[PATCH] ld: Don't define __rel[a]_iplt_start/__rel[a]_iplt_end in PIE

[PATCH] ld: Don't define __rel[a]_iplt_start/__rel[a]_iplt_end in PIE

[H.J. Lu]

__rel[a]_iplt_start and __rel[a]_iplt_end are defined to handle IFUNC in
static executables.  For PIE, since IFUNC is handled as the part of the
normal dynamic relocation processing, there is no need to define these
symbols in PIE.

	* scripttempl/elf.sc (CREATE_PIC): New.  Set for CREATE_SHLIB or
	CREATE_PIE.
	(__rel_iplt_start): Don't define for CREATE_PIC.
	(__rel_iplt_end): Likewise.
	(__rela_iplt_start): Likewise.
	(__rela_iplt_end): Likewise.
---
 ld/scripttempl/elf.sc | 17 +++++++++--------
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/ld/scripttempl/elf.sc b/ld/scripttempl/elf.sc
index bd7584120e..f9f0f7d402 100644
--- a/ld/scripttempl/elf.sc
+++ b/ld/scripttempl/elf.sc
@@ -109,6 +109,7 @@ else
   FILL=
 fi
 
+test -n "$CREATE_SHLIB$CREATE_PIE" && CREATE_PIC=" "
 test -z "$RODATA_NAME" && RODATA_NAME=rodata
 test -z "$SDATA_NAME" && SDATA_NAME=sdata
 test -z "$SBSS_NAME" && SBSS_NAME=sbss
@@ -160,15 +161,15 @@ REL_IFUNC=".rel.ifunc    ${RELOCATING-0} : { *(.rel.ifunc) }"
 RELA_IFUNC=".rela.ifunc   ${RELOCATING-0} : { *(.rela.ifunc) }"
 REL_IPLT=".rel.iplt     ${RELOCATING-0} :
     {
-      ${RELOCATING+${CREATE_SHLIB-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__rel_iplt_start = .);}}
+      ${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__rel_iplt_start = .);}}
       *(.rel.iplt)
-      ${RELOCATING+${CREATE_SHLIB-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__rel_iplt_end = .);}}
+      ${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__rel_iplt_end = .);}}
     }"
 RELA_IPLT=".rela.iplt    ${RELOCATING-0} :
     {
-      ${RELOCATING+${CREATE_SHLIB-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__rela_iplt_start = .);}}
+      ${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__rela_iplt_start = .);}}
       *(.rela.iplt)
-      ${RELOCATING+${CREATE_SHLIB-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__rela_iplt_end = .);}}
+      ${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__rela_iplt_end = .);}}
     }"
 DYNAMIC=".dynamic      ${RELOCATING-0} : { *(.dynamic) }"
 RODATA=".${RODATA_NAME}       ${RELOCATING-0} : { *(.${RODATA_NAME}${RELOCATING+ .${RODATA_NAME}.* .gnu.linkonce.r.*}) }"
@@ -463,16 +464,16 @@ cat >> ldscripts/dyntmp.$$ <<EOF
   .rel.plt      ${RELOCATING-0} :
     {
       *(.rel.plt)
-      ${IREL_IN_PLT+${RELOCATING+${CREATE_SHLIB-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__rel_iplt_start = .);}}}
+      ${IREL_IN_PLT+${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__rel_iplt_start = .);}}}
       ${IREL_IN_PLT+${RELOCATING+*(.rel.iplt)}}
-      ${IREL_IN_PLT+${RELOCATING+${CREATE_SHLIB-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__rel_iplt_end = .);}}}
+      ${IREL_IN_PLT+${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__rel_iplt_end = .);}}}
     }
   .rela.plt     ${RELOCATING-0} :
     {
       *(.rela.plt)
-      ${IREL_IN_PLT+${RELOCATING+${CREATE_SHLIB-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__rela_iplt_start = .);}}}
+      ${IREL_IN_PLT+${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__rela_iplt_start = .);}}}
       ${IREL_IN_PLT+${RELOCATING+*(.rela.iplt)}}
-      ${IREL_IN_PLT+${RELOCATING+${CREATE_SHLIB-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__rela_iplt_end = .);}}}
+      ${IREL_IN_PLT+${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__rela_iplt_end = .);}}}
     }
   ${OTHER_PLT_RELOC_SECTIONS}
 EOF
-- 
2.20.1

Re: [PATCH] ld: Don't define __rel[a]_iplt_start/__rel[a]_iplt_end in PIE

[Alan Modra]

On Wed, Apr 10, 2019 at 12:40:42PM -0700, H.J. Lu wrote:
> 	* scripttempl/elf.sc (CREATE_PIC): New.  Set for CREATE_SHLIB or
> 	CREATE_PIE.
> 	(__rel_iplt_start): Don't define for CREATE_PIC.
> 	(__rel_iplt_end): Likewise.
> 	(__rela_iplt_start): Likewise.
> 	(__rela_iplt_end): Likewise.

Looks fine to me.

-- 
Alan Modra
Australia Development Lab, IBM