From: "H.J. Lu" <hjl.tools@gmail.com>
To: Xi Ruoyao <xry111@mengyan1223.wang>
Cc: Carlos O'Donell <carlos@redhat.com>,
GNU C Library <libc-alpha@sourceware.org>,
syq@debian.org, Joseph Myers <joseph@codesourcery.com>,
Jiaxun Yang <jiaxun.yang@flygoat.com>
Subject: [PATCH] elf: Add <dl-r_debug.h>
Date: Sat, 29 Jan 2022 11:41:12 -0800 [thread overview]
Message-ID: <YfWYWIPX4VklUJYF@gmail.com> (raw)
In-Reply-To: <ecd049adf4953d0175b1dd191325df2cc22185f7.camel@mengyan1223.wang>
On Sat, Jan 29, 2022 at 06:04:12AM +0800, Xi Ruoyao wrote:
> On Fri, 2022-01-28 at 13:22 -0800, H.J. Lu wrote:
>
> > You should drop pldd in filename and also handle tst-dlmopen4.c
> > in the same header file.
>
> v3: pldd and tst-dlmopen4 change revised as a new patch series.
Can you try this patch instead?
H.J.
---
Add <dl-r_debug.h> to get the adddress of the r_debug structure after
relocation and its offset before relocation from the PT_DYNAMIC segment
to support DT_DEBUG, DT_MIPS_RLD_MAP_REL and DT_MIPS_RLD_MAP.
Co-developed-by: Xi Ruoyao <xry111@mengyan1223.wang>
---
elf/pldd-xx.c | 34 +++++++++++--------
elf/tst-dlmopen4.c | 15 +++------
sysdeps/generic/dl-r_debug.h | 36 ++++++++++++++++++++
sysdeps/mips/dl-r_debug.h | 64 ++++++++++++++++++++++++++++++++++++
4 files changed, 124 insertions(+), 25 deletions(-)
create mode 100644 sysdeps/generic/dl-r_debug.h
create mode 100644 sysdeps/mips/dl-r_debug.h
diff --git a/elf/pldd-xx.c b/elf/pldd-xx.c
index 1cdfb49c53..30513b423f 100644
--- a/elf/pldd-xx.c
+++ b/elf/pldd-xx.c
@@ -22,6 +22,8 @@
#define EW_(e, w, t) EW__(e, w, _##t)
#define EW__(e, w, t) e##w##t
+#include <dl-r_debug.h>
+
struct E(link_map)
{
EW(Addr) l_addr;
@@ -126,21 +128,25 @@ E(find_maps) (const char *exe, int memfd, pid_t pid, void *auxv,
!= p[i].p_filesz)
error (EXIT_FAILURE, 0, gettext ("cannot read dynamic section"));
- /* Search for the DT_DEBUG entry. */
+ /* Search for the struct r_debug. */
for (unsigned int j = 0; j < p[i].p_filesz / sizeof (EW(Dyn)); ++j)
- if (dyn[j].d_tag == DT_DEBUG && dyn[j].d_un.d_ptr != 0)
- {
- struct E(r_debug) r;
- if (pread (memfd, &r, sizeof (r), dyn[j].d_un.d_ptr)
- != sizeof (r))
- error (EXIT_FAILURE, 0, gettext ("cannot read r_debug"));
-
- if (r.r_map != 0)
- {
- list = r.r_map;
- break;
- }
- }
+ {
+ EW(Addr) off = offset + p[i].p_vaddr + sizeof (EW(Dyn)) * j;
+ off = E(r_debug_offset) (&dyn[j], memfd, off);
+ if (off != 0)
+ {
+ struct E(r_debug) r;
+ if (pread (memfd, &r, sizeof (r), off)
+ != sizeof (r))
+ error (EXIT_FAILURE, 0, gettext ("cannot read r_debug"));
+
+ if (r.r_map != 0)
+ {
+ list = r.r_map;
+ break;
+ }
+ }
+ }
free (dyn);
break;
diff --git a/elf/tst-dlmopen4.c b/elf/tst-dlmopen4.c
index d8bcf7e9d5..8456f89053 100644
--- a/elf/tst-dlmopen4.c
+++ b/elf/tst-dlmopen4.c
@@ -25,16 +25,9 @@
#include <support/check.h>
#include <support/test-driver.h>
-#ifndef ELF_MACHINE_GET_R_DEBUG
-# define ELF_MACHINE_GET_R_DEBUG(d) \
- (__extension__ ({ \
- struct r_debug_extended *debug; \
- if ((d)->d_tag == DT_DEBUG) \
- debug = (struct r_debug_extended *) (d)->d_un.d_ptr; \
- else \
- debug = NULL; \
- debug; }))
-#endif
+#define E(x) x
+#define EW(x) ElfW(x)
+#include <dl-r_debug.h>
static int
do_test (void)
@@ -44,7 +37,7 @@ do_test (void)
for (d = _DYNAMIC; d->d_tag != DT_NULL; ++d)
{
- debug = ELF_MACHINE_GET_R_DEBUG (d);
+ debug = (struct r_debug_extended *) r_debug_address (d);
if (debug != NULL)
break;
}
diff --git a/sysdeps/generic/dl-r_debug.h b/sysdeps/generic/dl-r_debug.h
new file mode 100644
index 0000000000..e3edeb4f06
--- /dev/null
+++ b/sysdeps/generic/dl-r_debug.h
@@ -0,0 +1,36 @@
+/* Function to access r_debug structure. Generic version.
