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authormengqinggang <mengqinggang@loongson.cn>2023-12-08 15:15:50 +0800
committerliuzhensong <liuzhensong@loongson.cn>2023-12-22 14:20:18 +0800
commitc3d507aba3ec2c9b3f9aa105a01cf80ecc0b8c9b (patch)
tree46b9a5155634c7e2122319f6adeba51d6ded0c03 /bfd
parent866a2ad35b75cbc60260c00b82bec2243877355f (diff)
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LoongArch: Add support for the third expression of .align for R_LARCH_ALIGN
If the symbol index is not zero, the addend is used to represent the first and the third expressions of the .align. The lowest 8 bits are used to represent the first expression. Other bits are used to represent the third expression. The addend of R_LARCH_ALIGN for ".align 5, ,4" is 0x405. The addend of R_LARCH_ALIGN for ".balign 32, ,4" is 0x405.
Diffstat (limited to 'bfd')
-rw-r--r--bfd/elfnn-loongarch.c71
-rw-r--r--bfd/elfxx-loongarch.c10
2 files changed, 52 insertions, 29 deletions
diff --git a/bfd/elfnn-loongarch.c b/bfd/elfnn-loongarch.c
index 87eb65a..faffe27 100644
--- a/bfd/elfnn-loongarch.c
+++ b/bfd/elfnn-loongarch.c
@@ -3858,44 +3858,53 @@ loongarch_relax_align (bfd *abfd, asection *sec,
Elf_Internal_Rela *rel,
bfd_vma symval)
{
- bfd_byte *contents = elf_section_data (sec)->this_hdr.contents;
- bfd_vma alignment = 1, pos;
- while (alignment <= rel->r_addend)
- alignment *= 2;
+ bfd_vma addend, max = 0, alignment = 1;
- symval -= rel->r_addend;
- bfd_vma aligned_addr = ((symval - 1) & ~(alignment - 1)) + alignment;
- bfd_vma nop_bytes = aligned_addr - symval;
+ int index = ELFNN_R_SYM (rel->r_info);
+ if (index > 0)
+ {
+ alignment = 1 << (rel->r_addend & 0xff);
+ max = rel->r_addend >> 8;
+ }
+ else
+ alignment = rel->r_addend + 4;
- /* Once we've handled an R_LARCH_ALIGN, we can't relax anything else. */
- sec->sec_flg0 = true;
+ addend = alignment - 4; /* The bytes of NOPs added by R_LARCH_ALIGN. */
+ symval -= addend; /* The address of first NOP added by R_LARCH_ALIGN. */
+ bfd_vma aligned_addr = ((symval - 1) & ~(alignment - 1)) + alignment;
+ bfd_vma need_nop_bytes = aligned_addr - symval; /* */
/* Make sure there are enough NOPs to actually achieve the alignment. */
- if (rel->r_addend < nop_bytes)
+ if (addend < need_nop_bytes)
{
_bfd_error_handler
(_("%pB(%pA+%#" PRIx64 "): %" PRId64 " bytes required for alignment "
"to %" PRId64 "-byte boundary, but only %" PRId64 " present"),
abfd, sym_sec, (uint64_t) rel->r_offset,
- (int64_t) nop_bytes, (int64_t) alignment, (int64_t) rel->r_addend);
+ (int64_t) need_nop_bytes, (int64_t) alignment, (int64_t) addend);
bfd_set_error (bfd_error_bad_value);
return false;
}
- /* Delete the reloc. */
+ /* Once we've handled an R_LARCH_ALIGN in a section,
+ we can't relax anything else in this section. */
+ sec->sec_flg0 = true;
rel->r_info = ELFNN_R_INFO (0, R_LARCH_NONE);
+ /* If skipping more bytes than the specified maximum,
+ then the alignment is not done at all and delete all NOPs. */
+ if (max > 0 && need_nop_bytes > max)
+ return loongarch_relax_delete_bytes (abfd, sec, rel->r_offset,
+ addend, link_info);
+
/* If the number of NOPs is already correct, there's nothing to do. */
- if (nop_bytes == rel->r_addend)
+ if (need_nop_bytes == addend)
return true;
- /* Write as many LOONGARCH NOPs as we need. */
- for (pos = 0; pos < (nop_bytes & -4); pos += 4)
- bfd_putl32 (LARCH_NOP, contents + rel->r_offset + pos);
-
/* Delete the excess NOPs. */
- return loongarch_relax_delete_bytes (abfd, sec, rel->r_offset + nop_bytes,
