From: David Mosberger <davidm@napali.hpl.hp.com>
To: libc-hacker@sources.redhat.com
Cc: davidm@napali.hpl.hp.com
Subject: [PATCH] move __gmon_start__ call out of .init section
Date: Wed, 30 Oct 2002 07:00:00 -0000 [thread overview]
Message-ID: <200210300722.g9U7MCXs000818@napali.hpl.hp.com> (raw)
The patch below changes the ia64 initfini.c such that the call to
__gmon_start__ is done via the .init_array section (if available).
The idea here is to keep the .init/.fini empty (apart from
prologue/epilogue) so as to ensure that the unwind info is always
correct.
Note: this patch should be applied _after_ HJ's init_array fixes as
otherwise gmon startup would fail for profiled binaries.
Thanks,
--david
2002-10-29 David Mosberger <davidm@hpl.hp.com>
* sysdeps/ia64/elf/initfini.c [HAVE_INITFINI_ARRAY]
(gmon_initializer): New function.
(.init prologue): If HAVE_INITFINI_ARRAY is true, don't call
__gmon_start__ here. Call it from gmon_initializer() instead.
Index: sysdeps/ia64/elf/initfini.c
===================================================================
RCS file: /cvs/glibc/libc/sysdeps/ia64/elf/initfini.c,v
retrieving revision 1.3
diff -u -r1.3 initfini.c
--- sysdeps/ia64/elf/sysdeps/ia64/elf/initfini.c 25 Aug 2002 00:34:23 -0000 1.3
+++ sysdeps/ia64/elf/sysdeps/ia64/elf/initfini.c 30 Oct 2002 04:37:13 -0000
@@ -27,81 +27,110 @@
* crtn.s puts the corresponding function epilogues
in the .init and .fini sections. */
-__asm__ ("\n\
-\n\
-#include \"defs.h\"\n\
-\n\
-/*@HEADER_ENDS*/\n\
-\n\
-/*@_init_PROLOG_BEGINS*/\n\
- .section .init\n\
- .align 16\n\
- .global _init#\n\
- .proc _init#\n\
-_init:\n\
- alloc r34 = ar.pfs, 0, 3, 0, 0\n\
- mov r32 = r12\n\
- mov r33 = b0\n\
- adds r12 = -16, r12\n\
- addl r14 = @ltoff(@fptr(__gmon_start__#)), gp\n\
- ;;\n\
- ld8 r15 = [r14]\n\
- ;;\n\
- cmp.eq p6, p7 = 0, r15\n\
- (p6) br.cond.dptk .L5\n\
-\n\
-/* we could use r35 to save gp, but we use the stack since that's what\n\
- * all the other init routines will do --davidm 00/04/05 */\n\
- st8 [r12] = gp, -16\n\
- br.call.sptk.many b0 = __gmon_start__# ;;\n\
- adds r12 = 16, r12\n\
- ;;\n\
- ld8 gp = [r12]\n\
- ;;\n\
-.L5:\n\
- .align 16\n\
- .endp _init#\n\
-\n\
-/*@_init_PROLOG_ENDS*/\n\
-\n\
-/*@_init_EPILOG_BEGINS*/\n\
- .section .init\n\
- .regstk 0,2,0,0\n\
- mov r12 = r32\n\
- mov ar.pfs = r34\n\
- mov b0 = r33\n\
- br.ret.sptk.many b0\n\
- .endp _init#\n\
-/*@_init_EPILOG_ENDS*/\n\
-\n\
-/*@_fini_PROLOG_BEGINS*/\n\
- .section .fini\n\
- .align 16\n\
- .global _fini#\n\
- .proc _fini#\n\
-_fini:\n\
- alloc r34 = ar.pfs, 0, 3, 0, 0\n\
- mov r32 = r12\n\
- mov r33 = b0\n\
- adds r12 = -16, r12\n\
- ;;\n\
- .align 16\n\
- .endp _fini#\n\
-\n\
-/*@_fini_PROLOG_ENDS*/\n\
- br.call.sptk.many b0 = i_am_not_a_leaf# ;;\n\
- ;;\n\
-\n\
-/*@_fini_EPILOG_BEGINS*/\n\
- .section .fini\n\
- mov r12 = r32\n\
- mov ar.pfs = r34\n\
- mov b0 = r33\n\
- br.ret.sptk.many b0\n\
- .endp _fini#\n\
-\n\
-/*@_fini_EPILOG_ENDS*/\n\
-\n\
-/*@TRAILER_BEGINS*/\n\
- .weak __gmon_start__#\n\
-");
+__asm__ ("\n\n"
+"#include \"defs.h\"\n"
+"\n"
+"/*@HEADER_ENDS*/\n"
+"\n"
+"/*@_init_PROLOG_BEGINS*/\n");
+
+#ifdef HAVE_INITFINI_ARRAY
+
+/* If we have working .init_array support, we want to keep the .init
+ section empty (apart from the mandatory prologue/epilogue. This
+ ensures that the default unwind conventions (return-pointer in b0,
+ frame state in ar.pfs, etc.) will do the Right Thing. To ensure
+ an empty .init section, we register gmon_initializer() via the
+ .init_array.
