[Mesa-dev] [Mesa-stable] [PATCH 3/3] amd: Apply elf relocations and allow code with relocations

[Jan Vesely]

On Thu, 2019-06-13 at 01:10 -0400, Marek Olšák wrote:
> FYI, I just pushed the new linker.

thanks. I've checked the handling and the current approach works for
sections as well (even if not handled explicitly).

Jan

> 
> Marek
> 
> On Mon, Jun 3, 2019 at 10:39 PM Jan Vesely <jan.vesely at rutgers.edu> wrote:
> 
> > Fixes piglits:
> >         call.cl
> >         calls-larget-struct.cl
> >         calls-struct.cl
> >         calls-workitem-id.cl
> >         realign-stack.cl
> >         tail-calls.cl
> > 
> > Cc: mesa-stable at lists.freedesktop.org
> > Signed-off-by: Jan Vesely <jan.vesely at rutgers.edu>
> > ---
> > The piglit test now pass using llvm-7,8,git.
> > ImageMagick works on my raven, but some test still fail on
> > carrizo/iceland.
> > Other workloads (like shoc) that used function calls also work ok.
> > ocltoys work after removing static keyword from .cl files.
> >  src/amd/common/ac_binary.c                | 30 +++++++++++++++++++++++
> >  src/gallium/drivers/radeonsi/si_compute.c |  6 -----
> >  2 files changed, 30 insertions(+), 6 deletions(-)
> > 
> > diff --git a/src/amd/common/ac_binary.c b/src/amd/common/ac_binary.c
> > index 18dc72c61f0..4d152fcf1be 100644
> > --- a/src/amd/common/ac_binary.c
> > +++ b/src/amd/common/ac_binary.c
> > @@ -178,6 +178,36 @@ bool ac_elf_read(const char *elf_data, unsigned
> > elf_size,
> > 
> >         parse_relocs(elf, relocs, symbols, symbol_sh_link, binary);
> > 
> > +       // Apply relocations
> > +       for (int i = 0; i < binary->reloc_count; ++i) {
> > +               struct ac_shader_reloc *r = &binary->relocs[i];
> > +               uint32_t *loc = (uint32_t*)(binary->code + r->offset);
> > +               /* Section target relocations store symbol offsets as
> > +                * values in reloc location. We're expected to adjust it
> > for
> > +                * start of the section. However, R_AMDGPU_REL32 are
> > +                * PC relative relocations, so we need to recompute the
> > +                * delta between reloc locatin and the target adress.
> > +                */
> > +               if (r->target_type == 0x3) { // section relocation
> > +                       uint32_t target_offset = *loc; // already adjusted
> > +                       int64_t diff = target_offset - r->offset;
> > +                       if (r->type == 0xa) { // R_AMDGPU_REL32_LO
> > +                               // address of the 'lo' instruction is 4B
> > below
> > +                               // the relocation point, but the target has
> > +                               // alredy been adjusted.
> > +                               *loc = (diff & 0xffffffff);
> > +                       } else if (r->type == 0xb) { // R_AMDGPU_REL32_HI
> > +                               // 'hi' relocation is 8B above 'lo'
> > relocation
> > +                               *loc = ((diff - 8) >> 32);
> > +                       } else {
> > +                               success = false;
> > +                               fprintf(stderr, "Unsupported section
> > relocation: type: %d, offset: %lx, value: %x\n",
> > +                                               r->type, r->offset, *loc);
> > +                       }
> > +               } else
> > +                       success = false;
> > +       }
> > +
> >         if (elf){
> >                 elf_end(elf);
> >         }
> > diff --git a/src/gallium/drivers/radeonsi/si_compute.c
> > b/src/gallium/drivers/radeonsi/si_compute.c
> > index b9cea00eeeb..88631369a62 100644
> > --- a/src/gallium/drivers/radeonsi/si_compute.c
> > +++ b/src/gallium/drivers/radeonsi/si_compute.c
> > @@ -246,12 +246,6 @@ static void *si_create_compute_state(
> >                         const amd_kernel_code_t *code_object =
> >                                 si_compute_get_code_object(program, 0);
> >                         code_object_to_config(code_object,
> > &program->shader.config);
> > -                       if (program->shader.binary.reloc_count != 0) {
> > -                               fprintf(stderr, "Error: %d unsupported
> > relocations\n",
> > -
> >  program->shader.binary.reloc_count);
> > -                               FREE(program);
> > -                               return NULL;
> > -                       }
> >                 } else {
> > 
> > si_shader_binary_read_config(&program->shader.binary,
> >                                      &program->shader.config, 0);
> > --
> > 2.21.0
> > 
> > _______________________________________________
> > mesa-stable mailing list
> > mesa-stable at lists.freedesktop.org
> > https://nam02.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.freedesktop.org%2Fmailman%2Flistinfo%2Fmesa-stable&data=02%7C01%7Cjan.vesely%40cs.rutgers.edu%7C799b455386104f3a30dd08d6efbd81dc%7Cb92d2b234d35447093ff69aca6632ffe%7C1%7C0%7C636959994551504256&sdata=E5usx69EyFtABg3cn24Q5idNveyntDYJ7xR5a7K%2BboA%3D&reserved=0

-- 
Jan Vesely <jan.vesely at rutgers.edu>
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