* [binutils-gdb] LoongArch: Remove "elf_seg_map (info->output_bfd) == NULL" relaxation condition
@ 2023-11-17 8:43 liu & zhensong
0 siblings, 0 replies; only message in thread
From: liu & zhensong @ 2023-11-17 8:43 UTC (permalink / raw)
To: bfd-cvs
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=4f2469d0cdd0f3bd1d9040521e002e8df0a63a98
commit 4f2469d0cdd0f3bd1d9040521e002e8df0a63a98
Author: mengqinggang <mengqinggang@loongson.cn>
Date: Thu Nov 16 19:19:14 2023 +0800
LoongArch: Remove "elf_seg_map (info->output_bfd) == NULL" relaxation condition
Previously the condition prevented shared objects from being relaxed.
To remove the limitation, we need to update program header size and
.eh_frame_hdr size before relaxation.
Diff:
---
bfd/elfnn-loongarch.c | 25 +++++++++++++++++++++----
ld/emultempl/loongarchelf.em | 18 ++++++++++++++++++
2 files changed, 39 insertions(+), 4 deletions(-)
diff --git a/bfd/elfnn-loongarch.c b/bfd/elfnn-loongarch.c
index 7436a14441f..987e5b98bc0 100644
--- a/bfd/elfnn-loongarch.c
+++ b/bfd/elfnn-loongarch.c
@@ -3738,7 +3738,7 @@ loongarch_relax_delete_bytes (bfd *abfd,
/* Relax pcalau12i,addi.d => pcaddi. */
static bool
-loongarch_relax_pcala_addi (bfd *abfd, asection *sec,
+loongarch_relax_pcala_addi (bfd *abfd, asection *sec, asection *sym_sec,
Elf_Internal_Rela *rel_hi, bfd_vma symval,
struct bfd_link_info *info, bool *again)
{
@@ -3747,7 +3747,24 @@ loongarch_relax_pcala_addi (bfd *abfd, asection *sec,
uint32_t pca = bfd_get (32, abfd, contents + rel_hi->r_offset);
uint32_t add = bfd_get (32, abfd, contents + rel_lo->r_offset);
uint32_t rd = pca & 0x1f;
+
+ /* This section's output_offset need to subtract the bytes of instructions
+ relaxed by the previous sections, so it needs to be updated beforehand.
+ size_input_section already took care of updating it after relaxation,
+ so we additionally update once here. */
+ sec->output_offset = sec->output_section->size;
bfd_vma pc = sec_addr (sec) + rel_hi->r_offset;
+
+ /* If pc and symbol not in the same segment, add/sub segment alignment.
+ FIXME: if there are multiple readonly segments? */
+ if (!(sym_sec->flags & SEC_READONLY))
+ {
+ if (symval > pc)
+ pc -= info->maxpagesize;
+ else if (symval < pc)
+ pc += info->maxpagesize;
+ }
+
const uint32_t addi_d = 0x02c00000;
const uint32_t pcaddi = 0x18000000;
@@ -3889,7 +3906,6 @@ loongarch_elf_relax_section (bfd *abfd, asection *sec,
|| sec->sec_flg0
|| (sec->flags & SEC_RELOC) == 0
|| sec->reloc_count == 0
- || elf_seg_map (info->output_bfd) == NULL
|| (info->disable_target_specific_optimizations
&& info->relax_pass == 0)
/* The exp_seg_relro_adjust is enum phase_enum (0x4),
@@ -4009,14 +4025,15 @@ loongarch_elf_relax_section (bfd *abfd, asection *sec,
break;
case R_LARCH_PCALA_HI20:
if (0 == info->relax_pass && (i + 4) <= sec->reloc_count)
- loongarch_relax_pcala_addi (abfd, sec, rel, symval, info, again);
+ loongarch_relax_pcala_addi (abfd, sec, sym_sec, rel, symval,
+ info, again);
break;
case R_LARCH_GOT_PC_HI20:
if (local_got && 0 == info->relax_pass
&& (i + 4) <= sec->reloc_count)
{
if (loongarch_relax_pcala_ld (abfd, sec, rel))
- loongarch_relax_pcala_addi (abfd, sec, rel, symval,
+ loongarch_relax_pcala_addi (abfd, sec, sym_sec, rel, symval,
info, again);
}
break;
diff --git a/ld/emultempl/loongarchelf.em b/ld/emultempl/loongarchelf.em
index 4850feb8767..d81c99da48b 100644
--- a/ld/emultempl/loongarchelf.em
+++ b/ld/emultempl/loongarchelf.em
@@ -62,6 +62,24 @@ gld${EMULATION_NAME}_after_allocation (void)
}
}
+ /* The program header size of executable file may increase. */
+ if (bfd_get_flavour (link_info.output_bfd) == bfd_target_elf_flavour
+ && !bfd_link_relocatable (&link_info))
+ {
+ if (lang_phdr_list == NULL)
+ elf_seg_map (link_info.output_bfd) = NULL;
+ if (!_bfd_elf_map_sections_to_segments (link_info.output_bfd,
+ &link_info,
+ NULL))
+ einfo (_("%F%P: map sections to segments failed: %E\n"));
+ }
+
+ /* Adjust program header size and .eh_frame_hdr size before
+ lang_relax_sections. Without it, the vma of data segment may increase. */
+ lang_do_assignments (lang_allocating_phase_enum);
+ lang_reset_memory_regions ();
+ lang_size_sections (NULL, true);
+
enum phase_enum *phase = &(expld.dataseg.phase);
bfd_elf${ELFSIZE}_loongarch_set_data_segment_info (&link_info, (int *) phase);
/* gld${EMULATION_NAME}_map_segments (need_layout); */
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2023-11-17 8:43 [binutils-gdb] LoongArch: Remove "elf_seg_map (info->output_bfd) == NULL" relaxation condition liu & zhensong
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