From: Alan Modra Date: Fri, 5 Jun 2015 09:05:40 +0000 (+0930) Subject: ppc476 linker workaround shared lib fixes X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=f8b447819b3d65c3bea65dee860110aa198c081e;p=binutils-gdb.git ppc476 linker workaround shared lib fixes When building a shared lib from non-PIC objects, we'll get dynamic text relocations. These need to move with any insns we move. Otherwise the dynamic reloc will modify the branch, resulting in crashes and other unpleasant behaviour. Also, ld -r --ppc476-workaround used with sufficiently aligned PIC objects needs a fix for emitted REL16 relocs. bfd/ * elf64-ppc.c (ppc_elf_relocate_section): Move dynamic text relocs with insns moved by --ppc476-workaround. Correct output of REL16 relocs. ld/testsuite/ * ld-powerpc/ppc476-shared.s, * ld-powerpc/ppc476-shared.lnk, * ld-powerpc/ppc476-shared.d, * ld-powerpc/ppc476-shared2.d: New tests. * ld-powerpc/powerpc.exp: Run them. --- diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 4001dce8a32..d7ba09b7547 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,9 @@ +2015-06-05 Alan Modra + + * elf64-ppc.c (ppc_elf_relocate_section): Move dynamic text + relocs with insns moved by --ppc476-workaround. Correct + output of REL16 relocs. + 2015-06-01 Jiong Wang * elfnn-aarch64.c (aarch64_reloc_got_type): Support diff --git a/bfd/elf32-ppc.c b/bfd/elf32-ppc.c index 663a8713a72..a947e8ef41d 100644 --- a/bfd/elf32-ppc.c +++ b/bfd/elf32-ppc.c @@ -9608,6 +9608,8 @@ ppc_elf_relocate_section (bfd *output_bfd, && rel->r_offset >= offset && rel->r_offset < offset + 4) { + asection *sreloc; + /* If the insn we are patching had a reloc, adjust the reloc r_offset so that the reloc applies to the moved location. This matters for -r and --emit-relocs. */ @@ -9620,6 +9622,56 @@ ppc_elf_relocate_section (bfd *output_bfd, relend[-1] = tmp; } relend[-1].r_offset += patch_off - offset; + + /* Adjust REL16 addends too. */ + switch (ELF32_R_TYPE (relend[-1].r_info)) + { + case R_PPC_REL16: + case R_PPC_REL16_LO: + case R_PPC_REL16_HI: + case R_PPC_REL16_HA: + relend[-1].r_addend += patch_off - offset; + break; + default: + break; + } + + /* If we are building a PIE or shared library with + non-PIC objects, perhaps we had a dynamic reloc too? + If so, the dynamic reloc must move with the insn. */ + sreloc = elf_section_data (input_section)->sreloc; + if (sreloc != NULL) + { + bfd_byte *slo, *shi, *srelend; + bfd_vma soffset; + + slo = sreloc->contents; + shi = srelend + = slo + sreloc->reloc_count * sizeof (Elf32_External_Rela); + soffset = (offset + input_section->output_section->vma + + input_section->output_offset); + while (slo < shi) + { + bfd_byte *srel = slo + (shi - slo) / 2; + bfd_elf32_swap_reloca_in (output_bfd, srel, &outrel); + if (outrel.r_offset < soffset) + slo = srel + 1; + else if (outrel.r_offset > soffset + 3) + shi = srel; + else + { + bfd_byte *nextr = srel + sizeof (Elf32_External_Rela); + if (nextr != srelend) + { + memmove (srel, nextr, srelend - nextr); + srel = srelend - sizeof (Elf32_External_Rela); + } + outrel.r_offset += patch_off - offset; + bfd_elf32_swap_reloca_out (output_bfd, &outrel, srel); + break; + } + } + } } else rel = NULL; diff --git a/ld/testsuite/ChangeLog