[v3] LoongArch: Fix the issue of excessive relocation generated by IE
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Commit Message
Currently, whether GD and IE generate dynamic relocation is
determined by SYMBOL_REFERENCES_LOCAL and bfd_link_executable.
This results in dynamic relocations still being generated in some
situations where dynamic relocations are not necessary (such as
the undefined weak symbol in static links).
We use RLARCH_TLS_GD_IE_NEED_DYN_RELOC macros to determine whether
GD/IE needs dynamic relocation. If GD/IE requires dynamic relocation,
set need_reloc to true and indx to be a dynamic index.
At the same time, some test cases were modified to use regular
expression matching instead of complete disassembly matching.
---
Changes from v1:
* A simpler way of calculating ie offset and desc offset is used.
* On LoongArch, the static tls and the dynamic tls use the same offset
calculation method, so tlsoff_base is added for offset calculation
of gd/desc/ie.
v1 link: https://sourceware.org/pipermail/binutils/2024-January/132071.html
---
Changes form v2:
* Variable and function names have been modified for easier understanding.
v2 link: https://sourceware.org/pipermail/binutils/2024-March/133139.html
---
bfd/elfnn-loongarch.c | 179 ++++++++++----------
ld/testsuite/ld-loongarch-elf/desc-ie.d | 4 +-
ld/testsuite/ld-loongarch-elf/tlsdesc-dso.d | 94 +++++-----
3 files changed, 142 insertions(+), 135 deletions(-)
Comments
On Thu, 2024-03-28 at 19:49 +0800, Lulu Cai wrote:
> Currently, whether GD and IE generate dynamic relocation is
> determined by SYMBOL_REFERENCES_LOCAL and bfd_link_executable.
> This results in dynamic relocations still being generated in some
> situations where dynamic relocations are not necessary (such as
> the undefined weak symbol in static links).
>
> We use RLARCH_TLS_GD_IE_NEED_DYN_RELOC macros to determine whether
> GD/IE needs dynamic relocation. If GD/IE requires dynamic relocation,
> set need_reloc to true and indx to be a dynamic index.
>
> At the same time, some test cases were modified to use regular
> expression matching instead of complete disassembly matching.
Hi,
The change has caused ld to emit some R_LARCH_NONE for many Glibc shared
libraries. I'm investigating the issue...
> ---
> Changes from v1:
> * A simpler way of calculating ie offset and desc offset is used.
>
> * On LoongArch, the static tls and the dynamic tls use the same offset
> calculation method, so tlsoff_base is added for offset calculation
> of gd/desc/ie.
>
> v1 link:
> https://sourceware.org/pipermail/binutils/2024-January/132071.html
>
> ---
> Changes form v2:
> * Variable and function names have been modified for easier
> understanding.
>
> v2 link:
> https://sourceware.org/pipermail/binutils/2024-March/133139.html
> ---
> bfd/elfnn-loongarch.c | 179 ++++++++++---------
> -
> ld/testsuite/ld-loongarch-elf/desc-ie.d | 4 +-
> ld/testsuite/ld-loongarch-elf/tlsdesc-dso.d | 94 +++++-----
> 3 files changed, 142 insertions(+), 135 deletions(-)
>
> diff --git a/bfd/elfnn-loongarch.c b/bfd/elfnn-loongarch.c
> index 6c5a9c5c0de..39a133465f6 100644
> --- a/bfd/elfnn-loongarch.c
> +++ b/bfd/elfnn-loongarch.c
> @@ -159,6 +159,27 @@ struct loongarch_elf_link_hash_table
> || (R_TYPE) == R_LARCH_TLS_LE64_LO20 \
> || (R_TYPE) == R_LARCH_TLS_LE64_HI12)
>
> +/* If TLS GD/IE need dynamic relocations, INDX will be the dynamic
> indx,
> + and set NEED_RELOC to true used in allocate_dynrelocs and
> + loongarch_elf_relocate_section for TLS GD/IE. */
> +#define LARCH_TLS_GD_IE_NEED_DYN_RELOC(INFO, DYN, H, INDX,
> NEED_RELOC) \
> + do \
> + { \
> + if ((H) != NULL \
> + && (H)->dynindx != -1 \
> + && WILL_CALL_FINISH_DYNAMIC_SYMBOL ((DYN), \
> + bfd_link_pic (INFO), (H))) \
> + (INDX) = (H)->dynindx; \
> + if (((H) == NULL \
> + || ELF_ST_VISIBILITY ((H)->other) == STV_DEFAULT \
> + || (H)->root.type != bfd_link_hash_undefweak) \
> + && (!bfd_link_executable (INFO) \
> + || (INDX) != 0)) \
> + (NEED_RELOC) = true; \
> + } \
> + while (0)
> +
> +
> /* Generate a PLT header. */
>
> static bool
> @@ -1294,40 +1315,24 @@ allocate_dynrelocs (struct elf_link_hash_entry
> *h, void *inf)
> h->got.offset = s->size;
> if (tls_type & (GOT_TLS_GD | GOT_TLS_IE | GOT_TLS_GDESC))
> {
> + int indx = 0;
> + bool need_reloc = false;
> + LARCH_TLS_GD_IE_NEED_DYN_RELOC (info, dyn, h, indx,
> + need_reloc);
> /* TLS_GD needs two dynamic relocs and two GOT slots. */
> if (tls_type & GOT_TLS_GD)
> {
> s->size += 2 * GOT_ENTRY_SIZE;
> - if (bfd_link_executable (info))
> - {
> - /* Link exe and not defined local. */
> - if (!SYMBOL_REFERENCES_LOCAL (info, h))
> - htab->elf.srelgot->size += 2 * sizeof
> (ElfNN_External_Rela);
> - }
> - else
> - {
> - if (SYMBOL_REFERENCES_LOCAL (info, h))
> - htab->elf.srelgot->size += sizeof
> (ElfNN_External_Rela);
> - else
> - htab->elf.srelgot->size += 2 * sizeof
> (ElfNN_External_Rela);
> - }
> + if (need_reloc)
> + htab->elf.srelgot->size += 2 * sizeof
> (ElfNN_External_Rela);
> }
>
> /* TLS_IE needs one dynamic reloc and one GOT slot. */
> if (tls_type & GOT_TLS_IE)
> {
> s->size += GOT_ENTRY_SIZE;
> -
> - if (bfd_link_executable (info))
> - {
> - /* Link exe and not defined local. */
> - if (!SYMBOL_REFERENCES_LOCAL (info, h))
> - htab->elf.srelgot->size += sizeof
> (ElfNN_External_Rela);
> - }
> - else
> - {
> - htab->elf.srelgot->size += sizeof
> (ElfNN_External_Rela);
> - }
> + if (need_reloc)
> + htab->elf.srelgot->size += 2 * sizeof
> (ElfNN_External_Rela);
> }
>
> /* TLS_DESC needs one dynamic reloc and two GOT slot. */
> @@ -2568,13 +2573,18 @@ loongarch_reloc_is_fatal (struct bfd_link_info
> *info,
> })
>
>
> +/* Compute the tp/dtp offset of a tls symbol.
