From: Richard Henderson <rth@twiddle.net>
To: libc-hacker@sources.redhat.com
Subject: Re: [rfa] alpha sjlj vs pointer mangling
Date: Thu, 12 Jan 2006 00:09:00 -0000 [thread overview]
Message-ID: <20060111195526.GA28361@twiddle.net> (raw)
In-Reply-To: <20060110003517.GA16111@twiddle.net>
Here's a revised patch, also tested on i686 to be sure that the
iconvdata dso's don't get a DT_NEEDED for ld.so.
r~
2006-01-11 Richard Henderson <rth@redhat.com>
* iconvdata/extra-module.mk ($(objpfx)$(mod).so): Depend on ld.so;
append --as-needed, if available, to LDFLAGS.so.
* sysdeps/alpha/__longjmp.S: Use PTR_DEMANGLE.
* sysdeps/alpha/setjmp.S: Likewise. Avoid __sigjmp_save for rtld;
tailcall in libc.so.
* sysdeps/unix/alpha/sysdep.h (PTR_MANGLE): New.
(PTR_MANGLE2): New.
Index: iconvdata/extra-module.mk
===================================================================
RCS file: /cvs/glibc/libc/iconvdata/extra-module.mk,v
retrieving revision 1.4
diff -u -p -d -r1.4 extra-module.mk
--- iconvdata/extra-module.mk 26 Apr 2003 23:38:36 -0000 1.4
+++ iconvdata/extra-module.mk 11 Jan 2006 19:48:42 -0000
@@ -10,7 +10,15 @@ $(objpfx)$(mod).so: $(addprefix $(objpfx
# Depend on libc.so so a DT_NEEDED is generated in the shared objects.
# This ensures they will load libc.so for needed symbols if loaded by
# a statically-linked program that hasn't already loaded it.
-$(objpfx)$(mod).so: $(common-objpfx)libc.so $(common-objpfx)libc_nonshared.a
+$(objpfx)$(mod).so: $(common-objpfx)libc.so \
+ $(common-objpfx)/elf/ld.so \
+ $(common-objpfx)libc_nonshared.a
+
+# Don't depend on ld.so if it isn't needed. This is a sort-of big hammer
+# to use for this, but it's easiest to avoid mucking with the Makerules.
+ifeq ($(have-as-needed),yes)
+$(objpfx)$(mod).so: LDFLAGS.so += -Wl,--as-needed
+endif
ifneq (,$(extra-modules-left))
include extra-module.mk
Index: sysdeps/alpha/__longjmp.S
===================================================================
RCS file: /cvs/glibc/libc/sysdeps/alpha/__longjmp.S,v
retrieving revision 1.3
diff -u -p -d -r1.3 __longjmp.S
--- sysdeps/alpha/__longjmp.S 6 Jul 2001 04:55:44 -0000 1.3
+++ sysdeps/alpha/__longjmp.S 11 Jan 2006 19:48:45 -0000
@@ -1,4 +1,4 @@
-/* Copyright (C) 1992, 1994, 1997 Free Software Foundation, Inc.
+/* Copyright (C) 1992, 1994, 1997, 2006 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
@@ -54,6 +54,11 @@ ENTRY(__longjmp)
ldt $f7, JB_F7*8(a0)
ldt $f8, JB_F8*8(a0)
ldt $f9, JB_F9*8(a0)
+#ifdef PTR_DEMANGLE
+ PTR_DEMANGLE(ra, t1)
+ PTR_DEMANGLE2(t0, t1)
+ PTR_DEMANGLE2(fp, t1)
+#endif
cmoveq v0, 1, v0
mov t0, sp
ret
Index: sysdeps/alpha/setjmp.S
===================================================================
RCS file: /cvs/glibc/libc/sysdeps/alpha/setjmp.S,v
retrieving revision 1.19
diff -u -p -d -r1.19 setjmp.S
--- sysdeps/alpha/setjmp.S 24 Jun 2003 16:29:21 -0000 1.19
+++ sysdeps/alpha/setjmp.S 11 Jan 2006 19:48:45 -0000
@@ -1,4 +1,5 @@
-/* Copyright (C) 1992, 1994, 1996, 1997, 2002 Free Software Foundation, Inc.
