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[binutils-gdb] Delay setting up compressed debug section names
- From: H.J.Lu <hjl at sourceware dot org>
- To: bfd-cvs at sourceware dot org
- Date: 23 Apr 2015 23:38:19 -0000
- Subject: [binutils-gdb] Delay setting up compressed debug section names
https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=3e19fb8f990e4ce8a08f9cf2817cd9e9398648d5
commit 3e19fb8f990e4ce8a08f9cf2817cd9e9398648d5
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Thu Apr 23 16:37:44 2015 -0700
Delay setting up compressed debug section names
When we set up st_name for output section name in elf_fake_sections, we
don't know if the compressed DWARF debug section will be smaller. We may
end up with compressed DWARF debug sections which are bigger than the
uncompressed ones. This patch delays setting up st_name for output DWARF
debug section to _bfd_elf_assign_file_positions_for_non_load which will
compress the output debug section. We also postpone placement of shstrtab
section after DWARF debug sections have been compressed. The net effect
is .shstrtab section is now placed after .symtab and .strtab sections.
bfd/
PR ld/18277
* compress.c (bfd_compress_section_contents): Remove the
write_compress argument.
(bfd_init_section_compress_status): Updated.
(bfd_compress_section): Likewise.
* elf.c (_bfd_elf_set_reloc_sh_name): New.
(_bfd_elf_init_reloc_shdr): Add delay_st_name_p. Set sh_name
to (unsigned int) -1 if delay_st_name_p is TRUE. Use
_bfd_elf_set_reloc_sh_name.
(elf_fake_sections): Don't rename DWARF debug section for
linker output if it will be compressed. Instead, set
delay_st_name_p to TRUE and pass it to _bfd_elf_init_reloc_shdr.
(assign_section_numbers): Call _bfd_elf_strtab_addref only if
sh_name != (unsigned int) -1. Don't finalize nor assign
shstrtab section here. Delay setting output section names to
_bfd_elf_write_object_contents.
(_bfd_elf_compute_section_file_positions): Update comments on
sh_offset for shstrtab section.
(assign_file_positions_for_non_load_sections): Set sh_offset to
-1 for shstrtab section.
(assign_file_positions_except_relocs): Likewise.
(_bfd_elf_assign_file_positions_for_non_load): Set up sh_name
when compressing DWARF debug sections. Place shstrtab section
after DWARF debug sections have been compressed.
(_bfd_elf_write_object_contents): Setting sh_name for output
sections.
ld/testsuite/
PR ld/18277
* ld-elf/compressed1d.d: New.
* ld-elf/compressed1e.d: Likewise.
Diff:
---
bfd/ChangeLog | 29 +++++++
bfd/compress.c | 15 ++--
bfd/elf.c | 170 +++++++++++++++++++++++++------------
ld/testsuite/ChangeLog | 6 ++
ld/testsuite/ld-elf/compressed1d.d | 9 ++
ld/testsuite/ld-elf/compressed1e.d | 9 ++
6 files changed, 175 insertions(+), 63 deletions(-)
diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 804c683..f9aa3a7 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,5 +1,34 @@
2015-04-23 H.J. Lu <hongjiu.lu@intel.com>
+ PR ld/18277
+ * compress.c (bfd_compress_section_contents): Remove the
+ write_compress argument.
+ (bfd_init_section_compress_status): Updated.
+ (bfd_compress_section): Likewise.
+ * elf.c (_bfd_elf_set_reloc_sh_name): New.
+ (_bfd_elf_init_reloc_shdr): Add delay_st_name_p. Set sh_name
+ to (unsigned int) -1 if delay_st_name_p is TRUE. Use
+ _bfd_elf_set_reloc_sh_name.
+ (elf_fake_sections): Don't rename DWARF debug section for
+ linker output if it will be compressed. Instead, set
+ delay_st_name_p to TRUE and pass it to _bfd_elf_init_reloc_shdr.
