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* elf-nacl.c (nacl_modify_segment_map): Fix logic reordering the
	elf_segment_map list.  If an executable segment is page-aligned
	but does not end with a full page, then append a fake section into
	the segment map entry that pads out the page.
	(nacl_final_write_processing): New function.  Write the code fill
	laid out in nacl_modify_segment_map.
	* elf-nacl.h: Declare it.
	* elf32-arm.c (elf32_arm_nacl_final_write_processing): New function.
	(elf_backend_final_write_processing): Define it for NaCl backend.
	* elf32-i386.c (elf_backend_final_write_processing): Likewise.
	* elf64-x86-64.c (elf_backend_final_write_processing): Likewise.

	* elf-nacl.c (segment_eligible_for_headers): Rename MAXPAGESIZE
	parameter to MINPAGESIZE.
	(nacl_modify_segment_map): Use minpagesize instead of maxpagesize.

	* elf32-arm.c (ELF_MINPAGESIZE, ELF_COMMONPAGESIZE): Set to
	0x10000	for NaCl targets.

ld/testsuite/
	* ld-x86-64/ilp32-4-nacl.d: Loosen .shstrtab line regexp to match
	any file offset.
	* ld-x86-64/tlsbin-nacl.rd: Update expected code segment PT_LOAD.
	* ld-x86-64/tlsbindesc-nacl.rd: Likewise.
	* ld-scripts/rgn-at3.d: XFAIL for *-*-nacl* targets.
	* ld-scripts/rgn-over8-ok.d: Likewise.
This commit is contained in:
Roland McGrath 2013-08-26 19:27:25 +00:00
parent 779bd27081
commit 887badb310
12 changed files with 266 additions and 81 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
bfd/ChangeLog
View File

@ -1,3 +1,23 @@
2013-08-26 Roland McGrath <mcgrathr@google.com>
* elf-nacl.c (nacl_modify_segment_map): Fix logic reordering the
elf_segment_map list. If an executable segment is page-aligned
but does not end with a full page, then append a fake section into
the segment map entry that pads out the page.
(nacl_final_write_processing): New function. Write the code fill
laid out in nacl_modify_segment_map.
* elf-nacl.h: Declare it.
* elf32-arm.c (elf32_arm_nacl_final_write_processing): New function.
(elf_backend_final_write_processing): Define it for NaCl backend.
* elf32-i386.c (elf_backend_final_write_processing): Likewise.
* elf64-x86-64.c (elf_backend_final_write_processing): Likewise.
* elf-nacl.c (segment_eligible_for_headers): Rename MAXPAGESIZE
parameter to MINPAGESIZE.
(nacl_modify_segment_map): Use minpagesize instead of maxpagesize.
* elf32-arm.c (ELF_MINPAGESIZE, ELF_COMMONPAGESIZE): #undef for NaCl.
2013-08-24 Maciej W. Rozycki <macro@linux-mips.org>
* elf32-tilepro.c (tilepro_elf_finish_dynamic_sections): Don't

