void
trap(struct trapframe *frame)
{
#ifdef KDTRACE_HOOKS
struct reg regs;
#endif
struct thread *td = curthread;
struct proc *p = td->td_proc;
int i = 0, ucode = 0, code;
u_int type;
register_t addr = 0;
ksiginfo_t ksi;
PCPU_INC(cnt.v_trap);
type = frame->tf_trapno;
#ifdef SMP
/* Handler for NMI IPIs used for stopping CPUs. */
if (type == T_NMI) {
if (ipi_nmi_handler() == 0)
goto out;
}
#endif /* SMP */
#ifdef KDB
if (kdb_active) {
kdb_reenter();
goto out;
}
#endif
if (type == T_RESERVED) {
trap_fatal(frame, 0);
goto out;
}
#ifdef HWPMC_HOOKS
/*
* CPU PMCs interrupt using an NMI. If the PMC module is
* active, pass the 'rip' value to the PMC module's interrupt
* handler. A return value of '1' from the handler means that
* the NMI was handled by it and we can return immediately.
*/
if (type == T_NMI && pmc_intr &&
(*pmc_intr)(PCPU_GET(cpuid), frame))
goto out;
#endif
if (type == T_MCHK) {
mca_intr();
goto out;
}
#ifdef KDTRACE_HOOKS
/*
* A trap can occur while DTrace executes a probe. Before
* executing the probe, DTrace blocks re-scheduling and sets
* a flag in its per-cpu flags to indicate that it doesn't
* want to fault. On returning from the probe, the no-fault
* flag is cleared and finally re-scheduling is enabled.
*/
if (dtrace_trap_func != NULL && (*dtrace_trap_func)(frame, type))
goto out;
#endif
if ((frame->tf_rflags & PSL_I) == 0) {
/*
* Buggy application or kernel code has disabled
* interrupts and then trapped. Enabling interrupts
* now is wrong, but it is better than running with
* interrupts disabled until they are accidentally
* enabled later.
*/
if (ISPL(frame->tf_cs) == SEL_UPL)
uprintf(
"pid %ld (%s): trap %d with interrupts disabled\n",
(long)curproc->p_pid, curthread->td_name, type);
else if (type != T_NMI && type != T_BPTFLT &&
type != T_TRCTRAP) {
/*
* XXX not quite right, since this may be for a
* multiple fault in user mode.
*/
printf("kernel trap %d with interrupts disabled\n",
type);
/*
* We shouldn't enable interrupts while holding a
* spin lock.
*/
if (td->td_md.md_spinlock_count == 0)
enable_intr();
}
}
code = frame->tf_err;
if (ISPL(frame->tf_cs) == SEL_UPL) {
/* user trap */
td->td_pticks = 0;
td->td_frame = frame;
addr = frame->tf_rip;
if (td->td_ucred != p->p_ucred)
cred_update_thread(td);
switch (type) {
case T_PRIVINFLT: /* privileged instruction fault */
i = SIGILL;
ucode = ILL_PRVOPC;
break;
case T_BPTFLT: /* bpt instruction fault */
case T_TRCTRAP: /* trace trap */
enable_intr();
#ifdef KDTRACE_HOOKS
if (type == T_BPTFLT) {
fill_frame_regs(frame, ®s);
if (dtrace_pid_probe_ptr != NULL &&
dtrace_pid_probe_ptr(®s) == 0)
goto out;
}
#endif
frame->tf_rflags &= ~PSL_T;
i = SIGTRAP;
ucode = (type == T_TRCTRAP ? TRAP_TRACE : TRAP_BRKPT);
break;
case T_ARITHTRAP: /* arithmetic trap */
ucode = fputrap_x87();
if (ucode == -1)
goto userout;
i = SIGFPE;
break;
case T_PROTFLT: /* general protection fault */
i = SIGBUS;
ucode = BUS_OBJERR;
break;
case T_STKFLT: /* stack fault */
case T_SEGNPFLT: /* segment not present fault */
i = SIGBUS;
ucode = BUS_ADRERR;
break;
case T_TSSFLT: /* invalid TSS fault */
i = SIGBUS;
ucode = BUS_OBJERR;
break;
case T_DOUBLEFLT: /* double fault */
default:
i = SIGBUS;
ucode = BUS_OBJERR;
break;
case T_PAGEFLT: /* page fault */
addr = frame->tf_addr;
i = trap_pfault(frame, TRUE);
if (i == -1)
goto userout;
if (i == 0)
goto user;
if (i == SIGSEGV)
ucode = SEGV_MAPERR;
else {
if (prot_fault_translation == 0) {
/*
* Autodetect.
* This check also covers the images
* without the ABI-tag ELF note.
*/
if (SV_CURPROC_ABI() == SV_ABI_FREEBSD
&& p->p_osrel >= P_OSREL_SIGSEGV) {
i = SIGSEGV;
ucode = SEGV_ACCERR;
} else {
i = SIGBUS;
ucode = BUS_PAGE_FAULT;
}
} else if (prot_fault_translation == 1) {
/*
* Always compat mode.
*/
i = SIGBUS;
ucode = BUS_PAGE_FAULT;
} else {
/*
* Always SIGSEGV mode.
*/
i = SIGSEGV;
ucode = SEGV_ACCERR;
}
}
break;
case T_DIVIDE: /* integer divide fault */
ucode = FPE_INTDIV;
i = SIGFPE;
break;
#ifdef DEV_ISA
case T_NMI:
/* machine/parity/power fail/"kitchen sink" faults */
if (isa_nmi(code) == 0) {
#ifdef KDB
/*
* NMI can be hooked up to a pushbutton
* for debugging.
*/
if (kdb_on_nmi) {
printf ("NMI ... going to debugger\n");
kdb_trap(type, 0, frame);
}
#endif /* KDB */
goto userout;
} else if (panic_on_nmi)
panic("NMI indicates hardware failure");
break;
#endif /* DEV_ISA */
case T_OFLOW: /* integer overflow fault */
ucode = FPE_INTOVF;
i = SIGFPE;
break;
case T_BOUND: /* bounds check fault */
ucode = FPE_FLTSUB;
i = SIGFPE;
break;
case T_DNA:
/* transparent fault (due to context switch "late") */
KASSERT(PCB_USER_FPU(td->td_pcb),
("kernel FPU ctx has leaked"));
fpudna();
goto userout;
case T_FPOPFLT: /* FPU operand fetch fault */
ucode = ILL_COPROC;
i = SIGILL;
break;
case T_XMMFLT: /* SIMD floating-point exception */
ucode = fputrap_sse();
if (ucode == -1)
goto userout;
i = SIGFPE;
break;
#ifdef KDTRACE_HOOKS
case T_DTRACE_RET:
enable_intr();
fill_frame_regs(frame, ®s);
if (dtrace_return_probe_ptr != NULL &&
dtrace_return_probe_ptr(®s) == 0)
goto out;
break;
#endif
}
} else {
/* kernel trap */
KASSERT(cold || td->td_ucred != NULL,
("kernel trap doesn't have ucred"));
switch (type) {
case T_PAGEFLT: /* page fault */
(void) trap_pfault(frame, FALSE);
goto out;
case T_DNA:
KASSERT(!PCB_USER_FPU(td->td_pcb),
("Unregistered use of FPU in kernel"));
fpudna();
goto out;
case T_ARITHTRAP: /* arithmetic trap */
case T_XMMFLT: /* SIMD floating-point exception */
case T_FPOPFLT: /* FPU operand fetch fault */
/*
* XXXKIB for now disable any FPU traps in kernel
* handler registration seems to be overkill
*/
trap_fatal(frame, 0);
goto out;
case T_STKFLT: /* stack fault */
break;
case T_PROTFLT: /* general protection fault */
case T_SEGNPFLT: /* segment not present fault */
if (td->td_intr_nesting_level != 0)
break;
/*
* Invalid segment selectors and out of bounds
* %rip's and %rsp'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.
