/* Native Client support for ELF
- Copyright (C) 2012-2017 Free Software Foundation, Inc.
+ Copyright (C) 2012-2021 Free Software Foundation, Inc.
This file is part of BFD, the Binary File Descriptor library.
#include "elf/common.h"
#include "elf/internal.h"
-static bfd_boolean
+static bool
segment_executable (struct elf_segment_map *seg)
{
if (seg->p_flags_valid)
unsigned int i;
for (i = 0; i < seg->count; ++i)
if (seg->sections[i]->flags & SEC_CODE)
- return TRUE;
+ return true;
}
- return FALSE;
+ return false;
}
/* Determine if this segment is eligible to receive the file and program
headers. It must be read-only and non-executable.
Its first section must start far enough past the page boundary to
allow space for the headers. */
-static bfd_boolean
+static bool
segment_eligible_for_headers (struct elf_segment_map *seg,
bfd_vma minpagesize, bfd_vma sizeof_headers)
{
unsigned int i;
if (seg->count == 0 || seg->sections[0]->lma % minpagesize < sizeof_headers)
- return FALSE;
+ return false;
for (i = 0; i < seg->count; ++i)
{
if ((seg->sections[i]->flags & (SEC_CODE|SEC_READONLY)) != SEC_READONLY)
- return FALSE;
+ return false;
}
- return TRUE;
+ return true;
}
/* We permute the segment_map to get BFD to do the file layout we want:
The first non-executable PT_LOAD segment appears first in the file
and contains the ELF file header and phdrs. */
-bfd_boolean
+bool
nacl_modify_segment_map (bfd *abfd, struct bfd_link_info *info)
{
const struct elf_backend_data *const bed = get_elf_backend_data (abfd);
struct elf_segment_map **m = &elf_seg_map (abfd);
struct elf_segment_map **first_load = NULL;
- struct elf_segment_map **last_load = NULL;
- bfd_boolean moved_headers = FALSE;
+ struct elf_segment_map **headers = NULL;
int sizeof_headers;
if (info != NULL && info->user_phdrs)
/* The linker script used PHDRS explicitly, so don't change what the
user asked for. */
- return TRUE;
+ return true;
if (info != NULL)
/* We're doing linking, so evalute SIZEOF_HEADERS as in a linker script. */
if (seg->p_type == PT_LOAD)
{
- bfd_boolean executable = segment_executable (seg);
+ bool executable = segment_executable (seg);
if (executable
&& seg->count > 0
secdata = bfd_zalloc (abfd, sizeof *secdata);
if (secdata == NULL)
- return FALSE;
+ return false;
sec = bfd_zalloc (abfd, sizeof *sec);
if (sec == NULL)
- return FALSE;
+ return false;
/* Fill in only the fields that actually affect the logic
in assign_file_positions_for_load_sections. */
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 *)));
+ newseg
+ = bfd_alloc (abfd, (sizeof (*newseg)
+ + seg->count * sizeof (asection *)));
if (newseg == NULL)
- return FALSE;
- memcpy (newseg, seg,
- sizeof *newseg + (seg->count * sizeof (asection *)));
+ return false;
+ memcpy (newseg, seg, (sizeof (*newseg) - sizeof (asection *)
+ + 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;
+ By the normal rules, this will be the lowest-addressed one. */
if (first_load == NULL)
- {
- if (!executable)
- goto next;
- first_load = m;
- }
+ 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
+ else if (headers == NULL
&& segment_eligible_for_headers (seg, bed->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;
- }
+ headers = m;
}
-
- next:
m = &seg->next;
}
- if (first_load != last_load && moved_headers)
+ if (headers != NULL)
{
- /* Now swap the first and last PT_LOAD segments'
- positions in segment_map. */
- struct elf_segment_map *first = *first_load;
- struct elf_segment_map *last = *last_load;
- *first_load = first->next;
- first->next = last->next;
- last->next = first;
+ struct elf_segment_map **last_load = NULL;
+ struct elf_segment_map *seg;
+
+ m = first_load;
+ while ((seg = *m) != NULL)
+ {
+ if (seg->p_type == PT_LOAD)
+ {
+ /* Clear the flags on any previous segment that
+ included the file header and phdrs. */