> + It is dtp offset in dynamic tls model (gd/ld) and tp
> + offset in static tls model (ie/le). Both offsets are
> + calculated the same way on LoongArch, so the same
> + function is used. */
> static bfd_vma
> -tls_dtpoff_base (struct bfd_link_info *info)
> +tlsoff (struct bfd_link_info *info, bfd_vma addr)
> {
> /* If tls_sec is NULL, we should have signalled an error already.
> */
> if (elf_hash_table (info)->tls_sec == NULL)
> return 0;
> - return elf_hash_table (info)->tls_sec->vma;
> + return addr - elf_hash_table (info)->tls_sec->vma;
> }
>
>
> @@ -2908,7 +2918,7 @@ loongarch_elf_relocate_section (bfd *output_bfd,
> struct bfd_link_info *info,
> is_undefweak, name, "TLS section not be
> created");
> }
> else
> - relocation -= elf_hash_table (info)->tls_sec->vma;
> + relocation = tlsoff (info, relocation);
> }
> else
> {
> @@ -3434,7 +3444,7 @@ loongarch_elf_relocate_section (bfd *output_bfd,
> struct bfd_link_info *info,
>
> case R_LARCH_TLS_LE_HI20_R:
> relocation += rel->r_addend;
> - relocation -= elf_hash_table (info)->tls_sec->vma;
> + relocation = tlsoff (info, relocation);
> RELOCATE_TLS_TP32_HI20 (relocation);
> break;
>
> @@ -3617,7 +3627,7 @@ loongarch_elf_relocate_section (bfd *output_bfd,
> struct bfd_link_info *info,
> BFD_ASSERT (resolved_local && elf_hash_table (info)-
> >tls_sec);
>
> relocation += rel->r_addend;
> - relocation -= elf_hash_table (info)->tls_sec->vma;
> + relocation = tlsoff (info, relocation);
> break;
>
> /* TLS IE LD/GD process separately is troublesome.
> @@ -3672,71 +3682,72 @@ loongarch_elf_relocate_section (bfd
> *output_bfd, struct bfd_link_info *info,
> /* If a tls variable is accessed in multiple ways, GD uses
> the first two slots of GOT, desc follows with two slots,
> and IE uses one slot at the end. */
> - desc_off = 0;
> - if (GOT_TLS_GD_BOTH_P (tls_type))
> - desc_off = 2 * GOT_ENTRY_SIZE;
> -
> - ie_off = 0;
> - if (GOT_TLS_GD_BOTH_P (tls_type) && (tls_type &
> GOT_TLS_IE))
> - ie_off = 4 * GOT_ENTRY_SIZE;
> - else if (GOT_TLS_GD_ANY_P (tls_type) && (tls_type &
> GOT_TLS_IE))
> - ie_off = 2 * GOT_ENTRY_SIZE;
> + off = 0;
> + if (tls_type & GOT_TLS_GD)
> + off += 2 * GOT_ENTRY_SIZE;
> + desc_off = off;
> + if (tls_type & GOT_TLS_GDESC)
> + off += 2 * GOT_ENTRY_SIZE;
> + ie_off = off;
>
> if ((got_off & 1) == 0)
> {
> Elf_Internal_Rela rela;
> asection *relgot = htab->elf.srelgot;
> - bfd_vma tls_block_off = 0;
>
> - if (SYMBOL_REFERENCES_LOCAL (info, h))
> - {
> - BFD_ASSERT (elf_hash_table (info)->tls_sec);
> - tls_block_off = relocation
> - - elf_hash_table (info)->tls_sec->vma;
> - }
> + int indx = 0;
> + bool need_reloc = false;
> + LARCH_TLS_GD_IE_NEED_DYN_RELOC (info, is_dyn, h, indx,
> + need_reloc);
>
> if (tls_type & GOT_TLS_GD)
> {
> - rela.r_offset = sec_addr (got) + got_off;
> - rela.r_addend = 0;
> - if (SYMBOL_REFERENCES_LOCAL (info, h))
> + if (need_reloc)
> {
> - /* Local sym, used in exec, set module id 1.
> */
> - if (bfd_link_executable (info))
> - bfd_put_NN (output_bfd, 1, got->contents +
> got_off);
> + /* Dynamic resolved Module ID. */
> + rela.r_offset = sec_addr (got) + got_off;
> + rela.r_addend = 0;
> + rela.r_info = ELFNN_R_INFO
> (indx,R_LARCH_TLS_DTPMODNN);
> + bfd_put_NN (output_bfd, 0, got->contents +
> got_off);
> + loongarch_elf_append_rela (output_bfd, relgot,
> &rela);
> +
> + if (indx == 0)
> + {
> + /* Local symbol, tp offset has been known.