271
bfd/elf-nacl.c
View File

@ -1,5 +1,5 @@
/* Native Client support for ELF
Copyright 2012 Free Software Foundation, Inc.
Copyright 2012, 2013 Free Software Foundation, Inc.
This file is part of BFD, the Binary File Descriptor library.
@ -20,6 +20,7 @@
#include "sysdep.h"
#include "bfd.h"
#include "libbfd.h"
#include "elf-bfd.h"
#include "elf-nacl.h"
#include "elf/common.h"
@ -33,11 +34,11 @@ segment_executable (struct elf_segment_map *seg)
else
{
/* The p_flags value has not been computed yet,
so we have to look through the sections. */
so we have to look through the sections. */
unsigned int i;
for (i = 0; i < seg->count; ++i)
if (seg->sections[i]->flags & SEC_CODE)
return TRUE;
if (seg->sections[i]->flags & SEC_CODE)
return TRUE;
}
return FALSE;
}
@ -48,18 +49,18 @@ segment_executable (struct elf_segment_map *seg)
allow space for the headers. */
static bfd_boolean
segment_eligible_for_headers (struct elf_segment_map *seg,
bfd_vma maxpagesize, bfd_vma sizeof_headers)
bfd_vma minpagesize, bfd_vma sizeof_headers)
{
bfd_boolean any_contents = FALSE;
unsigned int i;
if (seg->count == 0 || seg->sections[0]->lma % maxpagesize < sizeof_headers)
if (seg->count == 0 || seg->sections[0]->lma % minpagesize < sizeof_headers)
return FALSE;
for (i = 0; i < seg->count; ++i)
{
if ((seg->sections[i]->flags & (SEC_CODE|SEC_READONLY)) != SEC_READONLY)
return FALSE;
return FALSE;
if (seg->sections[i]->flags & SEC_HAS_CONTENTS)
any_contents = TRUE;
any_contents = TRUE;
}
return any_contents;
}
@ -76,7 +77,7 @@ nacl_modify_segment_map (bfd *abfd, struct bfd_link_info *info)
struct elf_segment_map **last_load = NULL;
bfd_boolean moved_headers = FALSE;
int sizeof_headers = info == NULL ? 0 : bfd_sizeof_headers (abfd, info);
bfd_vma maxpagesize = get_elf_backend_data (abfd)->maxpagesize;
bfd_vma minpagesize = get_elf_backend_data (abfd)->minpagesize;
if (info != NULL && info->user_phdrs)
/* The linker script used PHDRS explicitly, so don't change what the
@ -88,52 +89,124 @@ nacl_modify_segment_map (bfd *abfd, struct bfd_link_info *info)
struct elf_segment_map *seg = *m;
if (seg->p_type == PT_LOAD)
{
/* First, we're just finding the earliest PT_LOAD.
By the normal rules, this will be the lowest-addressed one.
We only have anything interesting to do if it's executable. */
last_load = m;
if (first_load == NULL)
{
if (!segment_executable (*m))
return TRUE;
first_load = m;
}
/* Now that we've noted the first PT_LOAD, we're looking for
the first non-executable PT_LOAD with a nonempty p_filesz. */
else if (!moved_headers
&& segment_eligible_for_headers (seg, maxpagesize,
sizeof_headers))
{
/* This is the one we were looking for!
{
bfd_boolean executable = segment_executable (seg);
First, clear the flags on previous segments that
say they include the file header and phdrs. */
struct elf_segment_map *prevseg;
for (prevseg = *first_load;
prevseg != seg;
prevseg = prevseg->next)
if (prevseg->p_type == PT_LOAD)
{
prevseg->includes_filehdr = 0;
prevseg->includes_phdrs = 0;
}
if (executable
&& seg->count > 0
&& seg->sections[0]->vma % minpagesize == 0)
{
asection *lastsec = seg->sections[seg->count - 1];
bfd_vma end = lastsec->vma + lastsec->size;
if (end % minpagesize != 0)
{
/* This is an executable segment that starts on a page
boundary but does not end on a page boundary. Fill
