android_kernel_xiaomi_sm8350/arch/um/kernel/tt/trap_user.c
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

67 lines
1.6 KiB
C

/*
* Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#include <stdlib.h>
#include <errno.h>
#include <signal.h>
#include "sysdep/ptrace.h"
#include "sysdep/sigcontext.h"
#include "signal_user.h"
#include "user_util.h"
#include "kern_util.h"
#include "task.h"
#include "tt.h"
void sig_handler_common_tt(int sig, void *sc_ptr)
{
struct sigcontext *sc = sc_ptr;
struct tt_regs save_regs, *r;
struct signal_info *info;
int save_errno = errno, is_user;
/* This is done because to allow SIGSEGV to be delivered inside a SEGV
* handler. This can happen in copy_user, and if SEGV is disabled,
* the process will die.
*/
if(sig == SIGSEGV)
change_sig(SIGSEGV, 1);
r = &TASK_REGS(get_current())->tt;
if ( sig == SIGFPE || sig == SIGSEGV ||
sig == SIGBUS || sig == SIGILL ||
sig == SIGTRAP ) {
GET_FAULTINFO_FROM_SC(r->faultinfo, sc);
}
save_regs = *r;
is_user = user_context(SC_SP(sc));
r->sc = sc;
if(sig != SIGUSR2)
r->syscall = -1;
info = &sig_info[sig];
if(!info->is_irq) unblock_signals();
(*info->handler)(sig, (union uml_pt_regs *) r);
if(is_user){
interrupt_end();
block_signals();
set_user_mode(NULL);
}
*r = save_regs;
errno = save_errno;
}
/*
* 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:
*/