*/
if (frame->tf_rip == (long)doreti_iret) {
frame->tf_rip = (long)doreti_iret_fault;
goto out;
}
if (frame->tf_rip == (long)ld_ds) {
frame->tf_rip = (long)ds_load_fault;
goto out;
}
if (frame->tf_rip == (long)ld_es) {
frame->tf_rip = (long)es_load_fault;
goto out;
}
if (frame->tf_rip == (long)ld_fs) {
frame->tf_rip = (long)fs_load_fault;
goto out;
}
if (frame->tf_rip == (long)ld_gs) {
frame->tf_rip = (long)gs_load_fault;
goto out;
}
if (frame->tf_rip == (long)ld_gsbase) {
frame->tf_rip = (long)gsbase_load_fault;
goto out;
}
if (frame->tf_rip == (long)ld_fsbase) {
frame->tf_rip = (long)fsbase_load_fault;
goto out;
}
if (curpcb->pcb_onfault != NULL) {
frame->tf_rip = (long)curpcb->pcb_onfault;
goto out;
}
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_rflags & PSL_NT) {
frame->tf_rflags &= ~PSL_NT;
goto out;
}
break;
case T_TRCTRAP: /* trace trap */
/*
* Ignore debug register trace traps due to
* accesses in the user's address space, which
* can happen under several conditions such as
* if a user sets a watchpoint on a buffer and
* then passes that buffer to a system call.
* We still want to get TRCTRAPS for addresses
* in kernel space because that is useful when
* debugging the kernel.
*/
if (user_dbreg_trap()) {
/*
* Reset breakpoint bits because the
* processor doesn't
*/
/* XXX check upper bits here */
load_dr6(rdr6() & 0xfffffff0);
goto out;
}
/*
* FALLTHROUGH (TRCTRAP kernel mode, kernel address)
*/
case T_BPTFLT:
/*
* If KDB is enabled, let it handle the debugger trap.
* Otherwise, debugger traps "can't happen".
*/
#ifdef KDB
if (kdb_trap(type, 0, frame))
goto out;
#endif
break;
#ifdef DEV_ISA
case T_NMI:
/* machine/parity/power fail/"kitchen sink" faults */
if (isa_nmi(code) == 0) {
#ifdef KDB
/*
* NMI can be hooked up to a pushbutton
* for debugging.
*/
if (kdb_on_nmi) {
printf ("NMI ... going to debugger\n");
kdb_trap(type, 0, frame);
}
#endif /* KDB */
goto out;
} else if (panic_on_nmi == 0)
goto out;
/* FALLTHROUGH */
#endif /* DEV_ISA */
}
trap_fatal(frame, 0);
goto out;
}
/* Translate fault for emulators (e.g. Linux) */
if (*p->p_sysent->sv_transtrap)
i = (*p->p_sysent->sv_transtrap)(i, type);
ksiginfo_init_trap(&ksi);
ksi.ksi_signo = i;
ksi.ksi_code = ucode;
ksi.ksi_trapno = type;
ksi.ksi_addr = (void *)addr;
if (uprintf_signal) {
uprintf("pid %d comm %s: signal %d err %lx code %d type %d "
"addr 0x%lx rsp 0x%lx rip 0x%lx "
"<%02x %02x %02x %02x %02x %02x %02x %02x>\n",
p->p_pid, p->p_comm, i, frame->tf_err, ucode, type, addr,
frame->tf_rsp, frame->tf_rip,
fubyte((void *)(frame->tf_rip + 0)),
fubyte((void *)(frame->tf_rip + 1)),
fubyte((void *)(frame->tf_rip + 2)),
fubyte((void *)(frame->tf_rip + 3)),
fubyte((void *)(frame->tf_rip + 4)),
fubyte((void *)(frame->tf_rip + 5)),
fubyte((void *)(frame->tf_rip + 6)),
fubyte((void *)(frame->tf_rip + 7)));
}
KASSERT((read_rflags() & PSL_I) != 0, ("interrupts disabled"));
trapsignal(td, &ksi);
user:
userret(td, frame);
KASSERT(PCB_USER_FPU(td->td_pcb),
("Return from trap with kernel FPU ctx leaked"));
userout:
out:
return;
}
void
trap(struct trapframe *frame)
{
struct thread *td = curthread;
struct proc *p = td->td_proc;
int i = 0, ucode = 0, code;
u_int type;
register_t addr = 0;
vm_offset_t eva;
ksiginfo_t ksi;
#ifdef POWERFAIL_NMI
static int lastalert = 0;
#endif
PCPU_INC(cnt.v_trap);
type = frame->tf_trapno;
#ifdef SMP
/* Handler for NMI IPIs used for stopping CPUs. */
if (type == T_NMI) {
if (ipi_nmi_handler() == 0)
goto out;
}
#endif /* SMP */
#ifdef KDB
if (kdb_active) {
kdb_reenter();
goto out;
}
#endif
if (type == T_RESERVED) {
trap_fatal(frame, 0);
goto out;
}
#ifdef HWPMC_HOOKS
/*
* CPU PMCs interrupt using an NMI so we check for that first.
* If the HWPMC module is active, 'pmc_hook' will point to
* the function to be called. A return value of '1' from the
* hook means that the NMI was handled by it and that we can
* return immediately.
*/
if (type == T_NMI && pmc_intr &&
(*pmc_intr)(PCPU_GET(cpuid), frame))
goto out;
#endif
if (type == T_MCHK) {
if (!mca_intr())
trap_fatal(frame, 0);
goto out;
}
#ifdef KDTRACE_HOOKS
/*
* A trap can occur while DTrace executes a probe. Before
* executing the probe, DTrace blocks re-scheduling and sets
* a flag in it's per-cpu flags to indicate that it doesn't
* want to fault. On returning from the probe, the no-fault
* flag is cleared and finally re-scheduling is enabled.
*
* If the DTrace kernel module has registered a trap handler,
* call it and if it returns non-zero, assume that it has
* handled the trap and modified the trap frame so that this
* function can return normally.
