x86: don't request useless overflow checking

Relocations with a bitsize matching the architecture's address width
can't usefully use an overflow checking approach other than "dont" or
"signed": All others involve perhaps complex calculations in
_bfd_relocate_contents() (or, not as severe, in bfd_check_overflow())
without ever finding anything to complain about - because of the address
width masking applied. Avoid this unnecessary overhead and switch all
such reloc types to "dont".

Note that "signed" checking with rela relocations (i.e. x86-64 here) is
only going to be useful if the addend actually got passed to
_bfd_relocate_contents() (and maybe others) instead of bogusly adding in
prior section contents (which apparently is assumed to be zero, and
hence again no overflow would ever be detected). See
https://sourceware.org/pipermail/binutils/2021-April/116164.html.

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index cdcf5d7616748e9c5c0a3c8855f5d0d2b0186a77..2659710787a9b97e8f475565cce8dfa3bdbaa7b5 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,10 @@
+2021-05-03  Jan Beulich  <jbeulich@suse.com>
+
+       * elf32-i386.c (elf_howto_table): Switch all 32-bit relocs to
+       complain_overflow_dont.
+       * elf64-x86-64.c (x86_64_elf_howto_table): Switch all 64-bit
+       relocs to complain_overflow_dont.
+
 2021-05-03  Alan Modra  <amodra@gmail.com>
 
        * elf32-ppc.c (allocate_dynrelocs): Keep dyn_relocs for undefweak

diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c
index ffe764422fffc810c4c9c3665873a8b14ed20193..4451f9b451c4fff6e206d332def768199b225441 100644 (file)
--- a/bfd/elf32-i386.c
+++ b/bfd/elf32-i386.c
@@ -33,34 +33,34 @@ static reloc_howto_type elf_howto_table[]=
   HOWTO(R_386_NONE, 0, 3, 0, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_NONE",
        true, 0x00000000, 0x00000000, false),
-  HOWTO(R_386_32, 0, 2, 32, false, 0, complain_overflow_bitfield,
+  HOWTO(R_386_32, 0, 2, 32, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_32",
        true, 0xffffffff, 0xffffffff, false),
-  HOWTO(R_386_PC32, 0, 2, 32, true, 0, complain_overflow_bitfield,
+  HOWTO(R_386_PC32, 0, 2, 32, true, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_PC32",
        true, 0xffffffff, 0xffffffff, true),
-  HOWTO(R_386_GOT32, 0, 2, 32, false, 0, complain_overflow_bitfield,
+  HOWTO(R_386_GOT32, 0, 2, 32, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_GOT32",
        true, 0xffffffff, 0xffffffff, false),
-  HOWTO(R_386_PLT32, 0, 2, 32, true, 0, complain_overflow_bitfield,
+  HOWTO(R_386_PLT32, 0, 2, 32, true, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_PLT32",
        true, 0xffffffff, 0xffffffff, true),
-  HOWTO(R_386_COPY, 0, 2, 32, false, 0, complain_overflow_bitfield,
+  HOWTO(R_386_COPY, 0, 2, 32, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_COPY",
        true, 0xffffffff, 0xffffffff, false),
-  HOWTO(R_386_GLOB_DAT, 0, 2, 32, false, 0, complain_overflow_bitfield,
+  HOWTO(R_386_GLOB_DAT, 0, 2, 32, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_GLOB_DAT",
        true, 0xffffffff, 0xffffffff, false),
-  HOWTO(R_386_JUMP_SLOT, 0, 2, 32, false, 0, complain_overflow_bitfield,
+  HOWTO(R_386_JUMP_SLOT, 0, 2, 32, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_JUMP_SLOT",
        true, 0xffffffff, 0xffffffff, false),
-  HOWTO(R_386_RELATIVE, 0, 2, 32, false, 0, complain_overflow_bitfield,
+  HOWTO(R_386_RELATIVE, 0, 2, 32, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_RELATIVE",
        true, 0xffffffff, 0xffffffff, false),
-  HOWTO(R_386_GOTOFF, 0, 2, 32, false, 0, complain_overflow_bitfield,
+  HOWTO(R_386_GOTOFF, 0, 2, 32, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_GOTOFF",
        true, 0xffffffff, 0xffffffff, false),
-  HOWTO(R_386_GOTPC, 0, 2, 32, true, 0, complain_overflow_bitfield,
+  HOWTO(R_386_GOTPC, 0, 2, 32, true, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_GOTPC",
        true, 0xffffffff, 0xffffffff, true),
 
