > 1291
>> > [hjl@gnu-tools-1 build-x86_64-linux]$ readelf -SW libc.so | egrep
>> > "data|bss">
>> > [15] .rodata PROGBITS 000000000014da60 14da60
>> >
>> > 021ad0 00 A 0 0 32
>> >
>> > [21] .tdata PROGBITS 000000000039f748 19f748
>> >
>> > 000010 00 WAT 0 0 8
>> >
>> > [22] .tbss NOBITS 000000000039f758 19f758
>> >
>> > 000058 00 WAT 0 0 8
>> >
>> > [27] .data.rel.ro PROGBITS 000000000039f880 19f880
>> >
>> > 003320 00 WA 0 0 32
>> >
>> > [31] .data PROGBITS 00000000003a3080 1a3080
>> >
>> > 0016d8 00 WA 0 0 32
>> >
>> > [32] .bss NOBITS 00000000003a4760 1a4758
>> >
>> > 004520 00 WA 0 0 32
>> > [hjl@gnu-tools-1 build-x86_64-linux]$
>> >
>> > x86-64 hjl/ifunc/test branch:
>> >
>> > [hjl@gnu-tools-1 build-x86_64-linux]$ readelf -r libc.so|wc -l1291
>> > [hjl@gnu-tools-1 build-x86_64-linux]$ readelf -SW libc.so | egrep
>> > "data|bss">
>> > [15] .rodata PROGBITS 000000000014eb20 14eb20
>> >
>> > 022270 00 A 0 0 32
>> >
>> > [21] .tdata PROGBITS 00000000003a1758 1a1758
>> >
>> > 000010 00 WAT 0 0 8
>> >
>> > [22] .tbss NOBITS 00000000003a1768 1a1768
>> >
>> > 000058 00 WAT 0 0 8
>> >
>> > [27] .data.rel.ro PROGBITS 00000000003a1880 1a1880
>> >
>> > 003320 00 WA 0 0 32
>> >
>> > [31] .data PROGBITS 00000000003a5080 1a5080
>> >
>> > 0016d8 00 WA 0 0 32
>> >
>> > [32] .bss NOBITS 00000000003a6760 1a6758
>> >
>> > 004520 00 WA 0 0 32
>> > [hjl@gnu-tools-1 build-x86_64-linux]$
>> >
>> > i686 master branch:
>> >
>> > [hjl@gnu-tools-1 build-i686-linux]$ readelf -r libc.so|wc -l
>> > 1360
>> > [hjl@gnu-tools-1 build-i686-linux]$ readelf -SW libc.so | egrep
>> > "data|bss">
>> > [15] .rodata PROGBITS 0014d140 14d140 01eed8 00
>> > A 0 0 32 [21] .tdata PROGBITS 001a51fc
>> > 1a51fc 000008 00 WAT 0 0 4 [22] .tbss NOBITS
>> > 001a5204 1a5204 000038 00 WAT 0 0 4 [27] .data.rel.ro
>> > PROGBITS 001a52a0 1a52a0 001b1c 00 WA 0 0 32 [31]
>> > .data PROGBITS 001a7040 1a7040 000e9c 00 WA
>> > 0 0 32 [32] .bss NOBITS 001a7ee0 1a7edc
>> > 002c1c 00 WA 0 0 32>
>> > [hjl@gnu-tools-1 build-i686-linux]$
>> >
>> > i686 hjl/ifunc/test branch:
>> >
>> > [hjl@gnu-tools-1 build-i686-linux]$ readelf -r libc.so|wc -l
>> > 1360
>> > [hjl@gnu-tools-1 build-i686-linux]$ readelf -SW libc.so | egrep
>> > "data|bss">
>> > [15] .rodata PROGBITS 0014e2a0 14e2a0 01f708 00
>> > A 0 0 32 [21] .tdata PROGBITS 001a6204
>> > 1a6204 000008 00 WAT 0 0 4 [22] .tbss NOBITS
>> > 001a620c 1a620c 000038 00 WAT 0 0 4 [27] .data.rel.ro
>> > PROGBITS 001a62a0 1a62a0 001b1c 00 WA 0 0 32 [31]
>> > .data PROGBITS 001a8040 1a8040 000e9c 00 WA
>> > 0 0 32 [32] .bss NOBITS 001a8ee0 1a8edc
>> > 002c1c 00 WA 0 0 32>
>> > [hjl@gnu-tools-1 build-i686-linux]$
>> >
>> > There are no changes in run-time relocations and .data/.bss section
>> > sizes. There are about 2K increases in .rodata section for IFUNC
>> > function name strings. OK to install?
>> >
>> > Thanks.
>>
>> PING.
>
> I think it's fine now but since Roland and Richard had comments on the
> previous versions of the patch, I'd like you to wait until Monday before
> you commit to give them a chance for an additional review.
>
> Btw. one next step would be to use this framework for the math tests. If
> you're not planning on doing this, I suggest you add this as a task to
> the glibc wiki.
I added it to:
http://sourceware.org/glibc/wiki/SmallProjects
--
H.J.