> */
> + BFD_ASSERT (! unresolved_reloc);
> + bfd_put_NN (output_bfd,
> + tlsoff (info, relocation),
> + (got->contents + got_off +
> GOT_ENTRY_SIZE));
> + }
> else
> {
> - rela.r_info = ELFNN_R_INFO (0,
> R_LARCH_TLS_DTPMODNN);
> + /* Dynamic resolved block offset. */
> + bfd_put_NN (output_bfd, 0,
> + got->contents + got_off +
> GOT_ENTRY_SIZE);
> + rela.r_info = ELFNN_R_INFO (indx,
> + R_LARCH_TLS_DTPRELNN)
> ;
> + rela.r_offset += GOT_ENTRY_SIZE;
> loongarch_elf_append_rela (output_bfd,
> relgot, &rela);
> }
> -
> - bfd_put_NN (output_bfd, tls_block_off,
> - got->contents + got_off +
> GOT_ENTRY_SIZE);
> }
> - /* Dynamic resolved. */
> else
> {
> - /* Dynamic relocate module id. */
> - rela.r_info = ELFNN_R_INFO (h->dynindx,
> -
> R_LARCH_TLS_DTPMODNN);
> - loongarch_elf_append_rela (output_bfd, relgot,
> &rela);
> -
> - /* Dynamic relocate offset of block. */
> - rela.r_offset += GOT_ENTRY_SIZE;
> - rela.r_info = ELFNN_R_INFO (h->dynindx,
> -
> R_LARCH_TLS_DTPRELNN);
> - loongarch_elf_append_rela (output_bfd, relgot,
> &rela);
> + /* In a static link or an executable link with
> the symbol
> + binding locally. Mark it as belonging to
> module 1. */
> + bfd_put_NN (output_bfd, 1, got->contents +
> got_off);
> + bfd_put_NN (output_bfd, tlsoff (info,
> relocation),
> + got->contents + got_off + GOT_ENTRY_SIZE);
> }
> }
> if (tls_type & GOT_TLS_GDESC)
> {
> /* Unless it is a static link, DESC always emits a
> dynamic relocation. */
> - int indx = h && h->dynindx != -1 ? h->dynindx : 0;
> + indx = h && h->dynindx != -1 ? h->dynindx : 0;
> rela.r_offset = sec_addr (got) + got_off +
> desc_off;
> rela.r_addend = 0;
> if (indx == 0)
> - rela.r_addend = relocation - tls_dtpoff_base
> (info);
> + rela.r_addend = tlsoff (info, relocation);
>
> rela.r_info = ELFNN_R_INFO (indx,
> R_LARCH_TLS_DESCNN);
> loongarch_elf_append_rela (output_bfd, relgot,
> &rela);
> @@ -3745,28 +3756,24 @@ loongarch_elf_relocate_section (bfd
> *output_bfd, struct bfd_link_info *info,
> }
> if (tls_type & GOT_TLS_IE)
> {
> - rela.r_offset = sec_addr (got) + got_off + ie_off;
> - if (SYMBOL_REFERENCES_LOCAL (info, h))
> + if (need_reloc)
> {
> - /* Local sym, used in exec, set module id 1.
> */
> - if (!bfd_link_executable (info))
> - {
> - rela.r_info = ELFNN_R_INFO (0,
> R_LARCH_TLS_TPRELNN);
> - rela.r_addend = tls_block_off;
> - loongarch_elf_append_rela (output_bfd,
> relgot, &rela);
> - }
> + bfd_put_NN (output_bfd, 0,
> + got->contents + got_off + ie_off);
> + rela.r_offset = sec_addr (got) + got_off +
> ie_off;
> + rela.r_addend = 0;
>
> - bfd_put_NN (output_bfd, tls_block_off,
> - got->contents + got_off + ie_off);
> + if (indx == 0)
> + rela.r_addend = tlsoff (info, relocation);
> + rela.r_info = ELFNN_R_INFO (indx,
> R_LARCH_TLS_TPRELNN);
> + loongarch_elf_append_rela (output_bfd, relgot,
> &rela);
> }
> - /* Dynamic resolved. */
> else
> {
> - /* Dynamic relocate offset of block. */
> - rela.r_info = ELFNN_R_INFO (h->dynindx,
> -
> R_LARCH_TLS_TPRELNN);
> - rela.r_addend = 0;
> - loongarch_elf_append_rela (output_bfd, relgot,
> &rela);
> + /* In a static link or an executable link with
> the symbol
> + bindinglocally, compute offset directly. */
> + bfd_put_NN (output_bfd, tlsoff (info,
> relocation),
> + got->contents + got_off + ie_off);
> }
> }
> }
> @@ -3805,7 +3812,7 @@ loongarch_elf_relocate_section (bfd *output_bfd,
> struct bfd_link_info *info,
>
> tls_type = _bfd_loongarch_elf_tls_type (input_bfd, h,
> r_symndx);
> /* Use both TLS_GD and TLS_DESC. */
> - if ((tls_type & GOT_TLS_GD) && (tls_type &
> GOT_TLS_GDESC))
> + if (GOT_TLS_GD_BOTH_P (tls_type))
> relocation += 2 * GOT_ENTRY_SIZE;
>
> if (r_type == R_LARCH_TLS_DESC64_PC_LO20)
> diff --git a/ld/testsuite/ld-loongarch-elf/desc-ie.d
> b/ld/testsuite/ld-loongarch-elf/desc-ie.d
> index e1f49e2d556..c833b233d42 100644
