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freebsd-skq/sys/kern/subr_trap.c
Bruce Evans 029b0fc88f Fix tracing of syscalls. The previous fix required the undocumented 
option DDB_NO_LCALLS to stop ddb getting control and broke all ddb
tracing.  Now there is no option and no way for ddb to trace at
address _Xsyscall or to _Xsyscall, but tracing everywhere else
works.  The previous fix did unnecessary things for Linux syscalls.

Don't bother checking that syscall frames are for user mode.

Make debugger traps inside the kernel (except at addresses _Xsyscall
and _Xsyscall+1) fatal if ddb is not configured.  They "can't happen".

Add prototypes.

Remove stupid comments, e.g., /*ARGSUSED*/ for args that are used.
1995-10-09 04:36:01 +00:00

1024 lines
23 KiB
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/*-
* 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.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* from: @(#)trap.c 7.4 (Berkeley) 5/13/91
* $Id: trap.c,v 1.60 1995/10/04 07:07:44 julian Exp $
*/
/*
* 386 Trap and System call handling
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/user.h>
#include <sys/acct.h>
#include <sys/kernel.h>
#include <sys/syscall.h>
#include <sys/sysent.h>
#ifdef KTRACE
#include <sys/ktrace.h>
#endif
#include <vm/vm_param.h>
#include <vm/pmap.h>
#include <vm/vm_kern.h>
#include <vm/vm_map.h>
#include <vm/vm_page.h>
#include <machine/cpu.h>
#include <machine/md_var.h>
#include <machine/psl.h>
#include <machine/reg.h>
#include <machine/trap.h>
#include <machine/../isa/isa_device.h>
#ifdef POWERFAIL_NMI
# include <syslog.h>
# include <machine/clock.h>
#endif
#include "isa.h"
#include "npx.h"
extern void trap __P((struct trapframe frame));
extern int trapwrite __P((unsigned addr));
extern void syscall __P((struct trapframe frame));
extern void linux_syscall __P((struct trapframe frame));
int trap_pfault __P((struct trapframe *, int));
void trap_fatal __P((struct trapframe *));
extern inthand_t IDTVEC(syscall);
#define MAX_TRAP_MSG 27
char *trap_msg[] = {
"", /* 0 unused */
"privileged instruction fault", /* 1 T_PRIVINFLT */
"", /* 2 unused */
"breakpoint instruction fault", /* 3 T_BPTFLT */
"", /* 4 unused */
"", /* 5 unused */
"arithmetic trap", /* 6 T_ARITHTRAP */
"system forced exception", /* 7 T_ASTFLT */
"", /* 8 unused */
"general protection fault", /* 9 T_PROTFLT */
"trace trap", /* 10 T_TRCTRAP */
"", /* 11 unused */
"page fault", /* 12 T_PAGEFLT */
"", /* 13 unused */
"alignment fault", /* 14 T_ALIGNFLT */
"", /* 15 unused */
"", /* 16 unused */
"", /* 17 unused */
"integer divide fault", /* 18 T_DIVIDE */
"non-maskable interrupt trap", /* 19 T_NMI */
"overflow trap", /* 20 T_OFLOW */
"FPU bounds check fault", /* 21 T_BOUND */
"FPU device not available", /* 22 T_DNA */
"double fault", /* 23 T_DOUBLEFLT */
"FPU operand fetch fault", /* 24 T_FPOPFLT */
"invalid TSS fault", /* 25 T_TSSFLT */
"segment not present fault", /* 26 T_SEGNPFLT */
"stack fault", /* 27 T_STKFLT */
};
static void userret __P((struct proc *p, struct trapframe *frame,
u_quad_t oticks));
static inline void
userret(p, frame, oticks)
struct proc *p;
struct trapframe *frame;
u_quad_t oticks;
{
int sig, s;
while ((sig = CURSIG(p)) != 0)
postsig(sig);
p->p_priority = p->p_usrpri;
if (want_resched) {
/*
* 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
* mi_switch()'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 ((sig = CURSIG(p)) != 0)
postsig(sig);
}
/*
* Charge system time if profiling.
