[PATCH] Align linkerscript symbols according to ABI
Andreas Krebbel
krebbel@linux.ibm.com
Tue Jul 4 12:18:32 GMT 2023
Apply ABI specific alignment to symbols generated in the default
linker script.
No regressions on x86 and s390x. Linkerscript on x86 does not change
with that.
Ok for mainline?
Bye,
Andreas
--- ld/emulparams/elf64_s390.sh | 1 +
ld/emulparams/elf_s390.sh | 1 + ld/scripttempl/elf.sc | 50
+++++++++++++++++++++++-------------- 3 files changed, 33
insertions(+), 19 deletions(-)
diff --git a/ld/emulparams/elf64_s390.sh b/ld/emulparams/elf64_s390.sh
index 899efd7f532..d0a2a59a092 100644
--- a/ld/emulparams/elf64_s390.sh
+++ b/ld/emulparams/elf64_s390.sh
@@ -17,6 +17,7 @@ EXTRA_EM_FILE=s390
IREL_IN_PLT=
SEPARATE_GOTPLT=0
test -z "$RELRO" && unset SEPARATE_GOTPLT
+SYMBOL_ABI_ALIGNMENT=2
# Treat a host that matches the target with the possible exception of "x"
# in the name as if it were native.
diff --git a/ld/emulparams/elf_s390.sh b/ld/emulparams/elf_s390.sh
index cb1c6b5b04d..1b2fca3f937 100644
--- a/ld/emulparams/elf_s390.sh
+++ b/ld/emulparams/elf_s390.sh
@@ -12,3 +12,4 @@ GENERATE_SHLIB_SCRIPT=yes
GENERATE_PIE_SCRIPT=yes
NO_SMALL_DATA=yes
IREL_IN_PLT=
+SYMBOL_ABI_ALIGNMENT=2
diff --git a/ld/scripttempl/elf.sc b/ld/scripttempl/elf.sc
index 1e3c5aa8504..9e95e6b4162 100644
--- a/ld/scripttempl/elf.sc
+++ b/ld/scripttempl/elf.sc
@@ -78,6 +78,8 @@
# USER_LABEL_PREFIX - prefix to add to user-visible symbols.
# RODATA_NAME, SDATA_NAME, SBSS_NAME, BSS_NAME - base parts of names
# for standard sections, without initial "." or suffixes.
+# SYMBOL_ABI_ALIGNMENT - minimum alignment in bytes which needs to be
+# applied to every symbol definition
#
# When adding sections, do note that the names of some sections are used
# when specifying the start address of the next.
@@ -165,19 +167,29 @@ if test -z "$GOT"; then
GOTPLT=".got.plt ${RELOCATING-0} : { *(.got.plt)${RELOCATING+ *(.igot.plt)} }"
fi
fi
+
+def_symbol()
+{
+ if [ -z "${SYMBOL_ABI_ALIGNMENT}" ]; then
+ echo "${USER_LABEL_PREFIX}$1 = . "
+ else
+ echo "${USER_LABEL_PREFIX}$1 = ALIGN(${SYMBOL_ABI_ALIGNMENT})"
+ fi
+}
+
REL_IFUNC=".rel.ifunc ${RELOCATING-0} : { *(.rel.ifunc) }"
RELA_IFUNC=".rela.ifunc ${RELOCATING-0} : { *(.rela.ifunc) }"
REL_IPLT=".rel.iplt ${RELOCATING-0} :
{
- ${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__rel_iplt_start = .);}}
+ ${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN ($(def_symbol "__rel_iplt_start"));}}
*(.rel.iplt)
- ${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__rel_iplt_end = .);}}
+ ${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN ($(def_symbol "__rel_iplt_end"));}}
}"
RELA_IPLT=".rela.iplt ${RELOCATING-0} :
{
- ${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__rela_iplt_start = .);}}
+ ${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN ($(def_symbol "__rela_iplt_start"));}}
*(.rela.iplt)
- ${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__rela_iplt_end = .);}}
+ ${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN ($(def_symbol "__rela_iplt_end"));}}
}"
DYNAMIC=".dynamic ${RELOCATING-0} : { *(.dynamic) }"
RODATA=".${RODATA_NAME} ${RELOCATING-0} : { *(.${RODATA_NAME}${RELOCATING+ .${RODATA_NAME}.* .gnu.linkonce.r.*}) }"
@@ -267,23 +279,23 @@ else
fi
PREINIT_ARRAY=".preinit_array :
{
- ${CREATE_SHLIB-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__preinit_array_start = .);}
+ ${CREATE_SHLIB-PROVIDE_HIDDEN ($(def_symbol "__preinit_array_start"));}
KEEP (*(.preinit_array))
- ${CREATE_SHLIB-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__preinit_array_end = .);}
+ ${CREATE_SHLIB-PROVIDE_HIDDEN ($(def_symbol "__preinit_array_end"));}
}"
INIT_ARRAY=".init_array :
{
- ${CREATE_SHLIB-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__init_array_start = .);}