> --- a/ld/testsuite/ld-loongarch-elf/desc-ie.d
> +++ b/ld/testsuite/ld-loongarch-elf/desc-ie.d
> @@ -9,6 +9,6 @@ Disassembly of section .text:
>
> [0-9a-f]+ <fn1>:
> +[0-9a-f]+: 1a000084 pcalau12i \$a0, .*
> - +[0-9a-f]+: 28cca084 ld.d \$a0, \$a0, .*
> + +[0-9a-f]+: 28cd0084 ld.d \$a0, \$a0, .*
> +[0-9a-f]+: 1a000084 pcalau12i \$a0, .*
> - +[0-9a-f]+: 28cca084 ld.d \$a0, \$a0, .*
> + +[0-9a-f]+: 28cd0084 ld.d \$a0, \$a0, .*
> diff --git a/ld/testsuite/ld-loongarch-elf/tlsdesc-dso.d
> b/ld/testsuite/ld-loongarch-elf/tlsdesc-dso.d
> index 84ea97e076b..8f66302f1cf 100644
> --- a/ld/testsuite/ld-loongarch-elf/tlsdesc-dso.d
> +++ b/ld/testsuite/ld-loongarch-elf/tlsdesc-dso.d
> @@ -8,53 +8,53 @@
>
> Disassembly of section .text:
>
> -0+448 <fun_gl1>:
> - 448: 18021584 pcaddi \$a0, 4268
> - 44c: 1a000084 pcalau12i \$a0, 4
> - 450: 28dc2084 ld.d \$a0, \$a0, 1800
> - 454: 18021364 pcaddi \$a0, 4251
> - 458: 180213c4 pcaddi \$a0, 4254
> - 45c: 28c00081 ld.d \$ra, \$a0, 0
> - 460: 4c000021 jirl \$ra, \$ra, 0
> - 464: 1a000084 pcalau12i \$a0, 4
> - 468: 28dae084 ld.d \$a0, \$a0, 1720
> - 46c: 1a000084 pcalau12i \$a0, 4
> - 470: 28dae084 ld.d \$a0, \$a0, 1720
> - 474: 18021364 pcaddi \$a0, 4251
> - 478: 18021344 pcaddi \$a0, 4250
> - 47c: 28c00081 ld.d \$ra, \$a0, 0
> - 480: 4c000021 jirl \$ra, \$ra, 0
> - 484: 1a000084 pcalau12i \$a0, 4
> - 488: 28dbc084 ld.d \$a0, \$a0, 1776
> +[0-9a-f]+ <fun_gl1>:
> + +[0-9a-f]+: 18021584 pcaddi \$a0, 4268
> + +[0-9a-f]+: 1a000084 pcalau12i \$a0, 4
> + +[0-9a-f]+: 28dd4084 ld.d \$a0, \$a0, 1872
> + +[0-9a-f]+: 18021364 pcaddi \$a0, 4251
> + +[0-9a-f]+: 180213c4 pcaddi \$a0, 4254
> + +[0-9a-f]+: 28c00081 ld.d \$ra, \$a0, 0
> + +[0-9a-f]+: 4c000021 jirl \$ra, \$ra, 0
> + +[0-9a-f]+: 1a000084 pcalau12i \$a0, 4
> + +[0-9a-f]+: 28dc0084 ld.d \$a0, \$a0, 1792
> + +[0-9a-f]+: 1a000084 pcalau12i \$a0, 4
> + +[0-9a-f]+: 28dc0084 ld.d \$a0, \$a0, 1792
> + +[0-9a-f]+: 18021364 pcaddi \$a0, 4251
> + +[0-9a-f]+: 180213c4 pcaddi \$a0, 4254
> + +[0-9a-f]+: 28c00081 ld.d \$ra, \$a0, 0
> + +[0-9a-f]+: 4c000021 jirl \$ra, \$ra, 0
> + +[0-9a-f]+: 1a000084 pcalau12i \$a0, 4
> + +[0-9a-f]+: 28dce084 ld.d \$a0, \$a0, 1848
>
> -0+48c <fun_lo>:
> - 48c: 1a000084 pcalau12i \$a0, 4
> - 490: 28d98084 ld.d \$a0, \$a0, 1632
> - 494: 18020de4 pcaddi \$a0, 4207
> - 498: 18020f04 pcaddi \$a0, 4216
> - 49c: 28c00081 ld.d \$ra, \$a0, 0
> - 4a0: 4c000021 jirl \$ra, \$ra, 0
> - 4a4: 18020e24 pcaddi \$a0, 4209
> - 4a8: 1a000084 pcalau12i \$a0, 4
> - 4ac: 28da2084 ld.d \$a0, \$a0, 1672
> - 4b0: 1a000084 pcalau12i \$a0, 4
> - 4b4: 28da2084 ld.d \$a0, \$a0, 1672
> - 4b8: 18020ec4 pcaddi \$a0, 4214
> - 4bc: 28c00081 ld.d \$ra, \$a0, 0
> - 4c0: 4c000021 jirl \$ra, \$ra, 0
> - 4c4: 18020e64 pcaddi \$a0, 4211
> - 4c8: 1a000084 pcalau12i \$a0, 4
> - 4cc: 28da8084 ld.d \$a0, \$a0, 1696
> +[0-9a-f]+ <fun_lo>:
> + +[0-9a-f]+: 1a000084 pcalau12i \$a0, 4
> + +[0-9a-f]+: 28daa084 ld.d \$a0, \$a0, 1704
> + +[0-9a-f]+: 18020de4 pcaddi \$a0, 4207
> + +[0-9a-f]+: 18020f04 pcaddi \$a0, 4216
> + +[0-9a-f]+: 28c00081 ld.d \$ra, \$a0, 0
> + +[0-9a-f]+: 4c000021 jirl \$ra, \$ra, 0
> + +[0-9a-f]+: 18020e24 pcaddi \$a0, 4209
> + +[0-9a-f]+: 1a000084 pcalau12i \$a0, 4
> + +[0-9a-f]+: 28db4084 ld.d \$a0, \$a0, 1744
> + +[0-9a-f]+: 1a000084 pcalau12i \$a0, 4
> + +[0-9a-f]+: 28db4084 ld.d \$a0, \$a0, 1744
> + +[0-9a-f]+: 18020f44 pcaddi \$a0, 4218
> + +[0-9a-f]+: 28c00081 ld.d \$ra, \$a0, 0
> + +[0-9a-f]+: 4c000021 jirl \$ra, \$ra, 0
> + +[0-9a-f]+: 18020e64 pcaddi \$a0, 4211
> + +[0-9a-f]+: 1a000084 pcalau12i \$a0, 4
> + +[0-9a-f]+: 28dba084 ld.d \$a0, \$a0, 1768
>
> -0+4d0 <fun_external>:
> - 4d0: 18020ec4 pcaddi \$a0, 4214
> - 4d4: 28c00081 ld.d \$ra, \$a0, 0
> - 4d8: 4c000021 jirl \$ra, \$ra, 0
> +[0-9a-f]+ <fun_external>:
> + +[0-9a-f]+: 18020ec4 pcaddi \$a0, 4214
> + +[0-9a-f]+: 28c00081 ld.d \$ra, \$a0, 0