*/
if ((type == T_PROTFLT || type == T_PAGEFLT) &&
dtrace_trap_func != NULL)
if ((*dtrace_trap_func)(frame, type))
goto out;
if (type == T_DTRACE_PROBE || type == T_DTRACE_RET ||
type == T_BPTFLT) {
struct reg regs;
fill_frame_regs(frame, ®s);
if (type == T_DTRACE_PROBE &&
dtrace_fasttrap_probe_ptr != NULL &&
dtrace_fasttrap_probe_ptr(®s) == 0)
goto out;
if (type == T_BPTFLT &&
dtrace_pid_probe_ptr != NULL &&
dtrace_pid_probe_ptr(®s) == 0)
goto out;
if (type == T_DTRACE_RET &&
dtrace_return_probe_ptr != NULL &&
dtrace_return_probe_ptr(®s) == 0)
goto out;
}
#endif
if ((frame->tf_eflags & PSL_I) == 0) {
/*
* Buggy application or kernel code has disabled
* interrupts and then trapped. Enabling interrupts
* now is wrong, but it is better than running with
* interrupts disabled until they are accidentally
* enabled later.
*/
if (ISPL(frame->tf_cs) == SEL_UPL || (frame->tf_eflags & PSL_VM))
uprintf(
"pid %ld (%s): trap %d with interrupts disabled\n",
(long)curproc->p_pid, curthread->td_name, type);
else if (type != T_BPTFLT && type != T_TRCTRAP &&
frame->tf_eip != (int)cpu_switch_load_gs) {
/*
* XXX not quite right, since this may be for a
* multiple fault in user mode.
*/
printf("kernel trap %d with interrupts disabled\n",
type);
/*
* Page faults need interrupts disabled until later,
* and we shouldn't enable interrupts while holding
* a spin lock or if servicing an NMI.
*/
if (type != T_NMI && type != T_PAGEFLT &&
td->td_md.md_spinlock_count == 0)
enable_intr();
}
}
eva = 0;
code = frame->tf_err;
if (type == T_PAGEFLT) {
/*
* For some Cyrix CPUs, %cr2 is clobbered by
* interrupts. This problem is worked around by using
* an interrupt gate for the pagefault handler. We
* are finally ready to read %cr2 and then must
* reenable interrupts.
*
* If we get a page fault while in a critical section, then
* it is most likely a fatal kernel page fault. The kernel
* is already going to panic trying to get a sleep lock to
* do the VM lookup, so just consider it a fatal trap so the
* kernel can print out a useful trap message and even get
* to the debugger.
*
* If we get a page fault while holding a non-sleepable
* lock, then it is most likely a fatal kernel page fault.
* If WITNESS is enabled, then it's going to whine about
* bogus LORs with various VM locks, so just skip to the
* fatal trap handling directly.
*/
eva = rcr2();
if (td->td_critnest != 0 ||
WITNESS_CHECK(WARN_SLEEPOK | WARN_GIANTOK, NULL,
"Kernel page fault") != 0)
trap_fatal(frame, eva);
else
enable_intr();
}
if ((ISPL(frame->tf_cs) == SEL_UPL) ||
((frame->tf_eflags & PSL_VM) &&
!(PCPU_GET(curpcb)->pcb_flags & PCB_VM86CALL))) {
/* user trap */
td->td_pticks = 0;
td->td_frame = frame;
addr = frame->tf_eip;
if (td->td_ucred != p->p_ucred)
cred_update_thread(td);
switch (type) {
case T_PRIVINFLT: /* privileged instruction fault */
i = SIGILL;
ucode = ILL_PRVOPC;
break;
case T_BPTFLT: /* bpt instruction fault */
case T_TRCTRAP: /* trace trap */
enable_intr();
frame->tf_eflags &= ~PSL_T;
i = SIGTRAP;
ucode = (type == T_TRCTRAP ? TRAP_TRACE : TRAP_BRKPT);
break;
case T_ARITHTRAP: /* arithmetic trap */
#ifdef DEV_NPX
ucode = npxtrap();
if (ucode == -1)
goto userout;
#else
ucode = 0;
#endif
i = SIGFPE;
break;
/*
* The following two traps can happen in
* vm86 mode, and, if so, we want to handle
* them specially.
*/
case T_PROTFLT: /* general protection fault */
case T_STKFLT: /* stack fault */
if (frame->tf_eflags & PSL_VM) {
i = vm86_emulate((struct vm86frame *)frame);
if (i == 0)
goto user;
break;
}
i = SIGBUS;
ucode = (type == T_PROTFLT) ? BUS_OBJERR : BUS_ADRERR;
break;
case T_SEGNPFLT: /* segment not present fault */
i = SIGBUS;
ucode = BUS_ADRERR;
break;
case T_TSSFLT: /* invalid TSS fault */
i = SIGBUS;
ucode = BUS_OBJERR;
break;
case T_DOUBLEFLT: /* double fault */
default:
i = SIGBUS;
ucode = BUS_OBJERR;
break;
case T_PAGEFLT: /* page fault */
i = trap_pfault(frame, TRUE, eva);
#if defined(I586_CPU) && !defined(NO_F00F_HACK)
if (i == -2) {
/*
* The f00f hack workaround has triggered, so
* treat the fault as an illegal instruction
* (T_PRIVINFLT) instead of a page fault.
*/
type = frame->tf_trapno = T_PRIVINFLT;
/* Proceed as in that case. */
ucode = ILL_PRVOPC;
i = SIGILL;
break;
}
#endif
if (i == -1)
goto userout;
if (i == 0)
goto user;
if (i == SIGSEGV)
ucode = SEGV_MAPERR;
else {
if (prot_fault_translation == 0) {
/*
* Autodetect.
* This check also covers the images
* without the ABI-tag ELF note.
*/
if (SV_CURPROC_ABI() == SV_ABI_FREEBSD
&& p->p_osrel >= P_OSREL_SIGSEGV) {
i = SIGSEGV;
ucode = SEGV_ACCERR;
} else {
i = SIGBUS;
ucode = BUS_PAGE_FAULT;
}
} else if (prot_fault_translation == 1) {
/*
* Always compat mode.
*/
i = SIGBUS;
ucode = BUS_PAGE_FAULT;
} else {
/*
* Always SIGSEGV mode.
*/
i = SIGSEGV;
ucode = SEGV_ACCERR;
}
}
addr = eva;
break;
case T_DIVIDE: /* integer divide fault */
ucode = FPE_INTDIV;
i = SIGFPE;
break;
#ifdef DEV_ISA
case T_NMI:
#ifdef POWERFAIL_NMI
#ifndef TIMER_FREQ
# define TIMER_FREQ 1193182
#endif
if (time_second - lastalert > 10) {
log(LOG_WARNING, "NMI: power fail\n");
sysbeep(880, hz);
lastalert = time_second;
}
goto userout;
#else /* !POWERFAIL_NMI */
/* machine/parity/power fail/"kitchen sink" faults */
if (isa_nmi(code) == 0) {
#ifdef KDB
/*
* NMI can be hooked up to a pushbutton
* for debugging.