+ (assign_section_numbers): Call _bfd_elf_strtab_addref only if
+ sh_name != (unsigned int) -1. Don't finalize nor assign
+ shstrtab section here. Delay setting output section names to
+ _bfd_elf_write_object_contents.
+ (_bfd_elf_compute_section_file_positions): Update comments on
+ sh_offset for shstrtab section.
+ (assign_file_positions_for_non_load_sections): Set sh_offset to
+ -1 for shstrtab section.
+ (assign_file_positions_except_relocs): Likewise.
+ (_bfd_elf_assign_file_positions_for_non_load): Set up sh_name
+ when compressing DWARF debug sections. Place shstrtab section
+ after DWARF debug sections have been compressed.
+ (_bfd_elf_write_object_contents): Setting sh_name for output
+ sections.
+
+2015-04-23 H.J. Lu <hongjiu.lu@intel.com>
+
PR binutils/18209
* bfd.c (bfd): Add is_linker_input.
* elf.c (convert_debug_to_zdebug): New.
diff --git a/bfd/compress.c b/bfd/compress.c
index dfde50e..d0f745f 100644
--- a/bfd/compress.c
+++ b/bfd/compress.c
@@ -72,8 +72,7 @@ decompress_contents (bfd_byte *compressed_buffer,
static bfd_size_type
bfd_compress_section_contents (bfd *abfd, sec_ptr sec,
bfd_byte *uncompressed_buffer,
- bfd_size_type uncompressed_size,
- bfd_boolean write_compress)
+ bfd_size_type uncompressed_size)
{
uLong compressed_size;
bfd_byte *buffer;
@@ -177,11 +176,8 @@ bfd_compress_section_contents (bfd *abfd, sec_ptr sec,
compressed_size += header_size;
/* PR binutils/18087: If compression didn't make the section smaller,
- just keep it uncompressed. We always generate .zdebug_* section
- when linking since section names have been finalized and they
- can't be changed easily. */
- if ((write_compress && compression_header_size == 0)
- || compressed_size < uncompressed_size)
+ just keep it uncompressed. */
+ if (compressed_size < uncompressed_size)
{
bfd_update_compression_header (abfd, buffer, sec);
@@ -547,8 +543,7 @@ bfd_init_section_compress_status (bfd *abfd, sec_ptr sec)
{
uncompressed_size = bfd_compress_section_contents (abfd, sec,
uncompressed_buffer,
- uncompressed_size,
- FALSE);
+ uncompressed_size);
ret = uncompressed_size != 0;
}
@@ -590,5 +585,5 @@ bfd_compress_section (bfd *abfd, sec_ptr sec, bfd_byte *uncompressed_buffer)
/* Compress it. */
return bfd_compress_section_contents (abfd, sec, uncompressed_buffer,
- uncompressed_size, TRUE) != 0;
+ uncompressed_size) != 0;
}
diff --git a/bfd/elf.c b/bfd/elf.c
index d67c22b..2ba43f4 100644
--- a/bfd/elf.c
+++ b/bfd/elf.c
@@ -2689,6 +2689,27 @@ _bfd_elf_single_rel_hdr (asection *sec)
return elf_section_data (sec)->rela.hdr;
}
+static bfd_boolean
+_bfd_elf_set_reloc_sh_name (bfd *abfd,
+ Elf_Internal_Shdr *rel_hdr,
+ const char *sec_name,
+ bfd_boolean use_rela_p)
+{
+ char *name = (char *) bfd_alloc (abfd,
+ sizeof ".rela" + strlen (sec_name));
+ if (name == NULL)
+ return FALSE;
+