@@ -72,22 +72,22 @@ static reloc_howto_type elf_howto_table[]=
 #define R_386_ext_offset (R_386_TLS_TPOFF - R_386_standard)
 
   /* These relocs are a GNU extension.  */
-  HOWTO(R_386_TLS_TPOFF, 0, 2, 32, false, 0, complain_overflow_bitfield,
+  HOWTO(R_386_TLS_TPOFF, 0, 2, 32, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_TLS_TPOFF",
        true, 0xffffffff, 0xffffffff, false),
-  HOWTO(R_386_TLS_IE, 0, 2, 32, false, 0, complain_overflow_bitfield,
+  HOWTO(R_386_TLS_IE, 0, 2, 32, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_TLS_IE",
        true, 0xffffffff, 0xffffffff, false),
-  HOWTO(R_386_TLS_GOTIE, 0, 2, 32, false, 0, complain_overflow_bitfield,
+  HOWTO(R_386_TLS_GOTIE, 0, 2, 32, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_TLS_GOTIE",
        true, 0xffffffff, 0xffffffff, false),
-  HOWTO(R_386_TLS_LE, 0, 2, 32, false, 0, complain_overflow_bitfield,
+  HOWTO(R_386_TLS_LE, 0, 2, 32, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_TLS_LE",
        true, 0xffffffff, 0xffffffff, false),
-  HOWTO(R_386_TLS_GD, 0, 2, 32, false, 0, complain_overflow_bitfield,
+  HOWTO(R_386_TLS_GD, 0, 2, 32, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_TLS_GD",
        true, 0xffffffff, 0xffffffff, false),
-  HOWTO(R_386_TLS_LDM, 0, 2, 32, false, 0, complain_overflow_bitfield,
+  HOWTO(R_386_TLS_LDM, 0, 2, 32, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_TLS_LDM",
        true, 0xffffffff, 0xffffffff, false),
   HOWTO(R_386_16, 0, 1, 16, false, 0, complain_overflow_bitfield,
@@ -106,40 +106,40 @@ static reloc_howto_type elf_howto_table[]=
 #define R_386_ext (R_386_PC8 + 1 - R_386_ext_offset)
 #define R_386_tls_offset (R_386_TLS_LDO_32 - R_386_ext)
   /* These are common with Solaris TLS implementation.  */
-  HOWTO(R_386_TLS_LDO_32, 0, 2, 32, false, 0, complain_overflow_bitfield,
+  HOWTO(R_386_TLS_LDO_32, 0, 2, 32, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_TLS_LDO_32",
        true, 0xffffffff, 0xffffffff, false),
-  HOWTO(R_386_TLS_IE_32, 0, 2, 32, false, 0, complain_overflow_bitfield,
+  HOWTO(R_386_TLS_IE_32, 0, 2, 32, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_TLS_IE_32",
        true, 0xffffffff, 0xffffffff, false),
-  HOWTO(R_386_TLS_LE_32, 0, 2, 32, false, 0, complain_overflow_bitfield,
+  HOWTO(R_386_TLS_LE_32, 0, 2, 32, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_TLS_LE_32",
        true, 0xffffffff, 0xffffffff, false),
-  HOWTO(R_386_TLS_DTPMOD32, 0, 2, 32, false, 0, complain_overflow_bitfield,
+  HOWTO(R_386_TLS_DTPMOD32, 0, 2, 32, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_TLS_DTPMOD32",
        true, 0xffffffff, 0xffffffff, false),
-  HOWTO(R_386_TLS_DTPOFF32, 0, 2, 32, false, 0, complain_overflow_bitfield,
+  HOWTO(R_386_TLS_DTPOFF32, 0, 2, 32, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_TLS_DTPOFF32",
        true, 0xffffffff, 0xffffffff, false),
-  HOWTO(R_386_TLS_TPOFF32, 0, 2, 32, false, 0, complain_overflow_bitfield,
+  HOWTO(R_386_TLS_TPOFF32, 0, 2, 32, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_TLS_TPOFF32",
        true, 0xffffffff, 0xffffffff, false),
-  HOWTO(R_386_SIZE32, 0, 2, 32, false, 0, complain_overflow_unsigned,
+  HOWTO(R_386_SIZE32, 0, 2, 32, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_SIZE32",
        true, 0xffffffff, 0xffffffff, false),
-  HOWTO(R_386_TLS_GOTDESC, 0, 2, 32, false, 0, complain_overflow_bitfield,
+  HOWTO(R_386_TLS_GOTDESC, 0, 2, 32, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_TLS_GOTDESC",
        true, 0xffffffff, 0xffffffff, false),
   HOWTO(R_386_TLS_DESC_CALL, 0, 3, 0, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_TLS_DESC_CALL",
        false, 0, 0, false),
-  HOWTO(R_386_TLS_DESC, 0, 2, 32, false, 0, complain_overflow_bitfield,
+  HOWTO(R_386_TLS_DESC, 0, 2, 32, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_TLS_DESC",
        true, 0xffffffff, 0xffffffff, false),
-  HOWTO(R_386_IRELATIVE, 0, 2, 32, false, 0, complain_overflow_bitfield,
+  HOWTO(R_386_IRELATIVE, 0, 2, 32, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_IRELATIVE",
        true, 0xffffffff, 0xffffffff, false),
-  HOWTO(R_386_GOT32X, 0, 2, 32, false, 0, complain_overflow_bitfield,
+  HOWTO(R_386_GOT32X, 0, 2, 32, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_386_GOT32X",
        true, 0xffffffff, 0xffffffff, false),
 

diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index 840555c2000aadf63e428210a577c8db7c04e13d..83a749e6ddc2c4869ff9743db2bf8d4e2bc2807e 100644 (file)
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@@ -47,7 +47,7 @@ static reloc_howto_type x86_64_elf_howto_table[] =
   HOWTO(R_X86_64_NONE, 0, 3, 0, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_X86_64_NONE", false, 0x00000000, 0x00000000,
        false),
-  HOWTO(R_X86_64_64, 0, 4, 64, false, 0, complain_overflow_bitfield,
+  HOWTO(R_X86_64_64, 0, 4, 64, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_X86_64_64", false, MINUS_ONE, MINUS_ONE,
        false),
   HOWTO(R_X86_64_PC32, 0, 2, 32, true, 0, complain_overflow_signed,
@@ -62,13 +62,13 @@ static reloc_howto_type x86_64_elf_howto_table[] =
   HOWTO(R_X86_64_COPY, 0, 2, 32, false, 0, complain_overflow_bitfield,
        bfd_elf_generic_reloc, "R_X86_64_COPY", false, 0xffffffff, 0xffffffff,
        false),
-  HOWTO(R_X86_64_GLOB_DAT, 0, 4, 64, false, 0, complain_overflow_bitfield,
+  HOWTO(R_X86_64_GLOB_DAT, 0, 4, 64, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_X86_64_GLOB_DAT", false, MINUS_ONE,
        MINUS_ONE, false),
-  HOWTO(R_X86_64_JUMP_SLOT, 0, 4, 64, false, 0, complain_overflow_bitfield,
+  HOWTO(R_X86_64_JUMP_SLOT, 0, 4, 64, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_X86_64_JUMP_SLOT", false, MINUS_ONE,
        MINUS_ONE, false),
-  HOWTO(R_X86_64_RELATIVE, 0, 4, 64, false, 0, complain_overflow_bitfield,
+  HOWTO(R_X86_64_RELATIVE, 0, 4, 64, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_X86_64_RELATIVE", false, MINUS_ONE,
        MINUS_ONE, false),
   HOWTO(R_X86_64_GOTPCREL, 0, 2, 32, true, 0, complain_overflow_signed,
@@ -88,13 +88,13 @@ static reloc_howto_type x86_64_elf_howto_table[] =
        bfd_elf_generic_reloc, "R_X86_64_8", false, 0xff, 0xff, false),
   HOWTO(R_X86_64_PC8, 0, 0, 8, true, 0, complain_overflow_signed,
        bfd_elf_generic_reloc, "R_X86_64_PC8", false, 0xff, 0xff, true),
-  HOWTO(R_X86_64_DTPMOD64, 0, 4, 64, false, 0, complain_overflow_bitfield,
+  HOWTO(R_X86_64_DTPMOD64, 0, 4, 64, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_X86_64_DTPMOD64", false, MINUS_ONE,
        MINUS_ONE, false),
-  HOWTO(R_X86_64_DTPOFF64, 0, 4, 64, false, 0, complain_overflow_bitfield,
+  HOWTO(R_X86_64_DTPOFF64, 0, 4, 64, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_X86_64_DTPOFF64", false, MINUS_ONE,
        MINUS_ONE, false),
