From: Alan Modra <amodra@gmail.com>
To: binutils@sourceware.org
Subject: PR30824 internal error with -z pack-relative-relocs
Date: Thu, 18 Jan 2024 09:45:59 +1030 [thread overview]
Message-ID: <ZahfrwaOWnX/Pq3Z@squeak.grove.modra.org> (raw)
This corrects a counting problem, where prior to relocate_section relr
encoded relative relocs were allowed when it was known they were on
even boundaries, but relocate_section can only put relative relocs
(non-relr) on eight byte boundaries.
Pushed to mainline and 2.42 branch.
PR 30824
* elf64-ppc.c (RELR_ALIGN): Define, use throughout.
(maybe_relr): New function, use throughout.
diff --git a/bfd/elf64-ppc.c b/bfd/elf64-ppc.c
index 3d1fdd3a7c9..e95f9fbe651 100644
--- a/bfd/elf64-ppc.c
+++ b/bfd/elf64-ppc.c
@@ -4749,6 +4749,24 @@ is_8byte_reloc (enum elf_ppc64_reloc_type r_type)
|| r_type == R_PPC64_PLTCALL);
}
+/* The RELR encoding doesn't allow odd addresses, so RELR_ALIGN must
+ be at least 1. R_PPC64_RELATIVE relocs require alignment of 2**3.
+ We use 3 here to avoid complexity in relocate_section, where for a
+ value of 1 we'd need to test for not just an output RELATIVE reloc
+ near the call to maybe_relr but also UADDR64 and some conditions on
+ the symbol. See PR30824. */
+#define RELR_ALIGN 3
+
+static bool
+maybe_relr (enum elf_ppc64_reloc_type r_type,
+ const Elf_Internal_Rela *rel,
+ const asection *sec)
+{
+ return ((r_type == R_PPC64_ADDR64 || r_type == R_PPC64_TOC)
+ && (rel->r_offset & ((1 << RELR_ALIGN) - 1)) == 0
+ && sec->alignment_power >= RELR_ALIGN);
+}
+
/* Like bfd_reloc_offset_in_range but without a howto. Return true
iff a field of SIZE bytes at OFFSET is within SEC limits. */
@@ -5401,9 +5419,7 @@ ppc64_elf_check_relocs (bfd *abfd, struct bfd_link_info *info,
p->count += 1;
if (!must_be_dyn_reloc (info, r_type))
p->pc_count += 1;
- if ((r_type == R_PPC64_ADDR64 || r_type == R_PPC64_TOC)
- && rel->r_offset % 2 == 0
- && sec->alignment_power != 0)
+ if (maybe_relr (r_type, rel, sec))
p->rel_count += 1;
}
else
@@ -5438,9 +5454,7 @@ ppc64_elf_check_relocs (bfd *abfd, struct bfd_link_info *info,
p->ifunc = is_ifunc;
}
p->count += 1;
- if ((r_type == R_PPC64_ADDR64 || r_type == R_PPC64_TOC)
- && rel->r_offset % 2 == 0
- && sec->alignment_power != 0)
+ if (maybe_relr (r_type, rel, sec))
p->rel_count += 1;
}
}
@@ -7291,9 +7305,7 @@ dec_dynrel_count (const Elf_Internal_Rela *rel,
{
if (!must_be_dyn_reloc (info, r_type))
p->pc_count -= 1;
- if ((r_type == R_PPC64_ADDR64 || r_type == R_PPC64_TOC)
- && rel->r_offset % 2 == 0
- && sec->alignment_power != 0)
+ if (maybe_relr (r_type, rel, sec))
p->rel_count -= 1;
p->count -= 1;
if (p->count == 0)
@@ -7326,9 +7338,7 @@ dec_dynrel_count (const Elf_Internal_Rela *rel,
{
if (p->sec == sec && p->ifunc == is_ifunc)
{
- if ((r_type == R_PPC64_ADDR64 || r_type == R_PPC64_TOC)
- && rel->r_offset % 2 == 0
- && sec->alignment_power != 0)
+ if (maybe_relr (r_type, rel, sec))
p->rel_count -= 1;
p->count -= 1;
if (p->count == 0)
@@ -13884,6 +13894,9 @@ ppc64_elf_size_stubs (struct bfd_link_info *info)
switch (r_type)
{
default:
+ if (info->enable_dt_relr
+ && maybe_relr (r_type, irela, section))
+ break;
continue;
case R_PPC64_REL24:
@@ -13895,14 +13908,6 @@ ppc64_elf_size_stubs (struct bfd_link_info *info)
if ((section->flags & SEC_CODE) != 0)
break;
continue;
-
- case R_PPC64_ADDR64:
- case R_PPC64_TOC:
- if (info->enable_dt_relr
- && irela->r_offset % 2 == 0
- && section->alignment_power != 0)
- break;
- continue;
}
/* Now determine the call target, its name, value,
@@ -15285,7 +15290,7 @@ ppc64_elf_build_stubs (struct bfd_link_info *info,
while (i < htab->relr_count)
{
bfd_vma base = relr_addr[i];
- BFD_ASSERT (base % 2 == 0);
+ BFD_ASSERT ((base & ((1 << RELR_ALIGN) - 1)) == 0);
bfd_put_64 (htab->elf.dynobj, base, loc);
loc += 8;
i++;
@@ -17517,9 +17522,8 @@ ppc64_elf_relocate_section (bfd *output_bfd,
if (!(info->enable_dt_relr
&& ELF64_R_TYPE (outrel.r_info) == R_PPC64_RELATIVE
- && rel->r_offset % 2 == 0
- && input_section->alignment_power != 0
- && ELF64_R_TYPE (orig_rel.r_info) != R_PPC64_UADDR64))
+ && maybe_relr (ELF64_R_TYPE (orig_rel.r_info),
+ rel, input_section)))
{
sreloc = elf_section_data (input_section)->sreloc;
if (h != NULL
--
Alan Modra
Australia Development Lab, IBM
reply other threads:[~2024-01-17 23:16 UTC|newest]
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