[PATCH v2] aarch64: Add support for GNU indirect functions.

[Jiong Wang]

On 27/09/13 10:39, Will Newton wrote:
 > Add support for STT_GNU_IFUNC symbols to the AArch64 bfd backend. The 
tests
 > are ported from the ld-ifunc tests but are enabled for cross builds 
so can
 > be run easily without hardware or a simulator.
 >
 > This version of the patch uses two passes over the symbols to ensure that
 > the dynamic relocs are output in the correct order.
 >
 >
 >     (elfNN_aarch64_allocate_ifunc_dynrelocs): New function.
 >     (elfNN_aarch64_allocate_local_ifunc_dynrelocs): New function.
 >
 >
 >   /* This is the most important function of all . Innocuosly named
 >      though !  */
 > @@ -5987,6 +6421,20 @@ elfNN_aarch64_size_dynamic_sections (bfd 
*output_bfd ATTRIBUTE_UNUSED,
 >     elf_link_hash_traverse (&htab->root, 
elfNN_aarch64_allocate_dynrelocs,
 >                 info);
 >
 > +  /* Allocate global ifunc sym .plt and .got entries, and space for 
global
 > +     ifunc sym dynamic relocs.  */
 > +  elf_link_hash_traverse (&htab->root, 
elfNN_aarch64_allocate_ifunc_dynrelocs,
 > +              info);
 > +
 > +  /* Allocate .plt and .got entries, and space for local symbols.  */
 > +  htab_traverse (htab->loc_hash_table,
 > +         elfNN_aarch64_allocate_local_dynrelocs,
 > +         info);
 > +
 > +  /* Allocate .plt and .got entries, and space for local ifunc 
symbols.  */
 > +  htab_traverse (htab->loc_hash_table,
 > +         elfNN_aarch64_allocate_local_ifunc_dynrelocs,
 > +         info);

Hi Will,

   I came across above code where extra traverses are introduced for 
IFUNC symbol, any particular
   reason we need them? purely to make sure IFUNC runtime relocations 
happens last? If it is, I
   noticed you are using next_jump_slot_index/next_irelative_index 
mechanism to solve the relocation
   order issue in your initial aarch64 IFUNC support, why it's dropped 
in your final version?

   thanks.

Regards,
Jiong