b/ld/testsuite/ChangeLog index fe629902c13..e51f16b48e2 100644 --- a/ld/testsuite/ChangeLog +++ b/ld/testsuite/ChangeLog @@ -1,3 +1,11 @@ +2015-06-05 Alan Modra + + * ld-powerpc/ppc476-shared.s, + * ld-powerpc/ppc476-shared.lnk, + * ld-powerpc/ppc476-shared.d, + * ld-powerpc/ppc476-shared2.d: New tests. + * ld-powerpc/powerpc.exp: Run them. + 2015-06-02 Jiong Wang * ld-aarch64/emit-relocs-313.s: Use gotpage_lo15. diff --git a/ld/testsuite/ld-powerpc/powerpc.exp b/ld/testsuite/ld-powerpc/powerpc.exp index 48aec4ae4fc..976e89bc013 100644 --- a/ld/testsuite/ld-powerpc/powerpc.exp +++ b/ld/testsuite/ld-powerpc/powerpc.exp @@ -325,3 +325,6 @@ run_dump_test "attr-gnu-12-11" run_dump_test "attr-gnu-12-21" run_dump_test "vle-multiseg-6" + +run_dump_test "ppc476-shared" +run_dump_test "ppc476-shared2" diff --git a/ld/testsuite/ld-powerpc/ppc476-shared.d b/ld/testsuite/ld-powerpc/ppc476-shared.d new file mode 100644 index 00000000000..8fda847b338 --- /dev/null +++ b/ld/testsuite/ld-powerpc/ppc476-shared.d @@ -0,0 +1,30 @@ +#source: ppc476-shared.s +#as: -a32 +#ld: -melf32ppc -q -shared --ppc476-workaround -T ppc476-shared.lnk +#objdump: -dr +#target: powerpc*-*-* + +.*: file format .* + +Disassembly of section \.text: + +0+fffc <\.text>: + fffc: (48 01 00 04|04 00 01 48) b 20000 .* + 10000: (38 63 00 00|00 00 63 38) addi r3,r3,0 + 1000[02]: R_PPC_ADDR16_LO .bss + \.\.\. + 1fff0: (42 9f 00 05|05 00 9f 42) bcl .* + 1fff4: (7d 28 02 a6|a6 02 28 7d) mflr r9 + 1fff8: (3d 29 00 00|00 00 29 3d) addis r9,r9,0 + 1fff[8a]: R_PPC_REL16_HA .bss\+0x[46] + 1fffc: (48 00 00 14|14 00 00 48) b 20010 .* + 20000: (3c 60 00 00|00 00 60 3c) lis r3,0 + 2000[02]: R_PPC_ADDR16_HA .bss + 20004: (4b fe ff fc|fc ff fe 4b) b 10000 .* + 20008: (48 00 00 02|02 00 00 48) ba 0 .* + 2000c: (48 00 00 02|02 00 00 48) ba 0 .* + 20010: (39 29 01 00|00 01 29 39) addi r9,r9,256 + 2001[02]: R_PPC_REL16_LO .bss\+0x1[ce] + 20014: (4b ff ff ec|ec ff ff 4b) b 20000 .* + 20018: (48 00 00 02|02 00 00 48) ba 0 .* + 2001c: (48 00 00 02|02 00 00 48) ba 0 .* diff --git a/ld/testsuite/ld-powerpc/ppc476-shared.lnk b/ld/testsuite/ld-powerpc/ppc476-shared.lnk new file mode 100644 index 00000000000..5339358dbdf --- /dev/null +++ b/ld/testsuite/ld-powerpc/ppc476-shared.lnk @@ -0,0 +1,6 @@ +SECTIONS +{ + . = 0xfffc; + .text : { *(.text) } + .bss : { *(.bss) } +} diff --git a/ld/testsuite/ld-powerpc/ppc476-shared.s b/ld/testsuite/ld-powerpc/ppc476-shared.s new file mode 100644 index 00000000000..6774badb17b --- /dev/null +++ b/ld/testsuite/ld-powerpc/ppc476-shared.s @@ -0,0 +1,13 @@ + .text + lis 3,x@ha + addi 3,3,x@l + + .org 0xfff4 + bcl 20,31,.+4 +0: + mflr 9 + addis 9,9,x-0b@ha + addi 9,9,x-0b@l + + .section .bss,"aw",@nobits +x: .space 4 diff --git a/ld/testsuite/ld-powerpc/ppc476-shared2.d b/ld/testsuite/ld-powerpc/ppc476-shared2.d new file mode 100644 index 00000000000..ebb8bf19ff7 --- /dev/null +++ b/ld/testsuite/ld-powerpc/ppc476-shared2.d @@ -0,0 +1,12 @@ +#source: ppc476-shared.s +#as: -a32 +#ld: -melf32ppc -shared --ppc476-workaround -T ppc476-shared.lnk +#objdump: -R +#target: powerpc*-*-* + +.*: file format .* + +DYNAMIC RELOCATION RECORDS +OFFSET TYPE VALUE +0001000[02] R_PPC_ADDR16_LO \.text\+0x000200f4 +0002000[02] R_PPC_ADDR16_HA \.text\+0x000200f4