it out to a whole page with code fill (the tail of
the segment will not be within any section). Thus
the entire code segment can be mapped from the file
as whole pages and that mapping will contain only
valid instructions.
/* This segment will include those headers instead. */
seg->includes_filehdr = 1;
seg->includes_phdrs = 1;
To accomplish this, we must fake out the code in
assign_file_positions_for_load_sections (elf.c) so
that it advances past the rest of the final page,
rather than trying to put the next (unaligned, or
unallocated) section. We do this by appending a
dummy section record to this element in the segment
map. No such output section ever actually exists,
but this gets the layout logic to advance the file
positions past this partial page. Since we are
lying to BFD like this, nothing will ever know to
write the section contents. So we do that by hand
after the fact, in nacl_final_write_processing, below. */
moved_headers = TRUE;
}
}
struct elf_segment_map *newseg;
asection *sec;
struct bfd_elf_section_data *secdata;
BFD_ASSERT (!seg->p_size_valid);
secdata = bfd_zalloc (abfd, sizeof *secdata);
if (secdata == NULL)
return FALSE;
sec = bfd_zalloc (abfd, sizeof *sec);
if (sec == NULL)
return FALSE;
/* Fill in only the fields that actually affect the logic
in assign_file_positions_for_load_sections. */
sec->vma = end;
sec->lma = lastsec->lma + lastsec->size;
sec->size = minpagesize - (end % minpagesize);
sec->flags = (SEC_ALLOC | SEC_LOAD
| SEC_READONLY | SEC_CODE | SEC_LINKER_CREATED);
sec->used_by_bfd = secdata;
secdata->this_hdr.sh_type = SHT_PROGBITS;
secdata->this_hdr.sh_flags = SHF_ALLOC | SHF_EXECINSTR;
secdata->this_hdr.sh_addr = sec->vma;
secdata->this_hdr.sh_size = sec->size;
newseg = bfd_alloc (abfd,
sizeof *newseg + ((seg->count + 1)
* sizeof (asection *)));
if (newseg == NULL)
return FALSE;
memcpy (newseg, seg,
sizeof *newseg + (seg->count * sizeof (asection *)));
newseg->sections[newseg->count++] = sec;
*m = seg = newseg;
}
}
/* First, we're just finding the earliest PT_LOAD.
By the normal rules, this will be the lowest-addressed one.
We only have anything interesting to do if it's executable. */
last_load = m;
if (first_load == NULL)
{
if (!executable)
goto next;
first_load = m;
}
/* Now that we've noted the first PT_LOAD, we're looking for
the first non-executable PT_LOAD with a nonempty p_filesz. */
else if (!moved_headers
&& segment_eligible_for_headers (seg, minpagesize,
sizeof_headers))
{
/* This is the one we were looking for!
First, clear the flags on previous segments that
say they include the file header and phdrs. */
struct elf_segment_map *prevseg;
for (prevseg = *first_load;
prevseg != seg;
prevseg = prevseg->next)
if (prevseg->p_type == PT_LOAD)
{
prevseg->includes_filehdr = 0;
prevseg->includes_phdrs = 0;
}
/* This segment will include those headers instead. */
seg->includes_filehdr = 1;
seg->includes_phdrs = 1;
moved_headers = TRUE;
}
}
next:
m = &seg->next;
}
if (first_load != last_load && moved_headers)
{
/* Now swap the first and last PT_LOAD segments'
positions in segment_map. */
positions in segment_map. */
struct elf_segment_map *first = *first_load;
struct elf_segment_map *last = *last_load;
*first_load = first->next;
@ -164,7 +237,7 @@ nacl_modify_program_headers (bfd *abfd, struct bfd_link_info *info)
