Add PT_GNU_SHR/SHF_GNU_SHARABLE/SHN_GNU_SHARABLE_COMMON support to gas/ldusers/hjl/sharable

PT_GNU_SHR/SHF_GNU_SHARABLE/SHN_GNU_SHARABLE_COMMON are used to group
data into a PT_GNU_SHR to improve performance on NUMA system.

7 files changed, 47 insertions, 0 deletions

diff --git a/ld/emulparams/elf32_x86_64.sh b/ld/emulparams/elf32_x86_64.sh
index 9050730..b5507e2 100644
--- a/ld/emulparams/elf32_x86_64.sh
+++ b/ld/emulparams/elf32_x86_64.sh
@@ -21,6 +21,7 @@ LARGE_SECTIONS=yes
 LARGE_BSS_AFTER_BSS=
 SEPARATE_GOTPLT="SIZEOF (.got.plt) >= 24 ? 24 : 0"
 IREL_IN_PLT=
+SHARABLE_SECTIONS=yes
 
 if [ "x${host}" = "x${target}" ]; then
   case " $EMULATION_LIBPATH " in
diff --git a/ld/emulparams/elf64_ia64.sh b/ld/emulparams/elf64_ia64.sh
index 7e5e54d..d8cf531 100644
--- a/ld/emulparams/elf64_ia64.sh
+++ b/ld/emulparams/elf64_ia64.sh
@@ -37,3 +37,4 @@ OTHER_READONLY_SECTIONS="${OTHER_READONLY_SECTIONS}
 # .dtors.  They have to be next to .sbss/.sbss2/.sdata/.sdata2.
 SMALL_DATA_CTOR=" "
 SMALL_DATA_DTOR=" "
+SHARABLE_SECTIONS=yes
diff --git a/ld/emulparams/elf_i386.sh b/ld/emulparams/elf_i386.sh
index b08e661..2dd59fe 100644
--- a/ld/emulparams/elf_i386.sh
+++ b/ld/emulparams/elf_i386.sh
@@ -21,6 +21,7 @@ IREL_IN_PLT=
 TINY_READONLY_SECTION="
 .plt.got      ${RELOCATING-0} : { *(.plt.got) }
 "
+SHARABLE_SECTIONS=yes
 
 # Linux modify the default library search path to first include
 # a 32-bit specific directory.
diff --git a/ld/emulparams/elf_x86_64.sh b/ld/emulparams/elf_x86_64.sh
index 6055204..f1cca77 100644
--- a/ld/emulparams/elf_x86_64.sh
+++ b/ld/emulparams/elf_x86_64.sh
@@ -26,6 +26,7 @@ TINY_READONLY_SECTION="
 .plt.got      ${RELOCATING-0} : { *(.plt.got) }
 .plt.bnd      ${RELOCATING-0} : { *(.plt.bnd) }
 "
+SHARABLE_SECTIONS=yes
 
 if [ "x${host}" = "x${target}" ]; then
   case " $EMULATION_LIBPATH " in
diff --git a/ld/emultempl/elf32.em b/ld/emultempl/elf32.em
index 47fa549..152fb93 100644
--- a/ld/emultempl/elf32.em
+++ b/ld/emultempl/elf32.em
@@ -106,6 +106,7 @@ gld${EMULATION_NAME}_before_parse (void)
   `if test -n "$CALL_NOP_BYTE" ; then echo link_info.call_nop_byte = $CALL_NOP_BYTE; fi`;
   link_info.check_relocs_after_open_input = `if test "x${CHECK_RELOCS_AFTER_OPEN_INPUT}" = xyes ; then echo TRUE ; else echo FALSE ; fi`;
   link_info.relro = DEFAULT_LD_Z_RELRO;
+  link_info.sharable_sections = `if test "$SHARABLE_SECTIONS" = "yes" ; then echo TRUE ; else echo FALSE ; fi`;
 }
 
 EOF
@@ -1854,6 +1855,12 @@ gld${EMULATION_NAME}_place_orphan (asection *s,
   flagword flags;
   asection *nexts;
 
