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-rw-r--r--bfd/ChangeLog11
-rw-r--r--bfd/elf-nacl.c88
-rw-r--r--bfd/elf.c99
3 files changed, 125 insertions, 73 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 5276305..a4a7b4f 100644
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,5 +1,16 @@
2018-10-08 Alan Modra <amodra@gmail.com>
+ * elf-nacl.c (nacl_modify_segment_map): Cope with header PT_LOAD
+ lacking sections.
+ * elf.c (_bfd_elf_map_sections_to_segments): Assume file and
+ program headers are required when info->load_phdrs. Reorganize
+ code handling program headers. Generate a mapping without
+ sections just for file and program headers when -z separate-code
+ would indicate they should be on a different page to the first
+ section.
+
+2018-10-08 Alan Modra <amodra@gmail.com>
+
* elf.c (assign_file_positions_for_load_sections): Set p_vaddr
from m->p_vaddr_offset for segments without sections. Invert
sign of p_vaddr_offset.
diff --git a/bfd/elf-nacl.c b/bfd/elf-nacl.c
index 5f446b4..71b2ad8 100644
--- a/bfd/elf-nacl.c
+++ b/bfd/elf-nacl.c
@@ -70,8 +70,7 @@ 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)
@@ -170,56 +169,61 @@ nacl_modify_segment_map (bfd *abfd, struct bfd_link_info *info)
}
/* 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;
+ /* 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;
diff --git a/bfd/elf.c b/bfd/elf.c
index 742a52e..5b3d27c 100644
--- a/bfd/elf.c
+++ b/bfd/elf.c
@@ -4597,7 +4597,7 @@ _bfd_elf_map_sections_to_segments (bfd *abfd, struct bfd_link_info *info)
unsigned int hdr_index;
bfd_vma maxpagesize;
asection **hdrpp;
- bfd_boolean phdr_in_segment = TRUE;
+ bfd_boolean phdr_in_segment;
bfd_boolean writable;
bfd_boolean executable;
int tls_count = 0;
@@ -4606,7 +4606,7 @@ _bfd_elf_map_sections_to_segments (bfd *abfd, struct bfd_link_info *info)
asection *dynsec, *eh_frame_hdr;
bfd_size_type amt;
bfd_vma addr_mask, wrap_to = 0;
- bfd_boolean linker_created_pt_phdr_segment = FALSE;
+ bfd_size_type phdr_size;
/* Select the allocated sections, and sort them. */
@@ -4638,8 +4638,23 @@ _bfd_elf_map_sections_to_segments (bfd *abfd, struct bfd_link_info *info)
qsort (sections, (size_t) count, sizeof (asection *), elf_sort_sections);
- /* Build the mapping. */
+ phdr_size = elf_program_header_size (abfd);
+ if (phdr_size == (bfd_size_type) -1)
+ phdr_size = get_program_header_size (abfd, info);
+ phdr_size += bed->s->sizeof_ehdr;
+ maxpagesize = bed->maxpagesize;
+ if (maxpagesize == 0)
+ maxpagesize = 1;
+ phdr_in_segment = info != NULL && info->load_phdrs;
+ if (count != 0
+ && (((sections[0]->lma & addr_mask) & (maxpagesize - 1))
+ >= (phdr_size & (maxpagesize - 1))))
+ /* For compatibility with old scripts that may not be using
+ SIZEOF_HEADERS, add headers when it looks like space has
+ been left for them. */
+ phdr_in_segment = TRUE;
+ /* Build the mapping. */
mfirst = NULL;
pm = &mfirst;
@@ -4658,7 +4673,7 @@ _bfd_elf_map_sections_to_segments (bfd *abfd, struct bfd_link_info *info)
m->p_flags = PF_R;
m->p_flags_valid = 1;
m->includes_phdrs = 1;
- linker_created_pt_phdr_segment = TRUE;
+ phdr_in_segment = TRUE;
*pm = m;
pm = &m->next;
@@ -4681,12 +4696,6 @@ _bfd_elf_map_sections_to_segments (bfd *abfd, struct bfd_link_info *info)
last_hdr = NULL;
last_size = 0;
hdr_index = 0;
- maxpagesize = bed->maxpagesize;
- /* PR 17512: file: c8455299.
