* [PATCH v4] ld.so: Initialize bootstrap_map.l_ld_readonly [BZ #28340]
@ 2021-10-18 18:35 H.J. Lu
2021-10-19 13:14 ` Florian Weimer
0 siblings, 1 reply; 2+ messages in thread
From: H.J. Lu @ 2021-10-18 18:35 UTC (permalink / raw)
To: libc-alpha
1. Define DL_RO_DYN_SECTION to initalize bootstrap_map.l_ld_readonly
before calling elf_get_dynamic_info to get dynamic info in bootstrap_map,
2. Define a single
static inline bool
dl_relocate_ld (const struct link_map *l)
{
/* Don't relocate dynamic section if it is readonly */
return !(l->l_ld_readonly || DL_RO_DYN_SECTION);
}
This updates BZ #28340 fix.
---
elf/rtld.c | 1 +
sysdeps/generic/dl-relocate-ld.h | 11 ++---------
sysdeps/generic/ldsodefs.h | 10 ++++++++++
sysdeps/mips/dl-relocate-ld.h | 11 ++---------
sysdeps/riscv/dl-relocate-ld.h | 11 ++---------
5 files changed, 17 insertions(+), 27 deletions(-)
diff --git a/elf/rtld.c b/elf/rtld.c
index c66a1d00bc..b8ba2d8836 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -547,6 +547,7 @@ _dl_start (void *arg)
/* Read our own dynamic section and fill in the info array. */
bootstrap_map.l_ld = (void *) bootstrap_map.l_addr + elf_machine_dynamic ();
+ bootstrap_map.l_ld_readonly = DL_RO_DYN_SECTION;
elf_get_dynamic_info (&bootstrap_map, true, false);
#if NO_TLS_OFFSET != 0
diff --git a/sysdeps/generic/dl-relocate-ld.h b/sysdeps/generic/dl-relocate-ld.h
index 5fae206db9..cfb86c2d6a 100644
--- a/sysdeps/generic/dl-relocate-ld.h
+++ b/sysdeps/generic/dl-relocate-ld.h
@@ -19,14 +19,7 @@
#ifndef _DL_RELOCATE_LD_H
#define _DL_RELOCATE_LD_H
-/* Return true if dynamic section in the shared library L should be
- relocated. */
-
-static inline bool
-dl_relocate_ld (const struct link_map *l)
-{
- /* Don't relocate dynamic section if it is readonly */
- return !l->l_ld_readonly;
-}
+/* The dynamic section is writable. */
+#define DL_RO_DYN_SECTION 0
#endif /* _DL_RELOCATE_LD_H */
diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h
index 9ec1511bb0..0410f777a6 100644
--- a/sysdeps/generic/ldsodefs.h
+++ b/sysdeps/generic/ldsodefs.h
@@ -69,6 +69,16 @@ __BEGIN_DECLS
`ElfW(TYPE)' is used in place of `Elf32_TYPE' or `Elf64_TYPE'. */
#define ELFW(type) _ElfW (ELF, __ELF_NATIVE_CLASS, type)
+/* Return true if dynamic section in the shared library L should be
+ relocated. */
+
+static inline bool
+dl_relocate_ld (const struct link_map *l)
+{
+ /* Don't relocate dynamic section if it is readonly */
+ return !(l->l_ld_readonly || DL_RO_DYN_SECTION);
+}
+
/* All references to the value of l_info[DT_PLTGOT],
l_info[DT_STRTAB], l_info[DT_SYMTAB], l_info[DT_RELA],
l_info[DT_REL], l_info[DT_JMPREL], and l_info[VERSYMIDX (DT_VERSYM)]
diff --git a/sysdeps/mips/dl-relocate-ld.h b/sysdeps/mips/dl-relocate-ld.h
index 0c18d9a567..376ad75dd1 100644
--- a/sysdeps/mips/dl-relocate-ld.h
+++ b/sysdeps/mips/dl-relocate-ld.h
@@ -19,14 +19,7 @@
#ifndef _DL_RELOCATE_LD_H
#define _DL_RELOCATE_LD_H
-/* Return true if dynamic section in the shared library L should be
- relocated. */
-
-static inline bool
-dl_relocate_ld (const struct link_map *l)
-{
- /* Never relocate dynamic section. */
- return false;
-}
+/* The dynamic section is readonly. */
+#define DL_RO_DYN_SECTION 1
#endif /* _DL_RELOCATE_LD_H */
diff --git a/sysdeps/riscv/dl-relocate-ld.h b/sysdeps/riscv/dl-relocate-ld.h
index 10327454b1..2ab2b8ac6c 100644
--- a/sysdeps/riscv/dl-relocate-ld.h
+++ b/sysdeps/riscv/dl-relocate-ld.h
@@ -19,14 +19,7 @@
#ifndef _DL_RELOCATE_LD_H
#define _DL_RELOCATE_LD_H
-/* Return true if dynamic section in the shared library L should be
- relocated. */
-
-static inline bool
-dl_relocate_ld (const struct link_map *l)
-{
- /* Never relocate dynamic section for ABI compatibility. */
- return false;
-}
+/* The dynamic section is readonly for ABI compatibility. */
+#define DL_RO_DYN_SECTION 1
#endif /* _DL_RELOCATE_LD_H */
--
2.32.0
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH v4] ld.so: Initialize bootstrap_map.l_ld_readonly [BZ #28340]
2021-10-18 18:35 [PATCH v4] ld.so: Initialize bootstrap_map.l_ld_readonly [BZ #28340] H.J. Lu
@ 2021-10-19 13:14 ` Florian Weimer
0 siblings, 0 replies; 2+ messages in thread
From: Florian Weimer @ 2021-10-19 13:14 UTC (permalink / raw)
To: H.J. Lu via Libc-alpha
* H. J. Lu via Libc-alpha:
> 1. Define DL_RO_DYN_SECTION to initalize bootstrap_map.l_ld_readonly
> before calling elf_get_dynamic_info to get dynamic info in bootstrap_map,
> 2. Define a single
>
> static inline bool
> dl_relocate_ld (const struct link_map *l)
> {
> /* Don't relocate dynamic section if it is readonly */
> return !(l->l_ld_readonly || DL_RO_DYN_SECTION);
> }
>
> This updates BZ #28340 fix.
> ---
> elf/rtld.c | 1 +
> sysdeps/generic/dl-relocate-ld.h | 11 ++---------
> sysdeps/generic/ldsodefs.h | 10 ++++++++++
> sysdeps/mips/dl-relocate-ld.h | 11 ++---------
> sysdeps/riscv/dl-relocate-ld.h | 11 ++---------
> 5 files changed, 17 insertions(+), 27 deletions(-)
This looks okay to me. Thanks.
Florian
^ permalink raw reply [flat|nested] 2+ messages in thread
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