* Improved backtrace for s390*.
@ 2003-12-05 17:48 Martin Schwidefsky
2003-12-06 0:14 ` Ulrich Drepper
0 siblings, 1 reply; 4+ messages in thread
From: Martin Schwidefsky @ 2003-12-05 17:48 UTC (permalink / raw)
To: libc-hacker
Hi
this patch makes the s390* version of backtrace use the _Unwind_Backtrace
and _Unwind_GetIP functions from the libgcc to do the job. They work
even with -fomit-frame-pointer (thanks Jakub for the blueprint :-).
blue skies,
Martin.
2003-12-05 Martin Schwidefsky <schwidefsky@de.ibm.com>
* sysdeps/s390/s390-32/backtrace.c (trace_arg): New structure.
(unwind_backtrace, unwind_getip): New variables.
(init, __backchain_backtrace, backtrace_helper): New functions.
(__backtrace): Use unwind info for backtrace instead of backchain
walking if the unwind functions can be found.
* sysdeps/s390/s390-64/backtrace.c: Likewise.
diff -urN libc/sysdeps/s390/s390-32/backtrace.c libc-s390/sysdeps/s390/s390-32/backtrace.c
--- libc/sysdeps/s390/s390-32/backtrace.c 2003-03-28 14:25:36.000000000 +0100
+++ libc-s390/sysdeps/s390/s390-32/backtrace.c 2003-11-13 15:33:24.000000000 +0100
@@ -1,5 +1,5 @@
/* Return backtrace of current program state.
- Copyright (C) 2000, 2001 Free Software Foundation, Inc.
+ Copyright (C) 2000, 2001, 2003 Free Software Foundation, Inc.
Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
This file is part of the GNU C Library.
@@ -18,8 +18,12 @@
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
+#include <bits/libc-lock.h>
+#include <dlfcn.h>
#include <execinfo.h>
#include <stddef.h>
+#include <stdlib.h>
+#include <unwind.h>
/* This is a global variable set at program start time. It marks the
highest used stack address. */
@@ -51,10 +55,31 @@
int empty[2];
};
-int
-__backtrace (array, size)
- void **array;
- int size;
+struct trace_arg
+{
+ void **array;
+ int cnt, size;
+};
+
+static _Unwind_Reason_Code (*unwind_backtrace) (_Unwind_Trace_Fn, void *);
+static _Unwind_Ptr (*unwind_getip) (struct _Unwind_Context *);
+
+static void
+init (void)
+{
+ void *handle = __libc_dlopen ("libgcc_s.so.1");
+
+ if (handle == NULL)
+ return;
+
+ unwind_backtrace = __libc_dlsym (handle, "_Unwind_Backtrace");
+ unwind_getip = __libc_dlsym (handle, "_Unwind_GetIP");
+ if (unwind_getip == NULL)
+ unwind_backtrace = NULL;
+}
+
+static int
+__backchain_backtrace (void **array, int size)
{
/* We assume that all the code is generated with frame pointers set. */
struct layout *stack;
@@ -71,11 +96,42 @@
out of range. */
break;
- array[cnt++] = stack->save_grps[8] & 0x7fffffff;
+ array[cnt++] = (void *) (stack->save_grps[8] & 0x7fffffff);
stack = (struct layout *) stack->back_chain;
}
return cnt;
}
+
+static _Unwind_Reason_Code
+backtrace_helper (struct _Unwind_Context *ctx, void *a)
+{
+ struct trace_arg *arg = a;
+
+ /* We are first called with address in the __backtrace function.
+ Skip it. */
+ if (arg->cnt != -1)
+ arg->array[arg->cnt] = (void *) unwind_getip (ctx);
+ if (++arg->cnt == arg->size)
+ return _URC_END_OF_STACK;
+ return _URC_NO_REASON;
+}
+
+int
+__backtrace (void **array, int size)
+{
+ struct trace_arg arg = { .array = array, .size = size, .cnt = -1 };
+ __libc_once_define (static, once);
+
+ __libc_once (once, init);
+ if (unwind_backtrace == NULL)
+ return __backchain_backtrace (array, size);
+
+ if (size >= 1)
+ unwind_backtrace (backtrace_helper, &arg);
+
+ return arg.cnt != -1 ? arg.cnt : 0;
+}
+
weak_alias (__backtrace, backtrace)
diff -urN libc/sysdeps/s390/s390-64/backtrace.c libc-s390/sysdeps/s390/s390-64/backtrace.c
--- libc/sysdeps/s390/s390-64/backtrace.c 2003-05-06 10:05:46.000000000 +0200
+++ libc-s390/sysdeps/s390/s390-64/backtrace.c 2003-11-13 15:33:24.000000000 +0100
@@ -1,5 +1,5 @@
/* Return backtrace of current program state. 64 bit S/390 version.
- Copyright (C) 2001 Free Software Foundation, Inc.
+ Copyright (C) 2001, 2003 Free Software Foundation, Inc.
