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trap.c:

Browse Source 
Vastly improved trap.c from me. This rewritten version has a variety of
features, amoung them: higher performance and much higher code quality.

support.s, cpufunc.h:
No longer use gs override to enforce range limits - compare directly
against VM_MAXUSER_ADDRESS instead. The old way caused problems in
preserving the gs selector...and this method is just as fast or faster.
This commit is contained in:
David Greenman 1994-06-06 14:54:41 +00:00
parent 2e4fabc7c7
commit 3c256f5395
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=1690
8 changed files with 1489 additions and 1478 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

114
sys/amd64/amd64/support.S
View File

@ -30,7 +30,7 @@
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id: support.s,v 1.6 1994/04/02 07:00:29 davidg Exp $
* $Id: support.s,v 1.10 1994/06/06 14:23:49 davidg Exp $
*/
#include "assym.s" /* system definitions */
@ -616,15 +616,22 @@ ENTRY(copyin)
movl 16(%esp),%edi /* caddr_t to */
movl 20(%esp),%ecx /* size_t len */
/*
* make sure address is valid
*/
movl %esi,%edx
addl %ecx,%edx
jc copyin_fault
cmpl $VM_MAXUSER_ADDRESS,%edx
ja copyin_fault
movb %cl,%al
shrl $2,%ecx /* copy longword-wise */
cld
gs
rep
movsl
movb %al,%cl
andb $3,%cl /* copy remaining bytes */
gs
rep
movsb
@ -651,8 +658,11 @@ ALTENTRY(fuiword)
ENTRY(fuword)
movl _curpcb,%ecx
movl $fusufault,PCB_ONFAULT(%ecx)
movl 4(%esp),%edx
gs
movl 4(%esp),%edx /* from */
cmpl $VM_MAXUSER_ADDRESS-4,%edx /* verify address is valid */
ja fusufault
movl (%edx),%eax
movl $0,PCB_ONFAULT(%ecx)
ret
@ -672,7 +682,10 @@ ENTRY(fusword)
movl _curpcb,%ecx
movl $fusufault,PCB_ONFAULT(%ecx)
movl 4(%esp),%edx
gs
cmpl $VM_MAXUSER_ADDRESS-2,%edx
ja fusufault
movzwl (%edx),%eax
movl $0,PCB_ONFAULT(%ecx)
ret
@ -682,7 +695,10 @@ ENTRY(fubyte)
movl _curpcb,%ecx
movl $fusufault,PCB_ONFAULT(%ecx)
movl 4(%esp),%edx
gs
cmpl $VM_MAXUSER_ADDRESS-1,%eax
ja fusufault
movzbl (%edx),%eax
movl $0,PCB_ONFAULT(%ecx)
ret
@ -732,8 +748,10 @@ ENTRY(suword)
#endif
2:
cmpl $VM_MAXUSER_ADDRESS-4,%edx /* verify address validity */
ja fusufault
movl 8(%esp),%eax
gs
movl %eax,(%edx)
xorl %eax,%eax
movl %eax,PCB_ONFAULT(%ecx)
@ -772,8 +790,10 @@ ENTRY(susword)
#endif
2:
cmpl $VM_MAXUSER_ADDRESS-2,%edx /* verify address validity */
ja fusufault
movw 8(%esp),%ax
gs
movw %ax,(%edx)
xorl %eax,%eax
movl %eax,PCB_ONFAULT(%ecx)
@ -812,8 +832,10 @@ ENTRY(subyte)
#endif
2:
cmpl $VM_MAXUSER_ADDRESS-1,%edx /* verify address validity */
ja fusufault
movb 8(%esp),%al
gs
movb %al,(%edx)
xorl %eax,%eax
movl %eax,PCB_ONFAULT(%ecx)
@ -849,8 +871,8 @@ ENTRY(copyoutstr)
* we look at a page at a time and the end address is on a page
* boundary.
*/
cmpl $VM_MAXUSER_ADDRESS,%edi
jae cpystrflt
cmpl $VM_MAXUSER_ADDRESS-1,%edi
ja cpystrflt
movl %edi,%eax
shrl $IDXSHIFT,%eax
@ -908,13 +930,11 @@ ENTRY(copyoutstr)
decl %edx
jz 2f
/*
* gs override doesn't work for stosb. Use the same explicit check
* as in copyout(). It's much slower now because it is per-char.
* XXX - however, it would be faster to rewrite this function to use
* XXX - would be faster to rewrite this function to use
* strlen() and copyout().
*/
cmpl $VM_MAXUSER_ADDRESS,%edi
jae cpystrflt
cmpl $VM_MAXUSER_ADDRESS-1,%edi
ja cpystrflt
lodsb
stosb
@ -932,6 +952,24 @@ ENTRY(copyoutstr)
#endif /* I486_CPU || I586_CPU */
cpystrflt:
movl $EFAULT,%eax
cpystrflt_x:
/* set *lencopied and return %eax */
movl _curpcb,%ecx
movl $0,PCB_ONFAULT(%ecx)
movl 20(%esp),%ecx
subl %edx,%ecx
movl 24(%esp),%edx
orl %edx,%edx
jz 1f
movl %ecx,(%edx)
1:
popl %edi
popl %esi
ret
/*
* copyinstr(from, to, maxlen, int *lencopied)
* copy a string from from to to, stop when a 0 character is reached.
@ -943,16 +981,18 @@ ENTRY(copyinstr)
pushl %esi
pushl %edi
movl _curpcb,%ecx
movl $cpystrflt,PCB_ONFAULT(%ecx)
movl $copyinstr_fault,PCB_ONFAULT(%ecx)
movl 12(%esp),%esi /* %esi = from */
movl 16(%esp),%edi /* %edi = to */
movl 20(%esp),%edx /* %edx = maxlen */
pushl %gs
movl __udatasel,%eax
movl %ax,%gs
incl %edx
1:
decl %edx
jz 4f
jz 2f
gs
lodsb
stosb
@ -962,26 +1002,26 @@ ENTRY(copyinstr)
/* Success -- 0 byte reached */
decl %edx
xorl %eax,%eax
jmp 6f
4:
jmp 3f
2:
/* edx is zero -- return ENAMETOOLONG */
movl $ENAMETOOLONG,%eax
jmp 6f
jmp 3f
cpystrflt:
copyinstr_fault:
movl $EFAULT,%eax
cpystrflt_x:
6:
3:
/* set *lencopied and return %eax */
movl _curpcb,%ecx
movl $0,PCB_ONFAULT(%ecx)
movl 20(%esp),%ecx
movl 24(%esp),%ecx
subl %edx,%ecx
movl 24(%esp),%edx
movl 28(%esp),%edx
orl %edx,%edx
jz 7f
jz 4f
movl %ecx,(%edx)
7:
4:
popl %gs
popl %edi
popl %esi
ret
@ -1097,15 +1137,6 @@ ENTRY(ssdtosd)
popl %ebx
ret
#if 0
/* tlbflush() */
ENTRY(tlbflush)
movl %cr3,%eax
orl $I386_CR3PAT,%eax
movl %eax,%cr3
ret
#endif
/* load_cr0(cr0) */
ENTRY(load_cr0)
movl 4(%esp),%eax
@ -1117,11 +1148,6 @@ ENTRY(rcr0)
movl %cr0,%eax
ret
/* rcr2() */
ENTRY(rcr2)
movl %cr2,%eax
ret
/* rcr3() */
ENTRY(rcr3)
movl %cr3,%eax

114
sys/amd64/amd64/support.s
View File

@ -30,7 +30,7 @@
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id: support.s,v 1.6 1994/04/02 07:00:29 davidg Exp $
* $Id: support.s,v 1.10 1994/06/06 14:23:49 davidg Exp $
*/
#include "assym.s" /* system definitions */
@ -616,15 +616,22 @@ ENTRY(copyin)
movl 16(%esp),%edi /* caddr_t to */
movl 20(%esp),%ecx /* size_t len */
/*
* make sure address is valid
*/
movl %esi,%edx
addl %ecx,%edx
jc copyin_fault
cmpl $VM_MAXUSER_ADDRESS,%edx
ja copyin_fault
movb %cl,%al
shrl $2,%ecx /* copy longword-wise */
cld
gs
rep
movsl
movb %al,%cl
andb $3,%cl /* copy remaining bytes */
gs
rep
movsb
@ -651,8 +658,11 @@ ALTENTRY(fuiword)
ENTRY(fuword)
movl _curpcb,%ecx
movl $fusufault,PCB_ONFAULT(%ecx)
movl 4(%esp),%edx
gs
movl 4(%esp),%edx /* from */
cmpl $VM_MAXUSER_ADDRESS-4,%edx /* verify address is valid */
ja fusufault
movl (%edx),%eax
movl $0,PCB_ONFAULT(%ecx)
ret
@ -672,7 +682,10 @@ ENTRY(fusword)
movl _curpcb,%ecx
movl $fusufault,PCB_ONFAULT(%ecx)
movl 4(%esp),%edx
gs
cmpl $VM_MAXUSER_ADDRESS-2,%edx
ja fusufault
movzwl (%edx),%eax
movl $0,PCB_ONFAULT(%ecx)
ret
@ -682,7 +695,10 @@ ENTRY(fubyte)
movl _curpcb,%ecx
movl $fusufault,PCB_ONFAULT(%ecx)
movl 4(%esp),%edx
gs
cmpl $VM_MAXUSER_ADDRESS-1,%eax
ja fusufault
movzbl (%edx),%eax
movl $0,PCB_ONFAULT(%ecx)
ret
@ -732,8 +748,10 @@ ENTRY(suword)
#endif
2:
cmpl $VM_MAXUSER_ADDRESS-4,%edx /* verify address validity */
ja fusufault
movl 8(%esp),%eax
gs
movl %eax,(%edx)
xorl %eax,%eax
movl %eax,PCB_ONFAULT(%ecx)
@ -772,8 +790,10 @@ ENTRY(susword)
#endif
2:
cmpl $VM_MAXUSER_ADDRESS-2,%edx /* verify address validity */
ja fusufault
movw 8(%esp),%ax
gs
movw %ax,(%edx)
xorl %eax,%eax
movl %eax,PCB_ONFAULT(%ecx)
@ -812,8 +832,10 @@ ENTRY(subyte)
#endif
2:
cmpl $VM_MAXUSER_ADDRESS-1,%edx /* verify address validity */
ja fusufault
movb 8(%esp),%al
gs
movb %al,(%edx)
xorl %eax,%eax
movl %eax,PCB_ONFAULT(%ecx)
@ -849,8 +871,8 @@ ENTRY(copyoutstr)
* we look at a page at a time and the end address is on a page
* boundary.
*/
cmpl $VM_MAXUSER_ADDRESS,%edi
jae cpystrflt
cmpl $VM_MAXUSER_ADDRESS-1,%edi
ja cpystrflt
movl %edi,%eax
shrl $IDXSHIFT,%eax
@ -908,13 +930,11 @@ ENTRY(copyoutstr)
decl %edx
jz 2f
/*
* gs override doesn't work for stosb. Use the same explicit check
* as in copyout(). It's much slower now because it is per-char.
* XXX - however, it would be faster to rewrite this function to use
* XXX - would be faster to rewrite this function to use
* strlen() and copyout().
*/
cmpl $VM_MAXUSER_ADDRESS,%edi
jae cpystrflt
cmpl $VM_MAXUSER_ADDRESS-1,%edi
ja cpystrflt
lodsb
stosb
@ -932,6 +952,24 @@ ENTRY(copyoutstr)
#endif /* I486_CPU || I586_CPU */
cpystrflt:
movl $EFAULT,%eax
cpystrflt_x:
/* set *lencopied and return %eax */
movl _curpcb,%ecx
movl $0,PCB_ONFAULT(%ecx)
movl 20(%esp),%ecx
subl %edx,%ecx
movl 24(%esp),%edx
orl %edx,%edx
jz 1f
movl %ecx,(%edx)
1:
popl %edi
popl %esi
ret
/*
* copyinstr(from, to, maxlen, int *lencopied)
* copy a string from from to to, stop when a 0 character is reached.
@ -943,16 +981,18 @@ ENTRY(copyinstr)
pushl %esi
pushl %edi
movl _curpcb,%ecx
movl $cpystrflt,PCB_ONFAULT(%ecx)
movl $copyinstr_fault,PCB_ONFAULT(%ecx)
movl 12(%esp),%esi /* %esi = from */
movl 16(%esp),%edi /* %edi = to */
movl 20(%esp),%edx /* %edx = maxlen */
pushl %gs
movl __udatasel,%eax
movl %ax,%gs
incl %edx
1:
decl %edx
jz 4f
jz 2f
gs
lodsb
stosb
@ -962,26 +1002,26 @@ ENTRY(copyinstr)
/* Success -- 0 byte reached */
decl %edx
xorl %eax,%eax
jmp 6f
4:
jmp 3f
2:
/* edx is zero -- return ENAMETOOLONG */
movl $ENAMETOOLONG,%eax
jmp 6f
jmp 3f
cpystrflt:
copyinstr_fault:
movl $EFAULT,%eax
cpystrflt_x:
6:
3:
/* set *lencopied and return %eax */
movl _curpcb,%ecx
movl $0,PCB_ONFAULT(%ecx)
movl 20(%esp),%ecx
movl 24(%esp),%ecx
subl %edx,%ecx
movl 24(%esp),%edx
movl 28(%esp),%edx
orl %edx,%edx
jz 7f
jz 4f
movl %ecx,(%edx)
7:
4:
popl %gs
popl %edi
popl %esi
ret
@ -1097,15 +1137,6 @@ ENTRY(ssdtosd)
popl %ebx
ret
#if 0
/* tlbflush() */
ENTRY(tlbflush)
movl %cr3,%eax
orl $I386_CR3PAT,%eax
movl %eax,%cr3
ret
#endif
/* load_cr0(cr0) */
ENTRY(load_cr0)
movl 4(%esp),%eax
@ -1117,11 +1148,6 @@ ENTRY(rcr0)
movl %cr0,%eax
ret
/* rcr2() */
ENTRY(rcr2)
movl %cr2,%eax
ret
/* rcr3() */
ENTRY(rcr3)
movl %cr3,%eax

