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

4 files changed, 41 insertions, 10 deletions

diff --git a/ChangeLog b/ChangeLog
index 721c791513..0c25bc33ee 100644
--- 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 a0d1732bdc..c392820cd0 100644
--- 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 22beb888a1..c0c15dc810 100644
--- 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 87c095238c..5639292da4 100644
--- 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