+ sprintf (name, "%s%s", use_rela_p ? ".rela" : ".rel", sec_name);
+ rel_hdr->sh_name =
+ (unsigned int) _bfd_elf_strtab_add (elf_shstrtab (abfd), name,
+ FALSE);
+ if (rel_hdr->sh_name == (unsigned int) -1)
+ return FALSE;
+
+ return TRUE;
+}
+
/* Allocate and initialize a section-header for a new reloc section,
containing relocations against ASECT. It is stored in RELDATA. If
USE_RELA_P is TRUE, we use RELA relocations; otherwise, we use REL
@@ -2698,10 +2719,10 @@ static bfd_boolean
_bfd_elf_init_reloc_shdr (bfd *abfd,
struct bfd_elf_section_reloc_data *reldata,
const char *sec_name,
- bfd_boolean use_rela_p)
+ bfd_boolean use_rela_p,
+ bfd_boolean delay_st_name_p)
{
Elf_Internal_Shdr *rel_hdr;
- char *name;
const struct elf_backend_data *bed = get_elf_backend_data (abfd);
bfd_size_type amt;
@@ -2710,15 +2731,10 @@ _bfd_elf_init_reloc_shdr (bfd *abfd,
rel_hdr = bfd_zalloc (abfd, amt);
reldata->hdr = rel_hdr;
- amt = sizeof ".rela" + strlen (sec_name);
- name = (char *) bfd_alloc (abfd, amt);
- if (name == NULL)
- return FALSE;
- sprintf (name, "%s%s", use_rela_p ? ".rela" : ".rel", sec_name);
- rel_hdr->sh_name =
- (unsigned int) _bfd_elf_strtab_add (elf_shstrtab (abfd), name,
- FALSE);
- if (rel_hdr->sh_name == (unsigned int) -1)
+ if (delay_st_name_p)
+ rel_hdr->sh_name = (unsigned int) -1;
+ else if (!_bfd_elf_set_reloc_sh_name (abfd, rel_hdr, sec_name,
+ use_rela_p))
return FALSE;
rel_hdr->sh_type = use_rela_p ? SHT_RELA : SHT_REL;
rel_hdr->sh_entsize = (use_rela_p
@@ -2761,6 +2777,7 @@ elf_fake_sections (bfd *abfd, asection *asect, void *fsarg)
Elf_Internal_Shdr *this_hdr;
unsigned int sh_type;
const char *name = asect->name;
+ bfd_boolean delay_st_name_p = FALSE;
if (arg->failed)
{
@@ -2783,19 +2800,10 @@ elf_fake_sections (bfd *abfd, asection *asect, void *fsarg)
compressed. */
asect->flags |= SEC_ELF_COMPRESS;
- if (arg->link_info->compress_debug != COMPRESS_DEBUG_GABI_ZLIB)
- {
- /* If SHF_COMPRESSED isn't used, rename compressed DWARF
- debug section to .zdebug_*. */
- char *new_name = convert_debug_to_zdebug (abfd, name);
- if (new_name == NULL)
- {
- arg->failed = TRUE;
- return;
- }
- bfd_rename_section (abfd, asect, new_name);
- name = asect->name;
- }
+ /* If this section will be compressed, delay adding setion
+ name to section name section after it is compressed in
+ _bfd_elf_assign_file_positions_for_non_load. */
+ delay_st_name_p = TRUE;
}
}
else if ((asect->flags & SEC_ELF_RENAME))
@@ -2834,12 +2842,18 @@ elf_fake_sections (bfd *abfd, asection *asect, void *fsarg)
}
}
- this_hdr->sh_name = (unsigned int) _bfd_elf_strtab_add (elf_shstrtab (abfd),
- name, FALSE);
- if (this_hdr->sh_name == (unsigned int) -1)
+ if (delay_st_name_p)
+ this_hdr->sh_name = (unsigned int) -1;
+ else
{
- arg->failed = TRUE;
- return;
+ this_hdr->sh_name
