morello-binutils: Use global GOT type to determine GOT action
In final_link_relocate we currently use whether the relocation we're looking at is a Morello relocation to decide whether we should treat the GOT entry as a Morello GOT entry or not.
This is problematic since we can have an AArch64 relocation against a capability GOT entry (even if it isn't a very useful thing to have).
The current patch decides whether we need to emit a MORELLO RELATIVE relocation in the GOT based on whether the GOT as a whole contains capabilities rather than based on whether the first relocation against this GOT is a Morello relocation.
Until now we did not see any problem from this. Here we add a testcase that triggers the problem.
############### Attachment also inlined for ease of reply ###############
diff --git a/bfd/elfnn-aarch64.c b/bfd/elfnn-aarch64.c index 68c88bce0b475a6af2097c3993f9a5753a774fdb..244b837f4458051fc0bce7e878a63a0b5278c26b 100644 --- a/bfd/elfnn-aarch64.c +++ b/bfd/elfnn-aarch64.c @@ -7220,9 +7220,6 @@ elfNN_aarch64_final_link_relocate (reloc_howto_type *howto, base_got = globals->root.sgot;
bfd_boolean is_dynamic = elf_hash_table (info)->dynamic_sections_created; - bfd_boolean c64_reloc = - (bfd_r_type == BFD_RELOC_MORELLO_LD128_GOT_LO12_NC - || bfd_r_type == BFD_RELOC_MORELLO_ADR_GOT_PAGE);
if (signed_addend != 0) { @@ -7267,9 +7264,9 @@ elfNN_aarch64_final_link_relocate (reloc_howto_type *howto, BFD_ASSERT (!WILL_CALL_FINISH_DYNAMIC_SYMBOL (is_dynamic, bfd_link_pic (info), h)); relative_reloc = TRUE; - c64_needs_frag_fixup = c64_reloc ? TRUE : FALSE; + c64_needs_frag_fixup = globals->c64_rel ? TRUE : FALSE; } - else if (!c64_reloc || !c64_needs_relocation (info, h)) + else if (!globals->c64_rel || !c64_needs_relocation (info, h)) { /* Symbol references via GOT in C64 should always have relocations of some kind unless they are undefined weak @@ -7308,7 +7305,7 @@ elfNN_aarch64_final_link_relocate (reloc_howto_type *howto, c64_needs_frag_fixup = TRUE; }
- if (c64_reloc + if (globals->c64_rel && c64_symbol_adjust (h, value, sym_sec, info, &frag_value)) signed_addend = (value | h->target_internal) - frag_value; else @@ -7354,7 +7351,7 @@ elfNN_aarch64_final_link_relocate (reloc_howto_type *howto, { bfd_vma frag_value;
- if (c64_reloc + if (globals->c64_rel && c64_symbol_adjust (h, value, sym_sec, info, &frag_value)) signed_addend = (value | sym->st_target_internal) - frag_value; else @@ -7375,7 +7372,7 @@ elfNN_aarch64_final_link_relocate (reloc_howto_type *howto, dynamic relocations). */ if (bfd_link_pic (info) || (!bfd_link_pic (info) && bfd_link_executable (info) - && c64_reloc)) + && globals->c64_rel)) { /* We have not handled the case for weak undefined symbols in this clause. That is because we believe there can not be @@ -7390,7 +7387,7 @@ elfNN_aarch64_final_link_relocate (reloc_howto_type *howto, would not see it in this clause. */ BFD_ASSERT (!weak_undef_p); relative_reloc = TRUE; - c64_needs_frag_fixup = c64_reloc ? TRUE : FALSE; + c64_needs_frag_fixup = globals->c64_rel ? TRUE : FALSE; }
symbol_got_offset_mark (input_bfd, h, r_symndx); @@ -7410,7 +7407,7 @@ elfNN_aarch64_final_link_relocate (reloc_howto_type *howto,
if (c64_needs_frag_fixup) { - BFD_ASSERT (c64_reloc); + BFD_ASSERT (globals->c64_rel); /* For a C64 relative relocation, also add size and permissions into the frag. */ bfd_reloc_status_type ret; @@ -7433,7 +7430,7 @@ elfNN_aarch64_final_link_relocate (reloc_howto_type *howto,
s = globals->root.srelgot;
- if (c64_reloc) + if (globals->c64_rel) { rtype = MORELLO_R (RELATIVE);
diff --git a/ld/testsuite/ld-aarch64/aarch64-elf.exp b/ld/testsuite/ld-aarch64/aarch64-elf.exp index 95c0e1bfec10bfb3810d88c5ae27c279dcbbb3b5..5af3bbfa84151cbfca25dd5580407def9387fba0 100644 --- a/ld/testsuite/ld-aarch64/aarch64-elf.exp +++ b/ld/testsuite/ld-aarch64/aarch64-elf.exp @@ -281,6 +281,7 @@ run_dump_test_lp64 "emit-relocs-morello-6b" run_dump_test_lp64 "emit-relocs-morello-7" run_dump_test_lp64 "emit-relocs-morello-8" run_dump_test_lp64 "emit-relocs-morello-9" +run_dump_test_lp64 "emit-relocs-morello-10" run_dump_test_lp64 "emit-relocs-morello-hidden" run_dump_test_lp64 "emit-morello-reloc-markers-1" run_dump_test_lp64 "emit-morello-reloc-markers-2" diff --git a/ld/testsuite/ld-aarch64/emit-relocs-morello-10.d b/ld/testsuite/ld-aarch64/emit-relocs-morello-10.d new file mode 100644 index 0000000000000000000000000000000000000000..9f423e8b2adff0e331d9e6340ffe85c6c4f5ac5c --- /dev/null +++ b/ld/testsuite/ld-aarch64/emit-relocs-morello-10.d @@ -0,0 +1,12 @@ +# Checking that we have two RELATIVE relocations, indicating that both the +# CAPINIT and the GOT entry were given a RELATIVE relocation. As opposed to +# before when the linker generated one RELATIVE relocation and an +# R_AARCH64_NONE relocation. +#as: -march=morello+c64 +#ld: +#readelf: --relocs + +Relocation section '.rela.dyn' at offset .* contains 2 entries: + Offset Info Type Sym. Value Sym. Name + Addend +[0-9a-f]+ [0-9a-f]+ R_MORELLO_RELATIV 0 +[0-9a-f]+ [0-9a-f]+ R_MORELLO_RELATIV 0 diff --git a/ld/testsuite/ld-aarch64/emit-relocs-morello-10.s b/ld/testsuite/ld-aarch64/emit-relocs-morello-10.s new file mode 100644 index 0000000000000000000000000000000000000000..b04bfe8d17aa291abaed77f9c547f4e9d2a8c36f --- /dev/null +++ b/ld/testsuite/ld-aarch64/emit-relocs-morello-10.s @@ -0,0 +1,21 @@ + .data +str: + .string "Hello there big bad world!" + .size str,.-str + .global ptr +ptr: + .8byte str + .align 4 + .type cap STT_OBJECT + .global cap +cap: + .chericap str + + .text + .globl _start + .type _start STT_FUNC +_start: + ldr x2, [x2, :got_lo12:cap] + adrp c2, :got:cap + ldr c2, [c2, :got_lo12:cap] + ldr c2, [x2, :got_lo12:cap]