+ seg->includes_filehdr = 0;
+ seg->includes_phdrs = 0;
+ seg->no_sort_lma = 1;
+ /* Also strip out empty segments. */
+ if (seg->count == 0)
+ {
+ if (headers == &seg->next)
+ headers = m;
+ *m = seg->next;
+ continue;
+ }
+ last_load = m;
+ }
+ m = &seg->next;
+ }
+
+ /* This segment will include those headers instead. */
+ seg = *headers;
+ seg->includes_filehdr = 1;
+ seg->includes_phdrs = 1;
+
+ if (last_load != NULL && first_load != last_load && first_load != headers)
+ {
+ /* Put the first PT_LOAD header last. */
+ struct elf_segment_map *first = *first_load;
+ struct elf_segment_map *last = *last_load;
+ *first_load = first->next;
+ first->next = last->next;
+ last->next = first;
+ }
}
- return TRUE;
+ return true;
}
/* After nacl_modify_segment_map has done its work, the file layout has
been done as we wanted. But the PT_LOAD phdrs are no longer in the
proper order for the ELF rule that they must appear in ascending address
order. So find the two segments we swapped before, and swap them back. */
-bfd_boolean
-nacl_modify_program_headers (bfd *abfd, struct bfd_link_info *info)
+bool
+nacl_modify_headers (bfd *abfd, struct bfd_link_info *info)
{
- struct elf_segment_map **m = &elf_seg_map (abfd);
- Elf_Internal_Phdr *phdr = elf_tdata (abfd)->phdr;
- Elf_Internal_Phdr *p = phdr;
-
if (info != NULL && info->user_phdrs)
/* The linker script used PHDRS explicitly, so don't change what the
user asked for. */
- return TRUE;
-
- /* Find the PT_LOAD that contains the headers (should be the first). */
- while (*m != NULL)
- {
- if ((*m)->p_type == PT_LOAD && (*m)->includes_filehdr)
- break;
-
- m = &(*m)->next;
- ++p;
- }
-
- if (*m != NULL)
+ ;
+ else
{
- struct elf_segment_map **first_load_seg = m;
- Elf_Internal_Phdr *first_load_phdr = p;
- struct elf_segment_map **next_load_seg = NULL;
- 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. */
-
- m = &(*m)->next;
- ++p;
+ struct elf_segment_map **m = &elf_seg_map (abfd);
+ Elf_Internal_Phdr *phdr = elf_tdata (abfd)->phdr;
+ Elf_Internal_Phdr *p = phdr;
+ /* Find the PT_LOAD that contains the headers (should be the first). */
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;
- }
+ if ((*m)->p_type == PT_LOAD && (*m)->includes_filehdr)
+ break;
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. */
- if (next_load_seg != NULL)
+ if (*m != 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;
+ struct elf_segment_map **first_load_seg = m;
+ Elf_Internal_Phdr *first_load_phdr = p;
+ struct elf_segment_map **next_load_seg = NULL;
+ 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. */
+
+ m = &(*m)->next;
+ ++p;
- if (next_load_seg == &first_seg->next)
+ while (*m != NULL)
{
- *first_load_seg = next_seg;
- next_seg->next = first_seg;
- first_seg->next = next_next;
+ 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;
}
- else
+
+ /* 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. */
+ if (next_load_seg != NULL)
{
- *first_load_seg = first_next;
- *next_load_seg = next_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_load_seg;
- *next_load_seg = first_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_load_seg;
- *first_load_seg = next_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;
+ return _bfd_elf_modify_headers (abfd, info);
}
-void
-nacl_final_write_processing (bfd *abfd, bfd_boolean linker ATTRIBUTE_UNUSED)
+bool
+nacl_final_write_processing (bfd *abfd)
{
struct elf_segment_map *seg;
for (seg = elf_seg_map (abfd); seg != NULL; seg = seg->next)
BFD_ASSERT (sec->flags & SEC_CODE);
BFD_ASSERT (sec->size > 0);
- fill = abfd->arch_info->fill (sec->size, bfd_big_endian (abfd), TRUE);
+ fill = abfd->arch_info->fill (sec->size, bfd_big_endian (abfd), true);
if (fill == NULL
|| bfd_seek (abfd, sec->filepos, SEEK_SET) != 0
free (fill);
}
+ return _bfd_elf_final_write_processing (abfd);
}