MatCat.OpenSource/8sa1-binutils-gdb
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ld: warn about PE base relocations to sections above .reloc

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Due to a bogus linker script, or perhaps because a section doesn't get
placed by a linker script while default placement puts it too high up,
sections can end up above .reloc. Since the process of determining its
contents (and hence its size) happens before final section placement,
relocations needed for such sections would no longer point at the
correct address in the final binary. Warn about this (down the road this
may want to become an error, unless size determination and content
creation for .reloc would get decoupled).

To avoid triggering the warning when .reloc gets discarded, suppress
populating the section in the first place in this case.
This commit is contained in:
Jan Beulich 2021-04-06 10:54:57 +02:00
parent d811a7cf74
commit bd3d1480a8
2 changed files with 15 additions and 1 deletions
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5
ld/ChangeLog
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@ -1,3 +1,8 @@
2021-04-06 Jan Beulich <jbeulich@suse.com>
* pe-dll.c (generate_reloc): Bail immediately when .reloc is
being discarded. Warn when relocated entry is above .reloc.
2021-04-05 Alan Modra <amodra@gmail.com> 2021-04-05 Alan Modra <amodra@gmail.com>
* configure.ac: Move initfini-array arg handling earlier. Don't * configure.ac: Move initfini-array arg handling earlier. Don't

11
ld/pe-dll.c
View File

@ -1516,7 +1516,7 @@ generate_reloc (bfd *abfd, struct bfd_link_info *info)
bfd *b; bfd *b;
struct bfd_section *s; struct bfd_section *s;
if (reloc_s == NULL) if (reloc_s == NULL || reloc_s->output_section == bfd_abs_section_ptr)
return; return;
total_relocs = 0; total_relocs = 0;
for (b = info->input_bfds; b; b = b->link.next) for (b = info->input_bfds; b; b = b->link.next)
@ -1627,6 +1627,15 @@ generate_reloc (bfd *abfd, struct bfd_link_info *info)
reloc_data[total_relocs].vma = sec_vma + relocs[i]->address; reloc_data[total_relocs].vma = sec_vma + relocs[i]->address;
reloc_data[total_relocs].idx = total_relocs; reloc_data[total_relocs].idx = total_relocs;
/* Since we're only about to determine .reloc's size,
subsequent output section VMA calculations will shift up
sections at this or higher addresses. Relocations for
such sections would hence end up not being correct. */
if (reloc_data[total_relocs].vma
>= reloc_s->output_section->vma)
einfo (_("%P: base relocation for section `%s' above "
".reloc section\n"), s->output_section->name);
#define BITS_AND_SHIFT(bits, shift) (bits * 1000 | shift) #define BITS_AND_SHIFT(bits, shift) (bits * 1000 | shift)
switch BITS_AND_SHIFT (relocs[i]->howto->bitsize, switch BITS_AND_SHIFT (relocs[i]->howto->bitsize,