while (*m != NULL)
{
if ((*m)->p_type == PT_LOAD && (*m)->includes_filehdr)
break;
break;
m = &(*m)->next;
++p;
@ -178,47 +251,95 @@ nacl_modify_program_headers (bfd *abfd, struct bfd_link_info *info)
Elf_Internal_Phdr *next_load_phdr = NULL;
/* Now move past that first one and find the PT_LOAD that should be
before it by address order. */
before it by address order. */
m = &(*m)->next;
++p;
while ((*m) != NULL)
{
if (p->p_type == PT_LOAD && p->p_vaddr < first_load_phdr->p_vaddr)
{
next_load_seg = m;
next_load_phdr = p;
break;
}
while (*m != NULL)
{
if (p->p_type == PT_LOAD && p->p_vaddr < first_load_phdr->p_vaddr)
{
next_load_seg = m;
next_load_phdr = p;
break;
}
m = &(*m)->next;
++p;
}
m = &(*m)->next;
++p;
}
/* Swap their positions in the segment_map back to how they used to be.
The phdrs have already been set up by now, so we have to slide up
the earlier ones to insert the one that should be first. */
The phdrs have already been set up by now, so we have to slide up
the earlier ones to insert the one that should be first. */
if (next_load_seg != NULL)
{
Elf_Internal_Phdr move_phdr;
struct elf_segment_map *first_seg = *first_load_seg;
struct elf_segment_map *next_seg = *next_load_seg;
struct elf_segment_map *first_next = first_seg->next;
struct elf_segment_map *next_next = next_seg->next;
{
Elf_Internal_Phdr move_phdr;
struct elf_segment_map *first_seg = *first_load_seg;
struct elf_segment_map *next_seg = *next_load_seg;
struct elf_segment_map *first_next = first_seg->next;
struct elf_segment_map *next_next = next_seg->next;
first_seg->next = next_next;
*first_load_seg = next_seg;
if (next_load_seg == &first_seg->next)
{
*first_load_seg = next_seg;
next_seg->next = first_seg;
first_seg->next = next_next;
}
else
{
*first_load_seg = first_next;
*next_load_seg = next_next;
next_seg->next = first_next;
*next_load_seg = first_seg;
first_seg->next = *next_load_seg;
*next_load_seg = first_seg;
move_phdr = *next_load_phdr;
memmove (first_load_phdr + 1, first_load_phdr,
(next_load_phdr - first_load_phdr) * sizeof move_phdr);
*first_load_phdr = move_phdr;
}
next_seg->next = *first_load_seg;
*first_load_seg = next_seg;
}
move_phdr = *next_load_phdr;
memmove (first_load_phdr + 1, first_load_phdr,
(next_load_phdr - first_load_phdr) * sizeof move_phdr);
*first_load_phdr = move_phdr;
}
}
return TRUE;
}
void
nacl_final_write_processing (bfd *abfd, bfd_boolean linker ATTRIBUTE_UNUSED)
{
struct elf_segment_map *seg;
for (seg = elf_seg_map (abfd); seg != NULL; seg = seg->next)
if (seg->p_type == PT_LOAD
&& seg->count > 1
&& seg->sections[seg->count - 1]->owner == NULL)
{
/* This is a fake section added in nacl_modify_segment_map, above.
It's not a real BFD section, so nothing wrote its contents.
Now write out its contents. */
asection *sec = seg->sections[seg->count - 1];
char *fill;
BFD_ASSERT (sec->flags & SEC_LINKER_CREATED);
BFD_ASSERT (sec->flags & SEC_CODE);
BFD_ASSERT (sec->size > 0);
fill = abfd->arch_info->fill (sec->size, bfd_big_endian (abfd), TRUE);
if (fill == NULL
|| bfd_seek (abfd, sec->filepos, SEEK_SET) != 0
|| bfd_bwrite (fill, sec->size, abfd) != sec->size)
{
/* We don't have a proper way to report an error here. So
instead fudge things so that elf_write_shdrs_and_ehdr will
fail. */
elf_elfheader (abfd)->e_shoff = (file_ptr) -1;
}
free (fill);
}
}

