ELF security enhancement: put .rodata into it's own load section instead

of putting it with the text. This removes the execute permission
from readonly data. This constrains the executable region to portions
of the executable which need to be executable. Note: not all processors
or mmus are capable of -X protection at the page level, but should
handle ELF images which specify specific RWX protections on each section.

7 files changed, 8 insertions, 1 deletions

diff --git a/gnu/usr.bin/binutils/bfd/elf.c b/gnu/usr.bin/binutils/bfd/elf.c
index b39fbe4d505..a9daa8b88c0 100644
--- a/gnu/usr.bin/binutils/bfd/elf.c
+++ b/gnu/usr.bin/binutils/bfd/elf.c
@@ -3103,7 +3103,7 @@ get_program_header_size (abfd)
      longer true. Now there can be several PT_LOAD sections. 6 seems
      to be enough with BSS_PLT, where we have text, data, GOT, dynamic,
      PLT, bss */
-  segs = 6;
+  segs = 7;
 
   s = bfd_get_section_by_name (abfd, ".interp");
   if (s != NULL && (s->flags & SEC_LOAD) != 0)
diff --git a/gnu/usr.bin/binutils/ld/emulparams/elf32_sparc.sh b/gnu/usr.bin/binutils/ld/emulparams/elf32_sparc.sh
index 68c9e4fb39f..fc23bb59c5e 100644
--- a/gnu/usr.bin/binutils/ld/emulparams/elf32_sparc.sh
+++ b/gnu/usr.bin/binutils/ld/emulparams/elf32_sparc.sh
@@ -8,6 +8,7 @@ ARCH=sparc
 MACHINE=
 TEMPLATE_NAME=elf32
 DATA_PLT=
+PAD_RO=
 PAD_PLT=
 PAD_GOT=
 GENERATE_SHLIB_SCRIPT=yes
diff --git a/gnu/usr.bin/binutils/ld/emulparams/elf32ppc.sh b/gnu/usr.bin/binutils/ld/emulparams/elf32ppc.sh
index 7c8b5c95caa..0fbbf68c7ec 100644
--- a/gnu/usr.bin/binutils/ld/emulparams/elf32ppc.sh
+++ b/gnu/usr.bin/binutils/ld/emulparams/elf32ppc.sh
@@ -9,6 +9,7 @@ MAXPAGESIZE=0x10000
 ARCH=powerpc
 MACHINE=
 BSS_PLT=
+PAD_RO=
 PAD_GOT=
 PAD_PLT=
 EXECUTABLE_SYMBOLS='PROVIDE (__stack = 0); PROVIDE (___stack = 0);'
diff --git a/gnu/usr.bin/binutils/ld/emulparams/elf64_sparc.sh b/gnu/usr.bin/binutils/ld/emulparams/elf64_sparc.sh
index 00790d59201..091824d5cf5 100644
--- a/gnu/usr.bin/binutils/ld/emulparams/elf64_sparc.sh
+++ b/gnu/usr.bin/binutils/ld/emulparams/elf64_sparc.sh
@@ -6,6 +6,7 @@ MAXPAGESIZE=0x100000
 ARCH="sparc:v9"
 MACHINE=
 DATA_PLT=
+PAD_RO=
 PAD_GOT=
 PAD_PLT=
 GENERATE_SHLIB_SCRIPT=yes
diff --git a/gnu/usr.bin/binutils/ld/emulparams/elf64alpha.sh b/gnu/usr.bin/binutils/ld/emulparams/elf64alpha.sh
index fa9fad04695..0abe219f84a 100644
--- a/gnu/usr.bin/binutils/ld/emulparams/elf64alpha.sh
+++ b/gnu/usr.bin/binutils/ld/emulparams/elf64alpha.sh
@@ -10,6 +10,7 @@ ARCH=alpha
 MACHINE=
 GENERATE_SHLIB_SCRIPT=yes
 DATA_PLT=
+PAD_RO=
 PAD_GOT=
 PAD_PLT=
 NOP=0x47ff041f
diff --git a/gnu/usr.bin/binutils/ld/emulparams/elf_i386.sh b/gnu/usr.bin/binutils/ld/emulparams/elf_i386.sh
index 0defc2d866f..aca49bcbaf6 100644
--- a/gnu/usr.bin/binutils/ld/emulparams/elf_i386.sh
+++ b/gnu/usr.bin/binutils/ld/emulparams/elf_i386.sh
@@ -6,6 +6,7 @@ NONPAGED_TEXT_START_ADDR=0x08048000
 ARCH=i386
 MACHINE=
 NOP=0x9090
+PAD_RO=
 PAD_GOT=
 TEMPLATE_NAME=elf32
 GENERATE_SHLIB_SCRIPT=yes
diff --git a/gnu/usr.bin/binutils/ld/scripttempl/elf.sc b/gnu/usr.bin/binutils/ld/scripttempl/elf.sc
index e155639eff9..8d47b4ad17b 100644
--- a/gnu/usr.bin/binutils/ld/scripttempl/elf.sc
+++ b/gnu/usr.bin/binutils/ld/scripttempl/elf.sc
@@ -70,6 +70,7 @@ DYNAMIC=".dynamic     ${RELOCATING-0} : { *(.dynamic) }"
 RODATA=".rodata ${RELOCATING-0} : { *(.rodata) ${RELOCATING+*(.rodata.*)} ${RELOCATING+*(.gnu.linkonce.r.*)} }"
 SBSS2=".sbss2 ${RELOCATING-0} : { *(.sbss2) ${RELOCATING+*(.sbss2.*)} ${RELOCATING+*(.gnu.linkonce.sb2.*)} }"
 SDATA2=".sdata2 ${RELOCATING-0} : { *(.sdata2) ${RELOCATING+*(.sdata2.*)} ${RELOCATING+*(.gnu.linkonce.s2.*)} }"
+test "$LD_FLAG" = "N" || test "$LD_FLAG" = "Z" || PAD_RO0="${RELOCATING+. = ALIGN(${MAXPAGESIZE}) + (. & (${MAXPAGESIZE} - 1));}"
 test "$LD_FLAG" = "N" || test "$LD_FLAG" = "Z" || PAD_PLT0="${RELOCATING+. = ALIGN(${MAXPAGESIZE}) + (. & (${MAXPAGESIZE} - 1));} .pltpad0 ${RELOCATING-0} : { ${RELOCATING+__plt_start = .;} }"
 test "$LD_FLAG" = "N" || test "$LD_FLAG" = "Z" || PAD_PLT1=".pltpad1 ${RELOCATING-0} : { ${RELOCATING+__plt_end = .;}} ${RELOCATING+. = ALIGN(${MAXPAGESIZE}) + (. & (${MAXPAGESIZE} - 1));}"
 test "$LD_FLAG" = "N" || test "$LD_FLAG" = "Z" || PAD_GOT0="${RELOCATING+. = ALIGN(${MAXPAGESIZE}) + (. & (${MAXPAGESIZE} - 1));} .gotpad0 ${RELOCATING-0} : { ${RELOCATING+__got_start = .;} }"
@@ -289,6 +290,7 @@ SECTIONS
   ${RELOCATING+PROVIDE (__etext = .);}
   ${RELOCATING+PROVIDE (_etext = .);}
   ${RELOCATING+PROVIDE (etext = .);}
+  ${PAD_RO+${PAD_RO0}}
   ${WRITABLE_RODATA-${RODATA}}
   .rodata1 ${RELOCATING-0} : { *(.rodata1) }
   ${CREATE_SHLIB-${SDATA2}}