kernel-ark/arch/x86/include/asm/math_emu.h
Tejun Heo d315760ffa x86: fix math_emu register frame access
do_device_not_available() is the handler for #NM and it declares that
it takes a unsigned long and calls math_emu(), which takes a long
argument and surprisingly expects the stack frame starting at the zero
argument would match struct math_emu_info, which isn't true regardless
of configuration in the current code.

This patch makes do_device_not_available() take struct pt_regs like
other exception handlers and initialize struct math_emu_info with
pointer to it and pass pointer to the math_emu_info to math_emulate()
like normal C functions do.  This way, unless gcc makes a copy of
struct pt_regs in do_device_not_available(), the register frame is
correctly accessed regardless of kernel configuration or compiler
used.

This doesn't fix all math_emu problems but it at least gets it
somewhat working.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-02-10 00:39:14 +01:00

19 lines
425 B
C

#ifndef _ASM_X86_MATH_EMU_H
#define _ASM_X86_MATH_EMU_H
#include <asm/ptrace.h>
#include <asm/vm86.h>
/* This structure matches the layout of the data saved to the stack
following a device-not-present interrupt, part of it saved
automatically by the 80386/80486.
*/
struct math_emu_info {
long ___orig_eip;
union {
struct pt_regs *regs;
struct kernel_vm86_regs *vm86;
};
};
#endif /* _ASM_X86_MATH_EMU_H */