3
bfd/elf-nacl.h
View File

@ -1,5 +1,5 @@
/* Native Client support for ELF
Copyright 2012 Free Software Foundation, Inc.
Copyright 2012, 2013 Free Software Foundation, Inc.
This file is part of BFD, the Binary File Descriptor library.
@ -22,3 +22,4 @@
bfd_boolean nacl_modify_segment_map (bfd *, struct bfd_link_info *);
bfd_boolean nacl_modify_program_headers (bfd *, struct bfd_link_info *);
void nacl_final_write_processing (bfd *, bfd_boolean linker);

20
bfd/elf32-arm.c
View File

@ -15860,6 +15860,14 @@ elf32_arm_nacl_modify_segment_map (bfd *abfd, struct bfd_link_info *info)
&& nacl_modify_segment_map (abfd, info));
}
static void
elf32_arm_nacl_final_write_processing (bfd *abfd, bfd_boolean linker)
{
elf32_arm_final_write_processing (abfd, linker);
nacl_final_write_processing (abfd, linker);
}
#undef elf32_bed
#define elf32_bed elf32_arm_nacl_bed
#undef bfd_elf32_bfd_link_hash_table_create
@ -15871,9 +15879,14 @@ elf32_arm_nacl_modify_segment_map (bfd *abfd, struct bfd_link_info *info)
#define elf_backend_modify_segment_map elf32_arm_nacl_modify_segment_map
#undef elf_backend_modify_program_headers
#define elf_backend_modify_program_headers nacl_modify_program_headers
#undef elf_backend_final_write_processing
#define elf_backend_final_write_processing elf32_arm_nacl_final_write_processing
#undef ELF_MAXPAGESIZE
#define ELF_MAXPAGESIZE 0x10000
#undef ELF_MINPAGESIZE
#undef ELF_COMMONPAGESIZE
#include "elf32-target.h"
@ -15882,6 +15895,13 @@ elf32_arm_nacl_modify_segment_map (bfd *abfd, struct bfd_link_info *info)
#undef elf_backend_modify_segment_map
#define elf_backend_modify_segment_map elf32_arm_modify_segment_map
#undef elf_backend_modify_program_headers
#undef elf_backend_final_write_processing
#define elf_backend_final_write_processing elf32_arm_final_write_processing
#undef ELF_MINPAGESIZE
#define ELF_MINPAGESIZE 0x1000
#undef ELF_COMMONPAGESIZE
#define ELF_COMMONPAGESIZE 0x1000
/* VxWorks Targets. */

3
bfd/elf32-i386.c
View File

@ -5302,12 +5302,15 @@ static const struct elf_i386_backend_data elf_i386_nacl_arch_bed =
#define elf_backend_modify_segment_map nacl_modify_segment_map
#undef elf_backend_modify_program_headers
#define elf_backend_modify_program_headers nacl_modify_program_headers
#undef elf_backend_final_write_processing
#define elf_backend_final_write_processing nacl_final_write_processing
#include "elf32-target.h"
/* Restore defaults. */
#undef elf_backend_modify_segment_map
#undef elf_backend_modify_program_headers
#undef elf_backend_final_write_processing
/* VxWorks support. */

3
bfd/elf64-x86-64.c
View File

@ -5399,6 +5399,8 @@ static const struct elf_x86_64_backend_data elf_x86_64_nacl_arch_bed =
#define elf_backend_modify_segment_map nacl_modify_segment_map
#undef elf_backend_modify_program_headers
#define elf_backend_modify_program_headers nacl_modify_program_headers
#undef elf_backend_final_write_processing
#define elf_backend_final_write_processing nacl_final_write_processing
#include "elf64-target.h"
@ -5443,6 +5445,7 @@ static const struct elf_x86_64_backend_data elf_x86_64_nacl_arch_bed =
#undef elf_backend_size_info
#undef elf_backend_modify_segment_map
#undef elf_backend_modify_program_headers
#undef elf_backend_final_write_processing
/* Intel L1OM support. */

9
ld/testsuite/ChangeLog
View File

@ -1,3 +1,12 @@
2013-08-26 Roland McGrath <mcgrathr@google.com>
* ld-x86-64/ilp32-4-nacl.d: Loosen .shstrtab line regexp to match
any file offset.
* ld-x86-64/tlsbin-nacl.rd: Update expected code segment PT_LOAD.
* ld-x86-64/tlsbindesc-nacl.rd: Likewise.
* ld-scripts/rgn-at3.d: XFAIL for *-*-nacl* targets.
* ld-scripts/rgn-over8-ok.d: Likewise.
2013-08-24 Maciej W. Rozycki <macro@linux-mips.org>
* ld-elf/comm-data.exp: Use check_shared_lib_support rather than