869
sys/amd64/amd64/trap.c
View File

@ -1,6 +1,7 @@
/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
* Copyright (C) 1994, David Greenman
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the University of Utah, and William Jolitz.
@ -34,7 +35,7 @@
* SUCH DAMAGE.
*
* from: @(#)trap.c 7.4 (Berkeley) 5/13/91
* $Id: trap.c,v 1.22 1994/04/07 10:51:00 davidg Exp $
* $Id: trap.c,v 1.24 1994/05/25 08:55:18 rgrimes Exp $
*/
/*
@ -69,21 +70,8 @@
#include "npx.h"
#include "ddb.h"
#ifdef __GNUC__
/*
* The "r" contraint could be "rm" except for fatal bugs in gas. As usual,
* we omit the size from the mov instruction to avoid nonfatal bugs in gas.
*/
#define read_gs() ({ u_short gs; __asm("mov %%gs,%0" : "=r" (gs)); gs; })
#define write_gs(newgs) __asm("mov %0,%%gs" : : "r" ((u_short) newgs))
#else /* not __GNUC__ */
u_short read_gs __P((void));
void write_gs __P((/* promoted u_short */ int gs));
#endif /* __GNUC__ */
int trap_pfault __P((struct trapframe *, int));
void trap_fatal __P((struct trapframe *));
extern int grow(struct proc *,u_int);
@ -101,7 +89,7 @@ char *trap_msg[] = {
"arithmetic trap", /* 6 T_ARITHTRAP */
"system forced exception", /* 7 T_ASTFLT */
"segmentation (limit) fault", /* 8 T_SEGFLT */
"protection fault", /* 9 T_PROTFLT */
"general protection fault", /* 9 T_PROTFLT */
"trace trap", /* 10 T_TRCTRAP */
"", /* 11 unused */
"page fault", /* 12 T_PAGEFLT */
@ -122,366 +110,18 @@ char *trap_msg[] = {
"stack fault", /* 27 T_STKFLT */
};
#define pde_v(v) (PTD[((v)>>PD_SHIFT)&1023].pd_v)
/*
* trap(frame):
* Exception, fault, and trap interface to BSD kernel. This
* common code is called from assembly language IDT gate entry
* routines that prepare a suitable stack frame, and restore this
* frame after the exception has been processed. Note that the
* effect is as if the arguments were passed call by reference.
*/
/*ARGSUSED*/
void
trap(frame)
struct trapframe frame;
static inline void
userret(p, frame, oticks)
struct proc *p;
struct trapframe *frame;
u_quad_t oticks;
{
register int i;
register struct proc *p = curproc;
u_quad_t sticks = 0;
int ucode, type, code, eva, fault_type;
int sig, s;
frame.tf_eflags &= ~PSL_NT; /* clear nested trap XXX */
type = frame.tf_trapno;
#if NDDB > 0
if (curpcb && curpcb->pcb_onfault) {
if (frame.tf_trapno == T_BPTFLT
|| frame.tf_trapno == T_TRCTRAP)
if (kdb_trap (type, 0, &frame))
return;
}
#endif
if (curpcb == 0 || curproc == 0)
goto skiptoswitch;
if (curpcb->pcb_onfault && frame.tf_trapno != T_PAGEFLT) {
extern int _udatasel;
if (read_gs() != (u_short) _udatasel)
/*
* Some user has corrupted %gs but we depend on it in
* copyout() etc. Fix it up and retry.
*
* (We don't preserve %fs or %gs, so users can change
* them to either _ucodesel, _udatasel or a not-present
* selector, possibly ORed with 0 to 3, making them
* volatile for other users. Not preserving them saves
* time and doesn't lose functionality or open security
* holes.)
*/
write_gs(_udatasel);
else
copyfault:
frame.tf_eip = (int)curpcb->pcb_onfault;
return;
}
if (ISPL(frame.tf_cs) == SEL_UPL) {
type |= T_USER;
p->p_md.md_regs = (int *)&frame;
sticks = p->p_sticks;
}
skiptoswitch:
ucode=0;
eva = rcr2();
code = frame.tf_err;
if ((type & ~T_USER) == T_PAGEFLT)
goto pfault;
switch (type) {
case T_SEGNPFLT|T_USER:
case T_STKFLT|T_USER:
case T_PROTFLT|T_USER: /* protection fault */
ucode = code + BUS_SEGM_FAULT ;
i = SIGBUS;
break;
case T_PRIVINFLT|T_USER: /* privileged instruction fault */
case T_RESADFLT|T_USER: /* reserved addressing fault */
case T_RESOPFLT|T_USER: /* reserved operand fault */
case T_FPOPFLT|T_USER: /* coprocessor operand fault */
ucode = type &~ T_USER;
i = SIGILL;
break;
case T_ASTFLT|T_USER: /* Allow process switch */
astoff();
cnt.v_soft++;
if ((p->p_flag & P_OWEUPC) && p->p_stats->p_prof.pr_scale) {
addupc(frame.tf_eip, &p->p_stats->p_prof, 1);
p->p_flag &= ~P_OWEUPC;
}
goto out;
case T_DNA|T_USER:
#if NNPX > 0
/* if a transparent fault (due to context switch "late") */
if (npxdna()) return;
#endif /* NNPX > 0 */
#if defined(MATH_EMULATE) || defined(GPL_MATH_EMULATE)
i = math_emulate(&frame);
if (i == 0) return;
#else /* MATH_EMULATE || GPL_MATH_EMULATE */
panic("trap: math emulation necessary!");
#endif /* MATH_EMULATE || GPL_MATH_EMULATE */
ucode = FPE_FPU_NP_TRAP;
break;
case T_BOUND|T_USER:
ucode = FPE_SUBRNG_TRAP;
i = SIGFPE;
break;
case T_OFLOW|T_USER:
ucode = FPE_INTOVF_TRAP;
i = SIGFPE;
break;
case T_DIVIDE|T_USER:
ucode = FPE_INTDIV_TRAP;
i = SIGFPE;
break;
case T_ARITHTRAP|T_USER:
ucode = code;
i = SIGFPE;
break;
pfault:
case T_PAGEFLT: /* allow page faults in kernel mode */
case T_PAGEFLT|T_USER: /* page fault */
{
vm_offset_t va;
struct vmspace *vm;
vm_map_t map = 0;
int rv = 0, oldflags;
vm_prot_t ftype;
unsigned v;
extern vm_map_t kernel_map;
va = trunc_page((vm_offset_t)eva);
/*
* Don't allow user-mode faults in kernel address space
*/
if ((type == (T_PAGEFLT|T_USER)) && (va >= KERNBASE)) {
goto nogo;
}
if ((p == 0) || (type == T_PAGEFLT && va >= KERNBASE)) {
vm = 0;
map = kernel_map;
} else {
vm = p->p_vmspace;
map = &vm->vm_map;
}
if (code & PGEX_W)
ftype = VM_PROT_READ | VM_PROT_WRITE;
else
ftype = VM_PROT_READ;
if (map != kernel_map) {
vm_offset_t pa;
vm_offset_t v = (vm_offset_t) vtopte(va);
vm_page_t ptepg;
/*
* Keep swapout from messing with us during this
* critical time.
*/
++p->p_lock;
/*
* Grow the stack if necessary
*/
if ((caddr_t)va > vm->vm_maxsaddr
&& (caddr_t)va < (caddr_t)USRSTACK) {
if (!grow(p, va)) {
rv = KERN_FAILURE;
--p->p_lock;
goto nogo;
}
}
/*
* Check if page table is mapped, if not,
* fault it first
*/
/* Fault the pte only if needed: */
*(volatile char *)v += 0;
ptepg = (vm_page_t) pmap_pte_vm_page(vm_map_pmap(map), v);
vm_page_hold(ptepg);
/* Fault in the user page: */
rv = vm_fault(map, va, ftype, FALSE);
vm_page_unhold(ptepg);
/*
* page table pages don't need to be kept if they
* are not held
*/
if( ptepg->hold_count == 0 && ptepg->wire_count == 0) {
pmap_page_protect( VM_PAGE_TO_PHYS(ptepg),
VM_PROT_NONE);
vm_page_free(ptepg);
}
--p->p_lock;
} else {
/*
* Since we know that kernel virtual address addresses
* always have pte pages mapped, we just have to fault
* the page.
*/
rv = vm_fault(map, va, ftype, FALSE);
}
if (rv == KERN_SUCCESS) {
if (type == T_PAGEFLT)
return;
goto out;
}
nogo:
if (type == T_PAGEFLT) {
if (curpcb->pcb_onfault)
goto copyfault;
goto we_re_toast;
}
i = (rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV;
/* kludge to pass faulting virtual address to sendsig */
ucode = type &~ T_USER;
frame.tf_err = eva;
break;
}
#if NDDB == 0
case T_TRCTRAP: /* trace trap -- someone single stepping lcall's */
frame.tf_eflags &= ~PSL_T;
/* Q: how do we turn it on again? */
return;
#endif
case T_BPTFLT|T_USER: /* bpt instruction fault */
case T_TRCTRAP|T_USER: /* trace trap */
frame.tf_eflags &= ~PSL_T;
i = SIGTRAP;
break;
#if NISA > 0
case T_NMI:
case T_NMI|T_USER:
#if NDDB > 0
/* NMI can be hooked up to a pushbutton for debugging */
printf ("NMI ... going to debugger\n");
if (kdb_trap (type, 0, &frame))
return;
#endif
/* machine/parity/power fail/"kitchen sink" faults */
if (isa_nmi(code) == 0) return;
/* FALL THROUGH */
#endif
default:
we_re_toast:
fault_type = type & ~T_USER;
#if NDDB > 0
if ((fault_type == T_BPTFLT) || (fault_type == T_TRCTRAP)) {
if (kdb_trap (type, 0, &frame))
return;
}
#endif
if (fault_type <= MAX_TRAP_MSG)
printf("\n\nFatal trap %d: %s while in %s mode\n",
fault_type, trap_msg[fault_type],
ISPL(frame.tf_cs) == SEL_UPL ? "user" : "kernel");
if (fault_type == T_PAGEFLT) {
printf("fault virtual address = 0x%x\n", eva);
printf("fault code = %s %s, %s\n",
code & PGEX_U ? "user" : "supervisor",
code & PGEX_W ? "write" : "read",
code & PGEX_P ? "protection violation" : "page not present");
}
printf("instruction pointer = 0x%x\n", frame.tf_eip);
printf("processor eflags = ");
if (frame.tf_eflags & EFL_TF)
printf("trace/trap, ");
if (frame.tf_eflags & EFL_IF)
printf("interrupt enabled, ");
if (frame.tf_eflags & EFL_NT)
printf("nested task, ");
if (frame.tf_eflags & EFL_RF)
printf("resume, ");
if (frame.tf_eflags & EFL_VM)
printf("vm86, ");
printf("IOPL = %d\n", (frame.tf_eflags & EFL_IOPL) >> 12);
printf("current process = ");
if (curproc) {
printf("%d (%s)\n",
curproc->p_pid, curproc->p_comm ?
curproc->p_comm : "");
} else {
printf("Idle\n");
}
printf("interrupt mask = ");
if ((cpl & net_imask) == net_imask)
printf("net ");
if ((cpl & tty_imask) == tty_imask)
printf("tty ");
if ((cpl & bio_imask) == bio_imask)
printf("bio ");
if (cpl == 0)
printf("none");
printf("\n");
#ifdef KDB
if (kdb_trap(&psl))
return;
#endif
#if NDDB > 0
if (kdb_trap (type, 0, &frame))
return;
#endif
if (fault_type <= MAX_TRAP_MSG)
panic(trap_msg[fault_type]);
else
panic("unknown/reserved trap");
/* NOTREACHED */
}
trapsignal(p, i, ucode);
if ((type & T_USER) == 0)
return;
#ifdef DIAGNOSTIC
fault_type = type & ~T_USER;
if (fault_type <= MAX_TRAP_MSG) {
uprintf("fatal process exception: %s",
trap_msg[fault_type]);
if ((fault_type == T_PAGEFLT) || (fault_type == T_PROTFLT))
uprintf(", fault VA = 0x%x", eva);
uprintf("\n");
}
#endif
out:
while (i = CURSIG(p))
postsig(i);
while (sig = CURSIG(p))
postsig(sig);
p->p_priority = p->p_usrpri;
if (want_resched) {
int s;
/*
* Since we are curproc, clock will normally just change
* our priority without moving us from one queue to another
@ -495,25 +135,390 @@ out:
p->p_stats->p_ru.ru_nivcsw++;
mi_switch();
splx(s);
while (i = CURSIG(p))
postsig(i);
while (sig = CURSIG(p))
postsig(sig);
}
if (p->p_stats->p_prof.pr_scale) {
u_quad_t ticks = p->p_sticks - sticks;
u_quad_t ticks = p->p_sticks - oticks;
if (ticks) {
#ifdef PROFTIMER
extern int profscale;
addupc(frame.tf_eip, &p->p_stats->p_prof,
addupc(frame->tf_eip, &p->p_stats->p_prof,
ticks * profscale);
#else
addupc(frame.tf_eip, &p->p_stats->p_prof, ticks);
addupc(frame->tf_eip, &p->p_stats->p_prof, ticks);
#endif
}
}
curpriority = p->p_priority;
}
/*
* trap(frame):
* Exception, fault, and trap interface to the FreeBSD kernel.
* This common code is called from assembly language IDT gate entry
* routines that prepare a suitable stack frame, and restore this