> + +[0-9a-f]+: 4c000021 jirl \$ra, \$ra, 0
>
> -0+4dc <fun_hidden>:
> - 4dc: 18021224 pcaddi \$a0, 4241
> - 4e0: 28c00081 ld.d \$ra, \$a0, 0
> - 4e4: 4c000021 jirl \$ra, \$ra, 0
> - 4e8: 18021144 pcaddi \$a0, 4234
> - 4ec: 28c00081 ld.d \$ra, \$a0, 0
> - 4f0: 4c000021 jirl \$ra, \$ra, 0
> +[0-9a-f]+ <fun_hidden>:
> + +[0-9a-f]+: 18021224 pcaddi \$a0, 4241
> + +[0-9a-f]+: 28c00081 ld.d \$ra, \$a0, 0
> + +[0-9a-f]+: 4c000021 jirl \$ra, \$ra, 0
> + +[0-9a-f]+: 18021144 pcaddi \$a0, 4234
> + +[0-9a-f]+: 28c00081 ld.d \$ra, \$a0, 0
> + +[0-9a-f]+: 4c000021 jirl \$ra, \$ra, 0
On Wed, 2024-06-19 at 13:02 +0800, Xi Ruoyao wrote:
> On Thu, 2024-03-28 at 19:49 +0800, Lulu Cai wrote:
> > Currently, whether GD and IE generate dynamic relocation is
> > determined by SYMBOL_REFERENCES_LOCAL and bfd_link_executable.
> > This results in dynamic relocations still being generated in some
> > situations where dynamic relocations are not necessary (such as
> > the undefined weak symbol in static links).
> >
> > We use RLARCH_TLS_GD_IE_NEED_DYN_RELOC macros to determine whether
> > GD/IE needs dynamic relocation. If GD/IE requires dynamic relocation,
> > set need_reloc to true and indx to be a dynamic index.
> >
> > At the same time, some test cases were modified to use regular
> > expression matching instead of complete disassembly matching.
>
> Hi,
>
> The change has caused ld to emit some R_LARCH_NONE for many Glibc shared
> libraries. I'm investigating the issue...
https://sourceware.org/pipermail/binutils/2024-June/134902.html
@@ -159,6 +159,27 @@ struct loongarch_elf_link_hash_table
|| (R_TYPE) == R_LARCH_TLS_LE64_LO20 \
|| (R_TYPE) == R_LARCH_TLS_LE64_HI12)
+/* If TLS GD/IE need dynamic relocations, INDX will be the dynamic indx,
+ and set NEED_RELOC to true used in allocate_dynrelocs and
+ loongarch_elf_relocate_section for TLS GD/IE. */
+#define LARCH_TLS_GD_IE_NEED_DYN_RELOC(INFO, DYN, H, INDX, NEED_RELOC) \
+ do \
+ { \
+ if ((H) != NULL \
+ && (H)->dynindx != -1 \
+ && WILL_CALL_FINISH_DYNAMIC_SYMBOL ((DYN), \
+ bfd_link_pic (INFO), (H))) \
+ (INDX) = (H)->dynindx; \
+ if (((H) == NULL \
+ || ELF_ST_VISIBILITY ((H)->other) == STV_DEFAULT \
+ || (H)->root.type != bfd_link_hash_undefweak) \
+ && (!bfd_link_executable (INFO) \
+ || (INDX) != 0)) \
+ (NEED_RELOC) = true; \
+ } \
+ while (0)
+
+
/* Generate a PLT header. */
static bool
@@ -1294,40 +1315,24 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf)
h->got.offset = s->size;
if (tls_type & (GOT_TLS_GD | GOT_TLS_IE | GOT_TLS_GDESC))
{
+ int indx = 0;
+ bool need_reloc = false;
+ LARCH_TLS_GD_IE_NEED_DYN_RELOC (info, dyn, h, indx,
+ need_reloc);
/* TLS_GD needs two dynamic relocs and two GOT slots. */
if (tls_type & GOT_TLS_GD)
{
s->size += 2 * GOT_ENTRY_SIZE;
- if (bfd_link_executable (info))
- {
- /* Link exe and not defined local. */
- if (!SYMBOL_REFERENCES_LOCAL (info, h))
- htab->elf.srelgot->size += 2 * sizeof (ElfNN_External_Rela);
- }
- else
- {
- if (SYMBOL_REFERENCES_LOCAL (info, h))
- htab->elf.srelgot->size += sizeof (ElfNN_External_Rela);
- else
- htab->elf.srelgot->size += 2 * sizeof (ElfNN_External_Rela);
- }
+ if (need_reloc)
+ htab->elf.srelgot->size += 2 * sizeof (ElfNN_External_Rela);
}
/* TLS_IE needs one dynamic reloc and one GOT slot. */
if (tls_type & GOT_TLS_IE)
{
s->size += GOT_ENTRY_SIZE;
-
- if (bfd_link_executable (info))
- {
- /* Link exe and not defined local. */
- if (!SYMBOL_REFERENCES_LOCAL (info, h))
- htab->elf.srelgot->size += sizeof (ElfNN_External_Rela);
- }
- else
- {
- htab->elf.srelgot->size += sizeof (ElfNN_External_Rela);
- }
+ if (need_reloc)
+ htab->elf.srelgot->size += 2 * sizeof (ElfNN_External_Rela);
}
/* TLS_DESC needs one dynamic reloc and two GOT slot. */
@@ -2568,13 +2573,18 @@ loongarch_reloc_is_fatal (struct bfd_link_info *info,
})
+/* Compute the tp/dtp offset of a tls symbol.