+ = (unsigned int) _bfd_elf_strtab_add (elf_shstrtab (abfd),
+ name, FALSE);
+ if (this_hdr->sh_name == (unsigned int) -1)
+ {
+ arg->failed = TRUE;
+ return;
+ }
}
/* Don't clear sh_flags. Assembler may set additional bits. */
@@ -3013,13 +3027,15 @@ elf_fake_sections (bfd *abfd, asection *asect, void *fsarg)
&& (arg->link_info->relocatable || arg->link_info->emitrelocations))
{
if (esd->rel.count && esd->rel.hdr == NULL
- && !_bfd_elf_init_reloc_shdr (abfd, &esd->rel, name, FALSE))
+ && !_bfd_elf_init_reloc_shdr (abfd, &esd->rel, name, FALSE,
+ delay_st_name_p))
{
arg->failed = TRUE;
return;
}
if (esd->rela.count && esd->rela.hdr == NULL
- && !_bfd_elf_init_reloc_shdr (abfd, &esd->rela, name, TRUE))
+ && !_bfd_elf_init_reloc_shdr (abfd, &esd->rela, name, TRUE,
+ delay_st_name_p))
{
arg->failed = TRUE;
return;
@@ -3029,7 +3045,8 @@ elf_fake_sections (bfd *abfd, asection *asect, void *fsarg)
(asect->use_rela_p
? &esd->rela : &esd->rel),
name,
- asect->use_rela_p))
+ asect->use_rela_p,
+ delay_st_name_p))
arg->failed = TRUE;
}
@@ -3214,7 +3231,7 @@ assign_section_numbers (bfd *abfd, struct bfd_link_info *link_info)
{
struct elf_obj_tdata *t = elf_tdata (abfd);
asection *sec;
- unsigned int section_number, secn;
+ unsigned int section_number;
Elf_Internal_Shdr **i_shdrp;
struct bfd_elf_section_data *d;
bfd_boolean need_symtab;
@@ -3251,11 +3268,13 @@ assign_section_numbers (bfd *abfd, struct bfd_link_info *link_info)
if (d->this_hdr.sh_type != SHT_GROUP)
d->this_idx = section_number++;
- _bfd_elf_strtab_addref (elf_shstrtab (abfd), d->this_hdr.sh_name);
+ if (d->this_hdr.sh_name != (unsigned int) -1)
+ _bfd_elf_strtab_addref (elf_shstrtab (abfd), d->this_hdr.sh_name);
if (d->rel.hdr)
{
d->rel.idx = section_number++;
- _bfd_elf_strtab_addref (elf_shstrtab (abfd), d->rel.hdr->sh_name);
+ if (d->rel.hdr->sh_name != (unsigned int) -1)
+ _bfd_elf_strtab_addref (elf_shstrtab (abfd), d->rel.hdr->sh_name);
}
else
d->rel.idx = 0;
@@ -3263,7 +3282,8 @@ assign_section_numbers (bfd *abfd, struct bfd_link_info *link_info)
if (d->rela.hdr)
{
d->rela.idx = section_number++;
- _bfd_elf_strtab_addref (elf_shstrtab (abfd), d->rela.hdr->sh_name);
+ if (d->rela.hdr->sh_name != (unsigned int) -1)
+ _bfd_elf_strtab_addref (elf_shstrtab (abfd), d->rela.hdr->sh_name);
}
else
d->rela.idx = 0;
@@ -3301,9 +3321,6 @@ assign_section_numbers (bfd *abfd, struct bfd_link_info *link_info)
return FALSE;
}
- _bfd_elf_strtab_finalize (elf_shstrtab (abfd));
- t->shstrtab_hdr.sh_size = _bfd_elf_strtab_size (elf_shstrtab (abfd));
-
elf_numsections (abfd) = section_number;
elf_elfheader (abfd)->e_shnum = section_number;
@@ -3519,9 +3536,10 @@ assign_section_numbers (bfd *abfd, struct bfd_link_info *link_info)
}
}
- for (secn = 1; secn < section_number; ++secn)
- i_shdrp[secn]->sh_name = _bfd_elf_strtab_offset (elf_shstrtab (abfd),