* frame after the exception has been processed.
*/
/*ARGSUSED*/
void
trap(frame)
struct trapframe frame;
{
struct proc *p = curproc;
u_quad_t sticks = 0;
int i = 0, ucode = 0, type, code, eva, fault_type;
frame.tf_eflags &= ~PSL_NT; /* clear nested trap XXX */
type = frame.tf_trapno;
code = frame.tf_err;
if (ISPL(frame.tf_cs) == SEL_UPL) {
/* user trap */
sticks = p->p_sticks;
p->p_md.md_regs = (int *)&frame;
switch (type) {
case T_RESADFLT: /* reserved addressing fault */
case T_PRIVINFLT: /* privileged instruction fault */
case T_RESOPFLT: /* reserved operand fault */
ucode = type;
i = SIGILL;
break;
case T_BPTFLT: /* bpt instruction fault */
case T_TRCTRAP: /* trace trap */
frame.tf_eflags &= ~PSL_T;
i = SIGTRAP;
break;
case T_ARITHTRAP: /* arithmetic trap */
ucode = code;
i = SIGFPE;
break;
case T_ASTFLT: /* Allow process switch */
astoff();
cnt.v_soft++;
if ((p->p_flag & P_OWEUPC) && p->p_stats->p_prof.pr_scale) {
addupc(frame.tf_eip, &p->p_stats->p_prof, 1);
p->p_flag &= ~P_OWEUPC;
}
goto out;
case T_PROTFLT: /* general protection fault */
case T_SEGNPFLT: /* segment not present fault */
case T_STKFLT: /* stack fault */
ucode = code + BUS_SEGM_FAULT ;
i = SIGBUS;
break;
case T_PAGEFLT: /* page fault */
i = trap_pfault(&frame, TRUE);
if (i == 0)
goto out;
ucode = T_PAGEFLT;
break;
case T_DIVIDE: /* integer divide fault */
ucode = FPE_INTDIV_TRAP;
i = SIGFPE;
break;
#if NISA > 0
case T_NMI:
#if NDDB > 0
/* NMI can be hooked up to a pushbutton for debugging */
printf ("NMI ... going to debugger\n");
if (kdb_trap (type, 0, &frame))
return;
#endif
/* machine/parity/power fail/"kitchen sink" faults */
if (isa_nmi(code) == 0) return;
/* FALL THROUGH */
#endif
case T_OFLOW: /* integer overflow fault */
ucode = FPE_INTOVF_TRAP;
i = SIGFPE;
break;
case T_BOUND: /* bounds check fault */
ucode = FPE_SUBRNG_TRAP;
i = SIGFPE;
break;
case T_DNA:
#if NNPX > 0
/* if a transparent fault (due to context switch "late") */
if (npxdna())
return;
#endif /* NNPX > 0 */
#if defined(MATH_EMULATE) || defined(GPL_MATH_EMULATE)
i = math_emulate(&frame);
if (i == 0) return;
#else /* MATH_EMULATE || GPL_MATH_EMULATE */
panic("trap: math emulation necessary!");
#endif /* MATH_EMULATE || GPL_MATH_EMULATE */
ucode = FPE_FPU_NP_TRAP;
break;
case T_FPOPFLT: /* FPU operand fetch fault */
ucode = T_FPOPFLT;
i = SIGILL;
break;
default:
trap_fatal(&frame);
}
} else {
/* kernel trap */
switch (type) {
case T_PAGEFLT: /* page fault */
(void) trap_pfault(&frame, FALSE);
return;
case T_PROTFLT: /* general protection fault */
case T_SEGNPFLT: /* segment not present fault */
if (curpcb && curpcb->pcb_onfault) {
frame.tf_eip = (int)curpcb->pcb_onfault;
return;
}
break;
#if NDDB > 0
case T_BPTFLT:
case T_TRCTRAP:
if (kdb_trap (type, 0, &frame))
return;
break;
#else
case T_TRCTRAP: /* trace trap -- someone single stepping lcall's */
/* Q: how do we turn it on again? */
frame.tf_eflags &= ~PSL_T;
return;
#endif
#if NISA > 0
case T_NMI:
#if NDDB > 0
/* NMI can be hooked up to a pushbutton for debugging */
printf ("NMI ... going to debugger\n");
if (kdb_trap (type, 0, &frame))
return;
#endif
/* machine/parity/power fail/"kitchen sink" faults */
if (isa_nmi(code) == 0) return;
/* FALL THROUGH */
#endif
}
trap_fatal(&frame);
}
trapsignal(p, i, ucode);
#ifdef DIAGNOSTIC
eva = rcr2();
if (type <= MAX_TRAP_MSG) {
uprintf("fatal process exception: %s",
trap_msg[type]);
if ((type == T_PAGEFLT) || (type == T_PROTFLT))
uprintf(", fault VA = 0x%x", eva);
uprintf("\n");
}
#endif
out:
userret(p, &frame, sticks);
}
int
trap_pfault(frame, usermode)
struct trapframe *frame;
int usermode;
{
vm_offset_t va;
struct vmspace *vm;
vm_map_t map = 0;
int rv = 0, oldflags;
vm_prot_t ftype;
extern vm_map_t kernel_map;
int eva;
struct proc *p = curproc;
eva = rcr2();
va = trunc_page((vm_offset_t)eva);
/*
* Don't allow user-mode faults in kernel address space
*/
if (usermode && (va >= KERNBASE)) {
goto nogo;
}
if ((p == 0) || (va >= KERNBASE)) {
vm = 0;
map = kernel_map;
} else {
vm = p->p_vmspace;
map = &vm->vm_map;
}
if (frame->tf_err & PGEX_W)
ftype = VM_PROT_READ | VM_PROT_WRITE;
else
ftype = VM_PROT_READ;
if (map != kernel_map) {
vm_offset_t pa;
vm_offset_t v = (vm_offset_t) vtopte(va);
vm_page_t ptepg;
/*
* Keep swapout from messing with us during this
* critical time.
*/
++p->p_lock;
/*
* Grow the stack if necessary
*/
if ((caddr_t)va > vm->vm_maxsaddr
&& (caddr_t)va < (caddr_t)USRSTACK) {
if (!grow(p, va)) {
rv = KERN_FAILURE;
--p->p_lock;
goto nogo;
}
}
/*
* Check if page table is mapped, if not,
* fault it first
*/
/* Fault the pte only if needed: */
*(volatile char *)v += 0;
ptepg = (vm_page_t) pmap_pte_vm_page(vm_map_pmap(map), v);
vm_page_hold(ptepg);
/* Fault in the user page: */
rv = vm_fault(map, va, ftype, FALSE);
vm_page_unhold(ptepg);
/*
* page table pages don't need to be kept if they
* are not held
*/
if( ptepg->hold_count == 0 && ptepg->wire_count == 0) {
pmap_page_protect( VM_PAGE_TO_PHYS(ptepg),
VM_PROT_NONE);
vm_page_free(ptepg);
}
--p->p_lock;
} else {
/*
* Since we know that kernel virtual address addresses
* always have pte pages mapped, we just have to fault
* the page.
*/
rv = vm_fault(map, va, ftype, FALSE);
}
if (rv == KERN_SUCCESS)
return (0);
nogo:
if (!usermode) {
if (curpcb->pcb_onfault) {
frame->tf_eip = (int)curpcb->pcb_onfault;
return (0);
}
trap_fatal(frame);
}
/* kludge to pass faulting virtual address to sendsig */
frame->tf_err = eva;
return((rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV);
}
void
trap_fatal(frame)
struct trapframe *frame;
{
int code, type, eva;
code = frame->tf_err;
type = frame->tf_trapno;
eva = rcr2();
if (type <= MAX_TRAP_MSG)
printf("\n\nFatal trap %d: %s while in %s mode\n",
type, trap_msg[type],
ISPL(frame->tf_cs) == SEL_UPL ? "user" : "kernel");
if (type == T_PAGEFLT) {
printf("fault virtual address = 0x%x\n", eva);
printf("fault code = %s %s, %s\n",
code & PGEX_U ? "user" : "supervisor",
code & PGEX_W ? "write" : "read",
code & PGEX_P ? "protection violation" : "page not present");
}
printf("instruction pointer = 0x%x\n", frame->tf_eip);
printf("processor eflags = ");
if (frame->tf_eflags & EFL_TF)
printf("trace/trap, ");
if (frame->tf_eflags & EFL_IF)
printf("interrupt enabled, ");
if (frame->tf_eflags & EFL_NT)
printf("nested task, ");
if (frame->tf_eflags & EFL_RF)
printf("resume, ");
if (frame->tf_eflags & EFL_VM)
printf("vm86, ");
printf("IOPL = %d\n", (frame->tf_eflags & EFL_IOPL) >> 12);
printf("current process = ");
if (curproc) {
printf("%d (%s)\n",
curproc->p_pid, curproc->p_comm ?
curproc->p_comm : "");
} else {
printf("Idle\n");
}
printf("interrupt mask = ");
if ((cpl & net_imask) == net_imask)
printf("net ");
if ((cpl & tty_imask) == tty_imask)
printf("tty ");
if ((cpl & bio_imask) == bio_imask)
printf("bio ");
if (cpl == 0)
printf("none");
printf("\n");
#ifdef KDB
if (kdb_trap(&psl))
return;
#endif
#if NDDB > 0
if (kdb_trap (type, 0, frame))
return;
#endif
if (type <= MAX_TRAP_MSG)
panic(trap_msg[type]);
else
panic("unknown/reserved trap");
}
/*
* Compensate for 386 brain damage (missing URKR).
* This is a little simpler than the pagefault handler in trap() because
@ -586,21 +591,17 @@ int trapwrite(addr)
/*ARGSUSED*/
void
syscall(frame)
volatile struct trapframe frame;
struct trapframe frame;
{
register int *locr0 = ((int *)&frame);
register caddr_t params;
register int i;
register struct sysent *callp;
register struct proc *p = curproc;
caddr_t params;
int i;
struct sysent *callp;
struct proc *p = curproc;
u_quad_t sticks;
int error, opc;
int args[8], rval[2];
u_int code;
#ifdef lint
r0 = 0; r0 = r0; r1 = 0; r1 = r1;
#endif
sticks = p->p_sticks;
if (ISPL(frame.tf_cs) != SEL_UPL)
panic("syscall");
@ -638,13 +639,11 @@ syscall(frame)
if ((i = callp->sy_narg * sizeof (int)) &&
(error = copyin(params, (caddr_t)args, (u_int)i))) {
frame.tf_eax = error;
frame.tf_eflags |= PSL_C; /* carry bit */
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSCALL))
ktrsyscall(p->p_tracep, code, callp->sy_narg, args);
#endif
goto done;
goto bad;
}
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSCALL))
@ -652,64 +651,38 @@ syscall(frame)
#endif
rval[0] = 0;
rval[1] = frame.tf_edx;
/*pg("%d. s %d\n", p->p_pid, code);*/
error = (*callp->sy_call)(p, args, rval);
if (error == ERESTART)
frame.tf_eip = opc;
else if (error != EJUSTRETURN) {
if (error) {
/*pg("error %d", error);*/
frame.tf_eax = error;
frame.tf_eflags |= PSL_C; /* carry bit */
} else {
frame.tf_eax = rval[0];
frame.tf_edx = rval[1];
frame.tf_eflags &= ~PSL_C; /* carry bit */
}
}
/* else if (error == EJUSTRETURN) */
/* nothing to do */
done:
/*
* Reinitialize proc pointer `p' as it may be different
* if this is a child returning from fork syscall.
*/
p = curproc;
while (i = CURSIG(p))
postsig(i);
p->p_priority = p->p_usrpri;
if (want_resched) {
int s;
/*
* Since we are curproc, clock will normally just change
* our priority without moving us from one queue to another
* (since the running process is not on a queue.)
* If that happened after we setrunqueue ourselves but before we
* swtch()'ed, we might not be on the queue indicated by
* our priority.
*/
s = splclock();
setrunqueue(p);
p->p_stats->p_ru.ru_nivcsw++;
mi_switch();
splx(s);
while (i = CURSIG(p))
postsig(i);
}
if (p->p_stats->p_prof.pr_scale) {
u_quad_t ticks = p->p_sticks - sticks;
if (ticks) {
#ifdef PROFTIMER
extern int profscale;
addupc(frame.tf_eip, &p->p_stats->p_prof,
ticks * profscale);
#else
addupc(frame.tf_eip, &p->p_stats->p_prof, ticks);
#endif
}
error = (*callp->sy_call)(p, args, rval);
switch (error) {
case 0:
/*
* Reinitialize proc pointer `p' as it may be different
* if this is a child returning from fork syscall.
*/
p = curproc;
frame.tf_eax = rval[0];
frame.tf_edx = rval[1];
frame.tf_eflags &= ~PSL_C; /* carry bit */
break;
case ERESTART:
frame.tf_eip = opc;
break;
case EJUSTRETURN:
break;
default:
bad:
frame.tf_eax = error;
frame.tf_eflags |= PSL_C; /* carry bit */
break;
}
curpriority = p->p_priority;
userret(p, &frame, sticks);
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSRET))
ktrsysret(p->p_tracep, code, error, rval[0]);