*/
if (p->p_flag & P_PROFIL) {
u_quad_t ticks = p->p_sticks - oticks;
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
}
}
curpriority = p->p_priority;
}
/*
* 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.
*/
void
trap(frame)
struct trapframe frame;
{
struct proc *p = curproc;
u_quad_t sticks = 0;
int i = 0, ucode = 0, type, code;
#ifdef DIAGNOSTIC
u_long eva;
#endif
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_PRIVINFLT: /* privileged instruction 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) {
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 */
case T_TSSFLT: /* invalid TSS fault */
case T_DOUBLEFLT: /* double fault */
default:
ucode = code + BUS_SEGM_FAULT ;
i = SIGBUS;
break;
case T_PAGEFLT: /* page fault */
i = trap_pfault(&frame, TRUE);
if (i == -1)
return;
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:
#ifdef POWERFAIL_NMI
goto handle_powerfail;
#else /* !POWERFAIL_NMI */
#ifdef DDB
/* NMI can be hooked up to a pushbutton for debugging */
printf ("NMI ... going to debugger\n");
if (kdb_trap (type, 0, &frame))
return;
#endif /* DDB */
/* machine/parity/power fail/"kitchen sink" faults */
if (isa_nmi(code) == 0) return;
panic("NMI indicates hardware failure");
#endif /* POWERFAIL_NMI */
#endif /* NISA > 0 */
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) {
if (!(frame.tf_eflags & PSL_T))
return;
frame.tf_eflags &= ~PSL_T;
i = SIGTRAP;
}
/* else ucode = emulator_only_knows() XXX */
#else /* MATH_EMULATE || GPL_MATH_EMULATE */
i = SIGFPE;
ucode = FPE_FPU_NP_TRAP;
#endif /* MATH_EMULATE || GPL_MATH_EMULATE */
break;
case T_FPOPFLT: /* FPU operand fetch fault */
ucode = T_FPOPFLT;
i = SIGILL;
break;
}
} 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 */
/*
* Invalid segment selectors and out of bounds
* %eip's and %esp's can be set up in user mode.
* This causes a fault in kernel mode when the
* kernel tries to return to user mode. We want
* to get this fault so that we can fix the
* problem here and not have to check all the
* selectors and pointers when the user changes
* them.
*/
#define MAYBE_DORETI_FAULT(where, whereto) \
do { \
if (frame.tf_eip == (int)where) { \
frame.tf_eip = (int)whereto; \
return; \
} \
} while (0)
if (intr_nesting_level == 0) {
MAYBE_DORETI_FAULT(doreti_iret,
doreti_iret_fault);
MAYBE_DORETI_FAULT(doreti_popl_ds,
doreti_popl_ds_fault);
MAYBE_DORETI_FAULT(doreti_popl_es,
doreti_popl_es_fault);
}
if (curpcb && curpcb->pcb_onfault) {
frame.tf_eip = (int)curpcb->pcb_onfault;
return;
}
break;
case T_TSSFLT:
/*
* PSL_NT can be set in user mode and isn't cleared
* automatically when the kernel is entered. This
* causes a TSS fault when the kernel attempts to
* `iret' because the TSS link is uninitialized. We
* want to get this fault so that we can fix the
* problem here and not every time the kernel is
* entered.
*/
if (frame.tf_eflags & PSL_NT) {
frame.tf_eflags &= ~PSL_NT;
return;
}
break;
case T_TRCTRAP: /* trace trap */
if (frame.tf_eip == (int)IDTVEC(syscall)) {
/*
* We've just entered system mode via the
* syscall lcall. Continue single stepping
* silently until the syscall handler has
* saved the flags.
*/
return;
}
if (frame.tf_eip == (int)IDTVEC(syscall) + 1) {
/*
* The syscall handler has now saved the
* flags. Stop single stepping it.
*/
frame.tf_eflags &= ~PSL_T;
return;
}
/*
* Fall through.
*/
case T_BPTFLT:
/*
* If DDB is enabled, let it handle the debugger trap.
* Otherwise, debugger traps "can't happen".
