Re: [PATCH, cross prelink] 0001-Pull-ld.so-s-name-from-PT_INTERP-to-avoid-the-runtim.patch

[Maxim Kuvyrkov <maxim@codesourcery.com>]

On 11/04/2012, at 8:23 AM, Mark Hatle wrote:

> On 4/10/12 2:56 PM, Maxim Kuvyrkov wrote:
>> On 11/04/2012, at 7:46 AM, Mark Hatle wrote:
>> 
>>> On 4/10/12 2:27 PM, Maxim Kuvyrkov wrote:
>>>> Mark,
>>>> 
>>>> This patch makes rtld emulator in cross prelink use ld.so's name as it is encoded in PT_INTERP header.
>>>> 
>>>> Currently, rtld emulator returns "lib/ld.so.1" for runtime linker's name, but the linker actually expects "/lib/ld.so.1" -- that one slash at the beginning causes prelink checks done by the runtime linker to fail and not use prelink information.
>>>> 
>>>> The runtime linker sets up a map for itself under the name stored in PT_INTERP header of the executable, and this patch makes rtld emulator follow the suit.
>>>> 
>>>> I have tested this patch using a different version of rtld emulator (the one that CodeSourcery / Mentor maintains), but the function in question is the same in both, so this patch is also relevant for Yocto's prelink.
>>>> 
>>>> Any comments?  Please merge at your leisure.
>>> 
>>> prelinker currently checks that the ld.so name matches what it's expecting for any given arch in the PL_ARCH structure.  Does this change any of that behavior?  Or does it simply change the internal prelink-rtld behavior so that it the prelink-rtld acts as if it's name is the PT_INTERP element?
>> 
>> It is the latter.  Only behavior of prelink-rtld is change to the effect that it outputs "/lib/ld.so.1 ->  /lib/ld.so.1 ..." as executable's dependency.
>> 
>> Forgot to mention: the dependency on ld.so.1 [usually] comes from libdl.so, which is, probably, why this bug wasn't noticed before.
> 
> Thanks, I think I understand what is going on now.  I'll look into getting this merged into the cross prelinker later today or tomorrow.

Mark,

This patch is still not merged to cross-prelink, did you encounter a problem with it?

Thank you,

--
Maxim Kuvyrkov
CodeSourcery / Mentor Graphics