9
sys/amd64/include/cpufunc.h
View File

@ -71,6 +71,14 @@ tlbflush()
__asm __volatile("movl %%cr3, %%eax; movl %%eax, %%cr3" : : : "ax");
}
static inline u_long
rcr2()
{
u_long data;
__asm __volatile("movl %%cr2,%%eax" : "=a" (data));
return data;
}
#else /* not __GNUC__ */
extern void insque __P((void *, void *));
extern void remque __P((void *));
@ -87,7 +95,6 @@ void load_cr0 __P((u_int cr0));
u_int rcr0 __P((void));
void load_cr3(u_long);
u_long rcr3(void);
u_long rcr2(void);
void setidt __P((int, void (*)(), int, int));
extern u_long kvtop(void *);

114
sys/i386/i386/support.s
View File

@ -30,7 +30,7 @@
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $Id: support.s,v 1.6 1994/04/02 07:00:29 davidg Exp $
* $Id: support.s,v 1.10 1994/06/06 14:23:49 davidg Exp $
*/
#include "assym.s" /* system definitions */
@ -616,15 +616,22 @@ ENTRY(copyin)
movl 16(%esp),%edi /* caddr_t to */
movl 20(%esp),%ecx /* size_t len */
/*
* make sure address is valid
*/
movl %esi,%edx
addl %ecx,%edx
jc copyin_fault
cmpl $VM_MAXUSER_ADDRESS,%edx
ja copyin_fault
movb %cl,%al
shrl $2,%ecx /* copy longword-wise */
cld
gs
rep
movsl
movb %al,%cl
andb $3,%cl /* copy remaining bytes */
gs
rep
movsb
@ -651,8 +658,11 @@ ALTENTRY(fuiword)
ENTRY(fuword)
movl _curpcb,%ecx
movl $fusufault,PCB_ONFAULT(%ecx)
movl 4(%esp),%edx
gs
movl 4(%esp),%edx /* from */
cmpl $VM_MAXUSER_ADDRESS-4,%edx /* verify address is valid */
ja fusufault
movl (%edx),%eax
movl $0,PCB_ONFAULT(%ecx)
ret
@ -672,7 +682,10 @@ ENTRY(fusword)
movl _curpcb,%ecx
movl $fusufault,PCB_ONFAULT(%ecx)
movl 4(%esp),%edx
gs
cmpl $VM_MAXUSER_ADDRESS-2,%edx
ja fusufault
movzwl (%edx),%eax
movl $0,PCB_ONFAULT(%ecx)
ret
@ -682,7 +695,10 @@ ENTRY(fubyte)
movl _curpcb,%ecx
movl $fusufault,PCB_ONFAULT(%ecx)
movl 4(%esp),%edx
gs
cmpl $VM_MAXUSER_ADDRESS-1,%eax
ja fusufault
movzbl (%edx),%eax
movl $0,PCB_ONFAULT(%ecx)
ret
@ -732,8 +748,10 @@ ENTRY(suword)
#endif
2:
cmpl $VM_MAXUSER_ADDRESS-4,%edx /* verify address validity */
ja fusufault
movl 8(%esp),%eax
gs
movl %eax,(%edx)
xorl %eax,%eax
movl %eax,PCB_ONFAULT(%ecx)
@ -772,8 +790,10 @@ ENTRY(susword)
#endif
2:
cmpl $VM_MAXUSER_ADDRESS-2,%edx /* verify address validity */
ja fusufault
movw 8(%esp),%ax
gs
movw %ax,(%edx)
xorl %eax,%eax
movl %eax,PCB_ONFAULT(%ecx)
@ -812,8 +832,10 @@ ENTRY(subyte)
#endif
2:
cmpl $VM_MAXUSER_ADDRESS-1,%edx /* verify address validity */
ja fusufault
movb 8(%esp),%al
gs
movb %al,(%edx)
xorl %eax,%eax
movl %eax,PCB_ONFAULT(%ecx)
@ -849,8 +871,8 @@ ENTRY(copyoutstr)
* we look at a page at a time and the end address is on a page
* boundary.
*/
cmpl $VM_MAXUSER_ADDRESS,%edi
jae cpystrflt
cmpl $VM_MAXUSER_ADDRESS-1,%edi
ja cpystrflt
movl %edi,%eax
shrl $IDXSHIFT,%eax
@ -908,13 +930,11 @@ ENTRY(copyoutstr)
decl %edx
jz 2f
/*
* gs override doesn't work for stosb. Use the same explicit check
* as in copyout(). It's much slower now because it is per-char.
* XXX - however, it would be faster to rewrite this function to use
* XXX - would be faster to rewrite this function to use
* strlen() and copyout().
*/
cmpl $VM_MAXUSER_ADDRESS,%edi
jae cpystrflt
cmpl $VM_MAXUSER_ADDRESS-1,%edi
ja cpystrflt
lodsb
stosb
@ -932,6 +952,24 @@ ENTRY(copyoutstr)
#endif /* I486_CPU || I586_CPU */
cpystrflt:
movl $EFAULT,%eax
cpystrflt_x:
/* set *lencopied and return %eax */
movl _curpcb,%ecx
movl $0,PCB_ONFAULT(%ecx)
movl 20(%esp),%ecx
subl %edx,%ecx
movl 24(%esp),%edx
orl %edx,%edx
jz 1f
movl %ecx,(%edx)
1:
popl %edi
popl %esi
ret
/*
* copyinstr(from, to, maxlen, int *lencopied)
* copy a string from from to to, stop when a 0 character is reached.
@ -943,16 +981,18 @@ ENTRY(copyinstr)
pushl %esi
pushl %edi
movl _curpcb,%ecx
movl $cpystrflt,PCB_ONFAULT(%ecx)
movl $copyinstr_fault,PCB_ONFAULT(%ecx)
movl 12(%esp),%esi /* %esi = from */
movl 16(%esp),%edi /* %edi = to */
movl 20(%esp),%edx /* %edx = maxlen */
pushl %gs
movl __udatasel,%eax
movl %ax,%gs
incl %edx
1:
decl %edx
jz 4f
jz 2f
gs
lodsb
stosb
@ -962,26 +1002,26 @@ ENTRY(copyinstr)
/* Success -- 0 byte reached */
decl %edx
xorl %eax,%eax
jmp 6f
4:
jmp 3f
2:
/* edx is zero -- return ENAMETOOLONG */
movl $ENAMETOOLONG,%eax
jmp 6f
jmp 3f
cpystrflt:
copyinstr_fault:
movl $EFAULT,%eax
cpystrflt_x:
6:
3:
/* set *lencopied and return %eax */
movl _curpcb,%ecx
movl $0,PCB_ONFAULT(%ecx)
movl 20(%esp),%ecx
movl 24(%esp),%ecx
subl %edx,%ecx
movl 24(%esp),%edx
movl 28(%esp),%edx
orl %edx,%edx
jz 7f
jz 4f
movl %ecx,(%edx)
7:
4:
popl %gs
popl %edi
popl %esi
ret
@ -1097,15 +1137,6 @@ ENTRY(ssdtosd)
popl %ebx
ret
#if 0
/* tlbflush() */
ENTRY(tlbflush)
movl %cr3,%eax
orl $I386_CR3PAT,%eax
movl %eax,%cr3
ret
#endif
/* load_cr0(cr0) */
ENTRY(load_cr0)
movl 4(%esp),%eax
@ -1117,11 +1148,6 @@ ENTRY(rcr0)
movl %cr0,%eax
ret
/* rcr2() */
ENTRY(rcr2)
movl %cr2,%eax
ret
/* rcr3() */
ENTRY(rcr3)
movl %cr3,%eax

