From: Samuel Thibault <samuel.thibault@ens-lyon.org>
To: gdb-patches@sourceware.org
Cc: Samuel Thibault <samuel.thibault@ens-lyon.org>
Subject: [PATCH] hurd: Add enough auxv support for AT_ENTRY for PIE binaries
Date: Wed, 27 Dec 2017 15:42:00 -0000 [thread overview]
Message-ID: <20171227154156.130174-1-samuel.thibault@ens-lyon.org> (raw)
gdb/ChangeLog:
* gdb/gnu-nat.c: Include <elf.h> and <link.h>.
(gnu_xfer_auxv): New function.
(gnu_xfer_partial): Call gnu_xfer_auxv when `object' is
TARGET_OBJECT_AUXV.
---
gdb/ChangeLog | 7 +++++++
gdb/gnu-nat.c | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 65 insertions(+)
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 4d85029b99..40d8e6e1cf 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,10 @@
+2017-12-22 Samuel Thibault <samuel.thibault@ens-lyon.org>
+
+ * gdb/gnu-nat.c: Include <elf.h> and <link.h>.
+ (gnu_xfer_auxv): New function.
+ (gnu_xfer_partial): Call gnu_xfer_auxv when `object' is
+ TARGET_OBJECT_AUXV.
+
2017-12-27 Franck Jullien <franck.jullien@gmail.com>
Stafford Horne <shorne@gmail.com>
diff --git a/gdb/gnu-nat.c b/gdb/gnu-nat.c
index 0d500ea38d..7d9c7d8dfa 100644
--- a/gdb/gnu-nat.c
+++ b/gdb/gnu-nat.c
@@ -52,6 +52,8 @@ extern "C"
#include <setjmp.h>
#include <signal.h>
#include <sys/ptrace.h>
+#include <elf.h>
+#include <link.h>
#include "inferior.h"
#include "symtab.h"
@@ -2541,6 +2543,60 @@ gnu_xfer_memory (gdb_byte *readbuf, const gdb_byte *writebuf,
}
}
+/* GNU does not have auxv, but we can at least fake the AT_ENTRY entry for PIE
+ binaries. */
+static enum target_xfer_status
+gnu_xfer_auxv (gdb_byte *readbuf, const gdb_byte *writebuf,
+ CORE_ADDR memaddr, ULONGEST len, ULONGEST *xfered_len)
+{
+ task_t task = (gnu_current_inf
+ ? (gnu_current_inf->task
+ ? gnu_current_inf->task->port : 0)
+ : 0);
+ process_t proc;
+ int res;
+ kern_return_t err;
+ vm_address_t entry;
+ ElfW(auxv_t) auxv[2];
+
+ if (task == MACH_PORT_NULL)
+ return TARGET_XFER_E_IO;
+ if (writebuf != NULL)
+ return TARGET_XFER_E_IO;
+
+ if (memaddr == sizeof (auxv))
+ return TARGET_XFER_EOF;
+ if (memaddr > sizeof (auxv))
+ return TARGET_XFER_E_IO;
+
+ err = proc_task2proc (proc_server, task, &proc);
+ if (err != 0)
+ return TARGET_XFER_E_IO;
+
+ /* Get entry from proc server. */
+ err = proc_get_entry (proc, &entry);
+ if (err != 0)
+ return TARGET_XFER_E_IO;
+
+ /* Fake auxv entry. */
+ auxv[0].a_type = AT_ENTRY;
+ auxv[0].a_un.a_val = entry;
+ auxv[1].a_type = AT_NULL;
+ auxv[1].a_un.a_val = 0;
+
+ inf_debug (gnu_current_inf, "reading auxv %s[%s] --> %s",
+ paddress (target_gdbarch (), memaddr), pulongest (len),
+ host_address_to_string (readbuf));
+
+ if (memaddr + len > sizeof (auxv))
+ len = sizeof (auxv) - memaddr;
+
+ memcpy (readbuf, (gdb_byte *) &auxv + memaddr, len);
+ *xfered_len = len;
+
+ return TARGET_XFER_OK;
+}
+
/* Target to_xfer_partial implementation. */
static enum target_xfer_status
@@ -2553,6 +2609,8 @@ gnu_xfer_partial (struct target_ops *ops, enum target_object object,
{
case TARGET_OBJECT_MEMORY:
return gnu_xfer_memory (readbuf, writebuf, offset, len, xfered_len);
+ case TARGET_OBJECT_AUXV:
+ return gnu_xfer_auxv (readbuf, writebuf, offset, len, xfered_len);
default:
return TARGET_XFER_E_IO;
}
--
2.11.0
next reply other threads:[~2017-12-27 15:42 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-27 15:42 Samuel Thibault [this message]
2017-12-28 2:19 ` Simon Marchi
2017-12-28 21:27 ` Samuel Thibault
2018-01-08 15:41 ` Simon Marchi
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=20171227154156.130174-1-samuel.thibault@ens-lyon.org \
--to=samuel.thibault@ens-lyon.org \
--cc=gdb-patches@sourceware.org \
/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).