*/
if (kdb_on_nmi) {
printf ("NMI ... going to debugger\n");
kdb_trap(type, 0, frame);
}
#endif /* KDB */
goto userout;
} else if (panic_on_nmi)
panic("NMI indicates hardware failure");
break;
#endif /* POWERFAIL_NMI */
#endif /* DEV_ISA */
case T_OFLOW: /* integer overflow fault */
ucode = FPE_INTOVF;
i = SIGFPE;
break;
case T_BOUND: /* bounds check fault */
ucode = FPE_FLTSUB;
i = SIGFPE;
break;
case T_DNA:
#ifdef DEV_NPX
KASSERT(PCB_USER_FPU(td->td_pcb),
("kernel FPU ctx has leaked"));
/* transparent fault (due to context switch "late") */
if (npxdna())
goto userout;
#endif
uprintf("pid %d killed due to lack of floating point\n",
p->p_pid);
i = SIGKILL;
ucode = 0;
break;
case T_FPOPFLT: /* FPU operand fetch fault */
ucode = ILL_COPROC;
i = SIGILL;
break;
case T_XMMFLT: /* SIMD floating-point exception */
ucode = 0; /* XXX */
i = SIGFPE;
break;
}
} else {
/* kernel trap */
KASSERT(cold || td->td_ucred != NULL,
("kernel trap doesn't have ucred"));
switch (type) {
case T_PAGEFLT: /* page fault */
(void) trap_pfault(frame, FALSE, eva);
goto out;
case T_DNA:
#ifdef DEV_NPX
KASSERT(!PCB_USER_FPU(td->td_pcb),
("Unregistered use of FPU in kernel"));
if (npxdna())
goto out;
#endif
break;
case T_ARITHTRAP: /* arithmetic trap */
case T_XMMFLT: /* SIMD floating-point exception */
case T_FPOPFLT: /* FPU operand fetch fault */
/*
* XXXKIB for now disable any FPU traps in kernel
* handler registration seems to be overkill
*/
trap_fatal(frame, 0);
goto out;
/*
* The following two traps can happen in
* vm86 mode, and, if so, we want to handle
* them specially.
*/
case T_PROTFLT: /* general protection fault */
case T_STKFLT: /* stack fault */
if (frame->tf_eflags & PSL_VM) {
i = vm86_emulate((struct vm86frame *)frame);
if (i != 0)
/*
* returns to original process
*/
vm86_trap((struct vm86frame *)frame);
goto out;
}
if (type == T_STKFLT)
break;
/* FALL THROUGH */
case T_SEGNPFLT: /* segment not present fault */
if (PCPU_GET(curpcb)->pcb_flags & PCB_VM86CALL)
break;
/*
* Invalid %fs's and %gs's can be created using
* procfs or PT_SETREGS or by invalidating the
* underlying LDT entry. This causes a fault
* in kernel mode when the kernel attempts to
* switch contexts. Lose the bad context
* (XXX) so that we can continue, and generate
* a signal.
*/
if (frame->tf_eip == (int)cpu_switch_load_gs) {
PCPU_GET(curpcb)->pcb_gs = 0;
#if 0
PROC_LOCK(p);
kern_psignal(p, SIGBUS);
PROC_UNLOCK(p);
#endif
goto out;
}
if (td->td_intr_nesting_level != 0)
break;
/*
* 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.
*/
if (frame->tf_eip == (int)doreti_iret) {
frame->tf_eip = (int)doreti_iret_fault;
goto out;
}
if (frame->tf_eip == (int)doreti_popl_ds) {
frame->tf_eip = (int)doreti_popl_ds_fault;
goto out;
}
if (frame->tf_eip == (int)doreti_popl_es) {
frame->tf_eip = (int)doreti_popl_es_fault;
goto out;
}
if (frame->tf_eip == (int)doreti_popl_fs) {
frame->tf_eip = (int)doreti_popl_fs_fault;
goto out;
}
if (PCPU_GET(curpcb)->pcb_onfault != NULL) {
frame->tf_eip =
(int)PCPU_GET(curpcb)->pcb_onfault;
goto out;
}
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;
goto out;
}
break;
case T_TRCTRAP: /* trace trap */
if (frame->tf_eip == (int)IDTVEC(lcall_syscall)) {
/*
* We've just entered system mode via the
* syscall lcall. Continue single stepping
* silently until the syscall handler has
* saved the flags.
*/
goto out;
}
if (frame->tf_eip == (int)IDTVEC(lcall_syscall) + 1) {
/*
* The syscall handler has now saved the
* flags. Stop single stepping it.
*/
frame->tf_eflags &= ~PSL_T;
goto out;
}
/*
* Ignore debug register trace traps due to
* accesses in the user's address space, which
* can happen under several conditions such as
* if a user sets a watchpoint on a buffer and
* then passes that buffer to a system call.
* We still want to get TRCTRAPS for addresses
* in kernel space because that is useful when
* debugging the kernel.
*/
if (user_dbreg_trap() &&
!(PCPU_GET(curpcb)->pcb_flags & PCB_VM86CALL)) {
/*
* Reset breakpoint bits because the
* processor doesn't
*/
load_dr6(rdr6() & 0xfffffff0);
goto out;
}
/*
* FALLTHROUGH (TRCTRAP kernel mode, kernel address)
*/
case T_BPTFLT:
/*
* If KDB is enabled, let it handle the debugger trap.
* Otherwise, debugger traps "can't happen".
*/
#ifdef KDB
if (kdb_trap(type, 0, frame))
goto out;
#endif
break;
#ifdef DEV_ISA
case T_NMI:
#ifdef POWERFAIL_NMI
if (time_second - lastalert > 10) {
log(LOG_WARNING, "NMI: power fail\n");
sysbeep(880, hz);
lastalert = time_second;
}
goto out;
#else /* !POWERFAIL_NMI */
/* machine/parity/power fail/"kitchen sink" faults */
if (isa_nmi(code) == 0) {
#ifdef KDB
/*
* NMI can be hooked up to a pushbutton
* for debugging.
*/
if (kdb_on_nmi) {
printf ("NMI ... going to debugger\n");
kdb_trap(type, 0, frame);
}
#endif /* KDB */
goto out;
} else if (panic_on_nmi == 0)
goto out;
/* FALLTHROUGH */
#endif /* POWERFAIL_NMI */
#endif /* DEV_ISA */
}
trap_fatal(frame, eva);
goto out;
}
/* Translate fault for emulators (e.g. Linux) */
if (*p->p_sysent->sv_transtrap)
i = (*p->p_sysent->sv_transtrap)(i, type);
ksiginfo_init_trap(&ksi);
ksi.ksi_signo = i;
ksi.ksi_code = ucode;
ksi.ksi_addr = (void *)addr;
ksi.ksi_trapno = type;
trapsignal(td, &ksi);
#ifdef DEBUG
if (type <= MAX_TRAP_MSG) {
uprintf("fatal process exception: %s",
trap_msg[type]);
if ((type == T_PAGEFLT) || (type == T_PROTFLT))
uprintf(", fault VA = 0x%lx", (u_long)eva);
uprintf("\n");
}
#endif
user:
userret(td, frame);
mtx_assert(&Giant, MA_NOTOWNED);
KASSERT(PCB_USER_FPU(td->td_pcb),
("Return from trap with kernel FPU ctx leaked"));
userout:
out:
return;
}
/*
* Exception, fault, and trap interface to the 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.