869
sys/i386/i386/trap.c
View File

@ -1,6 +1,7 @@
/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
* Copyright (C) 1994, David Greenman
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the University of Utah, and William Jolitz.
@ -34,7 +35,7 @@
* SUCH DAMAGE.
*
* from: @(#)trap.c 7.4 (Berkeley) 5/13/91
* $Id: trap.c,v 1.22 1994/04/07 10:51:00 davidg Exp $
* $Id: trap.c,v 1.24 1994/05/25 08:55:18 rgrimes Exp $
*/
/*
@ -69,21 +70,8 @@
#include "npx.h"
#include "ddb.h"
#ifdef __GNUC__
/*
* The "r" contraint could be "rm" except for fatal bugs in gas. As usual,
* we omit the size from the mov instruction to avoid nonfatal bugs in gas.
*/
#define read_gs() ({ u_short gs; __asm("mov %%gs,%0" : "=r" (gs)); gs; })
#define write_gs(newgs) __asm("mov %0,%%gs" : : "r" ((u_short) newgs))
#else /* not __GNUC__ */
u_short read_gs __P((void));
void write_gs __P((/* promoted u_short */ int gs));
#endif /* __GNUC__ */
int trap_pfault __P((struct trapframe *, int));
void trap_fatal __P((struct trapframe *));
extern int grow(struct proc *,u_int);
@ -101,7 +89,7 @@ char *trap_msg[] = {
"arithmetic trap", /* 6 T_ARITHTRAP */
"system forced exception", /* 7 T_ASTFLT */
"segmentation (limit) fault", /* 8 T_SEGFLT */
"protection fault", /* 9 T_PROTFLT */
"general protection fault", /* 9 T_PROTFLT */
"trace trap", /* 10 T_TRCTRAP */
"", /* 11 unused */
"page fault", /* 12 T_PAGEFLT */
@ -122,366 +110,18 @@ char *trap_msg[] = {
"stack fault", /* 27 T_STKFLT */
};
#define pde_v(v) (PTD[((v)>>PD_SHIFT)&1023].pd_v)
/*
* trap(frame):
* Exception, fault, and trap interface to BSD kernel. This
* common code is called from assembly language IDT gate entry
* routines that prepare a suitable stack frame, and restore this
* frame after the exception has been processed. Note that the
* effect is as if the arguments were passed call by reference.
*/
/*ARGSUSED*/
void
trap(frame)
struct trapframe frame;
static inline void
userret(p, frame, oticks)
struct proc *p;
struct trapframe *frame;
u_quad_t oticks;
{
register int i;
register struct proc *p = curproc;
u_quad_t sticks = 0;
int ucode, type, code, eva, fault_type;
int sig, s;
frame.tf_eflags &= ~PSL_NT; /* clear nested trap XXX */
type = frame.tf_trapno;
#if NDDB > 0
if (curpcb && curpcb->pcb_onfault) {
if (frame.tf_trapno == T_BPTFLT
|| frame.tf_trapno == T_TRCTRAP)
if (kdb_trap (type, 0, &frame))
return;
}
#endif
if (curpcb == 0 || curproc == 0)
goto skiptoswitch;
if (curpcb->pcb_onfault && frame.tf_trapno != T_PAGEFLT) {
extern int _udatasel;
if (read_gs() != (u_short) _udatasel)
/*
* Some user has corrupted %gs but we depend on it in
* copyout() etc. Fix it up and retry.
*
* (We don't preserve %fs or %gs, so users can change
* them to either _ucodesel, _udatasel or a not-present
* selector, possibly ORed with 0 to 3, making them
* volatile for other users. Not preserving them saves
* time and doesn't lose functionality or open security
* holes.)
*/
write_gs(_udatasel);
else
copyfault:
frame.tf_eip = (int)curpcb->pcb_onfault;
return;
}
if (ISPL(frame.tf_cs) == SEL_UPL) {
type |= T_USER;
p->p_md.md_regs = (int *)&frame;
sticks = p->p_sticks;
}
skiptoswitch:
ucode=0;
eva = rcr2();
code = frame.tf_err;
if ((type & ~T_USER) == T_PAGEFLT)
goto pfault;
switch (type) {
case T_SEGNPFLT|T_USER:
case T_STKFLT|T_USER:
case T_PROTFLT|T_USER: /* protection fault */
ucode = code + BUS_SEGM_FAULT ;
i = SIGBUS;
break;
case T_PRIVINFLT|T_USER: /* privileged instruction fault */
case T_RESADFLT|T_USER: /* reserved addressing fault */
case T_RESOPFLT|T_USER: /* reserved operand fault */
case T_FPOPFLT|T_USER: /* coprocessor operand fault */
ucode = type &~ T_USER;
i = SIGILL;
break;
case T_ASTFLT|T_USER: /* Allow process switch */
astoff();
cnt.v_soft++;
if ((p->p_flag & P_OWEUPC) && p->p_stats->p_prof.pr_scale) {
addupc(frame.tf_eip, &p->p_stats->p_prof, 1);
p->p_flag &= ~P_OWEUPC;
}
goto out;
case T_DNA|T_USER:
#if NNPX > 0
/* if a transparent fault (due to context switch "late") */
if (npxdna()) return;
#endif /* NNPX > 0 */
#if defined(MATH_EMULATE) || defined(GPL_MATH_EMULATE)
i = math_emulate(&frame);
if (i == 0) return;
#else /* MATH_EMULATE || GPL_MATH_EMULATE */
panic("trap: math emulation necessary!");
#endif /* MATH_EMULATE || GPL_MATH_EMULATE */
ucode = FPE_FPU_NP_TRAP;
break;
case T_BOUND|T_USER:
ucode = FPE_SUBRNG_TRAP;
i = SIGFPE;
break;
case T_OFLOW|T_USER:
ucode = FPE_INTOVF_TRAP;
i = SIGFPE;
break;
case T_DIVIDE|T_USER:
ucode = FPE_INTDIV_TRAP;
i = SIGFPE;
break;
case T_ARITHTRAP|T_USER:
ucode = code;
i = SIGFPE;
break;
pfault:
case T_PAGEFLT: /* allow page faults in kernel mode */
case T_PAGEFLT|T_USER: /* page fault */
{
vm_offset_t va;
struct vmspace *vm;
vm_map_t map = 0;
int rv = 0, oldflags;
vm_prot_t ftype;
unsigned v;
extern vm_map_t kernel_map;
va = trunc_page((vm_offset_t)eva);
/*
* Don't allow user-mode faults in kernel address space
*/
if ((type == (T_PAGEFLT|T_USER)) && (va >= KERNBASE)) {
goto nogo;
}
if ((p == 0) || (type == T_PAGEFLT && va >= KERNBASE)) {
vm = 0;
map = kernel_map;
} else {
vm = p->p_vmspace;
map = &vm->vm_map;
}
if (code & PGEX_W)
ftype = VM_PROT_READ | VM_PROT_WRITE;
else
ftype = VM_PROT_READ;
if (map != kernel_map) {
vm_offset_t pa;
vm_offset_t v = (vm_offset_t) vtopte(va);
vm_page_t ptepg;
/*
* Keep swapout from messing with us during this
* critical time.
*/
++p->p_lock;
/*
* Grow the stack if necessary
*/
if ((caddr_t)va > vm->vm_maxsaddr
&& (caddr_t)va < (caddr_t)USRSTACK) {
if (!grow(p, va)) {
rv = KERN_FAILURE;
--p->p_lock;
goto nogo;
}
}
/*
* Check if page table is mapped, if not,
* fault it first
*/
/* Fault the pte only if needed: */
*(volatile char *)v += 0;
ptepg = (vm_page_t) pmap_pte_vm_page(vm_map_pmap(map), v);
vm_page_hold(ptepg);
/* Fault in the user page: */
rv = vm_fault(map, va, ftype, FALSE);
vm_page_unhold(ptepg);
/*
* page table pages don't need to be kept if they
* are not held
*/
if( ptepg->hold_count == 0 && ptepg->wire_count == 0) {
pmap_page_protect( VM_PAGE_TO_PHYS(ptepg),
VM_PROT_NONE);
vm_page_free(ptepg);
}
--p->p_lock;
} else {
/*
* Since we know that kernel virtual address addresses
* always have pte pages mapped, we just have to fault
* the page.
*/
rv = vm_fault(map, va, ftype, FALSE);
}
if (rv == KERN_SUCCESS) {
if (type == T_PAGEFLT)
return;
goto out;
}
nogo:
if (type == T_PAGEFLT) {
if (curpcb->pcb_onfault)
goto copyfault;
goto we_re_toast;
}
i = (rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV;
/* kludge to pass faulting virtual address to sendsig */
ucode = type &~ T_USER;
frame.tf_err = eva;
break;
}
#if NDDB == 0
case T_TRCTRAP: /* trace trap -- someone single stepping lcall's */
frame.tf_eflags &= ~PSL_T;
/* Q: how do we turn it on again? */
return;
#endif
case T_BPTFLT|T_USER: /* bpt instruction fault */
case T_TRCTRAP|T_USER: /* trace trap */
frame.tf_eflags &= ~PSL_T;
i = SIGTRAP;
break;
#if NISA > 0
case T_NMI:
case T_NMI|T_USER:
#if NDDB > 0
/* NMI can be hooked up to a pushbutton for debugging */
printf ("NMI ... going to debugger\n");
if (kdb_trap (type, 0, &frame))
return;
#endif
/* machine/parity/power fail/"kitchen sink" faults */
if (isa_nmi(code) == 0) return;
/* FALL THROUGH */
#endif
default:
we_re_toast:
fault_type = type & ~T_USER;
#if NDDB > 0
if ((fault_type == T_BPTFLT) || (fault_type == T_TRCTRAP)) {
if (kdb_trap (type, 0, &frame))
return;
}
#endif
if (fault_type <= MAX_TRAP_MSG)
printf("\n\nFatal trap %d: %s while in %s mode\n",
fault_type, trap_msg[fault_type],
ISPL(frame.tf_cs) == SEL_UPL ? "user" : "kernel");
if (fault_type == T_PAGEFLT) {
printf("fault virtual address = 0x%x\n", eva);
printf("fault code = %s %s, %s\n",
code & PGEX_U ? "user" : "supervisor",
code & PGEX_W ? "write" : "read",
code & PGEX_P ? "protection violation" : "page not present");
}
printf("instruction pointer = 0x%x\n", frame.tf_eip);
printf("processor eflags = ");
if (frame.tf_eflags & EFL_TF)
printf("trace/trap, ");
if (frame.tf_eflags & EFL_IF)
printf("interrupt enabled, ");
if (frame.tf_eflags & EFL_NT)
printf("nested task, ");
if (frame.tf_eflags & EFL_RF)
printf("resume, ");
if (frame.tf_eflags & EFL_VM)
printf("vm86, ");
printf("IOPL = %d\n", (frame.tf_eflags & EFL_IOPL) >> 12);
printf("current process = ");
if (curproc) {
printf("%d (%s)\n",
curproc->p_pid, curproc->p_comm ?
curproc->p_comm : "");
} else {
printf("Idle\n");
}
printf("interrupt mask = ");
if ((cpl & net_imask) == net_imask)
printf("net ");
if ((cpl & tty_imask) == tty_imask)
printf("tty ");
if ((cpl & bio_imask) == bio_imask)
printf("bio ");
if (cpl == 0)
printf("none");
printf("\n");
#ifdef KDB
if (kdb_trap(&psl))
return;
#endif
#if NDDB > 0
if (kdb_trap (type, 0, &frame))
return;
#endif
if (fault_type <= MAX_TRAP_MSG)
panic(trap_msg[fault_type]);
else
panic("unknown/reserved trap");
/* NOTREACHED */
}
trapsignal(p, i, ucode);
if ((type & T_USER) == 0)
return;
#ifdef DIAGNOSTIC
fault_type = type & ~T_USER;
if (fault_type <= MAX_TRAP_MSG) {
uprintf("fatal process exception: %s",
trap_msg[fault_type]);
if ((fault_type == T_PAGEFLT) || (fault_type == T_PROTFLT))
uprintf(", fault VA = 0x%x", eva);
uprintf("\n");
}
#endif
out:
while (i = CURSIG(p))
postsig(i);
while (sig = CURSIG(p))
postsig(sig);
p->p_priority = p->p_usrpri;
if (want_resched) {
int s;
/*
* Since we are curproc, clock will normally just change
* our priority without moving us from one queue to another
@ -495,25 +135,390 @@ out:
p->p_stats->p_ru.ru_nivcsw++;
mi_switch();
splx(s);
while (i = CURSIG(p))
postsig(i);
while (sig = CURSIG(p))
postsig(sig);
}
if (p->p_stats->p_prof.pr_scale) {
u_quad_t ticks = p->p_sticks - sticks;
u_quad_t ticks = p->p_sticks - oticks;
if (ticks) {
#ifdef PROFTIMER
extern int profscale;
addupc(frame.tf_eip, &p->p_stats->p_prof,
addupc(frame->tf_eip, &p->p_stats->p_prof,
ticks * profscale);
#else
addupc(frame.tf_eip, &p->p_stats->p_prof, ticks);
addupc(frame->tf_eip, &p->p_stats->p_prof, ticks);
#endif
}
}
curpriority = p->p_priority;
}
/*
* trap(frame):
* Exception, fault, and trap interface to the FreeBSD kernel.
* This common code is called from assembly language IDT gate entry
* routines that prepare a suitable stack frame, and restore this