6
ld/testsuite/ld-scripts/rgn-at3.d
View File

@ -2,9 +2,13 @@
# source: rgn-at.s
# ld: -T rgn-at3.t
# objdump: -w -h
# xfail: rx-*-*
# xfail: rx-*-* *-*-nacl*
# FAILS on the RX because the linker has to set LMA == VMA for the
# Renesas loader.
# FAILs on NaCl targets because the linker extends the first segment
# to fill out the page, making its p_vaddr+p_memsz cover the sh_addr
# of .bss too, which makes BFD compute its LMA from the p_paddr of the
# text segment.
.*: file format .*

6
ld/testsuite/ld-scripts/rgn-over8-ok.d
View File

@ -2,9 +2,13 @@
# source: rgn-over8.s
# ld: -T rgn-over8.t
# objdump: -w -h
# xfail: rx-*-*
# xfail: rx-*-* *-*-nacl*
# FAILS on the RX because the linker has to set LMA == VMA for the
# Renesas loader.
# FAILs on NaCl targets because the linker extends the first segment
# to fill out the page, making its p_vaddr+p_memsz cover the sh_addr
# of .bss too, which makes BFD compute its LMA from the p_paddr of the
# text segment.
.*: file format .*

2
ld/testsuite/ld-x86-64/ilp32-4-nacl.d
View File

@ -14,7 +14,7 @@ Section Headers:
+\[ 3\] \.dynsym +DYNSYM +100000e0 +0+e0 +0+60 +10 +A +4 +2 +4
+\[ 4\] \.dynstr +STRTAB +10000140 +0+140 +0+19 +00 +A +0 +0 +1
+\[ 5\] \.dynamic +DYNAMIC +1001015c +0+15c +0+58 +08 +WA +4 +0 +4
+\[ 6\] \.shstrtab +STRTAB +0+ +0+10001 +0+40 +00 +0 +0 +1
+\[ 6\] \.shstrtab +STRTAB +0+ +[0-9a-f]+ +0+40 +00 +0 +0 +1
+\[ 7\] \.symtab +SYMTAB +0+0 +[0-9a-f]+ +[0-9a-f]+ +10 +8 +[0-9] +4
+\[ 8\] \.strtab +STRTAB +0+ +[0-9a-f]+ +[0-9a-f]+ +00 +0 +0 +1
Key to Flags:

2
ld/testsuite/ld-x86-64/tlsbin-nacl.rd
View File

@ -40,7 +40,7 @@ Program Headers:
+PHDR.*
+INTERP.*
.*Requesting program interpreter.*
+LOAD +0x0+10000 0x0+20000 0x0+20000 0x0+1231 0x0+1231 R E +0x10000
+LOAD +0x0+10000 0x0+20000 0x0+20000 0x0+10000 0x0+10000 R E +0x10000
+LOAD +0x0+ 0x0+10020000 0x0+10020000 0x0+3b0 0x0+3b0 R +0x10000
+LOAD +0x0+3b0 0x0+100303b0 0x0+100303b0 0x0+1e0 0x0+1e0 RW +0x10000
+DYNAMIC +0x0+410 0x0+10030410 0x0+10030410 0x0+140 0x0+140 RW +0x8

2
ld/testsuite/ld-x86-64/tlsbindesc-nacl.rd
View File

@ -38,7 +38,7 @@ Program Headers:
+PHDR.*
+INTERP.*
.*Requesting program interpreter.*
+LOAD +0x0+10000 0x0+20000 0x0+20000 0x0+1fd 0x0+1fd R E 0x10000
+LOAD +0x0+10000 0x0+20000 0x0+20000 0x0+10000 0x0+10000 R E 0x10000
+LOAD +0x0+ 0x0+10020000 0x0+10020000 0x0+370 0x0+370 R +0x10000
+LOAD +0x0+370 0x0+10030370 0x0+10030370 0x0+198 0x0+198 RW +0x10000
+DYNAMIC +0x0+3d0 0x0+100303d0 0x0+100303d0 0x0+100 0x0+100 RW +0x8