*
* This function is also called from doreti in an interlock to handle ASTs.
* For example: hardwareint->INTROUTINE->(set ast)->doreti->trap
*
* NOTE! We have to retrieve the fault address prior to potentially
* blocking, including blocking on any token.
*
* NOTE! NMI and kernel DBG traps remain on their respective pcpu IST
* stacks if taken from a kernel RPL. trap() cannot block in this
* situation. DDB entry or a direct report-and-return is ok.
*
* XXX gd_trap_nesting_level currently prevents lwkt_switch() from panicing
* if an attempt is made to switch from a fast interrupt or IPI.
*/
void
trap(struct trapframe *frame)
{
static struct krate sscpubugrate = { 1 };
struct globaldata *gd = mycpu;
struct thread *td = gd->gd_curthread;
struct lwp *lp = td->td_lwp;
struct proc *p;
int sticks = 0;
int i = 0, ucode = 0, type, code;
#ifdef INVARIANTS
int crit_count = td->td_critcount;
lwkt_tokref_t curstop = td->td_toks_stop;
#endif
vm_offset_t eva;
p = td->td_proc;
clear_quickret();
#ifdef DDB
/*
* We need to allow T_DNA faults when the debugger is active since
* some dumping paths do large bcopy() which use the floating
* point registers for faster copying.
*/
if (db_active && frame->tf_trapno != T_DNA) {
eva = (frame->tf_trapno == T_PAGEFLT ? frame->tf_addr : 0);
++gd->gd_trap_nesting_level;
trap_fatal(frame, eva);
--gd->gd_trap_nesting_level;
goto out2;
}
#endif
eva = 0;
if ((frame->tf_rflags & PSL_I) == 0) {
/*
* Buggy application or kernel code has disabled interrupts
* and then trapped. Enabling interrupts now is wrong, but
* it is better than running with interrupts disabled until
* they are accidentally enabled later.
*/
type = frame->tf_trapno;
if (ISPL(frame->tf_cs) == SEL_UPL) {
/* JG curproc can be NULL */
kprintf(
"pid %ld (%s): trap %d with interrupts disabled\n",
(long)curproc->p_pid, curproc->p_comm, type);
} else if ((type == T_STKFLT || type == T_PROTFLT ||
type == T_SEGNPFLT) &&
frame->tf_rip == (long)doreti_iret) {
/*
* iretq fault from kernel mode during return to
* userland.
*
* This situation is expected, don't complain.
*/
} else if (type != T_NMI && type != T_BPTFLT &&
type != T_TRCTRAP) {
/*
* XXX not quite right, since this may be for a
* multiple fault in user mode.
*/
kprintf("kernel trap %d (%s @ 0x%016jx) with "
"interrupts disabled\n",
type,
td->td_comm,
frame->tf_rip);
}
cpu_enable_intr();
}
type = frame->tf_trapno;
code = frame->tf_err;
if (ISPL(frame->tf_cs) == SEL_UPL) {
/* user trap */
KTR_LOG(kernentry_trap, p->p_pid, lp->lwp_tid,
frame->tf_trapno, eva);
userenter(td, p);
sticks = (int)td->td_sticks;
KASSERT(lp->lwp_md.md_regs == frame,
("Frame mismatch %p %p", lp->lwp_md.md_regs, frame));
switch (type) {
case T_PRIVINFLT: /* privileged instruction fault */
i = SIGILL;
ucode = ILL_PRVOPC;
break;
case T_BPTFLT: /* bpt instruction fault */
case T_TRCTRAP: /* trace trap */
frame->tf_rflags &= ~PSL_T;
i = SIGTRAP;
ucode = (type == T_TRCTRAP ? TRAP_TRACE : TRAP_BRKPT);
break;
case T_ARITHTRAP: /* arithmetic trap */
ucode = code;
i = SIGFPE;
break;
case T_ASTFLT: /* Allow process switch */
mycpu->gd_cnt.v_soft++;
if (mycpu->gd_reqflags & RQF_AST_OWEUPC) {
atomic_clear_int(&mycpu->gd_reqflags,
RQF_AST_OWEUPC);
addupc_task(p, p->p_prof.pr_addr,
p->p_prof.pr_ticks);
}
goto out;
case T_PROTFLT: /* general protection fault */
i = SIGBUS;
ucode = BUS_OBJERR;
break;
case T_STKFLT: /* stack fault */
case T_SEGNPFLT: /* segment not present fault */
i = SIGBUS;
ucode = BUS_ADRERR;
break;
case T_TSSFLT: /* invalid TSS fault */
case T_DOUBLEFLT: /* double fault */
default:
i = SIGBUS;
ucode = BUS_OBJERR;
break;
case T_PAGEFLT: /* page fault */
i = trap_pfault(frame, TRUE);
#ifdef DDB
if (frame->tf_rip == 0) {
/* used for kernel debugging only */
while (freeze_on_seg_fault)
tsleep(p, 0, "freeze", hz * 20);
}
#endif
if (i == -1 || i == 0)
goto out;
if (i == SIGSEGV) {
ucode = SEGV_MAPERR;
} else {
i = SIGSEGV;
ucode = SEGV_ACCERR;
}
break;
case T_DIVIDE: /* integer divide fault */
ucode = FPE_INTDIV;
i = SIGFPE;
break;
#if NISA > 0
case T_NMI:
/* machine/parity/power fail/"kitchen sink" faults */
if (isa_nmi(code) == 0) {
#ifdef DDB
/*
* NMI can be hooked up to a pushbutton
* for debugging.
*/
if (ddb_on_nmi) {
kprintf ("NMI ... going to debugger\n");
kdb_trap(type, 0, frame);
}
#endif /* DDB */
goto out2;
} else if (panic_on_nmi)
panic("NMI indicates hardware failure");
break;
#endif /* NISA > 0 */
case T_OFLOW: /* integer overflow fault */
ucode = FPE_INTOVF;
i = SIGFPE;
break;
case T_BOUND: /* bounds check fault */
ucode = FPE_FLTSUB;
i = SIGFPE;
break;
case T_DNA:
/*
* Virtual kernel intercept - pass the DNA exception
* to the virtual kernel if it asked to handle it.
* This occurs when the virtual kernel is holding
* onto the FP context for a different emulated
* process then the one currently running.
*
* We must still call npxdna() since we may have
* saved FP state that the virtual kernel needs
* to hand over to a different emulated process.
*/
if (lp->lwp_vkernel && lp->lwp_vkernel->ve &&
(td->td_pcb->pcb_flags & FP_VIRTFP)
) {
npxdna();
break;
}
/*
* The kernel may have switched out the FP unit's
* state, causing the user process to take a fault
* when it tries to use the FP unit. Restore the
* state here
*/
if (npxdna()) {
gd->gd_cnt.v_trap++;
goto out;
}
i = SIGFPE;
ucode = FPE_FPU_NP_TRAP;
break;
case T_FPOPFLT: /* FPU operand fetch fault */
ucode = ILL_COPROC;
i = SIGILL;
break;
case T_XMMFLT: /* SIMD floating-point exception */
ucode = 0; /* XXX */
i = SIGFPE;
break;
}
} else {
/* kernel trap */
switch (type) {
case T_PAGEFLT: /* page fault */
trap_pfault(frame, FALSE);
goto out2;
case T_DNA:
/*
* The kernel is apparently using fpu for copying.
