[src/trunk]: src/sys/arch/usermode Fix logic that checks if its the kernel or...

[reinoud <reinoud%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/717d4828754c
branches:  trunk
changeset: 772420:717d4828754c
user:      reinoud <reinoud%NetBSD.org@localhost>
date:      Tue Jan 03 10:53:46 2012 +0000

description:
Fix logic that checks if its the kernel or a userland process that causes the
trap. Signal sending still needs to be addressed.

diffstat:

 sys/arch/usermode/include/machdep.h  |   3 ++-
 sys/arch/usermode/include/pcb.h      |   3 ++-
 sys/arch/usermode/usermode/machdep.c |  12 ++++++++++--
 sys/arch/usermode/usermode/trap.c    |  30 +++++++++++++++++-------------
 4 files changed, 31 insertions(+), 17 deletions(-)

diffs (160 lines):

diff -r f8f6466c0a8f -r 717d4828754c sys/arch/usermode/include/machdep.h
--- a/sys/arch/usermode/include/machdep.h       Tue Jan 03 07:36:02 2012 +0000
+++ b/sys/arch/usermode/include/machdep.h       Tue Jan 03 10:53:46 2012 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: machdep.h,v 1.6 2011/12/14 18:51:39 reinoud Exp $ */
+/* $NetBSD: machdep.h,v 1.7 2012/01/03 10:53:46 reinoud Exp $ */
 
 /*-
  * Copyright (c) 2011 Reinoud Zandijk <reinoud%netbsd.org@localhost>
@@ -35,6 +35,7 @@
                int error, register_t *rval);
 void   md_syscall_inc_pc(ucontext_t *ucp, uint32_t opcode);
 void   md_syscall_dec_pc(ucontext_t *ucp, uint32_t opcode);
+register_t md_get_pc(ucontext_t *ucp);
 
 /* handlers */
 void   syscall(void);
diff -r f8f6466c0a8f -r 717d4828754c sys/arch/usermode/include/pcb.h
--- a/sys/arch/usermode/include/pcb.h   Tue Jan 03 07:36:02 2012 +0000
+++ b/sys/arch/usermode/include/pcb.h   Tue Jan 03 10:53:46 2012 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: pcb.h,v 1.14 2011/12/12 15:04:51 reinoud Exp $ */
+/* $NetBSD: pcb.h,v 1.15 2012/01/03 10:53:46 reinoud Exp $ */
 
 /*-
  * Copyright (c) 2007 Jared D. McNeill <jmcneill%invisible.ca@localhost>
@@ -51,6 +51,7 @@
 
        int              pcb_errno;             /* save/restore place */
        vaddr_t          pcb_fault_addr;        /* save place for fault addr */
+       vaddr_t          pcb_fault_pc;          /* save place for fault PC */
 };
 
 #endif /* !_ARCH_USERMODE_INCLUDE_PCB_H */
diff -r f8f6466c0a8f -r 717d4828754c sys/arch/usermode/usermode/machdep.c
--- a/sys/arch/usermode/usermode/machdep.c      Tue Jan 03 07:36:02 2012 +0000
+++ b/sys/arch/usermode/usermode/machdep.c      Tue Jan 03 10:53:46 2012 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: machdep.c,v 1.47 2011/12/29 21:22:49 jmcneill Exp $ */
+/* $NetBSD: machdep.c,v 1.48 2012/01/03 10:53:46 reinoud Exp $ */
 
 /*-
  * Copyright (c) 2011 Reinoud Zandijk <reinoud%netbsd.org@localhost>
@@ -37,7 +37,7 @@
 #include "opt_memsize.h"
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: machdep.c,v 1.47 2011/12/29 21:22:49 jmcneill Exp $");
+__KERNEL_RCSID(0, "$NetBSD: machdep.c,v 1.48 2012/01/03 10:53:46 reinoud Exp $");
 
 #include <sys/types.h>
 #include <sys/systm.h>
@@ -440,6 +440,14 @@
        //dump_regs(reg);
 }
 
