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LoongArch: Fix the issue of excessive relocation generated by GD and IE

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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.
This commit is contained in:
Lulu Cai 2024-03-21 16:33:21 +08:00 • committed by liuzhensong
parent 7918b183ec
commit b67a17aa7c
3 changed files with 142 additions and 135 deletions
Download patch file Download diff file Expand all files Collapse all files

179
bfd/elfnn-loongarch.c
View file

@ -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
@ -1276,40 +1297,24 @@ 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. */
@ -2550,13 +2555,18 @@ 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;
}
@ -2890,7 +2900,7 @@ 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
{
@ -3416,7 +3426,7 @@ 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;
@ -3599,7 +3609,7 @@ 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.
@ -3654,71 +3664,72 @@ 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);
@ -3727,28 +3738,24 @@ 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);
}
}
}
@ -3787,7 +3794,7 @@ 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)

4
ld/testsuite/ld-loongarch-elf/desc-ie.d
View file

@ -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, .*

94
ld/testsuite/ld-loongarch-elf/tlsdesc-dso.d
View file

@ -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