- Avoid divide-by-zero errors later on.
- FIXME: Should we abort if the maxpagesize is zero ? */
- if (maxpagesize == 0)
- maxpagesize = 1;
writable = FALSE;
executable = FALSE;
dynsec = bfd_get_section_by_name (abfd, ".dynamic");
@@ -4694,34 +4703,62 @@ _bfd_elf_map_sections_to_segments (bfd *abfd, struct bfd_link_info *info)
&& (dynsec->flags & SEC_LOAD) == 0)
dynsec = NULL;
+ if ((abfd->flags & D_PAGED) == 0)
+ phdr_in_segment = FALSE;
+
/* Deal with -Ttext or something similar such that the first section
is not adjacent to the program headers. This is an
approximation, since at this point we don't know exactly how many
program headers we will need. */
- if (count > 0)
+ if (phdr_in_segment && count > 0)
{
- bfd_size_type phdr_size = elf_program_header_size (abfd);
+ bfd_vma phdr_lma;
+ bfd_boolean separate_phdr = FALSE;
- if (phdr_size == (bfd_size_type) -1)
- phdr_size = get_program_header_size (abfd, info);
- phdr_size += bed->s->sizeof_ehdr;
- if ((abfd->flags & D_PAGED) == 0
- || (sections[0]->lma & addr_mask) < phdr_size
- || ((sections[0]->lma & addr_mask) % maxpagesize
- < phdr_size % maxpagesize)
- || (sections[0]->lma & addr_mask & -maxpagesize) < wrap_to)
+ phdr_lma = (sections[0]->lma - phdr_size) & addr_mask & -maxpagesize;
+ if (info != NULL
+ && info->separate_code
+ && (sections[0]->flags & SEC_CODE) != 0)
{
- /* PR 20815: The ELF standard says that a PT_PHDR segment, if
- present, must be included as part of the memory image of the
- program. Ie it must be part of a PT_LOAD segment as well.
- If we have had to create our own PT_PHDR segment, but it is
- not going to be covered by the first PT_LOAD segment, then
- force the inclusion if we can... */
- if ((abfd->flags & D_PAGED) != 0
- && linker_created_pt_phdr_segment)
- phdr_in_segment = TRUE;
- else
- phdr_in_segment = FALSE;
+ /* If data sections should be separate from code and
+ thus not executable, and the first section is
+ executable then put the file and program headers in
+ their own PT_LOAD. */
+ separate_phdr = TRUE;
+ if ((((phdr_lma + phdr_size - 1) & addr_mask & -maxpagesize)
+ == (sections[0]->lma & addr_mask & -maxpagesize)))
+ {
+ /* The file and program headers are currently on the
+ same page as the first section. Put them on the
+ previous page if we can. */
+ if (phdr_lma >= maxpagesize)
+ phdr_lma -= maxpagesize;
+ else
+ separate_phdr = FALSE;
+ }
+ }
+ if ((sections[0]->lma & addr_mask) < phdr_lma
+ || (sections[0]->lma & addr_mask) < phdr_size)
+ /* If file and program headers would be placed at the end
+ of memory then it's probably better to omit them. */
+ phdr_in_segment = FALSE;
+ else if (phdr_lma < wrap_to)
+ /* If a section wraps around to where we'll be placing
+ file and program headers, then the headers will be
+ overwritten. */
+ phdr_in_segment = FALSE;
+ else if (separate_phdr)
+ {
+ m = make_mapping (abfd, sections, 0, 0, phdr_in_segment);
+ if (m == NULL)
+ goto error_return;
+ m->p_paddr = phdr_lma;
+ m->p_vaddr_offset
+ = (sections[0]->vma - phdr_size) & addr_mask & -maxpagesize;
+ m->p_paddr_valid = 1;
+ *pm = m;
+ pm = &m->next;
+ phdr_in_segment = FALSE;
}
}
generated by cgit v1.1 at 2024-10-12 06:43:46 +0000