*/
#ifdef DDB
if (kdb_trap (type, 0, &frame))
return;
#endif
break;
#if NISA > 0
case T_NMI:
#ifdef POWERFAIL_NMI
#ifndef TIMER_FREQ
# define TIMER_FREQ 1193182
#endif
handle_powerfail:
{
static unsigned lastalert = 0;
if(time.tv_sec - lastalert > 10)
{
log(LOG_WARNING, "NMI: power fail\n");
sysbeep(TIMER_FREQ/880, hz);
lastalert = time.tv_sec;
}
return;
}
#else /* !POWERFAIL_NMI */
#ifdef DDB
/* NMI can be hooked up to a pushbutton for debugging */
printf ("NMI ... going to debugger\n");
if (kdb_trap (type, 0, &frame))
return;
#endif /* DDB */
/* machine/parity/power fail/"kitchen sink" faults */
if (isa_nmi(code) == 0) return;
/* FALL THROUGH */
#endif /* POWERFAIL_NMI */
#endif /* NISA > 0 */
}
trap_fatal(&frame);
return;
}
trapsignal(p, i, ucode);
#ifdef DEBUG
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);
}
#ifdef notyet
/*
* This version doesn't allow a page fault to user space while
* in the kernel. The rest of the kernel needs to be made "safe"
* before this can be used. I think the only things remaining
* to be made safe are the iBCS2 code and the process tracing/
* debugging code.
*/
int
trap_pfault(frame, usermode)
struct trapframe *frame;
int usermode;
{
vm_offset_t va;
struct vmspace *vm = NULL;
vm_map_t map = 0;
int rv = 0;
vm_prot_t ftype;
int eva;
struct proc *p = curproc;
if (frame->tf_err & PGEX_W)
ftype = VM_PROT_READ | VM_PROT_WRITE;
else
ftype = VM_PROT_READ;
eva = rcr2();
va = trunc_page((vm_offset_t)eva);
if (va < VM_MIN_KERNEL_ADDRESS) {
vm_offset_t v;
vm_page_t ptepg;
if (p == NULL ||
(!usermode && va < VM_MAXUSER_ADDRESS &&
(curpcb == NULL || curpcb->pcb_onfault == NULL))) {
trap_fatal(frame);
return (-1);
}
/*
* This is a fault on non-kernel virtual memory.
* vm is initialized above to NULL. If curproc is NULL
* or curproc->p_vmspace is NULL the fault is fatal.
*/
vm = p->p_vmspace;
if (vm == NULL)
goto nogo;
map = &vm->vm_map;
/*
* 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
*/
v = (vm_offset_t) vtopte(va);
/* Fault the pte only if needed: */
if (*((int *)vtopte(v)) == 0)
(void) vm_fault(map, trunc_page(v), VM_PROT_WRITE, FALSE);
pmap_use_pt( vm_map_pmap(map), va);
/* Fault in the user page: */
rv = vm_fault(map, va, ftype, FALSE);
pmap_unuse_pt( vm_map_pmap(map), va);
--p->p_lock;
} else {
/*
* Don't allow user-mode faults in kernel address space.
*/
if (usermode)
goto nogo;
/*
* Since we know that kernel virtual address addresses
* always have pte pages mapped, we just have to fault
* the page.
*/
rv = vm_fault(kernel_map, va, ftype, FALSE);
}
if (rv == KERN_SUCCESS)
return (0);
nogo:
if (!usermode) {
if (curpcb && curpcb->pcb_onfault) {
frame->tf_eip = (int)curpcb->pcb_onfault;
return (0);
}
trap_fatal(frame);
return (-1);
}
/* kludge to pass faulting virtual address to sendsig */
frame->tf_err = eva;
return((rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV);
}
#endif
int
trap_pfault(frame, usermode)
struct trapframe *frame;
int usermode;
{
vm_offset_t va;
struct vmspace *vm = NULL;
vm_map_t map = 0;
int rv = 0;
vm_prot_t ftype;
int eva;
struct proc *p = curproc;
eva = rcr2();
va = trunc_page((vm_offset_t)eva);
if (va >= KERNBASE) {
/*
* Don't allow user-mode faults in kernel address space.