+ ${CREATE_SHLIB-PROVIDE_HIDDEN ($(def_symbol "__init_array_start"));}
${SORT_INIT_ARRAY}
KEEP (*(.init_array ${CTORS_IN_INIT_ARRAY}))
- ${CREATE_SHLIB-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__init_array_end = .);}
+ ${CREATE_SHLIB-PROVIDE_HIDDEN ($(def_symbol "__init_array_end"));}
}"
FINI_ARRAY=".fini_array :
{
- ${CREATE_SHLIB-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__fini_array_start = .);}
+ ${CREATE_SHLIB-PROVIDE_HIDDEN ($(def_symbol "__fini_array_start"));}
${SORT_FINI_ARRAY}
KEEP (*(.fini_array ${DTORS_IN_FINI_ARRAY}))
- ${CREATE_SHLIB-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__fini_array_end = .);}
+ ${CREATE_SHLIB-PROVIDE_HIDDEN ($(def_symbol "__fini_array_end"));}
}"
CTOR=".ctors ${CONSTRUCTING-0} :
{
@@ -323,7 +335,7 @@ DTOR=".dtors ${CONSTRUCTING-0} :
}"
STACK=".stack ${RELOCATING-0}${RELOCATING+${STACK_ADDR}} :
{
- ${RELOCATING+${USER_LABEL_PREFIX}_stack = .;}
+ ${RELOCATING+$(def_symbol "_stack");}
*(.stack)
${RELOCATING+${STACK_SENTINEL}}
}"
@@ -494,16 +506,16 @@ cat >> ldscripts/dyntmp.$$ <<EOF
.rel.plt ${RELOCATING-0} :
{
*(.rel.plt)
- ${IREL_IN_PLT+${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__rel_iplt_start = .);}}}
+ ${IREL_IN_PLT+${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN ($(def_symbol "__rel_iplt_start"));}}}
${IREL_IN_PLT+${RELOCATING+*(.rel.iplt)}}
- ${IREL_IN_PLT+${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__rel_iplt_end = .);}}}
+ ${IREL_IN_PLT+${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN ($(def_symbol "__rel_iplt_end"));}}}
}
.rela.plt ${RELOCATING-0} :
{
*(.rela.plt)
- ${IREL_IN_PLT+${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__rela_iplt_start = .);}}}
+ ${IREL_IN_PLT+${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN ($(def_symbol "__rela_iplt_start"));}}}
${IREL_IN_PLT+${RELOCATING+*(.rela.iplt)}}
- ${IREL_IN_PLT+${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__rela_iplt_end = .);}}}
+ ${IREL_IN_PLT+${RELOCATING+${CREATE_PIC-PROVIDE_HIDDEN ($(def_symbol "__rela_iplt_end"));}}}
}
${OTHER_PLT_RELOC_SECTIONS}
EOF
@@ -628,7 +640,7 @@ cat <<EOF
/* Thread Local Storage sections */
.tdata ${RELOCATING-0} :
{
- ${RELOCATING+${CREATE_SHLIB-PROVIDE_HIDDEN (${USER_LABEL_PREFIX}__tdata_start = .);}}
+ ${RELOCATING+${CREATE_SHLIB-PROVIDE_HIDDEN ($(def_symbol "__tdata_start"));}}
*(.tdata${RELOCATING+ .tdata.* .gnu.linkonce.td.*})
}
.tbss ${RELOCATING-0} : { *(.tbss${RELOCATING+ .tbss.* .gnu.linkonce.tb.*})${RELOCATING+ *(.tcommon)} }
@@ -676,10 +688,10 @@ cat <<EOF
${SDATA_GOT+${OTHER_GOT_SECTIONS}}
${DATA_SDATA-${SDATA}}
${DATA_SDATA-${OTHER_SDATA_SECTIONS}}
- ${RELOCATING+${DATA_END_SYMBOLS-${CREATE_SHLIB+PROVIDE (}${USER_LABEL_PREFIX}_edata = .${CREATE_SHLIB+)}; PROVIDE (${USER_LABEL_PREFIX}edata = .);}}
+ ${RELOCATING+${DATA_END_SYMBOLS-${CREATE_SHLIB+PROVIDE (}$(def_symbol "_edata")${CREATE_SHLIB+)}; PROVIDE ($(def_symbol "edata"));}}
${PERSISTENT}
${RELOCATING+. = .;}
- ${RELOCATING+${CREATE_SHLIB+PROVIDE (}${USER_LABEL_PREFIX}__bss_start = .${CREATE_SHLIB+)};}
+ ${RELOCATING+${CREATE_SHLIB+PROVIDE (}$(def_symbol "__bss_start")${CREATE_SHLIB+)};}
${RELOCATING+${OTHER_BSS_SYMBOLS}}
${DATA_SDATA-${SBSS}}
${BSS_PLT+${PLT}}
@@ -713,7 +725,7 @@ cat <<EOF
${LARGE_BSS_AFTER_BSS-${LARGE_BSS}}
${RELOCATING+. = ALIGN(${ALIGNMENT});}
${RELOCATING+${OTHER_END_SYMBOLS}}
- ${RELOCATING+${END_SYMBOLS-${CREATE_SHLIB+PROVIDE (}${USER_LABEL_PREFIX}_end = .${CREATE_SHLIB+)}; PROVIDE (${USER_LABEL_PREFIX}end = .);}}
+ ${RELOCATING+${END_SYMBOLS-${CREATE_SHLIB+PROVIDE (}$(def_symbol "_end")${CREATE_SHLIB+)}; PROVIDE ($(def_symbol "end"));}}
${RELOCATING+${DATA_SEGMENT_END}}
${TINY_DATA_SECTION}
${TINY_BSS_SECTION}
--
2.41.0
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