This is the mail archive of the
gdb-patches@sources.redhat.com
mailing list for the GDB project.
[rfa:amd64] Fetch 32-bit thread area
- From: Andrew Cagney <ac131313 at redhat dot com>
- To: gdb-patches at sources dot redhat dot com
- Date: Thu, 26 Feb 2004 20:24:47 -0500
- Subject: [rfa:amd64] Fetch 32-bit thread area
Hello,
This modifies the amd64 code so that, when 32-bit, it fetches the 32-bit
thread area register (I think this has been posted before?).
ok?
Andrew
* amd64-linux-nat.c (ps_get_thread_area): When architecture is
i386 use PTRACE_GET_THREAD_AREA. Suggested by Roland McGrath.
Index: amd64-linux-nat.c
===================================================================
RCS file: /cvs/src/src/gdb/amd64-linux-nat.c,v
retrieving revision 1.1
diff -u -r1.1 amd64-linux-nat.c
--- amd64-linux-nat.c 25 Feb 2004 20:45:30 -0000 1.1
+++ amd64-linux-nat.c 27 Feb 2004 01:22:36 -0000
@@ -350,10 +350,14 @@
}
+/* This function is called by libthread_db as part of its handling of
+ a request for a thread's local storage address. */
+
ps_err_e
ps_get_thread_area (const struct ps_prochandle *ph,
lwpid_t lwpid, int idx, void **base)
{
+#if 0
/* This definition comes from prctl.h, but some kernels may not have it. */
#ifndef PTRACE_ARCH_PRCTL
#define PTRACE_ARCH_PRCTL 30
@@ -377,6 +381,67 @@
return PS_BADADDR;
}
return PS_ERR; /* ptrace failed. */
+#else
+ switch (TARGET_ARCHITECTURE->mach)
+ {
+ case bfd_mach_i386_i386:
+ case bfd_mach_i386_i386_intel_syntax:
+ {
+ /* The full structure is found in <asm-i386/ldt.h>. The
+ second integer is the LDT's base_address and that is used
+ to locate the thread's local storage. See i386-linux-nat.c
+ more info. */
+ unsigned int desc[4];
+
+ /* This code assumes that "int" is 32 bits and that
+ GET_THREAD_AREA returns no more than 4 int values. */
+ gdb_assert (sizeof (int) == 4);
+#ifndef PTRACE_GET_THREAD_AREA
+#define PTRACE_GET_THREAD_AREA 25
+#endif
+ if (ptrace (PTRACE_GET_THREAD_AREA,
+ lwpid, (void *) (long) idx, (unsigned long) &desc) < 0)
+ return PS_ERR;
+
+ /* Extend the value to 64 bits. Here it's assumed that a
+ "long" and a "void *" are the same. */
+ (*base) = (void *) (long) desc[1];
+ return PS_OK;
+ }
+
+ case bfd_mach_x86_64:
+ case bfd_mach_x86_64_intel_syntax:
+
+ /* This definition comes from prctl.h, but some kernels may not
+ have it. */
+#ifndef PTRACE_ARCH_PRCTL
+#define PTRACE_ARCH_PRCTL 30
+#endif
+ /* FIXME: ezannoni-2003-07-09 see comment above about include
+ file order. We could be getting bogus values for these two. */
+ gdb_assert (FS < ELF_NGREG);
+ gdb_assert (GS < ELF_NGREG);
+ switch (idx)
+ {
+ case FS:
+ if (ptrace (PTRACE_ARCH_PRCTL, lwpid, base, ARCH_GET_FS) == 0)
+ return PS_OK;
+ break;
+ case GS:
+ if (ptrace (PTRACE_ARCH_PRCTL, lwpid, base, ARCH_GET_GS) == 0)
+ return PS_OK;
+ break;
+ default: /* Should not happen. */
+ return PS_BADADDR;
+ }
+ return PS_ERR; /* ptrace failed. */
+
+ case bfd_mach_i386_i8086:
+ internal_error (__FILE__, __LINE__, "bad i8086 machine");
+ default:
+ internal_error (__FILE__, __LINE__, "bad_switch");
+ }
+#endif
}