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linux-2.6/arch/um/kernel/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

120 lines
2.9 KiB
C

/*
* Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL
*/
#include <stdlib.h>
#include <errno.h>
#include <setjmp.h>
#include <signal.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <asm/page.h>
#include <asm/unistd.h>
#include <asm/ptrace.h>
#include "init.h"
#include "sysdep/ptrace.h"
#include "sigcontext.h"
#include "sysdep/sigcontext.h"
#include "irq_user.h"
#include "signal_user.h"
#include "time_user.h"
#include "task.h"
#include "mode.h"
#include "choose-mode.h"
#include "kern_util.h"
#include "user_util.h"
#include "os.h"
void kill_child_dead(int pid)
{
kill(pid, SIGKILL);
kill(pid, SIGCONT);
do {
int n;
CATCH_EINTR(n = waitpid(pid, NULL, 0));
if (n > 0)
kill(pid, SIGCONT);
else
break;
} while(1);
}
/* Unlocked - don't care if this is a bit off */
int nsegfaults = 0;
struct {
unsigned long address;
int is_write;
int pid;
unsigned long sp;
int is_user;
} segfault_record[1024];
void segv_handler(int sig, union uml_pt_regs *regs)
{
int index, max;
struct faultinfo * fi = UPT_FAULTINFO(regs);
if(UPT_IS_USER(regs) && !SEGV_IS_FIXABLE(fi)){
bad_segv(*fi, UPT_IP(regs));
return;
}
max = sizeof(segfault_record)/sizeof(segfault_record[0]);
index = next_trap_index(max);
nsegfaults++;
segfault_record[index].address = FAULT_ADDRESS(*fi);
segfault_record[index].pid = os_getpid();
segfault_record[index].is_write = FAULT_WRITE(*fi);
segfault_record[index].sp = UPT_SP(regs);
segfault_record[index].is_user = UPT_IS_USER(regs);
segv(*fi, UPT_IP(regs), UPT_IS_USER(regs), regs);
}
void usr2_handler(int sig, union uml_pt_regs *regs)
{
CHOOSE_MODE(syscall_handler_tt(sig, regs), (void) 0);
}
struct signal_info sig_info[] = {
[ SIGTRAP ] { .handler = relay_signal,
.is_irq = 0 },
[ SIGFPE ] { .handler = relay_signal,
.is_irq = 0 },
[ SIGILL ] { .handler = relay_signal,
.is_irq = 0 },
[ SIGWINCH ] { .handler = winch,
.is_irq = 1 },
[ SIGBUS ] { .handler = bus_handler,
.is_irq = 0 },
[ SIGSEGV] { .handler = segv_handler,
.is_irq = 0 },
[ SIGIO ] { .handler = sigio_handler,
.is_irq = 1 },
[ SIGVTALRM ] { .handler = timer_handler,
.is_irq = 1 },
[ SIGALRM ] { .handler = timer_handler,
.is_irq = 1 },
[ SIGUSR2 ] { .handler = usr2_handler,
.is_irq = 0 },
};
void do_longjmp(void *b, int val)
{
sigjmp_buf *buf = b;
siglongjmp(*buf, val);
}
/*
* 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:
*/