Contributed by Martin Schwidefsky (schwidefsky@de.ibm.com).
This file is part of the GNU C Library.
@@ -18,8 +18,12 @@
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
+#include <bits/libc-lock.h>
+#include <dlfcn.h>
#include <execinfo.h>
#include <stddef.h>
+#include <stdlib.h>
+#include <unwind.h>
/* This is a global variable set at program start time. It marks the
@@ -50,10 +54,31 @@
long empty[2];
};
+struct trace_arg
+{
+ void **array;
+ int cnt, size;
+};
+
+static _Unwind_Reason_Code (*unwind_backtrace) (_Unwind_Trace_Fn, void *);
+static _Unwind_Ptr (*unwind_getip) (struct _Unwind_Context *);
+
+static void
+init (void)
+{
+ void *handle = __libc_dlopen ("libgcc_s.so.1");
+
+ if (handle == NULL)
+ return;
+
+ unwind_backtrace = __libc_dlsym (handle, "_Unwind_Backtrace");
+ unwind_getip = __libc_dlsym (handle, "_Unwind_GetIP");
+ if (unwind_getip == NULL)
+ unwind_backtrace = NULL;
+}
+
int
-__backtrace (array, size)
- void **array;
- int size;
+__backchain_backtrace (void **array, int size)
{
/* We assume that all the code is generated with frame pointers set. */
struct layout *stack;
@@ -77,4 +102,35 @@
return cnt;
}
+
+static _Unwind_Reason_Code
+backtrace_helper (struct _Unwind_Context *ctx, void *a)
+{
+ struct trace_arg *arg = a;
+
+ /* We are first called with address in the __backtrace function.
+ Skip it. */
+ if (arg->cnt != -1)
+ arg->array[arg->cnt] = (void *) unwind_getip (ctx);
+ if (++arg->cnt == arg->size)
+ return _URC_END_OF_STACK;
+ return _URC_NO_REASON;
+}
+
+int
+__backtrace (void **array, int size)
+{
+ struct trace_arg arg = { .array = array, .size = size, .cnt = -1 };
+ __libc_once_define (static, once);
+
+ __libc_once (once, init);
+ if (unwind_backtrace == NULL)
+ return __backchain_backtrace (array, size);
+
+ if (size >= 1)
+ unwind_backtrace (backtrace_helper, &arg);
+
+ return arg.cnt != -1 ? arg.cnt : 0;
+}
+
weak_alias (__backtrace, backtrace)
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Improved backtrace for s390*.
2003-12-05 17:48 Improved backtrace for s390* Martin Schwidefsky
@ 2003-12-06 0:14 ` Ulrich Drepper
0 siblings, 0 replies; 4+ messages in thread
From: Ulrich Drepper @ 2003-12-06 0:14 UTC (permalink / raw)
To: Martin Schwidefsky; +Cc: libc-hacker
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
Martin Schwidefsky wrote:
> 2003-12-05 Martin Schwidefsky <schwidefsky@de.ibm.com>
>
> * sysdeps/s390/s390-32/backtrace.c (trace_arg): New structure.
> (unwind_backtrace, unwind_getip): New variables.
> (init, __backchain_backtrace, backtrace_helper): New functions.
> (__backtrace): Use unwind info for backtrace instead of backchain
> walking if the unwind functions can be found.
> * sysdeps/s390/s390-64/backtrace.c: Likewise.
I assume you tested it. Applied. Thanks,
- --
⧠Ulrich Drepper ⧠Red Hat, Inc. ⧠444 Castro St ⧠Mountain View, CA â
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^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Improved backtrace for s390*.
2003-12-08 13:26 Martin Schwidefsky
@ 2003-12-11 19:22 ` Jakub Jelinek
0 siblings, 0 replies; 4+ messages in thread
From: Jakub Jelinek @ 2003-12-11 19:22 UTC (permalink / raw)
To: Martin Schwidefsky; +Cc: Ulrich Drepper, libc-hacker
[-- Attachment #1: Type: text/plain, Size: 830 bytes --]
On Mon, Dec 08, 2003 at 02:26:00PM +0100, Martin Schwidefsky wrote:
>
> > > 2003-12-05 Martin Schwidefsky <schwidefsky@de.ibm.com>
> > >
> > > * sysdeps/s390/s390-32/backtrace.c (trace_arg): New structure.
> > > (unwind_backtrace, unwind_getip): New variables.
> > > (init, __backchain_backtrace, backtrace_helper): New
> functions.
> > > (__backtrace): Use unwind info for backtrace instead of
> backchain
> > > walking if the unwind functions can be found.
> > > * sysdeps/s390/s390-64/backtrace.c: Likewise.
> >
> > I assume you tested it. Applied. Thanks,
>
> Yes, I did.
Also with GCC 3.2 or earlier compiled code (which had no
-fasynchronous-unwind-tables by default)?
I think you need something similar to following (which is for IA-32,
not for s390*):
Jakub
[-- Attachment #2: backtrace.c --]
[-- Type: text/plain, Size: 3974 bytes --]
/* Return backtrace of current program state.
