diff mbox series

ld.so: Initialize bootstrap_map.l_ld_readonly [BZ #28340]

Message ID 20210923161418.1491862-1-hjl.tools@gmail.com
State Superseded
Headers
Series ld.so: Initialize bootstrap_map.l_ld_readonly [BZ #28340] |

Checks

Context Check Description
dj/TryBot-apply_patch success Patch applied to master at the time it was sent
dj/TryBot-32bit success Build for i686

Commit Message

H.J. Lu Sept. 23, 2021, 4:14 p.m. UTC 
  Before calling elf_get_dynamic_info to get dynamic info in bootstrap_map,
initalize bootstrap_map.l_ld_readonly with BOOTSTRAP_MAP_RO_DYN_SECTION.

This updates BZ #28340 fix.
---
 elf/rtld.c                       | 1 +
 sysdeps/generic/dl-relocate-ld.h | 3 +++
 sysdeps/mips/dl-relocate-ld.h    | 3 +++
 sysdeps/riscv/dl-relocate-ld.h   | 4 ++++
 4 files changed, 11 insertions(+)

Comments

Florian Weimer Sept. 28, 2021, 2:07 p.m. UTC | #1 
* H. J. Lu:

> Before calling elf_get_dynamic_info to get dynamic info in bootstrap_map,
> initalize bootstrap_map.l_ld_readonly with BOOTSTRAP_MAP_RO_DYN_SECTION.

I think we should bring back DL_RO_DYN_SECTION and use that to define
one (generic) version of dl_relocate_ld, perhaps like this:

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);
}

Thanks,
Florian
H.J. Lu Sept. 28, 2021, 3:49 p.m. UTC | #2 
On Tue, Sep 28, 2021 at 7:07 AM Florian Weimer <fweimer@redhat.com> wrote:
>
> * H. J. Lu:
>
> > Before calling elf_get_dynamic_info to get dynamic info in bootstrap_map,
> > initalize bootstrap_map.l_ld_readonly with BOOTSTRAP_MAP_RO_DYN_SECTION.
>
> I think we should bring back DL_RO_DYN_SECTION and use that to define
> one (generic) version of dl_relocate_ld, perhaps like this:
>
> 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);
> }

Like this?

https://sourceware.org/pipermail/libc-alpha/2021-September/131495.html
diff mbox series

Patch

diff --git a/elf/rtld.c b/elf/rtld.c
index 8d2bba3d43..27e9f12560 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 = BOOTSTRAP_MAP_RO_DYN_SECTION;
   elf_get_dynamic_info (&bootstrap_map);
 
 #if NO_TLS_OFFSET != 0
diff --git a/sysdeps/generic/dl-relocate-ld.h b/sysdeps/generic/dl-relocate-ld.h
index 5fae206db9..09c7ba0448 100644
--- a/sysdeps/generic/dl-relocate-ld.h
+++ b/sysdeps/generic/dl-relocate-ld.h
@@ -19,6 +19,9 @@ 
 #ifndef _DL_RELOCATE_LD_H
 #define _DL_RELOCATE_LD_H
 
+/* The dynamic section in bootstrap_map is writable.  */
+#define BOOTSTRAP_MAP_RO_DYN_SECTION 0
+
 /* Return true if dynamic section in the shared library L should be
    relocated.  */
 
diff --git a/sysdeps/mips/dl-relocate-ld.h b/sysdeps/mips/dl-relocate-ld.h
index 0c18d9a567..2c4edbe9f4 100644
--- a/sysdeps/mips/dl-relocate-ld.h
+++ b/sysdeps/mips/dl-relocate-ld.h
@@ -19,6 +19,9 @@ 
 #ifndef _DL_RELOCATE_LD_H
 #define _DL_RELOCATE_LD_H
 
+/* The dynamic section in bootstrap_map is readonly.  */
+#define BOOTSTRAP_MAP_RO_DYN_SECTION 1
+
 /* Return true if dynamic section in the shared library L should be
    relocated.  */
 
diff --git a/sysdeps/riscv/dl-relocate-ld.h b/sysdeps/riscv/dl-relocate-ld.h
index 10327454b1..240f85b79e 100644
--- a/sysdeps/riscv/dl-relocate-ld.h
+++ b/sysdeps/riscv/dl-relocate-ld.h
@@ -19,6 +19,10 @@ 
 #ifndef _DL_RELOCATE_LD_H
 #define _DL_RELOCATE_LD_H
 
+/* The dynamic section in bootstrap_map is writable.  This is ignored
+   on RISC-V.  */
+#define BOOTSTRAP_MAP_RO_DYN_SECTION 0
+
 /* Return true if dynamic section in the shared library L should be
    relocated.  */