+register_t
+md_get_pc(ucontext_t *ucp)
+{
+       register_t *reg = (register_t *) &ucp->uc_mcontext;
+
+       return reg[14];                 /* EIP */
+}
+
 int
 md_syscall_check_opcode(ucontext_t *ucp)
 {
diff -r f8f6466c0a8f -r 717d4828754c sys/arch/usermode/usermode/trap.c
--- a/sys/arch/usermode/usermode/trap.c Tue Jan 03 07:36:02 2012 +0000
+++ b/sys/arch/usermode/usermode/trap.c Tue Jan 03 10:53:46 2012 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: trap.c,v 1.49 2012/01/02 22:02:51 reinoud Exp $ */
+/* $NetBSD: trap.c,v 1.50 2012/01/03 10:53:46 reinoud Exp $ */
 
 /*-
  * Copyright (c) 2011 Reinoud Zandijk <reinoud%netbsd.org@localhost>
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.49 2012/01/02 22:02:51 reinoud Exp $");
+__KERNEL_RCSID(0, "$NetBSD: trap.c,v 1.50 2012/01/03 10:53:46 reinoud Exp $");
 
 #include <sys/types.h>
 #include <sys/param.h>
@@ -108,7 +108,7 @@
        ucontext_t *uct = ctx;
        struct lwp *l;
        struct pcb *pcb;
-       vaddr_t va;
+       vaddr_t va, pc;
 
        assert((info->si_signo == SIGSEGV) || (info->si_signo == SIGBUS));
 
@@ -147,9 +147,13 @@
        l = curlwp;
        pcb = lwp_getpcb(l);
 
+       /* get address of faulted memory access and make it page aligned */
        va = (vaddr_t) info->si_addr;
        va = trunc_page(va);
 
+       /* get PC address of faulted memory instruction */
+       pc = md_get_pc(ctx);
+
 #if 0  /* disabled for now, these checks need to move */
 #ifdef DIAGNOSTIC
        /* sanity */
@@ -169,6 +173,7 @@
        /* remember our parameters */
 //     assert((void *) pcb->pcb_fault_addr == NULL);
        pcb->pcb_fault_addr = va;
+       pcb->pcb_fault_pc   = pc;
 
        /* switch to the pagefault entry on return from signal */
        memcpy(uct, &pcb->pcb_pagefault_ucp, sizeof(ucontext_t));
@@ -259,26 +264,25 @@
        struct vmspace *vm;
        struct vm_map *vm_map;
        vm_prot_t atype;
-       vaddr_t va;
+       vaddr_t va, pc;
        void *onfault;
-       int kmem, lwp_errno, rv;
+       int from_kernel, lwp_errno, rv;
 
        l = curlwp;
        pcb = lwp_getpcb(l);
        p = l->l_proc;
        vm = p->p_vmspace;
        va = pcb->pcb_fault_addr;
+       pc = pcb->pcb_fault_pc;
 
        lwp_errno = thunk_geterrno();
 
-       kmem = 1;
-       vm_map = kernel_map;
-       if ((va >= VM_MIN_ADDRESS) && (va < VM_MAXUSER_ADDRESS)) {
-               kmem = 0;
-               vm_map = &vm->vm_map;
-       }
+       vm_map = &vm->vm_map;
+       from_kernel = (pc >= VM_MIN_KERNEL_ADDRESS);
+       if (from_kernel && (va >= VM_MIN_KERNEL_ADDRESS))
+               vm_map = kernel_map;
 
-       dprintf_debug("pagefault : va = %p\n", (void *) va);
+       dprintf_debug("pagefault : pc %p, va %p\n", (void *) pc, (void *) va);
 
        /* can pmap handle it? on its own? (r/m) */
        onfault = pcb->pcb_onfault;
@@ -300,7 +304,7 @@
                dprintf_debug("uvm_fault returned error %d\n", rv);
 
                /* something got wrong */
-               if (kmem) {
+               if (from_kernel) {
                        /* copyin / copyout */
                        if (!onfault)
                                panic("kernel fault");