- i_shdrp[secn]->sh_name);
+ /* Delay setting sh_name to _bfd_elf_write_object_contents so that
+ _bfd_elf_assign_file_positions_for_non_load can convert DWARF
+ debug section name from .debug_* to .zdebug_* if needed. */
+
return TRUE;
}
@@ -3778,7 +3796,7 @@ _bfd_elf_compute_section_file_positions (bfd *abfd,
shstrtab_hdr->sh_entsize = 0;
shstrtab_hdr->sh_link = 0;
shstrtab_hdr->sh_info = 0;
- /* sh_offset is set in assign_file_positions_except_relocs. */
+ /* sh_offset is set in _bfd_elf_assign_file_positions_for_non_load. */
shstrtab_hdr->sh_addralign = 1;
if (!assign_file_positions_except_relocs (abfd, link_info))
@@ -5188,7 +5206,8 @@ assign_file_positions_for_non_load_sections (bfd *abfd,
/* Compress DWARF debug sections. */
|| hdr == i_shdrpp[elf_onesymtab (abfd)]
|| hdr == i_shdrpp[elf_symtab_shndx (abfd)]
- || hdr == i_shdrpp[elf_strtab_sec (abfd)])
+ || hdr == i_shdrpp[elf_strtab_sec (abfd)]
+ || hdr == i_shdrpp[elf_shstrtab_sec (abfd)])
hdr->sh_offset = -1;
else
off = _bfd_elf_assign_file_position_for_section (hdr, off, TRUE);
@@ -5441,7 +5460,8 @@ assign_file_positions_except_relocs (bfd *abfd,
/* Compress DWARF debug sections. */
|| i == elf_onesymtab (abfd)
|| i == elf_symtab_shndx (abfd)
- || i == elf_strtab_sec (abfd))
+ || i == elf_strtab_sec (abfd)
+ || i == elf_shstrtab_sec (abfd))
{
hdr->sh_offset = -1;
}
@@ -5597,6 +5617,7 @@ _bfd_elf_assign_file_positions_for_non_load (bfd *abfd)
{
file_ptr off;
Elf_Internal_Shdr **shdrpp, **end_shdrpp;
+ Elf_Internal_Shdr *shdrp;
Elf_Internal_Ehdr *i_ehdrp;
const struct elf_backend_data *bed;
@@ -5606,26 +5627,59 @@ _bfd_elf_assign_file_positions_for_non_load (bfd *abfd)
end_shdrpp = shdrpp + elf_numsections (abfd);
for (shdrpp++; shdrpp < end_shdrpp; shdrpp++)
{
- Elf_Internal_Shdr *shdrp;
-
shdrp = *shdrpp;
if (shdrp->sh_offset == -1)
{
+ asection *sec = shdrp->bfd_section;
bfd_boolean is_rel = (shdrp->sh_type == SHT_REL
|| shdrp->sh_type == SHT_RELA);
if (is_rel
- || (shdrp->bfd_section != NULL
- && (shdrp->bfd_section->flags & SEC_ELF_COMPRESS)))
+ || (sec != NULL && (sec->flags & SEC_ELF_COMPRESS)))
{
if (!is_rel)
{
+ const char *name = sec->name;
+ struct bfd_elf_section_data *d;
+
/* Compress DWARF debug sections. */
- if (!bfd_compress_section (abfd, shdrp->bfd_section,
+ if (!bfd_compress_section (abfd, sec,
shdrp->contents))
return FALSE;
+
+ if (sec->compress_status == COMPRESS_SECTION_DONE
+ && (abfd->flags & BFD_COMPRESS_GABI) == 0)
+ {
+ /* If section is compressed with zlib-gnu, convert
+ section name from .debug_* to .zdebug_*. */
+ char *new_name
+ = convert_debug_to_zdebug (abfd, name);
+ if (new_name == NULL)
+ return FALSE;
+ name = new_name;
+ }
+ /* Add setion name to section name section. */
+ if (shdrp->sh_name != (unsigned int) -1)
+ abort ();
+ shdrp->sh_name
+ = (unsigned int) _bfd_elf_strtab_add (elf_shstrtab (abfd),