+/* Copyright (C) 1992, 1994, 1996, 1997, 2002, 2006
+ 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
@@ -23,16 +24,22 @@
#define _SETJMP_H
#include <bits/setjmp.h>
- .ent __sigsetjmp
- .global __sigsetjmp
+ .ent __sigsetjmp
+ .global __sigsetjmp
__sigsetjmp:
- ldgp gp, 0(pv)
+ ldgp gp, 0(pv)
$sigsetjmp_local:
- subq sp, 16, sp
- .frame sp, 16, ra, 0
- stq ra, 0(sp)
- .mask 0x04000000, -16
+#ifndef PIC
+#define FRAME 16
+ subq sp, FRAME, sp
+ .frame sp, FRAME, ra, 0
+ stq ra, 0(sp)
+ .mask 0x04000000, -FRAME
+#else
+#define FRAME 0
+ .frame sp, FRAME, ra, 0
+#endif
#ifdef PROF
.set noat
lda AT, _mcount
@@ -47,10 +54,27 @@ $sigsetjmp_local:
stq s3, JB_S3*8(a0)
stq s4, JB_S4*8(a0)
stq s5, JB_S5*8(a0)
+#ifdef PTR_MANGLE
+ PTR_MANGLE(t1, ra, t0)
+ stq t1, JB_PC*8(a0)
+#else
stq ra, JB_PC*8(a0)
- addq sp, 16, t0
+#endif
+#if defined(PTR_MANGLE) && FRAME == 0
+ PTR_MANGLE2(t1, sp, t0)
+#else
+ addq sp, FRAME, t1
+# ifdef PTR_MANGLE
+ PTR_MANGLE2(t1, t1, t0)
+# endif
+#endif
+ stq t1, JB_SP*8(a0)
+#ifdef PTR_MANGLE
+ PTR_MANGLE2(t1, fp, t0)
+ stq t1, JB_FP*8(a0)
+#else
stq fp, JB_FP*8(a0)
- stq t0, JB_SP*8(a0)
+#endif
stt $f2, JB_F2*8(a0)
stt $f3, JB_F3*8(a0)
stt $f4, JB_F4*8(a0)
@@ -60,12 +84,20 @@ $sigsetjmp_local:
stt $f8, JB_F8*8(a0)
stt $f9, JB_F9*8(a0)
+#ifndef PIC
/* Call to C to (potentially) save our signal mask. */
jsr ra, __sigjmp_save
-
ldq ra, 0(sp)
addq sp, 16, sp
ret
+#elif defined NOT_IN_libc && defined IS_IN_rtld
+ /* In ld.so we never save the signal mask. */
+ mov 0, v0
+ ret
+#else
+ /* Tailcall to save the signal mask. */
+ br $31, __sigjmp_save !samegp
+#endif
END(__sigsetjmp)
Index: sysdeps/unix/alpha/sysdep.h
===================================================================
RCS file: /cvs/glibc/libc/sysdeps/unix/alpha/sysdep.h,v
retrieving revision 1.27
diff -u -p -d -r1.27 sysdep.h
--- sysdeps/unix/alpha/sysdep.h 20 Sep 2005 05:35:42 -0000 1.27
+++ sysdeps/unix/alpha/sysdep.h 11 Jan 2006 19:48:47 -0000
@@ -1,4 +1,4 @@
-/* Copyright (C) 1992, 1995, 1996, 2000, 2003, 2004
+/* Copyright (C) 1992, 1995, 1996, 2000, 2003, 2004, 2006
Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Brendan Kehoe (brendan@zen.org).
@@ -397,4 +397,42 @@ __LABEL(name) \
_sc_ret = _sc_0, _sc_err = _sc_19; \
}
+/* Pointer mangling support. Note that tls access is slow enough that
+ we don't deoptimize things by placing the pointer check value there. */
+
+#include <stdint.h>
+
+#if defined NOT_IN_libc && defined IS_IN_rtld
+# ifdef __ASSEMBLER__
+# define PTR_MANGLE(dst, src, tmp) \
+ ldah tmp, __pointer_chk_guard_local($29) !gprelhigh; \
+ ldq tmp, __pointer_chk_guard_local(tmp) !gprellow; \
+ xor src, tmp, dst
+# define PTR_MANGLE2(dst, src, tmp) \
+ xor src, tmp, dst
+# define PTR_DEMANGLE(dst, tmp) PTR_MANGLE(dst, dst, tmp)
+# define PTR_DEMANGLE2(dst, tmp) PTR_MANGLE2(dst, dst, tmp)
+# else
+extern uintptr_t __pointer_chk_guard_local attribute_relro attribute_hidden;
+# define PTR_MANGLE(var) \
+ (var) = (void *) ((uintptr_t) (var) ^ __pointer_chk_guard_local)
+# define PTR_DEMANGLE(var) PTR_MANGLE(var)
+# endif
+#elif defined PIC
+# ifdef __ASSEMBLER__
+# define PTR_MANGLE(dst, src, tmp) \
+ ldq tmp, __pointer_chk_guard; \
+ xor src, tmp, dst
+# define PTR_MANGLE2(dst, src, tmp) \
+ xor src, tmp, dst
+# define PTR_DEMANGLE(dst, tmp) PTR_MANGLE(dst, dst, tmp)
+# define PTR_DEMANGLE2(dst, tmp) PTR_MANGLE2(dst, dst, tmp)
+# else
+extern uintptr_t __pointer_chk_guard attribute_relro;
+# define PTR_MANGLE(var) \
+ (var) = (void *) ((uintptr_t) (var) ^ __pointer_chk_guard)
+# define PTR_DEMANGLE(var) PTR_MANGLE(var)
+# endif
+#endif
+
#endif /* ASSEMBLER */
next prev parent reply other threads:[~2006-01-12 0:09 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-01-10 0:35 Richard Henderson
2006-01-10 1:52 ` Roland McGrath
2006-01-10 2:03 ` Ulrich Drepper
2006-01-10 2:10 ` Richard Henderson
2006-01-10 18:18 ` Ulrich Drepper
2006-01-10 18:27 ` Ulrich Drepper
2006-01-12 0:09 ` Richard Henderson [this message]
2006-01-12 0:24 ` Ulrich Drepper
2006-01-13 21:09 ` Richard Henderson
2006-01-13 21:49 ` Ulrich Drepper
2006-01-12 0:12 ` Ulrich Drepper
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