* XXX this should be fatal unless the kernel has
* registered such use.
*/
if (npxdna()) {
gd->gd_cnt.v_trap++;
goto out2;
}
break;
case T_STKFLT: /* stack fault */
case T_PROTFLT: /* general protection fault */
case T_SEGNPFLT: /* segment not present fault */
/*
* Invalid segment selectors and out of bounds
* %rip's and %rsp'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.
*/
if (mycpu->gd_intr_nesting_level == 0) {
/*
* NOTE: in 64-bit mode traps push rsp/ss
* even if no ring change occurs.
*/
if (td->td_pcb->pcb_onfault &&
td->td_pcb->pcb_onfault_sp ==
frame->tf_rsp) {
frame->tf_rip = (register_t)
td->td_pcb->pcb_onfault;
goto out2;
}
/*
* If the iretq in doreti faults during
* return to user, it will be special-cased
* in IDTVEC(prot) to get here. We want
* to 'return' to doreti_iret_fault in
* ipl.s in approximately the same state we
* were in at the iretq.
*/
if (frame->tf_rip == (long)doreti_iret) {
frame->tf_rip = (long)doreti_iret_fault;
goto out2;
}
}
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_rflags & PSL_NT) {
frame->tf_rflags &= ~PSL_NT;
#if 0
/* do we need this? */
if (frame->tf_rip == (long)doreti_iret)
frame->tf_rip = (long)doreti_iret_fault;
#endif
goto out2;
}
break;
case T_TRCTRAP: /* trace trap */
/*
* Detect historical CPU artifact on syscall or int $3
* entry (if not shortcutted in exception.s via
* DIRECT_DISALLOW_SS_CPUBUG).
*/
gd->gd_cnt.v_trap++;
if (frame->tf_rip == (register_t)IDTVEC(fast_syscall)) {
krateprintf(&sscpubugrate,
"Caught #DB at syscall cpu artifact\n");
goto out2;
}
if (frame->tf_rip == (register_t)IDTVEC(bpt)) {
krateprintf(&sscpubugrate,
"Caught #DB at int $N cpu artifact\n");
goto out2;
}
/*
* Ignore debug register trace traps due to
* accesses in the user's address space, which
* can happen under several conditions such as
* if a user sets a watchpoint on a buffer and
* then passes that buffer to a system call.
* We still want to get TRCTRAPS for addresses
* in kernel space because that is useful when
* debugging the kernel.
*/
if (user_dbreg_trap()) {
/*
* Reset breakpoint bits because the
* processor doesn't
*/
load_dr6(rdr6() & ~0xf);
goto out2;
}
/*
* FALLTHROUGH (TRCTRAP kernel mode, kernel address)
*/
case T_BPTFLT:
/*
* If DDB is enabled, let it handle the debugger trap.
* Otherwise, debugger traps "can't happen".
*/
ucode = TRAP_BRKPT;
#ifdef DDB
if (kdb_trap(type, 0, frame))
goto out2;
#endif
break;
#if NISA > 0
case T_NMI:
/* machine/parity/power fail/"kitchen sink" faults */
if (isa_nmi(code) == 0) {
#ifdef DDB
/*
* NMI can be hooked up to a pushbutton
* for debugging.
*/
if (ddb_on_nmi) {
kprintf ("NMI ... going to debugger\n");
kdb_trap(type, 0, frame);
}
#endif /* DDB */
goto out2;
} else if (panic_on_nmi == 0)
goto out2;
/* FALL THROUGH */
#endif /* NISA > 0 */
}
trap_fatal(frame, 0);
goto out2;
}
/*
* Fault from user mode, virtual kernel interecept.
*
* If the fault is directly related to a VM context managed by a
* virtual kernel then let the virtual kernel handle it.
*/
if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
vkernel_trap(lp, frame);
goto out;
}
/* Translate fault for emulators (e.g. Linux) */
if (*p->p_sysent->sv_transtrap)
i = (*p->p_sysent->sv_transtrap)(i, type);
gd->gd_cnt.v_trap++;
trapsignal(lp, i, ucode);
#ifdef DEBUG
if (type <= MAX_TRAP_MSG) {
uprintf("fatal process exception: %s",
trap_msg[type]);
if ((type == T_PAGEFLT) || (type == T_PROTFLT))
uprintf(", fault VA = 0x%lx", frame->tf_addr);
uprintf("\n");
}
#endif
out:
userret(lp, frame, sticks);
userexit(lp);
out2: ;
if (p != NULL && lp != NULL)
KTR_LOG(kernentry_trap_ret, p->p_pid, lp->lwp_tid);
#ifdef INVARIANTS
KASSERT(crit_count == td->td_critcount,
("trap: critical section count mismatch! %d/%d",
crit_count, td->td_pri));
KASSERT(curstop == td->td_toks_stop,
("trap: extra tokens held after trap! %ld/%ld",
curstop - &td->td_toks_base,
td->td_toks_stop - &td->td_toks_base));
#endif
}
void
trap(struct trapframe *frame)
{
struct globaldata *gd = mycpu;
struct thread *td = gd->gd_curthread;
struct lwp *lp = td->td_lwp;
struct proc *p;
int sticks = 0;
int i = 0, ucode = 0, type, code;
int have_mplock = 0;
#ifdef INVARIANTS
int crit_count = td->td_critcount;
lwkt_tokref_t curstop = td->td_toks_stop;
#endif
vm_offset_t eva;
p = td->td_proc;
#ifdef DDB
/*
* We need to allow T_DNA faults when the debugger is active since
* some dumping paths do large bcopy() which use the floating
* point registers for faster copying.
*/
if (db_active && frame->tf_trapno != T_DNA) {
eva = (frame->tf_trapno == T_PAGEFLT ? rcr2() : 0);
++gd->gd_trap_nesting_level;
MAKEMPSAFE(have_mplock);
trap_fatal(frame, eva);
--gd->gd_trap_nesting_level;
goto out2;
}
#endif
eva = 0;
++gd->gd_trap_nesting_level;
if (frame->tf_trapno == T_PAGEFLT) {
/*
* For some Cyrix CPUs, %cr2 is clobbered by interrupts.
* This problem is worked around by using an interrupt
* gate for the pagefault handler. We are finally ready
* to read %cr2 and then must reenable interrupts.
*
* XXX this should be in the switch statement, but the
* NO_FOOF_HACK and VM86 goto and ifdefs obfuscate the
* flow of control too much for this to be obviously
* correct.
*/
eva = rcr2();
cpu_enable_intr();
}
--gd->gd_trap_nesting_level;
if (!(frame->tf_eflags & PSL_I)) {
/*
* Buggy application or kernel code has disabled interrupts
* and then trapped. Enabling interrupts now is wrong, but
* it is better than running with interrupts disabled until
* they are accidentally enabled later.