+ name, FALSE);
+ d = elf_section_data (sec);
+
+ /* Add reloc setion name to section name section. */
+ if (d->rel.hdr
+ && !_bfd_elf_set_reloc_sh_name (abfd,
+ d->rel.hdr,
+ name, FALSE))
+ return FALSE;
+ if (d->rela.hdr
+ && !_bfd_elf_set_reloc_sh_name (abfd,
+ d->rela.hdr,
+ name, FALSE))
+ return FALSE;
+
/* Update section size and contents. */
- shdrp->sh_size = shdrp->bfd_section->size;
- shdrp->contents = shdrp->bfd_section->contents;
+ shdrp->sh_size = sec->size;
+ shdrp->contents = sec->contents;
shdrp->bfd_section->contents = NULL;
}
off = _bfd_elf_assign_file_position_for_section (shdrp,
@@ -5635,7 +5689,14 @@ _bfd_elf_assign_file_positions_for_non_load (bfd *abfd)
}
}
-/* Place the section headers. */
+ /* Place section name section after DWARF debug sections have been
+ compressed. */
+ _bfd_elf_strtab_finalize (elf_shstrtab (abfd));
+ shdrp = &elf_tdata (abfd)->shstrtab_hdr;
+ shdrp->sh_size = _bfd_elf_strtab_size (elf_shstrtab (abfd));
+ off = _bfd_elf_assign_file_position_for_section (shdrp, off, TRUE);
+
+ /* Place the section headers. */
i_ehdrp = elf_elfheader (abfd);
bed = get_elf_backend_data (abfd);
off = align_file_position (off, 1 << bed->s->log_file_align);
@@ -5673,6 +5734,9 @@ _bfd_elf_write_object_contents (bfd *abfd)
num_sec = elf_numsections (abfd);
for (count = 1; count < num_sec; count++)
{
+ i_shdrp[count]->sh_name
+ = _bfd_elf_strtab_offset (elf_shstrtab (abfd),
+ i_shdrp[count]->sh_name);
if (bed->elf_backend_section_processing)
(*bed->elf_backend_section_processing) (abfd, i_shdrp[count]);
if (i_shdrp[count]->contents)
diff --git a/ld/testsuite/ChangeLog b/ld/testsuite/ChangeLog
index 356a134..15cbf24 100644
--- a/ld/testsuite/ChangeLog
+++ b/ld/testsuite/ChangeLog
@@ -1,3 +1,9 @@
+2015-04-23 H.J. Lu <hongjiu.lu@intel.com>
+
+ PR ld/18277
+ * ld-elf/compressed1d.d: New.
+ * ld-elf/compressed1e.d: Likewise.
+
2015-04-23 Alan Modra <amodra@gmail.com>
* ld-powerpc/ambiguousv1b.d: Update for aligned .got.
diff --git a/ld/testsuite/ld-elf/compressed1d.d b/ld/testsuite/ld-elf/compressed1d.d
new file mode 100644
index 0000000..cd6042c
--- /dev/null
+++ b/ld/testsuite/ld-elf/compressed1d.d
@@ -0,0 +1,9 @@
+#source: compress1.s
+#as: --compress-debug-sections=none
+#ld: -r --compress-debug-sections=zlib-gnu
+#readelf: -SW
+
+#failif
+#...
+ \[[ 0-9]+\] \.zdebug_aranges[ ]+(PROGBITS|MIPS_DWARF)[ 0-9a-z]+ .*
+#...
diff --git a/ld/testsuite/ld-elf/compressed1e.d b/ld/testsuite/ld-elf/compressed1e.d
new file mode 100644
index 0000000..8f23347
--- /dev/null
+++ b/ld/testsuite/ld-elf/compressed1e.d
@@ -0,0 +1,9 @@
+#source: compress1.s
+#as: --compress-debug-sections=none
+#ld: -shared --compress-debug-sections=zlib-gnu
+#readelf: -SW
+
+#failif
+#...
+ \[[ 0-9]+\] \.zdebug_aranges[ ]+(PROGBITS|MIPS_DWARF)[ 0-9a-z]+ .*
+#...