x32: Don't lose high bits of %rbp in setjmp/longjmp mangling/demangling.

diff --git a/ChangeLog b/ChangeLog
index 721c791..0c25bc3 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2012-05-21  Roland McGrath  <roland@hack.frob.com>
+
+       * sysdeps/x86_64/setjmp.S [PTR_MANGLE] [__ILP32__]: Preserve high bits
+       of %rbp unmolested in the jmp_buf while mangling the low bits.
+       * sysdeps/x86_64/__longjmp.S [PTR_DEMANGLE] [__ILP32__]: Restore the
+       unmolested high bits of %rbp while demangling the low bits.
+       * sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S: Likewise.
+
 2012-05-21  Andreas Jaeger  <aj@suse.de>
 
        * include/shlib-compat.h (libc_sunrpc_symbol): New macro.

diff --git a/sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S b/sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S
index a0d1732..c392820 100644 (file)
--- a/sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S
+++ b/sysdeps/unix/sysv/linux/x86_64/____longjmp_chk.S
@@ -1,4 +1,4 @@
-/* Copyright (C) 2001,2004,2005,2006,2009,2010,2011 Free Software Foundation, Inc.
+/* Copyright (C) 2001-2012 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
@@ -55,12 +55,20 @@ longjmp_msg:
 ENTRY(____longjmp_chk)
        /* Restore registers.  */
        mov     (JB_RSP*8)(%rdi), %R8_LP
-       movq    (JB_RBP*8)(%rdi), %r9
+       mov     (JB_RBP*8)(%rdi),%R9_LP
        mov     (JB_PC*8)(%rdi), %RDX_LP
 #ifdef PTR_DEMANGLE
        PTR_DEMANGLE (%R8_LP)
-       PTR_DEMANGLE (%r9)
+       PTR_DEMANGLE (%R9_LP)
        PTR_DEMANGLE (%RDX_LP)
+# ifdef __ILP32__
+       /* We ignored the high bits of the %rbp value because only the low
+          bits are mangled.  But we cannot presume that %rbp is being used
+          as a pointer and truncate it, so recover the high bits.  */
+       movl (JB_RBP*8 + 4)(%rdi), %eax
+       shlq $32, %rax
+       orq %rax, %r9
+# endif
 #endif
 
        cmp     %R8_LP, %RSP_LP

diff --git a/sysdeps/x86_64/__longjmp.S b/sysdeps/x86_64/__longjmp.S
index 22beb88..c0c15dc 100644 (file)
--- a/sysdeps/x86_64/__longjmp.S
+++ b/sysdeps/x86_64/__longjmp.S
@@ -1,4 +1,4 @@
-/* Copyright (C) 2001,2004,2005,2006,2009 Free Software Foundation, Inc.
+/* Copyright (C) 2001-2012 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
@@ -26,12 +26,20 @@
 ENTRY(__longjmp)
        /* Restore registers.  */
        mov (JB_RSP*8)(%rdi),%R8_LP
-       movq (JB_RBP*8)(%rdi),%r9
+       mov (JB_RBP*8)(%rdi),%R9_LP
        mov (JB_PC*8)(%rdi),%RDX_LP
 #ifdef PTR_DEMANGLE
        PTR_DEMANGLE (%R8_LP)
-       PTR_DEMANGLE (%r9)
+       PTR_DEMANGLE (%R9_LP)
        PTR_DEMANGLE (%RDX_LP)
+# ifdef __ILP32__
+       /* We ignored the high bits of the %rbp value because only the low
+          bits are mangled.  But we cannot presume that %rbp is being used
+          as a pointer and truncate it, so recover the high bits.  */
+       movl (JB_RBP*8 + 4)(%rdi), %eax
+       shlq $32, %rax
+       orq %rax, %r9
+# endif
 #endif
        /* We add unwind information for the target here.  */
        cfi_def_cfa(%rdi, 0)

diff --git a/sysdeps/x86_64/setjmp.S b/sysdeps/x86_64/setjmp.S
index 87c0952..5639292 100644 (file)
--- a/sysdeps/x86_64/setjmp.S
+++ b/sysdeps/x86_64/setjmp.S
@@ -1,5 +1,5 @@
 /* setjmp for x86-64.
-   Copyright (C) 2001, 2003, 2005, 2006 Free Software Foundation, Inc.
+   Copyright (C) 2001-2012 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
@@ -24,9 +24,16 @@ ENTRY (__sigsetjmp)
        /* Save registers.  */
        movq %rbx, (JB_RBX*8)(%rdi)
 #ifdef PTR_MANGLE
-       movq %rbp, %rax
-       PTR_MANGLE (%rax)
-       movq %rax, (JB_RBP*8)(%rdi)
+# ifdef __ILP32__
+       /* Save the high bits of %rbp first, since PTR_MANGLE will
+          only handle the low bits but we cannot presume %rbp is
+          being used as a pointer and truncate it.  Here we write all
+          of %rbp, but the low bits will be overwritten below.  */
+       movq %rbp, (JB_RBP*8)(%rdi)
+# endif
+       mov %RBP_LP, %RAX_LP
+       PTR_MANGLE (%RAX_LP)
+       mov %RAX_LP, (JB_RBP*8)(%rdi)
 #else
        movq %rbp, (JB_RBP*8)(%rdi)
 #endif