*/
type = frame->tf_trapno;
if (ISPL(frame->tf_cs)==SEL_UPL || (frame->tf_eflags & PSL_VM)) {
MAKEMPSAFE(have_mplock);
kprintf(
"pid %ld (%s): trap %d with interrupts disabled\n",
(long)curproc->p_pid, curproc->p_comm, type);
} else if (type != T_BPTFLT && type != T_TRCTRAP) {
/*
* XXX not quite right, since this may be for a
* multiple fault in user mode.
*/
MAKEMPSAFE(have_mplock);
kprintf("kernel trap %d with interrupts disabled\n",
type);
}
cpu_enable_intr();
}
#if defined(I586_CPU) && !defined(NO_F00F_HACK)
restart:
#endif
type = frame->tf_trapno;
code = frame->tf_err;
if (in_vm86call) {
if (frame->tf_eflags & PSL_VM &&
(type == T_PROTFLT || type == T_STKFLT)) {
KKASSERT(get_mplock_count(curthread) > 0);
i = vm86_emulate((struct vm86frame *)frame);
KKASSERT(get_mplock_count(curthread) > 0);
if (i != 0) {
/*
* returns to original process
*/
vm86_trap((struct vm86frame *)frame,
have_mplock);
KKASSERT(0); /* NOT REACHED */
}
goto out2;
}
switch (type) {
/*
* these traps want either a process context, or
* assume a normal userspace trap.
*/
case T_PROTFLT:
case T_SEGNPFLT:
trap_fatal(frame, eva);
goto out2;
case T_TRCTRAP:
type = T_BPTFLT; /* kernel breakpoint */
/* FALL THROUGH */
}
goto kernel_trap; /* normal kernel trap handling */
}
if ((ISPL(frame->tf_cs) == SEL_UPL) || (frame->tf_eflags & PSL_VM)) {
/* user trap */
KTR_LOG(kernentry_trap, p->p_pid, lp->lwp_tid,
frame->tf_trapno, eva);
userenter(td, p);
sticks = (int)td->td_sticks;
lp->lwp_md.md_regs = frame;
switch (type) {
case T_PRIVINFLT: /* privileged instruction fault */
i = SIGILL;
ucode = ILL_PRVOPC;
break;
case T_BPTFLT: /* bpt instruction fault */
case T_TRCTRAP: /* trace trap */
frame->tf_eflags &= ~PSL_T;
i = SIGTRAP;
ucode = (type == T_TRCTRAP ? TRAP_TRACE : TRAP_BRKPT);
break;
case T_ARITHTRAP: /* arithmetic trap */
ucode = code;
i = SIGFPE;
break;
case T_ASTFLT: /* Allow process switch */
mycpu->gd_cnt.v_soft++;
if (mycpu->gd_reqflags & RQF_AST_OWEUPC) {
atomic_clear_int(&mycpu->gd_reqflags,
RQF_AST_OWEUPC);
addupc_task(p, p->p_prof.pr_addr,
p->p_prof.pr_ticks);
}
goto out;
/*
* The following two traps can happen in
* vm86 mode, and, if so, we want to handle
* them specially.
*/
case T_PROTFLT: /* general protection fault */
case T_STKFLT: /* stack fault */
if (frame->tf_eflags & PSL_VM) {
i = vm86_emulate((struct vm86frame *)frame);
if (i == 0)
goto out;
break;
}
i = SIGBUS;
ucode = (type == T_PROTFLT) ? BUS_OBJERR : BUS_ADRERR;
break;
case T_SEGNPFLT: /* segment not present fault */
i = SIGBUS;
ucode = BUS_ADRERR;
break;
case T_TSSFLT: /* invalid TSS fault */
case T_DOUBLEFLT: /* double fault */
default:
i = SIGBUS;
ucode = BUS_OBJERR;
break;
case T_PAGEFLT: /* page fault */
i = trap_pfault(frame, TRUE, eva);
if (i == -1)
goto out;
#if defined(I586_CPU) && !defined(NO_F00F_HACK)
if (i == -2)
goto restart;
#endif
if (i == 0)
goto out;
if (i == SIGSEGV)
ucode = SEGV_MAPERR;
else {
i = SIGSEGV;
ucode = SEGV_ACCERR;
}
break;
case T_DIVIDE: /* integer divide fault */
ucode = FPE_INTDIV;
i = SIGFPE;
break;
#if NISA > 0
case T_NMI:
MAKEMPSAFE(have_mplock);
#ifdef POWERFAIL_NMI
goto handle_powerfail;
#else /* !POWERFAIL_NMI */
/* machine/parity/power fail/"kitchen sink" faults */
if (isa_nmi(code) == 0) {
#ifdef DDB
/*
* NMI can be hooked up to a pushbutton
* for debugging.
*/
if (ddb_on_nmi) {
kprintf ("NMI ... going to debugger\n");
kdb_trap (type, 0, frame);
}
#endif /* DDB */
goto out2;
} else if (panic_on_nmi)
panic("NMI indicates hardware failure");
break;
#endif /* POWERFAIL_NMI */
#endif /* NISA > 0 */
case T_OFLOW: /* integer overflow fault */
ucode = FPE_INTOVF;
i = SIGFPE;
break;
case T_BOUND: /* bounds check fault */
ucode = FPE_FLTSUB;
i = SIGFPE;
break;
case T_DNA:
/*
* Virtual kernel intercept - pass the DNA exception
* to the virtual kernel if it asked to handle it.
* This occurs when the virtual kernel is holding
* onto the FP context for a different emulated
* process then the one currently running.
*
* We must still call npxdna() since we may have
* saved FP state that the virtual kernel needs
* to hand over to a different emulated process.
*/
if (lp->lwp_vkernel && lp->lwp_vkernel->ve &&
(td->td_pcb->pcb_flags & FP_VIRTFP)
) {
npxdna();
break;
}
#if NNPX > 0
/*
* The kernel may have switched out the FP unit's
* state, causing the user process to take a fault
* when it tries to use the FP unit. Restore the
* state here
*/
if (npxdna())
goto out;
#endif
if (!pmath_emulate) {
i = SIGFPE;
ucode = FPE_FPU_NP_TRAP;
break;
}
i = (*pmath_emulate)(frame);
if (i == 0) {
if (!(frame->tf_eflags & PSL_T))
goto out2;
frame->tf_eflags &= ~PSL_T;
i = SIGTRAP;
}
/* else ucode = emulator_only_knows() XXX */
break;
case T_FPOPFLT: /* FPU operand fetch fault */
ucode = ILL_COPROC;
i = SIGILL;
break;
case T_XMMFLT: /* SIMD floating-point exception */
ucode = 0; /* XXX */
i = SIGFPE;
break;
}
} else {
kernel_trap:
/* kernel trap */
switch (type) {
case T_PAGEFLT: /* page fault */
trap_pfault(frame, FALSE, eva);
goto out2;
case T_DNA:
#if NNPX > 0
/*
* The kernel may be using npx for copying or other
* purposes.