* frame after the exception has been processed.
*/
/*ARGSUSED*/
void
trap(frame)
struct trapframe frame;
{
struct proc *p = curproc;
u_quad_t sticks = 0;
int i = 0, ucode = 0, type, code, eva, fault_type;
frame.tf_eflags &= ~PSL_NT; /* clear nested trap XXX */
type = frame.tf_trapno;
code = frame.tf_err;
if (ISPL(frame.tf_cs) == SEL_UPL) {
/* user trap */
sticks = p->p_sticks;
p->p_md.md_regs = (int *)&frame;
switch (type) {
case T_RESADFLT: /* reserved addressing fault */
case T_PRIVINFLT: /* privileged instruction fault */
case T_RESOPFLT: /* reserved operand fault */
ucode = type;
i = SIGILL;
break;
case T_BPTFLT: /* bpt instruction fault */
case T_TRCTRAP: /* trace trap */
frame.tf_eflags &= ~PSL_T;
i = SIGTRAP;
break;
case T_ARITHTRAP: /* arithmetic trap */
ucode = code;
i = SIGFPE;
break;
case T_ASTFLT: /* Allow process switch */
astoff();
cnt.v_soft++;
if ((p->p_flag & P_OWEUPC) && p->p_stats->p_prof.pr_scale) {
addupc(frame.tf_eip, &p->p_stats->p_prof, 1);
p->p_flag &= ~P_OWEUPC;
}
goto out;
case T_PROTFLT: /* general protection fault */
case T_SEGNPFLT: /* segment not present fault */
case T_STKFLT: /* stack fault */
ucode = code + BUS_SEGM_FAULT ;
i = SIGBUS;
break;
case T_PAGEFLT: /* page fault */
i = trap_pfault(&frame, TRUE);
if (i == 0)
goto out;
ucode = T_PAGEFLT;
break;
case T_DIVIDE: /* integer divide fault */
ucode = FPE_INTDIV_TRAP;
i = SIGFPE;
break;
#if NISA > 0
case T_NMI:
#if NDDB > 0
/* NMI can be hooked up to a pushbutton for debugging */
printf ("NMI ... going to debugger\n");
if (kdb_trap (type, 0, &frame))
return;
#endif
/* machine/parity/power fail/"kitchen sink" faults */
if (isa_nmi(code) == 0) return;
/* FALL THROUGH */
#endif
case T_OFLOW: /* integer overflow fault */
ucode = FPE_INTOVF_TRAP;
i = SIGFPE;
break;
case T_BOUND: /* bounds check fault */
ucode = FPE_SUBRNG_TRAP;
i = SIGFPE;
break;
case T_DNA:
#if NNPX > 0
/* if a transparent fault (due to context switch "late") */
if (npxdna())
return;
#endif /* NNPX > 0 */
#if defined(MATH_EMULATE) || defined(GPL_MATH_EMULATE)
i = math_emulate(&frame);
if (i == 0) return;
#else /* MATH_EMULATE || GPL_MATH_EMULATE */
panic("trap: math emulation necessary!");
#endif /* MATH_EMULATE || GPL_MATH_EMULATE */
ucode = FPE_FPU_NP_TRAP;
break;
case T_FPOPFLT: /* FPU operand fetch fault */
ucode = T_FPOPFLT;
i = SIGILL;
break;
default:
trap_fatal(&frame);
}
} else {
/* kernel trap */
switch (type) {
case T_PAGEFLT: /* page fault */
(void) trap_pfault(&frame, FALSE);
return;
case T_PROTFLT: /* general protection fault */
case T_SEGNPFLT: /* segment not present fault */
if (curpcb && curpcb->pcb_onfault) {
frame.tf_eip = (int)curpcb->pcb_onfault;
return;
}
break;
#if NDDB > 0
case T_BPTFLT:
case T_TRCTRAP:
if (kdb_trap (type, 0, &frame))
return;
break;
#else
case T_TRCTRAP: /* trace trap -- someone single stepping lcall's */
/* Q: how do we turn it on again? */
frame.tf_eflags &= ~PSL_T;
return;
#endif
#if NISA > 0
case T_NMI:
#if NDDB > 0
/* NMI can be hooked up to a pushbutton for debugging */
printf ("NMI ... going to debugger\n");
if (kdb_trap (type, 0, &frame))
return;
#endif
/* machine/parity/power fail/"kitchen sink" faults */
if (isa_nmi(code) == 0) return;
/* FALL THROUGH */
#endif
}
trap_fatal(&frame);
}
trapsignal(p, i, ucode);
#ifdef DIAGNOSTIC
eva = rcr2();
if (type <= MAX_TRAP_MSG) {
uprintf("fatal process exception: %s",
trap_msg[type]);
if ((type == T_PAGEFLT) || (type == T_PROTFLT))
uprintf(", fault VA = 0x%x", eva);
uprintf("\n");
}
#endif
out:
userret(p, &frame, sticks);
}
int
trap_pfault(frame, usermode)
struct trapframe *frame;
int usermode;
{
vm_offset_t va;
struct vmspace *vm;
vm_map_t map = 0;
int rv = 0, oldflags;
vm_prot_t ftype;
extern vm_map_t kernel_map;
int eva;
struct proc *p = curproc;
eva = rcr2();
va = trunc_page((vm_offset_t)eva);
/*
* Don't allow user-mode faults in kernel address space
*/
if (usermode && (va >= KERNBASE)) {
goto nogo;
}
if ((p == 0) || (va >= KERNBASE)) {
vm = 0;
map = kernel_map;
} else {
vm = p->p_vmspace;
map = &vm->vm_map;
}
if (frame->tf_err & PGEX_W)
ftype = VM_PROT_READ | VM_PROT_WRITE;
else
ftype = VM_PROT_READ;
if (map != kernel_map) {
vm_offset_t pa;
vm_offset_t v = (vm_offset_t) vtopte(va);
vm_page_t ptepg;
/*
* Keep swapout from messing with us during this
* critical time.
*/
++p->p_lock;
/*
* Grow the stack if necessary
*/
if ((caddr_t)va > vm->vm_maxsaddr
&& (caddr_t)va < (caddr_t)USRSTACK) {
if (!grow(p, va)) {
rv = KERN_FAILURE;
--p->p_lock;
goto nogo;
}
}
/*
* Check if page table is mapped, if not,
* fault it first
*/
/* Fault the pte only if needed: */
*(volatile char *)v += 0;
ptepg = (vm_page_t) pmap_pte_vm_page(vm_map_pmap(map), v);
vm_page_hold(ptepg);
/* Fault in the user page: */
rv = vm_fault(map, va, ftype, FALSE);
vm_page_unhold(ptepg);
/*
* page table pages don't need to be kept if they
* are not held
*/
if( ptepg->hold_count == 0 && ptepg->wire_count == 0) {
pmap_page_protect( VM_PAGE_TO_PHYS(ptepg),
VM_PROT_NONE);
vm_page_free(ptepg);
}
--p->p_lock;
} else {
/*
* Since we know that kernel virtual address addresses
* always have pte pages mapped, we just have to fault
* the page.
*/
rv = vm_fault(map, va, ftype, FALSE);
}
if (rv == KERN_SUCCESS)
return (0);
nogo:
if (!usermode) {
if (curpcb->pcb_onfault) {
frame->tf_eip = (int)curpcb->pcb_onfault;
return (0);
}
trap_fatal(frame);
}
/* kludge to pass faulting virtual address to sendsig */
frame->tf_err = eva;
return((rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV);
}
void
trap_fatal(frame)
struct trapframe *frame;
{
int code, type, eva;
code = frame->tf_err;
type = frame->tf_trapno;
eva = rcr2();
if (type <= MAX_TRAP_MSG)
printf("\n\nFatal trap %d: %s while in %s mode\n",
type, trap_msg[type],
ISPL(frame->tf_cs) == SEL_UPL ? "user" : "kernel");
if (type == T_PAGEFLT) {
printf("fault virtual address = 0x%x\n", eva);
printf("fault code = %s %s, %s\n",
code & PGEX_U ? "user" : "supervisor",
code & PGEX_W ? "write" : "read",
code & PGEX_P ? "protection violation" : "page not present");
}
printf("instruction pointer = 0x%x\n", frame->tf_eip);
printf("processor eflags = ");
if (frame->tf_eflags & EFL_TF)
printf("trace/trap, ");
if (frame->tf_eflags & EFL_IF)
printf("interrupt enabled, ");
if (frame->tf_eflags & EFL_NT)
printf("nested task, ");
if (frame->tf_eflags & EFL_RF)
printf("resume, ");
if (frame->tf_eflags & EFL_VM)
printf("vm86, ");
printf("IOPL = %d\n", (frame->tf_eflags & EFL_IOPL) >> 12);
printf("current process = ");
if (curproc) {
printf("%d (%s)\n",
curproc->p_pid, curproc->p_comm ?
curproc->p_comm : "");
} else {
printf("Idle\n");
}
printf("interrupt mask = ");
if ((cpl & net_imask) == net_imask)
printf("net ");
if ((cpl & tty_imask) == tty_imask)
printf("tty ");
if ((cpl & bio_imask) == bio_imask)
printf("bio ");
if (cpl == 0)
printf("none");
printf("\n");
#ifdef KDB
if (kdb_trap(&psl))
return;
#endif
#if NDDB > 0
if (kdb_trap (type, 0, frame))
return;
#endif
if (type <= MAX_TRAP_MSG)
panic(trap_msg[type]);
else
panic("unknown/reserved trap");
}
/*
* Compensate for 386 brain damage (missing URKR).
* This is a little simpler than the pagefault handler in trap() because
@ -586,21 +591,17 @@ int trapwrite(addr)
/*ARGSUSED*/
void
syscall(frame)
volatile struct trapframe frame;
struct trapframe frame;
{
register int *locr0 = ((int *)&frame);
register caddr_t params;
register int i;
register struct sysent *callp;
register struct proc *p = curproc;
caddr_t params;
int i;
struct sysent *callp;
struct proc *p = curproc;
u_quad_t sticks;
int error, opc;
int args[8], rval[2];
u_int code;
#ifdef lint
r0 = 0; r0 = r0; r1 = 0; r1 = r1;
#endif
sticks = p->p_sticks;
if (ISPL(frame.tf_cs) != SEL_UPL)
panic("syscall");
@ -638,13 +639,11 @@ syscall(frame)
if ((i = callp->sy_narg * sizeof (int)) &&
(error = copyin(params, (caddr_t)args, (u_int)i))) {
frame.tf_eax = error;
frame.tf_eflags |= PSL_C; /* carry bit */
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSCALL))
ktrsyscall(p->p_tracep, code, callp->sy_narg, args);
#endif
goto done;
goto bad;
}
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSCALL))
@ -652,64 +651,38 @@ syscall(frame)
#endif
rval[0] = 0;
rval[1] = frame.tf_edx;
/*pg("%d. s %d\n", p->p_pid, code);*/
error = (*callp->sy_call)(p, args, rval);
if (error == ERESTART)
frame.tf_eip = opc;
else if (error != EJUSTRETURN) {
if (error) {
/*pg("error %d", error);*/
frame.tf_eax = error;
frame.tf_eflags |= PSL_C; /* carry bit */
} else {
frame.tf_eax = rval[0];
frame.tf_edx = rval[1];
frame.tf_eflags &= ~PSL_C; /* carry bit */
}
}
/* else if (error == EJUSTRETURN) */
/* nothing to do */
done:
/*
* Reinitialize proc pointer `p' as it may be different
* if this is a child returning from fork syscall.
*/
p = curproc;
while (i = CURSIG(p))
postsig(i);
p->p_priority = p->p_usrpri;
if (want_resched) {
int s;
/*
* Since we are curproc, clock will normally just change
* our priority without moving us from one queue to another
* (since the running process is not on a queue.)
* If that happened after we setrunqueue ourselves but before we
* swtch()'ed, we might not be on the queue indicated by
* our priority.
*/
s = splclock();
setrunqueue(p);
p->p_stats->p_ru.ru_nivcsw++;
mi_switch();
splx(s);
while (i = CURSIG(p))
postsig(i);
}
if (p->p_stats->p_prof.pr_scale) {
u_quad_t ticks = p->p_sticks - sticks;
if (ticks) {
#ifdef PROFTIMER
extern int profscale;
addupc(frame.tf_eip, &p->p_stats->p_prof,
ticks * profscale);
#else
addupc(frame.tf_eip, &p->p_stats->p_prof, ticks);
#endif
}
error = (*callp->sy_call)(p, args, rval);
switch (error) {
case 0:
/*
* Reinitialize proc pointer `p' as it may be different
* if this is a child returning from fork syscall.
*/
p = curproc;
frame.tf_eax = rval[0];
frame.tf_edx = rval[1];
frame.tf_eflags &= ~PSL_C; /* carry bit */
break;
case ERESTART:
frame.tf_eip = opc;
break;
case EJUSTRETURN:
break;
default:
bad:
frame.tf_eax = error;
frame.tf_eflags |= PSL_C; /* carry bit */
break;
}
curpriority = p->p_priority;
userret(p, &frame, sticks);
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSRET))
ktrsysret(p->p_tracep, code, error, rval[0]);

