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| author | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2020-07-29 15:47:50 +0100 |
|---|---|---|
| committer | Szabolcs Nagy <szabolcs.nagy@arm.com> | 2020-08-11 09:51:17 +0100 |
| commit | e3b314d3a61db4b0b36975fa00eb9043a6142448 (patch) | |
| tree | 7b1786bac466dc55f9a8bd5af1c25b01a4072ddf | |
| parent | 26b6ab7a0e4106597c3e4949bb17208bd863ce98 (diff) | |
| download | binutils-gdb-e3b314d3a61db4b0b36975fa00eb9043a6142448.tar.gz | |
aarch64: set sh_entsize of .plt to 0
On aarch64 the first PLT entry is 32 bytes, subsequent entries
are 16 bytes by default but can be 24 bytes with BTI or with
PAC-PLT.
sh_entsize of .plt was set to the PLT entry size, so in some
cases sh_size % sh_entsize != 0, which breaks some tools.
Note that PLT0 (and the TLSDESC stub code which is also in the
PLT) were historically not padded up to meet the sh_size
requirement, but to ensure that PLT stub code is aligned on
cache lines. Similar layout is present on other targets too
which just happens to make sh_size a multiple of sh_entsize and
it is not expected that sh_entsize of .plt is used for anything.
This patch sets sh_entsize of .plt to 0: the section does not
hold a table of fixed-size entries so other values are not
conforming in principle to the ELF spec.
bfd/ChangeLog:
Backport from mainline.
2020-07-30 Szabolcs Nagy <szabolcs.nagy@arm.com>
PR ld/26312
* elfnn-aarch64.c (elfNN_aarch64_init_small_plt0_entry): Set sh_entsize
to 0.
(elfNN_aarch64_finish_dynamic_sections): Remove sh_entsize setting.
(cherry picked from commit 4d3bb35620e70d543d438bf21be1307f7ea0f5d0)
| -rw-r--r-- | bfd/ChangeLog | 10 | ||||
| -rw-r--r-- | bfd/elfnn-aarch64.c | 11 |
2 files changed, 15 insertions, 6 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog index ca87f744a3d..ecd099580a4 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,13 @@ +2020-08-11 Szabolcs Nagy <szabolcs.nagy@arm.com> + + Backport from mainline. + 2020-07-30 Szabolcs Nagy <szabolcs.nagy@arm.com> + + PR ld/26312 + * elfnn-aarch64.c (elfNN_aarch64_init_small_plt0_entry): Set sh_entsize + to 0. + (elfNN_aarch64_finish_dynamic_sections): Remove sh_entsize setting. + 2020-04-21 Tamar Christina <tamar.christina@arm.com> Backport from mainline. diff --git a/bfd/elfnn-aarch64.c b/bfd/elfnn-aarch64.c index 5fabcd8f646..0493cbb080a 100644 --- a/bfd/elfnn-aarch64.c +++ b/bfd/elfnn-aarch64.c @@ -9571,8 +9571,11 @@ elfNN_aarch64_init_small_plt0_entry (bfd *output_bfd ATTRIBUTE_UNUSED, memcpy (htab->root.splt->contents, htab->plt0_entry, htab->plt_header_size); - elf_section_data (htab->root.splt->output_section)->this_hdr.sh_entsize = - htab->plt_header_size; + + /* PR 26312: Explicitly set the sh_entsize to 0 so that + consumers do not think that the section contains fixed + sized objects. */ + elf_section_data (htab->root.splt->output_section)->this_hdr.sh_entsize = 0; plt_got_2nd_ent = (htab->root.sgotplt->output_section->vma + htab->root.sgotplt->output_offset @@ -9674,10 +9677,6 @@ elfNN_aarch64_finish_dynamic_sections (bfd *output_bfd, { elfNN_aarch64_init_small_plt0_entry (output_bfd, htab); - elf_section_data (htab->root.splt->output_section)-> - this_hdr.sh_entsize = htab->plt_entry_size; - - if (htab->tlsdesc_plt && !(info->flags & DF_BIND_NOW)) { BFD_ASSERT (htab->dt_tlsdesc_got != (bfd_vma)-1); |