android_kernel_xiaomi_sm8350/arch/um/include/sysdep-i386/faultinfo.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

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C

/*
* Copyright (C) 2004 Fujitsu Siemens Computers GmbH
* Author: Bodo Stroesser <bstroesser@fujitsu-siemens.com>
* Licensed under the GPL
*/
#ifndef __FAULTINFO_I386_H
#define __FAULTINFO_I386_H
/* this structure contains the full arch-specific faultinfo
* from the traps.
* On i386, ptrace_faultinfo unfortunately doesn't provide
* all the info, since trap_no is missing.
* All common elements are defined at the same position in
* both structures, thus making it easy to copy the
* contents without knowledge about the structure elements.
*/
struct faultinfo {
int error_code; /* in ptrace_faultinfo misleadingly called is_write */
unsigned long cr2; /* in ptrace_faultinfo called addr */
int trap_no; /* missing in ptrace_faultinfo */
};
#define FAULT_WRITE(fi) ((fi).error_code & 2)
#define FAULT_ADDRESS(fi) ((fi).cr2)
#define PTRACE_FULL_FAULTINFO 0
#endif