Re: [PATCH 2/2] elf: Use nocancel pread64() instead of lseek()+read()

[Lukasz Majewski <lukma at denx dot de>]

On Fri, 18 Oct 2019 16:02:22 -0400
Carlos O'Donell <carlos@redhat.com> wrote:

> On 10/3/19 9:59 AM, Carlos O'Donell wrote:
> > On 8/5/19 5:56 PM, Leandro Pereira wrote:  
> >> Transforms this, when linking in a shared object:
> >>
> >>   openat(AT_FDCWD, "/lib64/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
> >>   read(3, "\177ELF\2\1\1\3"..., 832) = 832
> >>   lseek(3, 792, SEEK_SET)           = 792
> >>   read(3, "\4\0\0\0\24\0\0\0"..., 68) = 68
> >>   fstat(3, {st_mode=S_IFREG|0755, st_size=6699224, ...}) = 0
> >>   lseek(3, 792, SEEK_SET)           = 792
> >>   read(3, "\4\0\0\0\24\0\0\0"..., 68) = 68
> >>   lseek(3, 864, SEEK_SET)           = 864
> >>   read(3, "\4\0\0\0\20\0\0\0"..., 32) = 32
> >>
> >> Into this:
> >>
> >>   openat(AT_FDCWD, "/lib64/libc.so.6", O_RDONLY|O_CLOEXEC) = 3
> >>   read(3, "\177ELF\2\1\1\3"..., 832) = 832
> >>   pread(3, "\4\0\0\0\24\0\0\0"..., 68, 792) = 68
> >>   fstat(3, {st_mode=S_IFREG|0755, st_size=6699224, ...}) = 0
> >>   pread(3, "\4\0\0\0\24\0\0\0"..., 68, 792) = 68
> >>   pread(3, "\4\0\0\0\20\0\0\0"..., 32, 864) = 32
> >>
> >> 2019-08-05  Leandro Pereira  <leandro.pereira@microsoft.com>
> >>
> >> 	* elf/dl-load.c: Use __pread64_nocancel() instead of
> >> __lseek()+ __read_nocancel().
> >> 	* sysdeps/x86/dl-prop.h: Likewise.  
> > 
> > OK for master. I'll push after testing with bmg. No regressions on
> > x86_64.
> > 
> > Reviewed-by: Carlos O'Donell <carlos@redhat.com>  
> 
> Pushed.
> 

Unfortunately, I've found a regression on HURD when using
build-many-glibcs.py (for testing some other code):

../glibc-many-build/src/glibc/libio/../sysdeps/posix/libc_fatal.c:161:
multiple definition of `__libc_fatal';
../glibc-many-build/build/glibcs/i686-gnu/glibc/elf/dl-allobjs.os:/work/lukma/glibc/glibc-many-build/src/glibc/elf/dl-minimal.c\
:188: first defined here

To reproduce:
../src/scripts/build-many-glibcs.py
<path>/glibc/glibc-many-build glibcs i686-gnu

emacs logs/glibcs/i686-gnu/004-glibcs-i686-gnu-build-log.txt




Best regards,

Lukasz Majewski

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