9
sys/i386/include/cpufunc.h
View File

@ -71,6 +71,14 @@ tlbflush()
__asm __volatile("movl %%cr3, %%eax; movl %%eax, %%cr3" : : : "ax");
}
static inline u_long
rcr2()
{
u_long data;
__asm __volatile("movl %%cr2,%%eax" : "=a" (data));
return data;
}
#else /* not __GNUC__ */
extern void insque __P((void *, void *));
extern void remque __P((void *));
@ -87,7 +95,6 @@ void load_cr0 __P((u_int cr0));
u_int rcr0 __P((void));
void load_cr3(u_long);
u_long rcr3(void);
u_long rcr2(void);
void setidt __P((int, void (*)(), int, int));
extern u_long kvtop(void *);

869
sys/kern/subr_trap.c
View File

@ -1,6 +1,7 @@
/*-
* Copyright (c) 1990 The Regents of the University of California.
* All rights reserved.
* Copyright (C) 1994, David Greenman
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the University of Utah, and William Jolitz.
@ -34,7 +35,7 @@
* SUCH DAMAGE.
*
* from: @(#)trap.c 7.4 (Berkeley) 5/13/91
* $Id: trap.c,v 1.22 1994/04/07 10:51:00 davidg Exp $
* $Id: trap.c,v 1.24 1994/05/25 08:55:18 rgrimes Exp $
*/
/*
@ -69,21 +70,8 @@
#include "npx.h"
#include "ddb.h"
#ifdef __GNUC__
/*
* The "r" contraint could be "rm" except for fatal bugs in gas. As usual,
* we omit the size from the mov instruction to avoid nonfatal bugs in gas.
*/
#define read_gs() ({ u_short gs; __asm("mov %%gs,%0" : "=r" (gs)); gs; })
#define write_gs(newgs) __asm("mov %0,%%gs" : : "r" ((u_short) newgs))
#else /* not __GNUC__ */
u_short read_gs __P((void));
void write_gs __P((/* promoted u_short */ int gs));
#endif /* __GNUC__ */
int trap_pfault __P((struct trapframe *, int));
void trap_fatal __P((struct trapframe *));
extern int grow(struct proc *,u_int);
@ -101,7 +89,7 @@ char *trap_msg[] = {
"arithmetic trap", /* 6 T_ARITHTRAP */
"system forced exception", /* 7 T_ASTFLT */
"segmentation (limit) fault", /* 8 T_SEGFLT */
"protection fault", /* 9 T_PROTFLT */
"general protection fault", /* 9 T_PROTFLT */
"trace trap", /* 10 T_TRCTRAP */
"", /* 11 unused */
"page fault", /* 12 T_PAGEFLT */
@ -122,366 +110,18 @@ char *trap_msg[] = {
"stack fault", /* 27 T_STKFLT */
};
#define pde_v(v) (PTD[((v)>>PD_SHIFT)&1023].pd_v)
/*
* trap(frame):
* Exception, fault, and trap interface to BSD kernel. This
* common code is called from assembly language IDT gate entry
* routines that prepare a suitable stack frame, and restore this
* frame after the exception has been processed. Note that the
* effect is as if the arguments were passed call by reference.
*/
/*ARGSUSED*/
void
trap(frame)
struct trapframe frame;
static inline void
userret(p, frame, oticks)
struct proc *p;
struct trapframe *frame;
u_quad_t oticks;
{
register int i;
register struct proc *p = curproc;
u_quad_t sticks = 0;
int ucode, type, code, eva, fault_type;
int sig, s;
frame.tf_eflags &= ~PSL_NT; /* clear nested trap XXX */
type = frame.tf_trapno;
#if NDDB > 0
if (curpcb && curpcb->pcb_onfault) {
if (frame.tf_trapno == T_BPTFLT
|| frame.tf_trapno == T_TRCTRAP)
if (kdb_trap (type, 0, &frame))
return;
}
#endif
if (curpcb == 0 || curproc == 0)
goto skiptoswitch;
if (curpcb->pcb_onfault && frame.tf_trapno != T_PAGEFLT) {
extern int _udatasel;
if (read_gs() != (u_short) _udatasel)
/*
* Some user has corrupted %gs but we depend on it in
* copyout() etc. Fix it up and retry.
*
* (We don't preserve %fs or %gs, so users can change
* them to either _ucodesel, _udatasel or a not-present
* selector, possibly ORed with 0 to 3, making them
* volatile for other users. Not preserving them saves
* time and doesn't lose functionality or open security
* holes.)
*/
write_gs(_udatasel);
else
copyfault:
frame.tf_eip = (int)curpcb->pcb_onfault;
return;
}
if (ISPL(frame.tf_cs) == SEL_UPL) {
type |= T_USER;
p->p_md.md_regs = (int *)&frame;
sticks = p->p_sticks;
}
skiptoswitch:
ucode=0;
eva = rcr2();
code = frame.tf_err;
if ((type & ~T_USER) == T_PAGEFLT)
goto pfault;
switch (type) {
case T_SEGNPFLT|T_USER:
case T_STKFLT|T_USER:
case T_PROTFLT|T_USER: /* protection fault */
ucode = code + BUS_SEGM_FAULT ;
i = SIGBUS;
break;
case T_PRIVINFLT|T_USER: /* privileged instruction fault */
case T_RESADFLT|T_USER: /* reserved addressing fault */
case T_RESOPFLT|T_USER: /* reserved operand fault */
case T_FPOPFLT|T_USER: /* coprocessor operand fault */
ucode = type &~ T_USER;
i = SIGILL;
break;
case T_ASTFLT|T_USER: /* Allow process switch */
astoff();
cnt.v_soft++;
if ((p->p_flag & P_OWEUPC) && p->p_stats->p_prof.pr_scale) {
addupc(frame.tf_eip, &p->p_stats->p_prof, 1);
p->p_flag &= ~P_OWEUPC;
}
goto out;
case T_DNA|T_USER:
#if NNPX > 0
/* if a transparent fault (due to context switch "late") */
if (npxdna()) return;
#endif /* NNPX > 0 */
#if defined(MATH_EMULATE) || defined(GPL_MATH_EMULATE)
i = math_emulate(&frame);
if (i == 0) return;
#else /* MATH_EMULATE || GPL_MATH_EMULATE */
panic("trap: math emulation necessary!");
#endif /* MATH_EMULATE || GPL_MATH_EMULATE */
ucode = FPE_FPU_NP_TRAP;
break;
case T_BOUND|T_USER:
ucode = FPE_SUBRNG_TRAP;
i = SIGFPE;
break;
case T_OFLOW|T_USER:
ucode = FPE_INTOVF_TRAP;
i = SIGFPE;
break;
case T_DIVIDE|T_USER:
ucode = FPE_INTDIV_TRAP;
i = SIGFPE;
break;
case T_ARITHTRAP|T_USER:
ucode = code;
i = SIGFPE;
break;
pfault:
case T_PAGEFLT: /* allow page faults in kernel mode */
case T_PAGEFLT|T_USER: /* page fault */
{
vm_offset_t va;
struct vmspace *vm;
vm_map_t map = 0;
int rv = 0, oldflags;
vm_prot_t ftype;
unsigned v;
extern vm_map_t kernel_map;
va = trunc_page((vm_offset_t)eva);
/*
* Don't allow user-mode faults in kernel address space
*/
if ((type == (T_PAGEFLT|T_USER)) && (va >= KERNBASE)) {
goto nogo;
}
if ((p == 0) || (type == T_PAGEFLT && va >= KERNBASE)) {
vm = 0;
map = kernel_map;
} else {
vm = p->p_vmspace;
map = &vm->vm_map;
}
if (code & PGEX_W)
ftype = VM_PROT_READ | VM_PROT_WRITE;
else
ftype = VM_PROT_READ;
if (map != kernel_map) {
vm_offset_t pa;
vm_offset_t v = (vm_offset_t) vtopte(va);
vm_page_t ptepg;
/*
* Keep swapout from messing with us during this
* critical time.
*/
++p->p_lock;
/*
* Grow the stack if necessary
*/
if ((caddr_t)va > vm->vm_maxsaddr
&& (caddr_t)va < (caddr_t)USRSTACK) {
if (!grow(p, va)) {
rv = KERN_FAILURE;
--p->p_lock;
goto nogo;
}
}
/*
* Check if page table is mapped, if not,
* fault it first
*/
/* Fault the pte only if needed: */
*(volatile char *)v += 0;
ptepg = (vm_page_t) pmap_pte_vm_page(vm_map_pmap(map), v);
vm_page_hold(ptepg);
/* Fault in the user page: */
rv = vm_fault(map, va, ftype, FALSE);
vm_page_unhold(ptepg);
/*
* page table pages don't need to be kept if they
* are not held
*/
if( ptepg->hold_count == 0 && ptepg->wire_count == 0) {
pmap_page_protect( VM_PAGE_TO_PHYS(ptepg),
VM_PROT_NONE);
vm_page_free(ptepg);
}
--p->p_lock;
} else {
/*
* Since we know that kernel virtual address addresses
* always have pte pages mapped, we just have to fault
* the page.
*/
rv = vm_fault(map, va, ftype, FALSE);
}
if (rv == KERN_SUCCESS) {
if (type == T_PAGEFLT)
return;
goto out;
}
nogo:
if (type == T_PAGEFLT) {
if (curpcb->pcb_onfault)
goto copyfault;
goto we_re_toast;
}
i = (rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV;
/* kludge to pass faulting virtual address to sendsig */
ucode = type &~ T_USER;
frame.tf_err = eva;
break;
}
#if NDDB == 0
case T_TRCTRAP: /* trace trap -- someone single stepping lcall's */
frame.tf_eflags &= ~PSL_T;
/* Q: how do we turn it on again? */
return;
#endif
case T_BPTFLT|T_USER: /* bpt instruction fault */
case T_TRCTRAP|T_USER: /* trace trap */
frame.tf_eflags &= ~PSL_T;
i = SIGTRAP;
break;
#if NISA > 0
case T_NMI:
case T_NMI|T_USER:
#if NDDB > 0
/* NMI can be hooked up to a pushbutton for debugging */
printf ("NMI ... going to debugger\n");
if (kdb_trap (type, 0, &frame))
return;
#endif
/* machine/parity/power fail/"kitchen sink" faults */
if (isa_nmi(code) == 0) return;
/* FALL THROUGH */
#endif
default:
we_re_toast:
fault_type = type & ~T_USER;
#if NDDB > 0
if ((fault_type == T_BPTFLT) || (fault_type == T_TRCTRAP)) {
if (kdb_trap (type, 0, &frame))
return;
}
#endif
if (fault_type <= MAX_TRAP_MSG)
printf("\n\nFatal trap %d: %s while in %s mode\n",
fault_type, trap_msg[fault_type],
ISPL(frame.tf_cs) == SEL_UPL ? "user" : "kernel");
if (fault_type == T_PAGEFLT) {
printf("fault virtual address = 0x%x\n", eva);
printf("fault code = %s %s, %s\n",
code & PGEX_U ? "user" : "supervisor",
code & PGEX_W ? "write" : "read",
code & PGEX_P ? "protection violation" : "page not present");
}
printf("instruction pointer = 0x%x\n", frame.tf_eip);
printf("processor eflags = ");
if (frame.tf_eflags & EFL_TF)
printf("trace/trap, ");
if (frame.tf_eflags & EFL_IF)
printf("interrupt enabled, ");
if (frame.tf_eflags & EFL_NT)
printf("nested task, ");
if (frame.tf_eflags & EFL_RF)
printf("resume, ");
if (frame.tf_eflags & EFL_VM)
printf("vm86, ");
printf("IOPL = %d\n", (frame.tf_eflags & EFL_IOPL) >> 12);
printf("current process = ");
if (curproc) {
printf("%d (%s)\n",
curproc->p_pid, curproc->p_comm ?
curproc->p_comm : "");
} else {
printf("Idle\n");
}
printf("interrupt mask = ");
if ((cpl & net_imask) == net_imask)
printf("net ");
if ((cpl & tty_imask) == tty_imask)
printf("tty ");
if ((cpl & bio_imask) == bio_imask)
printf("bio ");
if (cpl == 0)
printf("none");
printf("\n");
#ifdef KDB
if (kdb_trap(&psl))
return;
#endif
#if NDDB > 0
if (kdb_trap (type, 0, &frame))
return;
#endif
if (fault_type <= MAX_TRAP_MSG)
panic(trap_msg[fault_type]);
else
panic("unknown/reserved trap");
/* NOTREACHED */
}
trapsignal(p, i, ucode);
if ((type & T_USER) == 0)
return;
#ifdef DIAGNOSTIC
fault_type = type & ~T_USER;
if (fault_type <= MAX_TRAP_MSG) {
uprintf("fatal process exception: %s",
trap_msg[fault_type]);
if ((fault_type == T_PAGEFLT) || (fault_type == T_PROTFLT))
uprintf(", fault VA = 0x%x", eva);
uprintf("\n");
}
#endif
out:
while (i = CURSIG(p))
postsig(i);
while (sig = CURSIG(p))
postsig(sig);
p->p_priority = p->p_usrpri;
if (want_resched) {
int s;
/*
* Since we are curproc, clock will normally just change
* our priority without moving us from one queue to another
@ -495,25 +135,390 @@ out:
p->p_stats->p_ru.ru_nivcsw++;
mi_switch();
splx(s);
while (i = CURSIG(p))
postsig(i);
while (sig = CURSIG(p))
postsig(sig);
}
if (p->p_stats->p_prof.pr_scale) {
u_quad_t ticks = p->p_sticks - sticks;
u_quad_t ticks = p->p_sticks - oticks;
if (ticks) {
#ifdef PROFTIMER
extern int profscale;
addupc(frame.tf_eip, &p->p_stats->p_prof,
addupc(frame->tf_eip, &p->p_stats->p_prof,
ticks * profscale);
#else
addupc(frame.tf_eip, &p->p_stats->p_prof, ticks);
