From: mengqinggang <mengqinggang@loongson.cn>
To: binutils@sourceware.org
Cc: xuchenghua@loongson.cn, chenglulu@loongson.cn,
cailulu@loongson.cn, xry111@xry111.site, i.swmail@xen0n.name,
maskray@google.com, luweining@loongson.cn, hejinyang@loongson.cn,
mengqinggang@loongson.cn
Subject: [PATCH v2] LoongArch: ld: Move .got .got.plt before .data and protect .got with relro
Date: Mon, 8 Apr 2024 14:49:53 +0800 [thread overview]
Message-ID: <20240408064953.3562476-1-mengqinggang@loongson.cn> (raw)
Move .got .got.plt before .data so .got can be protected with -zrelro.
And the first two entries of .got.plt (_dl_runtime_resolve and link map)
are placed within the relro region.
---
Changes v1 -> v2:
- Add --hash-style=both option in data-got.d.
v1 link: https://sourceware.org/pipermail/binutils/2024-April/133300.html
bfd/elfnn-loongarch.c | 2 ++
ld/emulparams/elf64loongarch-defs.sh | 5 ++++-
ld/testsuite/ld-loongarch-elf/data-got.d | 16 ++++++++++++++++
ld/testsuite/ld-loongarch-elf/data-got.s | 6 ++++++
.../ld-loongarch-elf/ld-loongarch-elf.exp | 1 +
5 files changed, 29 insertions(+), 1 deletion(-)
create mode 100644 ld/testsuite/ld-loongarch-elf/data-got.d
create mode 100644 ld/testsuite/ld-loongarch-elf/data-got.s
diff --git a/bfd/elfnn-loongarch.c b/bfd/elfnn-loongarch.c
index eb70799b06a..e8632905019 100644
--- a/bfd/elfnn-loongarch.c
+++ b/bfd/elfnn-loongarch.c
@@ -127,6 +127,8 @@ struct loongarch_elf_link_hash_table
#define GOT_ENTRY_SIZE (LARCH_ELF_WORD_BYTES)
+/* Reserve two entries of GOTPLT for ld.so, one is used for PLT
+ resolver _dl_runtime_resolve, the other is used for link map. */
#define GOTPLT_HEADER_SIZE (GOT_ENTRY_SIZE * 2)
#define elf_backend_want_got_plt 1
diff --git a/ld/emulparams/elf64loongarch-defs.sh b/ld/emulparams/elf64loongarch-defs.sh
index c793f5d8388..a8147bf71d7 100644
--- a/ld/emulparams/elf64loongarch-defs.sh
+++ b/ld/emulparams/elf64loongarch-defs.sh
@@ -34,6 +34,9 @@ TEXT_START_ADDR=0x120000000
MAXPAGESIZE="CONSTANT (MAXPAGESIZE)"
COMMONPAGESIZE="CONSTANT (COMMONPAGESIZE)"
-SEPARATE_GOTPLT=0
+# Put .got before .data
+DATA_GOT=" "
+# First two entries for PLT resolver _dl_runtime_resolve and link map.
+SEPARATE_GOTPLT="SIZEOF (.got.plt) >= 16 ? 16 : 0"
INITIAL_READONLY_SECTIONS=".interp : { *(.interp) } ${CREATE_PIE-${INITIAL_READONLY_SECTIONS}}"
INITIAL_READONLY_SECTIONS="${RELOCATING+${CREATE_SHLIB-${INITIAL_READONLY_SECTIONS}}}"
diff --git a/ld/testsuite/ld-loongarch-elf/data-got.d b/ld/testsuite/ld-loongarch-elf/data-got.d
new file mode 100644
index 00000000000..a754478a655
--- /dev/null
+++ b/ld/testsuite/ld-loongarch-elf/data-got.d
@@ -0,0 +1,16 @@
+# line 11 test the first two entries of .got.plt in relro region
+# relro segment size is .dynamic size + .got size + 0x10
+# line 13 test .got .got.plt before .got
+# line 15 test .got in relro segment
+#as:
+#ld: -shared -z relro --hash-style=both
+#readelf: -l --wide
+#skip: loongarch32-*-*
+
+#...
+ GNU_RELRO 0x003c10 0x0000000000007c10 0x0000000000007c10 0x0003f0 0x0003f0 R 0x1
+#...
+ 01 .dynamic .got .got.plt .data
+#...
+ 03 .dynamic .got
+#pass
diff --git a/ld/testsuite/ld-loongarch-elf/data-got.s b/ld/testsuite/ld-loongarch-elf/data-got.s
new file mode 100644
index 00000000000..364fcf64c0e
--- /dev/null
+++ b/ld/testsuite/ld-loongarch-elf/data-got.s
@@ -0,0 +1,6 @@
+.text
+b foo
+.section .got
+.space 0x2a8, 4
+.data
+.zero 24
diff --git a/ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp b/ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp
index 759acab80d4..c2d616b8d0a 100644
--- a/ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp
+++ b/ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp
@@ -133,6 +133,7 @@ if [istarget "loongarch64-*-*"] {
run_dump_test "tlsdesc-dso"
run_dump_test "desc-norelax"
run_dump_test "desc-relax"
+ run_dump_test "data-got"
}
if [check_pie_support] {
--
2.36.0
next reply other threads:[~2024-04-08 6:50 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-08 6:49 mengqinggang [this message]
2024-04-08 12:14 ` Xi Ruoyao
2024-04-09 6:36 ` mengqinggang
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