+ It is dtp offset in dynamic tls model (gd/ld) and tp
+ offset in static tls model (ie/le). Both offsets are
+ calculated the same way on LoongArch, so the same
+ function is used. */
static bfd_vma
-tls_dtpoff_base (struct bfd_link_info *info)
+tlsoff (struct bfd_link_info *info, bfd_vma addr)
{
/* If tls_sec is NULL, we should have signalled an error already. */
if (elf_hash_table (info)->tls_sec == NULL)
return 0;
- return elf_hash_table (info)->tls_sec->vma;
+ return addr - elf_hash_table (info)->tls_sec->vma;
}
@@ -2908,7 +2918,7 @@ loongarch_elf_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
is_undefweak, name, "TLS section not be created");
}
else
- relocation -= elf_hash_table (info)->tls_sec->vma;
+ relocation = tlsoff (info, relocation);
}
else
{
@@ -3434,7 +3444,7 @@ loongarch_elf_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
case R_LARCH_TLS_LE_HI20_R:
relocation += rel->r_addend;
- relocation -= elf_hash_table (info)->tls_sec->vma;
+ relocation = tlsoff (info, relocation);
RELOCATE_TLS_TP32_HI20 (relocation);
break;
@@ -3617,7 +3627,7 @@ loongarch_elf_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
BFD_ASSERT (resolved_local && elf_hash_table (info)->tls_sec);
relocation += rel->r_addend;
- relocation -= elf_hash_table (info)->tls_sec->vma;
+ relocation = tlsoff (info, relocation);
break;
/* TLS IE LD/GD process separately is troublesome.
@@ -3672,71 +3682,72 @@ loongarch_elf_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
/* If a tls variable is accessed in multiple ways, GD uses
the first two slots of GOT, desc follows with two slots,
and IE uses one slot at the end. */
- desc_off = 0;
- if (GOT_TLS_GD_BOTH_P (tls_type))
- desc_off = 2 * GOT_ENTRY_SIZE;
-
- ie_off = 0;
- if (GOT_TLS_GD_BOTH_P (tls_type) && (tls_type & GOT_TLS_IE))
- ie_off = 4 * GOT_ENTRY_SIZE;
- else if (GOT_TLS_GD_ANY_P (tls_type) && (tls_type & GOT_TLS_IE))
- ie_off = 2 * GOT_ENTRY_SIZE;
+ off = 0;
+ if (tls_type & GOT_TLS_GD)
+ off += 2 * GOT_ENTRY_SIZE;
+ desc_off = off;
+ if (tls_type & GOT_TLS_GDESC)
+ off += 2 * GOT_ENTRY_SIZE;
+ ie_off = off;
if ((got_off & 1) == 0)
{
Elf_Internal_Rela rela;
asection *relgot = htab->elf.srelgot;
- bfd_vma tls_block_off = 0;
- if (SYMBOL_REFERENCES_LOCAL (info, h))
- {
- BFD_ASSERT (elf_hash_table (info)->tls_sec);
- tls_block_off = relocation
- - elf_hash_table (info)->tls_sec->vma;
- }
+ int indx = 0;
+ bool need_reloc = false;
+ LARCH_TLS_GD_IE_NEED_DYN_RELOC (info, is_dyn, h, indx,
+ need_reloc);
if (tls_type & GOT_TLS_GD)
{
- rela.r_offset = sec_addr (got) + got_off;
- rela.r_addend = 0;
- if (SYMBOL_REFERENCES_LOCAL (info, h))
+ if (need_reloc)
{
- /* Local sym, used in exec, set module id 1. */
- if (bfd_link_executable (info))
- bfd_put_NN (output_bfd, 1, got->contents + got_off);
+ /* Dynamic resolved Module ID. */
+ rela.r_offset = sec_addr (got) + got_off;
+ rela.r_addend = 0;
+ rela.r_info = ELFNN_R_INFO (indx,R_LARCH_TLS_DTPMODNN);
+ bfd_put_NN (output_bfd, 0, got->contents + got_off);
+ loongarch_elf_append_rela (output_bfd, relgot, &rela);
+
+ if (indx == 0)
+ {
+ /* Local symbol, tp offset has been known. */
+ BFD_ASSERT (! unresolved_reloc);
+ bfd_put_NN (output_bfd,
+ tlsoff (info, relocation),
+ (got->contents + got_off + GOT_ENTRY_SIZE));
+ }
else
{
- rela.r_info = ELFNN_R_INFO (0, R_LARCH_TLS_DTPMODNN);
+ /* Dynamic resolved block offset. */
+ bfd_put_NN (output_bfd, 0,
+ got->contents + got_off + GOT_ENTRY_SIZE);