+  /* Orphaned sharable sections won't have correct page
+     requirements.  */
+  if (elf_section_flags (s) & SHF_GNU_SHARABLE)
+    einfo ("%F%P: unable to place orphaned sharable section %A (%B)\n",
+	   s, s->owner);
+
   if (!bfd_link_relocatable (&link_info)
       && link_info.combreloc
       && (s->flags & SEC_ALLOC))
diff --git a/ld/ldmain.c b/ld/ldmain.c
index e7a8dff..7be0999 100644
--- a/ld/ldmain.c
+++ b/ld/ldmain.c
@@ -285,6 +285,7 @@ main (int argc, char **argv)
 #ifdef DEFAULT_FLAG_COMPRESS_DEBUG
   link_info.compress_debug = COMPRESS_DEBUG_GABI_ZLIB;
 #endif
+  link_info.sharable_sections = FALSE;
 
   ldfile_add_arch ("");
   emulation = get_emulation (argc, argv);
diff --git a/ld/scripttempl/elf.sc b/ld/scripttempl/elf.sc
index f0c6439..24af0eb 100644
--- a/ld/scripttempl/elf.sc
+++ b/ld/scripttempl/elf.sc
@@ -308,6 +308,40 @@ STACK="  .stack        ${RELOCATING-0}${RELOCATING+${STACK_ADDR}} :
     ${RELOCATING+${USER_LABEL_PREFIX}_stack = .;}
     *(.stack)
   }"
+test "${SHARABLE_SECTIONS}" = "yes" && OTHER_READWRITE_SECTIONS="
+  ${OTHER_READWRITE_SECTIONS}
+  /* Sharable data sections.  */
+  .sharable_data ${RELOCATING-0} : ${RELOCATING+ALIGN(${MAXPAGESIZE})}
+  {
+    ${RELOCATING+PROVIDE_HIDDEN (__sharable_data_start = .);}
+    *(.sharable_data${RELOCATING+ .sharable_data.* .gnu.linkonce.shrd.*})
+    /* Align here to ensure that the sharable data section ends at the
+       page boundary.  */
+    ${RELOCATING+. = ALIGN(. != 0 ? ${MAXPAGESIZE} : 1);}
+    ${RELOCATING+PROVIDE_HIDDEN (__sharable_data_end = .);}
+  }
+"
+test "${SHARABLE_SECTIONS}" = "yes" && OTHER_BSS_SECTIONS="
+  ${OTHER_BSS_SECTIONS}
+  /* Sharable bss sections  */
+  .sharable_bss ${RELOCATING-0} : ${RELOCATING+ALIGN(${MAXPAGESIZE})}
+  {
+    ${RELOCATING+PROVIDE_HIDDEN (__sharable_bss_start = .);}
+    *(.dynsharablebss)
+    *(.sharable_bss${RELOCATING+ .sharable_bss.* .gnu.linkonce.shrb.*}) 
+    *(SHARABLE_COMMON)
+    /* Align here to ensure that the sharable bss section ends at the
+       page boundary.  */
+    ${RELOCATING+. = ALIGN(. != 0 ? ${MAXPAGESIZE} : 1);}
+    ${RELOCATING+PROVIDE_HIDDEN (__sharable_bss_end = .);}
+  }
+"
+test "${SHARABLE_SECTIONS}" = "yes" && REL_SHARABLE="
+  .rel.sharable_data	${RELOCATING-0} : { *(.rel.sharable_data${RELOCATING+ .rel.sharable_data.* .rel.gnu.linkonce.shrd.*}) }
+  .rela.sharable_data	${RELOCATING-0} : { *(.rela.sharable_data${RELOCATING+ .rela.sharable_data.* .rela.gnu.linkonce.shrd.*}) }
+  .rel.sharable_bss	${RELOCATING-0} : { *(.rel.sharable_bss${RELOCATING+ .rel.sharable_bss.* .rel.gnu.linkonce.shrb.*}) }
+  .rela.sharable_bss	${RELOCATING-0} : { *(.rela.sharable_bss${RELOCATING+ .rela.sharable_bss.* .rela.gnu.linkonce.shrb.*}) }
+"
 
 TEXT_START_ADDR="SEGMENT_START(\"text-segment\", ${TEXT_START_ADDR})"
 SHLIB_TEXT_START_ADDR="SEGMENT_START(\"text-segment\", ${SHLIB_TEXT_START_ADDR:-0})"
@@ -408,6 +442,7 @@ eval $COMBRELOCCAT <<EOF
   .rel.got      ${RELOCATING-0} : { *(.rel.got) }
   .rela.got     ${RELOCATING-0} : { *(.rela.got) }
   ${OTHER_GOT_RELOC_SECTIONS}
+  ${REL_SHARABLE}
   ${REL_SDATA}
   ${REL_SBSS}
   ${REL_SDATA2}