*/
if (usermode)
goto nogo;
map = kernel_map;
} else {
/*
* This is a fault on non-kernel virtual memory.
* vm is initialized above to NULL. If curproc is NULL
* or curproc->p_vmspace is NULL the fault is fatal.
*/
if (p != NULL)
vm = p->p_vmspace;
if (vm == NULL)
goto nogo;
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 v;
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
*/
v = (vm_offset_t) vtopte(va);
/* Fault the pte only if needed: */
if (*((int *)vtopte(v)) == 0)
(void) vm_fault(map, trunc_page(v), VM_PROT_WRITE, FALSE);
pmap_use_pt( vm_map_pmap(map), va);
/* Fault in the user page: */
rv = vm_fault(map, va, ftype, FALSE);
pmap_unuse_pt( vm_map_pmap(map), va);
--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 && curpcb->pcb_onfault) {
frame->tf_eip = (int)curpcb->pcb_onfault;
return (0);
}
trap_fatal(frame);
return (-1);
}
/* 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;
struct soft_segment_descriptor softseg;
code = frame->tf_err;
type = frame->tf_trapno;
eva = rcr2();
sdtossd(&gdt[IDXSEL(frame->tf_cs & 0xffff)].sd, &softseg);
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:0x%x\n", frame->tf_cs & 0xffff, frame->tf_eip);
printf("code segment = base 0x%x, limit 0x%x, type 0x%x\n",
softseg.ssd_base, softseg.ssd_limit, softseg.ssd_type);
printf(" = DPL %d, pres %d, def32 %d, gran %d\n",
softseg.ssd_dpl, softseg.ssd_p, softseg.ssd_def32, softseg.ssd_gran);
printf("processor eflags = ");
if (frame->tf_eflags & PSL_T)
printf("trace/trap, ");
if (frame->tf_eflags & PSL_I)
printf("interrupt enabled, ");
if (frame->tf_eflags & PSL_NT)
printf("nested task, ");
if (frame->tf_eflags & PSL_RF)
printf("resume, ");
if (frame->tf_eflags & PSL_VM)
printf("vm86, ");
printf("IOPL = %d\n", (frame->tf_eflags & PSL_IOPL) >> 12);
printf("current process = ");
if (curproc) {
printf("%lu (%s)\n",
(u_long)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
#ifdef DDB
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
* it the page tables have already been faulted in and high addresses
* are thrown out early for other reasons.
*/
int trapwrite(addr)
unsigned addr;
{
struct proc *p;
vm_offset_t va, v;
struct vmspace *vm;
int rv;
va = trunc_page((vm_offset_t)addr);
/*
* XXX - MAX is END. Changed > to >= for temp. fix.
*/
if (va >= VM_MAXUSER_ADDRESS)
return (1);
p = curproc;
vm = p->p_vmspace;
++p->p_lock;
if ((caddr_t)va >= vm->vm_maxsaddr
&& (caddr_t)va < (caddr_t)USRSTACK) {
if (!grow(p, va)) {
--p->p_lock;
return (1);
}
}
v = trunc_page(vtopte(va));
/*
* wire the pte page
*/
if (va < USRSTACK) {
vm_map_pageable(&vm->vm_map, v, round_page(v+1), FALSE);
}
/*
* fault the data page
*/
rv = vm_fault(&vm->vm_map, va, VM_PROT_READ|VM_PROT_WRITE, FALSE);
/*
* unwire the pte page
*/
if (va < USRSTACK) {
vm_map_pageable(&vm->vm_map, v, round_page(v+1), TRUE);
}
--p->p_lock;
if (rv != KERN_SUCCESS)
return 1;
return (0);
}
/*
* System call request from POSIX system call gate interface to kernel.
* Like trap(), argument is call by reference.
*/
void
syscall(frame)
struct trapframe frame;
{
caddr_t params;
int i;
struct sysent *callp;
struct proc *p = curproc;
u_quad_t sticks;
int error;
int args[8], rval[2];
u_int code;
sticks = p->p_sticks;
if (ISPL(frame.tf_cs) != SEL_UPL)
panic("syscall");
p->p_md.md_regs = (int *)&frame;
params = (caddr_t)frame.tf_esp + sizeof(int);
code = frame.tf_eax;
/*
* Need to check if this is a 32 bit or 64 bit syscall.