+ rela.r_info = ELFNN_R_INFO (indx,
+ R_LARCH_TLS_DTPRELNN);
+ rela.r_offset += GOT_ENTRY_SIZE;
loongarch_elf_append_rela (output_bfd, relgot, &rela);
}
-
- bfd_put_NN (output_bfd, tls_block_off,
- got->contents + got_off + GOT_ENTRY_SIZE);
}
- /* Dynamic resolved. */
else
{
- /* Dynamic relocate module id. */
- rela.r_info = ELFNN_R_INFO (h->dynindx,
- R_LARCH_TLS_DTPMODNN);
- loongarch_elf_append_rela (output_bfd, relgot, &rela);
-
- /* Dynamic relocate offset of block. */
- rela.r_offset += GOT_ENTRY_SIZE;
- rela.r_info = ELFNN_R_INFO (h->dynindx,
- R_LARCH_TLS_DTPRELNN);
- loongarch_elf_append_rela (output_bfd, relgot, &rela);
+ /* In a static link or an executable link with the symbol
+ binding locally. Mark it as belonging to module 1. */
+ bfd_put_NN (output_bfd, 1, got->contents + got_off);
+ bfd_put_NN (output_bfd, tlsoff (info, relocation),
+ got->contents + got_off + GOT_ENTRY_SIZE);
}
}
if (tls_type & GOT_TLS_GDESC)
{
/* Unless it is a static link, DESC always emits a
dynamic relocation. */
- int indx = h && h->dynindx != -1 ? h->dynindx : 0;
+ indx = h && h->dynindx != -1 ? h->dynindx : 0;
rela.r_offset = sec_addr (got) + got_off + desc_off;
rela.r_addend = 0;
if (indx == 0)
- rela.r_addend = relocation - tls_dtpoff_base (info);
+ rela.r_addend = tlsoff (info, relocation);
rela.r_info = ELFNN_R_INFO (indx, R_LARCH_TLS_DESCNN);
loongarch_elf_append_rela (output_bfd, relgot, &rela);
@@ -3745,28 +3756,24 @@ loongarch_elf_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
}
if (tls_type & GOT_TLS_IE)
{
- rela.r_offset = sec_addr (got) + got_off + ie_off;
- if (SYMBOL_REFERENCES_LOCAL (info, h))
+ if (need_reloc)
{
- /* Local sym, used in exec, set module id 1. */
- if (!bfd_link_executable (info))
- {
- rela.r_info = ELFNN_R_INFO (0, R_LARCH_TLS_TPRELNN);
- rela.r_addend = tls_block_off;
- loongarch_elf_append_rela (output_bfd, relgot, &rela);
- }
+ bfd_put_NN (output_bfd, 0,
+ got->contents + got_off + ie_off);
+ rela.r_offset = sec_addr (got) + got_off + ie_off;
+ rela.r_addend = 0;
- bfd_put_NN (output_bfd, tls_block_off,
- got->contents + got_off + ie_off);
+ if (indx == 0)
+ rela.r_addend = tlsoff (info, relocation);
+ rela.r_info = ELFNN_R_INFO (indx, R_LARCH_TLS_TPRELNN);
+ loongarch_elf_append_rela (output_bfd, relgot, &rela);
}
- /* Dynamic resolved. */
else
{
- /* Dynamic relocate offset of block. */
- rela.r_info = ELFNN_R_INFO (h->dynindx,
- R_LARCH_TLS_TPRELNN);
- rela.r_addend = 0;
- loongarch_elf_append_rela (output_bfd, relgot, &rela);
+ /* In a static link or an executable link with the symbol
+ bindinglocally, compute offset directly. */
+ bfd_put_NN (output_bfd, tlsoff (info, relocation),
+ got->contents + got_off + ie_off);
}
}
}
@@ -3805,7 +3812,7 @@ loongarch_elf_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
tls_type = _bfd_loongarch_elf_tls_type (input_bfd, h, r_symndx);
/* Use both TLS_GD and TLS_DESC. */
- if ((tls_type & GOT_TLS_GD) && (tls_type & GOT_TLS_GDESC))
+ if (GOT_TLS_GD_BOTH_P (tls_type))
relocation += 2 * GOT_ENTRY_SIZE;
if (r_type == R_LARCH_TLS_DESC64_PC_LO20)
@@ -9,6 +9,6 @@ Disassembly of section .text:
[0-9a-f]+ <fn1>:
+[0-9a-f]+: 1a000084 pcalau12i \$a0, .*
- +[0-9a-f]+: 28cca084 ld.d \$a0, \$a0, .*
+ +[0-9a-f]+: 28cd0084 ld.d \$a0, \$a0, .*
+[0-9a-f]+: 1a000084 pcalau12i \$a0, .*
- +[0-9a-f]+: 28cca084 ld.d \$a0, \$a0, .*
+ +[0-9a-f]+: 28cd0084 ld.d \$a0, \$a0, .*
@@ -8,53 +8,53 @@
Disassembly of section .text:
-0+448 <fun_gl1>:
- 448: 18021584 pcaddi \$a0, 4268
- 44c: 1a000084 pcalau12i \$a0, 4
- 450: 28dc2084 ld.d \$a0, \$a0, 1800
- 454: 18021364 pcaddi \$a0, 4251
- 458: 180213c4 pcaddi \$a0, 4254
- 45c: 28c00081 ld.d \$ra, \$a0, 0
- 460: 4c000021 jirl \$ra, \$ra, 0
- 464: 1a000084 pcalau12i \$a0, 4
- 468: 28dae084 ld.d \$a0, \$a0, 1720
- 46c: 1a000084 pcalau12i \$a0, 4
- 470: 28dae084 ld.d \$a0, \$a0, 1720
- 474: 18021364 pcaddi \$a0, 4251
- 478: 18021344 pcaddi \$a0, 4250
- 47c: 28c00081 ld.d \$ra, \$a0, 0
- 480: 4c000021 jirl \$ra, \$ra, 0
- 484: 1a000084 pcalau12i \$a0, 4
- 488: 28dbc084 ld.d \$a0, \$a0, 1776
+[0-9a-f]+ <fun_gl1>:
+ +[0-9a-f]+: 18021584 pcaddi \$a0, 4268
+ +[0-9a-f]+: 1a000084 pcalau12i \$a0, 4
+ +[0-9a-f]+: 28dd4084 ld.d \$a0, \$a0, 1872
+ +[0-9a-f]+: 18021364 pcaddi \$a0, 4251
+ +[0-9a-f]+: 180213c4 pcaddi \$a0, 4254
+ +[0-9a-f]+: 28c00081 ld.d \$ra, \$a0, 0
+ +[0-9a-f]+: 4c000021 jirl \$ra, \$ra, 0
+ +[0-9a-f]+: 1a000084 pcalau12i \$a0, 4
+ +[0-9a-f]+: 28dc0084 ld.d \$a0, \$a0, 1792
+ +[0-9a-f]+: 1a000084 pcalau12i \$a0, 4
+ +[0-9a-f]+: 28dc0084 ld.d \$a0, \$a0, 1792
+ +[0-9a-f]+: 18021364 pcaddi \$a0, 4251
+ +[0-9a-f]+: 180213c4 pcaddi \$a0, 4254
+ +[0-9a-f]+: 28c00081 ld.d \$ra, \$a0, 0
+ +[0-9a-f]+: 4c000021 jirl \$ra, \$ra, 0
+ +[0-9a-f]+: 1a000084 pcalau12i \$a0, 4
+ +[0-9a-f]+: 28dce084 ld.d \$a0, \$a0, 1848
-0+48c <fun_lo>:
- 48c: 1a000084 pcalau12i \$a0, 4
- 490: 28d98084 ld.d \$a0, \$a0, 1632
- 494: 18020de4 pcaddi \$a0, 4207
- 498: 18020f04 pcaddi \$a0, 4216
- 49c: 28c00081 ld.d \$ra, \$a0, 0
- 4a0: 4c000021 jirl \$ra, \$ra, 0
- 4a4: 18020e24 pcaddi \$a0, 4209
- 4a8: 1a000084 pcalau12i \$a0, 4
- 4ac: 28da2084 ld.d \$a0, \$a0, 1672
- 4b0: 1a000084 pcalau12i \$a0, 4
- 4b4: 28da2084 ld.d \$a0, \$a0, 1672
- 4b8: 18020ec4 pcaddi \$a0, 4214
- 4bc: 28c00081 ld.d \$ra, \$a0, 0
- 4c0: 4c000021 jirl \$ra, \$ra, 0
- 4c4: 18020e64 pcaddi \$a0, 4211
- 4c8: 1a000084 pcalau12i \$a0, 4
- 4cc: 28da8084 ld.d \$a0, \$a0, 1696
+[0-9a-f]+ <fun_lo>:
+ +[0-9a-f]+: 1a000084 pcalau12i \$a0, 4
+ +[0-9a-f]+: 28daa084 ld.d \$a0, \$a0, 1704
+ +[0-9a-f]+: 18020de4 pcaddi \$a0, 4207
+ +[0-9a-f]+: 18020f04 pcaddi \$a0, 4216
+ +[0-9a-f]+: 28c00081 ld.d \$ra, \$a0, 0
+ +[0-9a-f]+: 4c000021 jirl \$ra, \$ra, 0
+ +[0-9a-f]+: 18020e24 pcaddi \$a0, 4209
+ +[0-9a-f]+: 1a000084 pcalau12i \$a0, 4
+ +[0-9a-f]+: 28db4084 ld.d \$a0, \$a0, 1744
+ +[0-9a-f]+: 1a000084 pcalau12i \$a0, 4
+ +[0-9a-f]+: 28db4084 ld.d \$a0, \$a0, 1744
+ +[0-9a-f]+: 18020f44 pcaddi \$a0, 4218
+ +[0-9a-f]+: 28c00081 ld.d \$ra, \$a0, 0
+ +[0-9a-f]+: 4c000021 jirl \$ra, \$ra, 0
+ +[0-9a-f]+: 18020e64 pcaddi \$a0, 4211
+ +[0-9a-f]+: 1a000084 pcalau12i \$a0, 4
+ +[0-9a-f]+: 28dba084 ld.d \$a0, \$a0, 1768
-0+4d0 <fun_external>:
- 4d0: 18020ec4 pcaddi \$a0, 4214
- 4d4: 28c00081 ld.d \$ra, \$a0, 0
- 4d8: 4c000021 jirl \$ra, \$ra, 0
+[0-9a-f]+ <fun_external>:
+ +[0-9a-f]+: 18020ec4 pcaddi \$a0, 4214
+ +[0-9a-f]+: 28c00081 ld.d \$ra, \$a0, 0
+ +[0-9a-f]+: 4c000021 jirl \$ra, \$ra, 0
-0+4dc <fun_hidden>:
- 4dc: 18021224 pcaddi \$a0, 4241
- 4e0: 28c00081 ld.d \$ra, \$a0, 0
- 4e4: 4c000021 jirl \$ra, \$ra, 0
- 4e8: 18021144 pcaddi \$a0, 4234
- 4ec: 28c00081 ld.d \$ra, \$a0, 0
- 4f0: 4c000021 jirl \$ra, \$ra, 0
+[0-9a-f]+ <fun_hidden>:
+ +[0-9a-f]+: 18021224 pcaddi \$a0, 4241
+ +[0-9a-f]+: 28c00081 ld.d \$ra, \$a0, 0
+ +[0-9a-f]+: 4c000021 jirl \$ra, \$ra, 0
+ +[0-9a-f]+: 18021144 pcaddi \$a0, 4234
+ +[0-9a-f]+: 28c00081 ld.d \$ra, \$a0, 0
+ +[0-9a-f]+: 4c000021 jirl \$ra, \$ra, 0