+
+ --davidm 02/10/29 */
+
+static void
+gmon_initializer (void)
+{
+ extern void weak_function __gmon_start__ (void);
+
+ if (__gmon_start__)
+ (*__gmon_start__)();
+}
+
+__asm__ (".section .init_array, \"aw\"\n"
+ "\tdata8 @fptr(gmon_initializer)\n");
+
+#endif
+
+__asm__ (".section .init\n"
+" .align 16\n"
+" .global _init#\n"
+" .proc _init#\n"
+"_init:\n"
+" alloc r34 = ar.pfs, 0, 3, 0, 0\n"
+" mov r32 = r12\n"
+" mov r33 = b0\n"
+" adds r12 = -16, r12\n"
+#ifdef HAVE_INITFINI_ARRAY
+ " ;;\n" /* see gmon_initializer() below */
+#else
+" .weak __gmon_start__#\n"
+" addl r14 = @ltoff(@fptr(__gmon_start__#)), gp\n"
+" ;;\n"
+" ld8 r15 = [r14]\n"
+" ;;\n"
+" cmp.eq p6, p7 = 0, r15\n"
+" (p6) br.cond.dptk .L5\n"
+"\n"
+"/* we could use r35 to save gp, but we use the stack since that's what\n"
+" * all the other init routines will do --davidm 00/04/05 */\n"
+" st8 [r12] = gp, -16\n"
+" br.call.sptk.many b0 = __gmon_start__# ;;\n"
+" adds r12 = 16, r12\n"
+" ;;\n"
+" ld8 gp = [r12]\n"
+" ;;\n"
+".L5:\n"
+#endif
+" .align 16\n"
+" .endp _init#\n"
+"\n"
+"/*@_init_PROLOG_ENDS*/\n"
+"\n"
+"/*@_init_EPILOG_BEGINS*/\n"
+" .section .init\n"
+" .regstk 0,2,0,0\n"
+" mov r12 = r32\n"
+" mov ar.pfs = r34\n"
+" mov b0 = r33\n"
+" br.ret.sptk.many b0\n"
+" .endp _init#\n"
+"/*@_init_EPILOG_ENDS*/\n"
+"\n"
+"/*@_fini_PROLOG_BEGINS*/\n"
+" .section .fini\n"
+" .align 16\n"
+" .global _fini#\n"
+" .proc _fini#\n"
+"_fini:\n"
+" alloc r34 = ar.pfs, 0, 3, 0, 0\n"
+" mov r32 = r12\n"
+" mov r33 = b0\n"
+" adds r12 = -16, r12\n"
+" ;;\n"
+" .align 16\n"
+" .endp _fini#\n"
+"\n"
+"/*@_fini_PROLOG_ENDS*/\n"
+" br.call.sptk.many b0 = i_am_not_a_leaf# ;;\n"
+" ;;\n"
+"\n"
+"/*@_fini_EPILOG_BEGINS*/\n"
+" .section .fini\n"
+" mov r12 = r32\n"
+" mov ar.pfs = r34\n"
+" mov b0 = r33\n"
+" br.ret.sptk.many b0\n"
+" .endp _fini#\n"
+"\n"
+"/*@_fini_EPILOG_ENDS*/\n"
+"\n"
+"/*@TRAILER_BEGINS*/\n"
+);
next reply other threads:[~2002-10-30 7:22 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-10-30 7:00 David Mosberger [this message]
2002-11-07 13:45 ` Roland McGrath
2002-11-07 14:08 ` David Mosberger
2002-11-07 14:27 ` Roland McGrath
2002-11-07 14:32 ` David Mosberger
2002-11-07 17:43 ` Roland McGrath
2002-11-08 3:05 ` Andreas Schwab
2002-11-08 11:15 ` David Mosberger
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