-  HOWTO(R_X86_64_TPOFF64, 0, 4, 64, false, 0, complain_overflow_bitfield,
+  HOWTO(R_X86_64_TPOFF64, 0, 4, 64, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_X86_64_TPOFF64", false, MINUS_ONE,
        MINUS_ONE, false),
   HOWTO(R_X86_64_TLSGD, 0, 2, 32, true, 0, complain_overflow_signed,
@@ -112,10 +112,10 @@ static reloc_howto_type x86_64_elf_howto_table[] =
   HOWTO(R_X86_64_TPOFF32, 0, 2, 32, false, 0, complain_overflow_signed,
        bfd_elf_generic_reloc, "R_X86_64_TPOFF32", false, 0xffffffff,
        0xffffffff, false),
-  HOWTO(R_X86_64_PC64, 0, 4, 64, true, 0, complain_overflow_bitfield,
+  HOWTO(R_X86_64_PC64, 0, 4, 64, true, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_X86_64_PC64", false, MINUS_ONE, MINUS_ONE,
        true),
-  HOWTO(R_X86_64_GOTOFF64, 0, 4, 64, false, 0, complain_overflow_bitfield,
+  HOWTO(R_X86_64_GOTOFF64, 0, 4, 64, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_X86_64_GOTOFF64",
        false, MINUS_ONE, MINUS_ONE, false),
   HOWTO(R_X86_64_GOTPC32, 0, 2, 32, true, 0, complain_overflow_signed,
@@ -139,7 +139,7 @@ static reloc_howto_type x86_64_elf_howto_table[] =
   HOWTO(R_X86_64_SIZE32, 0, 2, 32, false, 0, complain_overflow_unsigned,
        bfd_elf_generic_reloc, "R_X86_64_SIZE32", false, 0xffffffff, 0xffffffff,
        false),
-  HOWTO(R_X86_64_SIZE64, 0, 4, 64, false, 0, complain_overflow_unsigned,
+  HOWTO(R_X86_64_SIZE64, 0, 4, 64, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_X86_64_SIZE64", false, MINUS_ONE, MINUS_ONE,
        false),
   HOWTO(R_X86_64_GOTPC32_TLSDESC, 0, 2, 32, true, 0,
@@ -151,13 +151,13 @@ static reloc_howto_type x86_64_elf_howto_table[] =
        "R_X86_64_TLSDESC_CALL",
        false, 0, 0, false),
   HOWTO(R_X86_64_TLSDESC, 0, 4, 64, false, 0,
-       complain_overflow_bitfield, bfd_elf_generic_reloc,
+       complain_overflow_dont, bfd_elf_generic_reloc,
        "R_X86_64_TLSDESC",
        false, MINUS_ONE, MINUS_ONE, false),
-  HOWTO(R_X86_64_IRELATIVE, 0, 4, 64, false, 0, complain_overflow_bitfield,
+  HOWTO(R_X86_64_IRELATIVE, 0, 4, 64, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_X86_64_IRELATIVE", false, MINUS_ONE,
        MINUS_ONE, false),
-  HOWTO(R_X86_64_RELATIVE64, 0, 4, 64, false, 0, complain_overflow_bitfield,
+  HOWTO(R_X86_64_RELATIVE64, 0, 4, 64, false, 0, complain_overflow_dont,
        bfd_elf_generic_reloc, "R_X86_64_RELATIVE64", false, MINUS_ONE,
        MINUS_ONE, false),
   HOWTO(R_X86_64_PC32_BND, 0, 2, 32, true, 0, complain_overflow_signed,