- rel->r_addend - nop_bytes, link_info);
+ return loongarch_relax_delete_bytes (abfd, sec,
+ rel->r_offset + need_nop_bytes,
+ addend - need_nop_bytes, link_info);
}
static bool
@@ -3904,8 +3913,8 @@ loongarch_elf_relax_section (bfd *abfd, asection *sec,
bool *again)
{
struct loongarch_elf_link_hash_table *htab = loongarch_elf_hash_table (info);
- Elf_Internal_Shdr *symtab_hdr = &elf_symtab_hdr (abfd);
struct bfd_elf_section_data *data = elf_section_data (sec);
+ Elf_Internal_Shdr *symtab_hdr = &elf_symtab_hdr (abfd);
Elf_Internal_Rela *relocs;
*again = false;
@@ -3938,7 +3947,7 @@ loongarch_elf_relax_section (bfd *abfd, asection *sec,
0, NULL, NULL, NULL)))
return true;
- data->relocs = relocs;
+ data->relocs = relocs;
for (unsigned int i = 0; i < sec->reloc_count; i++)
{
@@ -3946,6 +3955,7 @@ loongarch_elf_relax_section (bfd *abfd, asection *sec,
asection *sym_sec;
bfd_vma symval;
unsigned long r_symndx = ELFNN_R_SYM (rel->r_info);
+ unsigned long r_type = ELFNN_R_TYPE (rel->r_info);
bool local_got = false;
char symtype;
struct elf_link_hash_entry *h = NULL;
@@ -3957,7 +3967,7 @@ loongarch_elf_relax_section (bfd *abfd, asection *sec,
if (ELF_ST_TYPE (sym->st_info) == STT_GNU_IFUNC)
continue;
- if (sym->st_shndx == SHN_UNDEF)
+ if (sym->st_shndx == SHN_UNDEF || R_LARCH_ALIGN == r_type)
{
sym_sec = sec;
symval = rel->r_offset;
@@ -3983,9 +3993,9 @@ loongarch_elf_relax_section (bfd *abfd, asection *sec,
continue;
if ((h->root.type == bfd_link_hash_defined
- || h->root.type == bfd_link_hash_defweak)
- && h->root.u.def.section != NULL
- && h->root.u.def.section->output_section != NULL)
+ || h->root.type == bfd_link_hash_defweak)
+ && h->root.u.def.section != NULL
+ && h->root.u.def.section->output_section != NULL)
{
symval = h->root.u.def.value;
sym_sec = h->root.u.def.section;
@@ -4011,12 +4021,21 @@ loongarch_elf_relax_section (bfd *abfd, asection *sec,
if (symtype != STT_SECTION)
symval += rel->r_addend;
}
+ /* For R_LARCH_ALIGN, symval is sec_addr (sym_sec) + rel->r_offset
+ + (alingmeng - 4).
+ If r_symndx is 0, alignmeng-4 is r_addend.
+ If r_symndx > 0, alignment-4 is 2^(r_addend & 0xff)-4. */
+ else if (R_LARCH_ALIGN == r_type)
+ if (r_symndx > 0)
+ symval += ((1 << (rel->r_addend & 0xff)) - 4);
+ else
+ symval += rel->r_addend;
else
symval += rel->r_addend;
symval += sec_addr (sym_sec);
- switch (ELFNN_R_TYPE (rel->r_info))
+ switch (r_type)
{
case R_LARCH_ALIGN:
if (1 == info->relax_pass)
diff --git a/bfd/elfxx-loongarch.c b/bfd/elfxx-loongarch.c
index d93b790..679b79f 100644
--- a/bfd/elfxx-loongarch.c
+++ b/bfd/elfxx-loongarch.c
@@ -1395,9 +1395,13 @@ static loongarch_reloc_howto_type loongarch_howto_table[] =
NULL, /* adjust_reloc_bits. */
NULL), /* larch_reloc_type_name. */
- /* Indicates an alignment statement. The addend field encodes how many
- bytes of NOPs follow the statement. The desired alignment is the
- addend rounded up to the next power of two. */
+ /* Indicates an alignment statement. f the symbol index is 0,
+ the addend indicates the number of bytes occupied by nop instructions
+ at the relocation offset. The alignment boundary is specified by the
+ addend rounded up to the next power of two.
+ If the symbol index is not 0, the addend indicates the first and third
+ expressions of .align. The lowest 8 bits are used to represent the first
+ expression, other bits are used to represent the third expression. */
LOONGARCH_HOWTO (R_LARCH_ALIGN, /* type (102). */
0, /* rightshift. */
0, /* size. */