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linux/include/asm-um/processor-i386.h
Bodo Stroesser c578455a3e [PATCH] uml: S390 preparation, abstract host page fault data
This patch removes the arch-specific fault/trap-infos from thread and
skas-regs.

It adds a new struct faultinfo, that is arch-specific defined in
sysdep/faultinfo.h.

The structure is inserted in thread.arch and thread.regs.skas and
thread.regs.tt

Now, segv and other trap-handlers can copy the contents from regs.X.faultinfo
to thread.arch.faultinfo with one simple assignment.

Also, the number of macros necessary is reduced to

FAULT_ADDRESS(struct faultinfo)
    extracts the faulting address from faultinfo

FAULT_WRITE(struct faultinfo)
    extracts the "is_write" flag

SEGV_IS_FIXABLE(struct faultinfo)
    is true for the fixable segvs, i.e. (TRAP == 14)
    on i386

UPT_FAULTINFO(regs)
    result is (struct faultinfo *) to the faultinfo
    in regs->skas.faultinfo

GET_FAULTINFO_FROM_SC(struct faultinfo, struct sigcontext *)
    copies the relevant parts of the sigcontext to
    struct faultinfo.

On SIGSEGV, call user_signal() instead of handle_segv(), if the architecture
provides the information needed in PTRACE_FAULTINFO, or if PTRACE_FAULTINFO is
missing, because segv-stub will provide the info.

The benefit of the change is, that in case of a non-fixable SIGSEGV, we can
give user processes a SIGSEGV, instead of possibly looping on pagefault
handling.

Since handle_segv() sikked arch_fixup() implicitly by passing ip==0 to segv(),
I changed segv() to call arch_fixup() only, if !is_user.

Signed-off-by: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-05 16:36:36 -07:00

60 lines
1.5 KiB
C

/*
* Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#ifndef __UM_PROCESSOR_I386_H
#define __UM_PROCESSOR_I386_H
extern int host_has_xmm;
extern int host_has_cmov;
/* include faultinfo structure */
#include "sysdep/faultinfo.h"
struct arch_thread {
unsigned long debugregs[8];
int debugregs_seq;
struct faultinfo faultinfo;
};
#define INIT_ARCH_THREAD { .debugregs = { [ 0 ... 7 ] = 0 }, \
.debugregs_seq = 0, \
.faultinfo = { 0, 0, 0 } }
#include "asm/arch/user.h"
/* REP NOP (PAUSE) is a good thing to insert into busy-wait loops. */
static inline void rep_nop(void)
{
__asm__ __volatile__("rep;nop": : :"memory");
}
#define cpu_relax() rep_nop()
/*
* Default implementation of macro that returns current
* instruction pointer ("program counter"). Stolen
* from asm-i386/processor.h
*/
#define current_text_addr() \
({ void *pc; __asm__("movl $1f,%0\n1:":"=g" (pc)); pc; })
#define ARCH_IS_STACKGROW(address) \
(address + 32 >= UPT_SP(&current->thread.regs.regs))
#include "asm/processor-generic.h"
#endif
/*
* Overrides for Emacs so that we follow Linus's tabbing style.
* Emacs will notice this stuff at the end of the file and automatically
* adjust the settings for this buffer only. This must remain at the end
* of the file.
* ---------------------------------------------------------------------------
* Local variables:
* c-file-style: "linux"
* End:
*/