Copyright (C) 2003 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Jakub Jelinek <jakub@redhat.com>, 2003.
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, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <bits/libc-lock.h>
#include <dlfcn.h>
#include <execinfo.h>
#include <stdlib.h>
#include <unwind.h>
struct trace_arg
{
void **array;
int cnt, size;
void *lastebp, *lastesp;
};
static _Unwind_Reason_Code (*unwind_backtrace) (_Unwind_Trace_Fn, void *);
static _Unwind_Ptr (*unwind_getip) (struct _Unwind_Context *);
static _Unwind_Ptr (*unwind_getcfa) (struct _Unwind_Context *);
static _Unwind_Ptr (*unwind_getgr) (struct _Unwind_Context *, int);
static void
init (void)
{
void *handle = __libc_dlopen ("libgcc_s.so.1");
if (handle == NULL)
return;
unwind_backtrace = __libc_dlsym (handle, "_Unwind_Backtrace");
unwind_getip = __libc_dlsym (handle, "_Unwind_GetIP");
unwind_getcfa = __libc_dlsym (handle, "_Unwind_GetCFA");
unwind_getgr = __libc_dlsym (handle, "_Unwind_GetGR");
if (unwind_getip == NULL || unwind_getgr == NULL || unwind_getcfa == NULL)
unwind_backtrace = NULL;
}
static _Unwind_Reason_Code
backtrace_helper (struct _Unwind_Context *ctx, void *a)
{
struct trace_arg *arg = a;
/* We are first called with address in the __backtrace function.
Skip it. */
if (arg->cnt != -1)
arg->array[arg->cnt] = (void *) unwind_getip (ctx);
if (++arg->cnt == arg->size)
return _URC_END_OF_STACK;
/* %ebp is DWARF2 register 5 on IA-32. */
arg->lastebp = (void *) unwind_getgr (ctx, 5);
arg->lastesp = (void *) unwind_getcfa (ctx);
return _URC_NO_REASON;
}
/* This is a global variable set at program start time. It marks the
highest used stack address. */
extern void *__libc_stack_end;
/* This is the stack layout we see with every stack frame
if not compiled without frame pointer.
+-----------------+ +-----------------+
%ebp -> | %ebp last frame--------> | %ebp last frame--->...
| | | |
| return address | | return address |
+-----------------+ +-----------------+
First try as far to get as far as possible using
_Unwind_Backtrace which handles -fomit-frame-pointer
as well, but requires .eh_frame info. Then fall back to
walking the stack manually. */
struct layout
{
struct layout *ebp;
void *ret;
};
int
__backtrace (array, size)
void **array;
int size;
{
struct trace_arg arg = { .array = array, .size = size, .cnt = -1 };
__libc_once_define (static, once);
__libc_once (once, init);
if (unwind_backtrace == NULL)
return 0;
if (size >= 1)
unwind_backtrace (backtrace_helper, &arg);
if (arg.cnt > 1 && arg.array[arg.cnt - 1] == NULL)
--arg.cnt;
else if (arg.cnt < size)
{
struct layout *ebp = (struct layout *) arg.lastebp;
while (arg.cnt < size)
{
/* Check for out of range. */
if ((void *) ebp < arg.lastesp || (void *) ebp > __libc_stack_end
|| ((long) ebp & 3))
break;
array[arg.cnt++] = ebp->ret;
ebp = ebp->ebp;
}
}
return arg.cnt != -1 ? arg.cnt : 0;
}
weak_alias (__backtrace, backtrace)
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: Improved backtrace for s390*.
@ 2003-12-08 13:26 Martin Schwidefsky
2003-12-11 19:22 ` Jakub Jelinek
0 siblings, 1 reply; 4+ messages in thread
From: Martin Schwidefsky @ 2003-12-08 13:26 UTC (permalink / raw)
To: Ulrich Drepper; +Cc: libc-hacker
> > 2003-12-05 Martin Schwidefsky <schwidefsky@de.ibm.com>
> >
> > * sysdeps/s390/s390-32/backtrace.c (trace_arg): New structure.
> > (unwind_backtrace, unwind_getip): New variables.
> > (init, __backchain_backtrace, backtrace_helper): New
functions.
> > (__backtrace): Use unwind info for backtrace instead of
backchain
> > walking if the unwind functions can be found.
> > * sysdeps/s390/s390-64/backtrace.c: Likewise.
>
> I assume you tested it. Applied. Thanks,
Yes, I did.
blue skies,
Martin
Linux/390 Design & Development, IBM Deutschland Entwicklung GmbH
Schönaicherstr. 220, D-71032 Böblingen, Telefon: 49 - (0)7031 - 16-2247
E-Mail: schwidefsky@de.ibm.com
^ permalink raw reply [flat|nested] 4+ messages in thread
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2003-12-05 17:48 Improved backtrace for s390* Martin Schwidefsky
2003-12-06 0:14 ` Ulrich Drepper
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