addupc(frame->tf_eip, &p->p_stats->p_prof, ticks);
#endif
}
}
curpriority = p->p_priority;
}
/*
* trap(frame):
* Exception, fault, and trap interface to the FreeBSD kernel.
* This common code is called from assembly language IDT gate entry
* routines that prepare a suitable stack frame, and restore this
* frame after the exception has been processed.
*/
/*ARGSUSED*/
void
trap(frame)
struct trapframe frame;
{
struct proc *p = curproc;
u_quad_t sticks = 0;
int i = 0, ucode = 0, type, code, eva, fault_type;
frame.tf_eflags &= ~PSL_NT; /* clear nested trap XXX */
type = frame.tf_trapno;
code = frame.tf_err;
if (ISPL(frame.tf_cs) == SEL_UPL) {
/* user trap */
sticks = p->p_sticks;
p->p_md.md_regs = (int *)&frame;
switch (type) {
case T_RESADFLT: /* reserved addressing fault */
case T_PRIVINFLT: /* privileged instruction fault */
case T_RESOPFLT: /* reserved operand fault */
ucode = type;
i = SIGILL;
break;
case T_BPTFLT: /* bpt instruction fault */
case T_TRCTRAP: /* trace trap */
frame.tf_eflags &= ~PSL_T;
i = SIGTRAP;
break;
case T_ARITHTRAP: /* arithmetic trap */
ucode = code;
i = SIGFPE;
break;
case T_ASTFLT: /* Allow process switch */
astoff();
cnt.v_soft++;
if ((p->p_flag & P_OWEUPC) && p->p_stats->p_prof.pr_scale) {
addupc(frame.tf_eip, &p->p_stats->p_prof, 1);
p->p_flag &= ~P_OWEUPC;
}
goto out;
case T_PROTFLT: /* general protection fault */
case T_SEGNPFLT: /* segment not present fault */
case T_STKFLT: /* stack fault */
ucode = code + BUS_SEGM_FAULT ;
i = SIGBUS;
break;
case T_PAGEFLT: /* page fault */
i = trap_pfault(&frame, TRUE);
if (i == 0)
goto out;
ucode = T_PAGEFLT;
break;
case T_DIVIDE: /* integer divide fault */
ucode = FPE_INTDIV_TRAP;
i = SIGFPE;
break;
#if NISA > 0
case T_NMI:
#if NDDB > 0
/* NMI can be hooked up to a pushbutton for debugging */
printf ("NMI ... going to debugger\n");
if (kdb_trap (type, 0, &frame))
return;
#endif
/* machine/parity/power fail/"kitchen sink" faults */
if (isa_nmi(code) == 0) return;
/* FALL THROUGH */
#endif
case T_OFLOW: /* integer overflow fault */
ucode = FPE_INTOVF_TRAP;
i = SIGFPE;
break;
case T_BOUND: /* bounds check fault */
ucode = FPE_SUBRNG_TRAP;
i = SIGFPE;
break;
case T_DNA:
#if NNPX > 0
/* if a transparent fault (due to context switch "late") */
if (npxdna())
return;
#endif /* NNPX > 0 */
#if defined(MATH_EMULATE) || defined(GPL_MATH_EMULATE)
i = math_emulate(&frame);
if (i == 0) return;
#else /* MATH_EMULATE || GPL_MATH_EMULATE */
panic("trap: math emulation necessary!");
#endif /* MATH_EMULATE || GPL_MATH_EMULATE */
ucode = FPE_FPU_NP_TRAP;
break;
case T_FPOPFLT: /* FPU operand fetch fault */
ucode = T_FPOPFLT;
i = SIGILL;
break;
default:
trap_fatal(&frame);
}
} else {
/* kernel trap */
switch (type) {
case T_PAGEFLT: /* page fault */
(void) trap_pfault(&frame, FALSE);
return;
case T_PROTFLT: /* general protection fault */
case T_SEGNPFLT: /* segment not present fault */
if (curpcb && curpcb->pcb_onfault) {
frame.tf_eip = (int)curpcb->pcb_onfault;
return;
}
break;
#if NDDB > 0
case T_BPTFLT:
case T_TRCTRAP:
if (kdb_trap (type, 0, &frame))
return;
break;
#else
case T_TRCTRAP: /* trace trap -- someone single stepping lcall's */
/* Q: how do we turn it on again? */
frame.tf_eflags &= ~PSL_T;
return;
#endif
#if NISA > 0
case T_NMI:
#if NDDB > 0
/* NMI can be hooked up to a pushbutton for debugging */
printf ("NMI ... going to debugger\n");
if (kdb_trap (type, 0, &frame))
return;
#endif
/* machine/parity/power fail/"kitchen sink" faults */
if (isa_nmi(code) == 0) return;
/* FALL THROUGH */
#endif
}
trap_fatal(&frame);
}
trapsignal(p, i, ucode);
#ifdef DIAGNOSTIC
eva = rcr2();
if (type <= MAX_TRAP_MSG) {
uprintf("fatal process exception: %s",
trap_msg[type]);
if ((type == T_PAGEFLT) || (type == T_PROTFLT))
uprintf(", fault VA = 0x%x", eva);
uprintf("\n");
}
#endif
out:
userret(p, &frame, sticks);
}
int
trap_pfault(frame, usermode)
struct trapframe *frame;
int usermode;
{
vm_offset_t va;
struct vmspace *vm;
vm_map_t map = 0;
int rv = 0, oldflags;
vm_prot_t ftype;
extern vm_map_t kernel_map;
int eva;
struct proc *p = curproc;
eva = rcr2();
va = trunc_page((vm_offset_t)eva);
/*
* Don't allow user-mode faults in kernel address space
*/
if (usermode && (va >= KERNBASE)) {
goto nogo;
}
if ((p == 0) || (va >= KERNBASE)) {
vm = 0;
map = kernel_map;
} else {
vm = p->p_vmspace;
map = &vm->vm_map;
}
if (frame->tf_err & PGEX_W)
ftype = VM_PROT_READ | VM_PROT_WRITE;
else
ftype = VM_PROT_READ;
if (map != kernel_map) {
vm_offset_t pa;
vm_offset_t v = (vm_offset_t) vtopte(va);
vm_page_t ptepg;
/*
* Keep swapout from messing with us during this
* critical time.
*/
++p->p_lock;
/*
* Grow the stack if necessary
*/
if ((caddr_t)va > vm->vm_maxsaddr
&& (caddr_t)va < (caddr_t)USRSTACK) {
if (!grow(p, va)) {
rv = KERN_FAILURE;
--p->p_lock;
goto nogo;
}
}
/*
* Check if page table is mapped, if not,
* fault it first
*/
/* Fault the pte only if needed: */
*(volatile char *)v += 0;
ptepg = (vm_page_t) pmap_pte_vm_page(vm_map_pmap(map), v);
vm_page_hold(ptepg);
/* Fault in the user page: */
rv = vm_fault(map, va, ftype, FALSE);
vm_page_unhold(ptepg);
/*
* page table pages don't need to be kept if they
* are not held
*/
if( ptepg->hold_count == 0 && ptepg->wire_count == 0) {
pmap_page_protect( VM_PAGE_TO_PHYS(ptepg),
VM_PROT_NONE);
vm_page_free(ptepg);
}
--p->p_lock;
} else {
/*
* Since we know that kernel virtual address addresses
* always have pte pages mapped, we just have to fault
* the page.
*/
rv = vm_fault(map, va, ftype, FALSE);
}
if (rv == KERN_SUCCESS)
return (0);
nogo:
if (!usermode) {
if (curpcb->pcb_onfault) {
frame->tf_eip = (int)curpcb->pcb_onfault;
return (0);
}
trap_fatal(frame);
}
/* kludge to pass faulting virtual address to sendsig */
frame->tf_err = eva;
return((rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV);
}
void
trap_fatal(frame)
struct trapframe *frame;
{
int code, type, eva;
code = frame->tf_err;
type = frame->tf_trapno;
eva = rcr2();
if (type <= MAX_TRAP_MSG)
printf("\n\nFatal trap %d: %s while in %s mode\n",
type, trap_msg[type],
ISPL(frame->tf_cs) == SEL_UPL ? "user" : "kernel");
if (type == T_PAGEFLT) {
printf("fault virtual address = 0x%x\n", eva);
printf("fault code = %s %s, %s\n",
code & PGEX_U ? "user" : "supervisor",
code & PGEX_W ? "write" : "read",
code & PGEX_P ? "protection violation" : "page not present");
}
printf("instruction pointer = 0x%x\n", frame->tf_eip);
printf("processor eflags = ");
if (frame->tf_eflags & EFL_TF)
printf("trace/trap, ");
if (frame->tf_eflags & EFL_IF)
printf("interrupt enabled, ");
if (frame->tf_eflags & EFL_NT)
printf("nested task, ");
if (frame->tf_eflags & EFL_RF)
printf("resume, ");
if (frame->tf_eflags & EFL_VM)
printf("vm86, ");
printf("IOPL = %d\n", (frame->tf_eflags & EFL_IOPL) >> 12);
printf("current process = ");
if (curproc) {
printf("%d (%s)\n",
curproc->p_pid, curproc->p_comm ?
curproc->p_comm : "");
} else {
printf("Idle\n");
}
printf("interrupt mask = ");
if ((cpl & net_imask) == net_imask)
printf("net ");
if ((cpl & tty_imask) == tty_imask)
printf("tty ");
if ((cpl & bio_imask) == bio_imask)
printf("bio ");
if (cpl == 0)
printf("none");
printf("\n");
#ifdef KDB
if (kdb_trap(&psl))
return;
#endif
#if NDDB > 0
if (kdb_trap (type, 0, frame))
return;
#endif
if (type <= MAX_TRAP_MSG)
panic(trap_msg[type]);
else
panic("unknown/reserved trap");
}
/*
* Compensate for 386 brain damage (missing URKR).
* This is a little simpler than the pagefault handler in trap() because
@ -586,21 +591,17 @@ int trapwrite(addr)
/*ARGSUSED*/
void
syscall(frame)
volatile struct trapframe frame;
struct trapframe frame;
{
register int *locr0 = ((int *)&frame);
register caddr_t params;
register int i;
register struct sysent *callp;
register struct proc *p = curproc;
caddr_t params;
int i;
struct sysent *callp;
struct proc *p = curproc;
u_quad_t sticks;
int error, opc;
int args[8], rval[2];
u_int code;
#ifdef lint
r0 = 0; r0 = r0; r1 = 0; r1 = r1;
#endif
sticks = p->p_sticks;
if (ISPL(frame.tf_cs) != SEL_UPL)
panic("syscall");
@ -638,13 +639,11 @@ syscall(frame)
if ((i = callp->sy_narg * sizeof (int)) &&
(error = copyin(params, (caddr_t)args, (u_int)i))) {
frame.tf_eax = error;
frame.tf_eflags |= PSL_C; /* carry bit */
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSCALL))
ktrsyscall(p->p_tracep, code, callp->sy_narg, args);
#endif
goto done;
goto bad;
}
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSCALL))
@ -652,64 +651,38 @@ syscall(frame)
#endif
rval[0] = 0;
rval[1] = frame.tf_edx;
/*pg("%d. s %d\n", p->p_pid, code);*/
error = (*callp->sy_call)(p, args, rval);
if (error == ERESTART)
frame.tf_eip = opc;
else if (error != EJUSTRETURN) {
if (error) {
/*pg("error %d", error);*/
frame.tf_eax = error;
frame.tf_eflags |= PSL_C; /* carry bit */
} else {
frame.tf_eax = rval[0];
frame.tf_edx = rval[1];
frame.tf_eflags &= ~PSL_C; /* carry bit */
}
}
/* else if (error == EJUSTRETURN) */
/* nothing to do */
done:
/*
* Reinitialize proc pointer `p' as it may be different
* if this is a child returning from fork syscall.
*/
p = curproc;
while (i = CURSIG(p))
postsig(i);
p->p_priority = p->p_usrpri;
if (want_resched) {
int s;
/*
* Since we are curproc, clock will normally just change
* our priority without moving us from one queue to another
* (since the running process is not on a queue.)
* If that happened after we setrunqueue ourselves but before we
* swtch()'ed, we might not be on the queue indicated by
* our priority.
*/
s = splclock();
setrunqueue(p);
p->p_stats->p_ru.ru_nivcsw++;
mi_switch();
splx(s);
while (i = CURSIG(p))
postsig(i);
}
if (p->p_stats->p_prof.pr_scale) {
u_quad_t ticks = p->p_sticks - sticks;
if (ticks) {
#ifdef PROFTIMER
extern int profscale;
addupc(frame.tf_eip, &p->p_stats->p_prof,
ticks * profscale);
#else
addupc(frame.tf_eip, &p->p_stats->p_prof, ticks);
#endif
}
error = (*callp->sy_call)(p, args, rval);
switch (error) {
case 0:
/*
* Reinitialize proc pointer `p' as it may be different
* if this is a child returning from fork syscall.
*/
p = curproc;
frame.tf_eax = rval[0];
frame.tf_edx = rval[1];
frame.tf_eflags &= ~PSL_C; /* carry bit */
break;
case ERESTART:
frame.tf_eip = opc;
break;
case EJUSTRETURN:
break;
default:
bad:
frame.tf_eax = error;
frame.tf_eflags |= PSL_C; /* carry bit */
break;
}
curpriority = p->p_priority;
userret(p, &frame, sticks);
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSRET))
ktrsysret(p->p_tracep, code, error, rval[0]);