+ Copyright (C) 2022 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+/* Return the address of the struct r_debug after relocation. */
+
+static inline EW(Addr)
+E(r_debug_address) (EW(Dyn) *d)
+{
+ if (d->d_tag == DT_DEBUG)
+ return (EW(Addr)) d->d_un.d_ptr;
+
+ return 0;
+}
+
+/* Return the offset of the struct r_debug before relocation. */
+
+static inline EW(Addr)
+E(r_debug_offset) (EW(Dyn) *d, int fd, EW(Addr) offset)
+{
+ return E(r_debug_address) (d);
+}
diff --git a/sysdeps/mips/dl-r_debug.h b/sysdeps/mips/dl-r_debug.h
new file mode 100644
index 0000000000..edd83d46fd
--- /dev/null
+++ b/sysdeps/mips/dl-r_debug.h
@@ -0,0 +1,64 @@
+/* Function to access r_debug structure. MIPS specific version.
+ Copyright (C) 2022 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#ifdef EW_
+/* Return the offset of the struct r_debug before relocation. */
+
+static inline EW(Addr)
+E(r_debug_offset) (EW(Dyn) *d, int fd, EW(Addr) offset)
+{
+ switch (d->d_tag)
+ {
+ case DT_MIPS_RLD_MAP_REL:
+ offset += d->d_un.d_val;
+ break;
+ case DT_MIPS_RLD_MAP:
+ offset = d->d_un.d_ptr;
+ break;
+ default:
+ return 0;
+ }
+
+ if (pread (fd, &offset, sizeof (offset), offset) != sizeof (offset))
+ return 0;
+
+ return offset;
+}
+#else
+/* Return the address of the struct r_debug after relocation. */
+
+static inline EW(Addr)
+E(r_debug_address) (EW(Dyn) *d)
+{
+ EW(Addr) ptr;
+
+ switch (d->d_tag)
+ {
+ case DT_MIPS_RLD_MAP_REL:
+ ptr = ((EW(Addr)) d) + d->d_un.d_val;
+ break;
+ case DT_MIPS_RLD_MAP:
+ ptr = d->d_un.d_ptr;
+ break;
+ default:
+ return 0;
+ }
+
+ return *(EW(Addr) *) ptr;
+}
+#endif
--
2.34.1
next prev parent reply other threads:[~2022-01-29 19:41 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-28 18:56 [PATCH] mips: pldd: support DT_MIPS_RLD_MAP and DT_MIPS_RLD_MAP_REL Xi Ruoyao
2022-01-28 20:45 ` H.J. Lu
2022-01-28 20:48 ` Adhemerval Zanella
2022-01-28 20:50 ` Carlos O'Donell
2022-01-28 21:17 ` [PATCH v2] " Xi Ruoyao
2022-01-28 21:22 ` H.J. Lu
2022-01-28 22:04 ` [PATCH v3 0/3] mips: add target-specific r_debug offset Xi Ruoyao
2022-01-28 22:05 ` [PATCH v3 1/3] add sysdeps/{generic,mips}/elfxx-r_debug.h Xi Ruoyao
2022-01-28 22:08 ` [PATCH v3 3/3] elf: tst-dlmopen4: use target specific r_debug_offset function Xi Ruoyao
2022-01-28 22:07 ` [PATCH v3 2/3] pldd: use target-specific " Xi Ruoyao
2022-01-29 19:41 ` H.J. Lu [this message]
2022-01-29 19:56 ` [PATCH] elf: Add <dl-r_debug.h> Xi Ruoyao
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YfWYWIPX4VklUJYF@gmail.com \
--to=hjl.tools@gmail.com \
--cc=carlos@redhat.com \
--cc=jiaxun.yang@flygoat.com \
--cc=joseph@codesourcery.com \
--cc=libc-alpha@sourceware.org \
--cc=syq@debian.org \
--cc=xry111@mengyan1223.wang \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).