commit def3c5d0a34e4b09b3cea4435c17209ad347104d
author H. Peter Anvin <hpa@zytor.com> Mon Oct 12 14:09:07 2009 -0700
committer H. Peter Anvin <hpa@zytor.com> Mon Oct 12 14:19:34 2009 -0700
tree f9a38b4908dc05a1a5c33a351cd821c0c49adad3
parent d93a8f829fe1d2f3002f2c6ddb553d12db420412

x86: use kernel_stack_pointer() in process_32.c

The way to obtain a kernel-mode stack pointer from a struct pt_regs in
32-bit mode is "subtle": the stack doesn't actually contain the stack
pointer, but rather the location where it would have been marks the
actual previous stack frame.  For clarity, use kernel_stack_pointer()
instead of coding this weirdness explicitly.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

arch/x86/kernel/process_32.c

diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 4cf7956..35e6fad 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -134,7 +134,7 @@
 		ss = regs->ss & 0xffff;
 		gs = get_user_gs(regs);
 	} else {
-		sp = (unsigned long) (&regs->sp);
+		sp = kernel_stack_pointer(regs);
 		savesegment(ss, ss);
 		savesegment(gs, gs);
 	}