*/
if (code == SYS_syscall) {
/*
* Code is first argument, followed by actual args.
*/
code = fuword(params);
params += sizeof(int);
} else if (code == SYS___syscall) {
/*
* Like syscall, but code is a quad, so as to maintain
* quad alignment for the rest of the arguments.
*/
code = fuword(params);
params += sizeof(quad_t);
}
if (p->p_sysent->sv_mask)
code &= p->p_sysent->sv_mask;
if (code >= p->p_sysent->sv_size)
callp = &p->p_sysent->sv_table[0];
else
callp = &p->p_sysent->sv_table[code];
if ((i = callp->sy_narg * sizeof(int)) &&
(error = copyin(params, (caddr_t)args, (u_int)i))) {
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSCALL))
ktrsyscall(p->p_tracep, code, callp->sy_narg, args);
#endif
goto bad;
}
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSCALL))
ktrsyscall(p->p_tracep, code, callp->sy_narg, args);
#endif
rval[0] = 0;
rval[1] = frame.tf_edx;
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;
break;
case ERESTART:
/*
* Reconstruct pc, assuming lcall $X,y is 7 bytes.
*/
frame.tf_eip -= 7;
break;
case EJUSTRETURN:
break;
default:
bad:
if (p->p_sysent->sv_errsize)
if (error >= p->p_sysent->sv_errsize)
error = -1; /* XXX */
else
error = p->p_sysent->sv_errtbl[error];
frame.tf_eax = error;
frame.tf_eflags |= PSL_C;
break;
}
if (frame.tf_eflags & PSL_T) {
/* Traced syscall. */
frame.tf_eflags &= ~PSL_T;
trapsignal(p, SIGTRAP, 0);
}
userret(p, &frame, sticks);
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSRET))
ktrsysret(p->p_tracep, code, error, rval[0]);
#endif
}
#ifdef COMPAT_LINUX
void
linux_syscall(frame)
struct trapframe frame;
{
int i;
struct proc *p = curproc;
struct sysent *callp;
u_quad_t sticks;
int error;
int rval[2];
u_int code;
struct linux_syscall_args {
int arg1;
int arg2;
int arg3;
int arg4;
int arg5;
} args;
args.arg1 = frame.tf_ebx;
args.arg2 = frame.tf_ecx;
args.arg3 = frame.tf_edx;
args.arg4 = frame.tf_esi;
args.arg5 = frame.tf_edi;
sticks = p->p_sticks;
if (ISPL(frame.tf_cs) != SEL_UPL)
panic("linux syscall");
p->p_md.md_regs = (int *)&frame;
code = frame.tf_eax;
if (p->p_sysent->sv_mask)
code &= p->p_sysent->sv_mask;
if (code >= p->p_sysent->sv_size)
callp = &p->p_sysent->sv_table[0];
else
callp = &p->p_sysent->sv_table[code];
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSCALL))
ktrsyscall(p->p_tracep, code, callp->sy_narg, (int *)&args);
#endif
rval[0] = 0;
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_eflags &= ~PSL_C;
break;
case ERESTART:
/* Reconstruct pc, subtract size of int 0x80 */
frame.tf_eip -= 2;
break;
case EJUSTRETURN:
break;
default:
if (p->p_sysent->sv_errsize)
if (error >= p->p_sysent->sv_errsize)
error = -1; /* XXX */
else
error = p->p_sysent->sv_errtbl[error];
frame.tf_eax = -error;
frame.tf_eflags |= PSL_C;
break;
}
if (frame.tf_eflags & PSL_T) {
/* Traced syscall. */
frame.tf_eflags &= ~PSL_T;
trapsignal(p, SIGTRAP, 0);
}
userret(p, &frame, sticks);
#ifdef KTRACE
if (KTRPOINT(p, KTR_SYSRET))
ktrsysret(p->p_tracep, code, error, rval[0]);
#endif
}
#endif /* COMPAT_LINUX */
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