*/
if (npxdna())
goto out2;
#endif
break;
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; \
goto out2; \
} \
} while (0)
if (mycpu->gd_intr_nesting_level == 0) {
/*
* Invalid %fs's and %gs's can be created using
* procfs or PT_SETREGS or by invalidating the
* underlying LDT entry. This causes a fault
* in kernel mode when the kernel attempts to
* switch contexts. Lose the bad context
* (XXX) so that we can continue, and generate
* a signal.
*/
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);
MAYBE_DORETI_FAULT(doreti_popl_fs,
doreti_popl_fs_fault);
MAYBE_DORETI_FAULT(doreti_popl_gs,
doreti_popl_gs_fault);
/*
* NOTE: cpu doesn't push esp on kernel trap
*/
if (td->td_pcb->pcb_onfault &&
td->td_pcb->pcb_onfault_sp ==
(int)&frame->tf_esp) {
frame->tf_eip =
(register_t)td->td_pcb->pcb_onfault;
goto out2;
}
}
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;
goto out2;
}
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.
*/
goto out2;
}
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;
goto out2;
}
/*
* Ignore debug register trace traps due to
* accesses in the user's address space, which
* can happen under several conditions such as
* if a user sets a watchpoint on a buffer and
* then passes that buffer to a system call.
* We still want to get TRCTRAPS for addresses
* in kernel space because that is useful when
* debugging the kernel.
*/
if (user_dbreg_trap()) {
/*
* Reset breakpoint bits because the
* processor doesn't
*/
load_dr6(rdr6() & 0xfffffff0);
goto out2;
}
/*
* FALLTHROUGH (TRCTRAP kernel mode, kernel address)
*/
case T_BPTFLT:
/*
* If DDB is enabled, let it handle the debugger trap.
* Otherwise, debugger traps "can't happen".
*/
ucode = TRAP_BRKPT;
#ifdef DDB
MAKEMPSAFE(have_mplock);
if (kdb_trap (type, 0, frame))
goto out2;
#endif
break;
#if NISA > 0
case T_NMI:
MAKEMPSAFE(have_mplock);
#ifdef POWERFAIL_NMI
#ifndef TIMER_FREQ
# define TIMER_FREQ 1193182
#endif
handle_powerfail:
{
static unsigned lastalert = 0;
if (time_uptime - lastalert > 10) {
log(LOG_WARNING, "NMI: power fail\n");
sysbeep(TIMER_FREQ/880, hz);
lastalert = time_uptime;
}
/* YYY mp count */
goto out2;
}
#else /* !POWERFAIL_NMI */
/* machine/parity/power fail/"kitchen sink" faults */
if (isa_nmi(code) == 0) {
#ifdef DDB
/*
* NMI can be hooked up to a pushbutton
* for debugging.
*/
if (ddb_on_nmi) {
kprintf ("NMI ... going to debugger\n");
kdb_trap (type, 0, frame);
}
#endif /* DDB */
goto out2;
} else if (panic_on_nmi == 0)
goto out2;
/* FALL THROUGH */
#endif /* POWERFAIL_NMI */
#endif /* NISA > 0 */
}
MAKEMPSAFE(have_mplock);
trap_fatal(frame, eva);
goto out2;
}
/*
* Virtual kernel intercept - if the fault is directly related to a
* VM context managed by a virtual kernel then let the virtual kernel
* handle it.
*/
if (lp->lwp_vkernel && lp->lwp_vkernel->ve) {
vkernel_trap(lp, frame);
goto out;
}
/* Translate fault for emulators (e.g. Linux) */
if (*p->p_sysent->sv_transtrap)
i = (*p->p_sysent->sv_transtrap)(i, type);
MAKEMPSAFE(have_mplock);
trapsignal(lp, i, ucode);
#ifdef DEBUG
if (type <= MAX_TRAP_MSG) {
uprintf("fatal process exception: %s",
trap_msg[type]);
if ((type == T_PAGEFLT) || (type == T_PROTFLT))
uprintf(", fault VA = 0x%lx", (u_long)eva);
uprintf("\n");
}
#endif
out:
userret(lp, frame, sticks);
userexit(lp);
out2: ;
if (have_mplock)
rel_mplock();
if (p != NULL && lp != NULL)
KTR_LOG(kernentry_trap_ret, p->p_pid, lp->lwp_tid);
#ifdef INVARIANTS
KASSERT(crit_count == td->td_critcount,
("trap: critical section count mismatch! %d/%d",
crit_count, td->td_pri));
KASSERT(curstop == td->td_toks_stop,
("trap: extra tokens held after trap! %zd/%zd",
curstop - &td->td_toks_base,
td->td_toks_stop - &td->td_toks_base));
#endif
}
void
trap(struct trapframe *frame)
{
struct thread *td = curthread;
struct proc *p = td->td_proc;
int i = 0, ucode = 0, code;
u_int type;
register_t addr = 0;
ksiginfo_t ksi;
PCPU_INC(cnt.v_trap);
type = frame->tf_trapno;
#ifdef SMP
#ifdef STOP_NMI
/* Handler for NMI IPIs used for stopping CPUs. */
if (type == T_NMI) {
if (ipi_nmi_handler() == 0)
goto out;
}
#endif /* STOP_NMI */
#endif /* SMP */
#ifdef KDB
if (kdb_active) {
kdb_reenter();
goto out;
}
#endif
#ifdef HWPMC_HOOKS
/*
* CPU PMCs interrupt using an NMI. If the PMC module is
* active, pass the 'rip' value to the PMC module's interrupt
* handler. A return value of '1' from the handler means that
* the NMI was handled by it and we can return immediately.
*/
if (type == T_NMI && pmc_intr &&
(*pmc_intr)(PCPU_GET(cpuid), frame))
goto out;
#endif
if (type == T_MCHK) {
if (!mca_intr())
trap_fatal(frame, 0);
goto out;
}
#ifdef KDTRACE_HOOKS
/*
* A trap can occur while DTrace executes a probe. Before
* executing the probe, DTrace blocks re-scheduling and sets
* a flag in it's per-cpu flags to indicate that it doesn't
* want to fault. On returning from the the probe, the no-fault
* flag is cleared and finally re-scheduling is enabled.
*
* If the DTrace kernel module has registered a trap handler,
* call it and if it returns non-zero, assume that it has
* handled the trap and modified the trap frame so that this
* function can return normally.
*/
if (dtrace_trap_func != NULL)
if ((*dtrace_trap_func)(frame, type))
goto out;
#endif
if ((frame->tf_rflags & PSL_I) == 0) {
/*
* Buggy application or kernel code has disabled
* interrupts and then trapped. Enabling interrupts
* now is wrong, but it is better than running with
* interrupts disabled until they are accidentally
* enabled later.
*/
if (ISPL(frame->tf_cs) == SEL_UPL)
printf(
"pid %ld (%s): trap %d with interrupts disabled\n",
(long)curproc->p_pid, curproc->p_comm, type);
else if (type != T_NMI && type != T_BPTFLT &&
type != T_TRCTRAP) {
/*
* XXX not quite right, since this may be for a
* multiple fault in user mode.
*/
printf("kernel trap %d with interrupts disabled\n",
type);
/*
* We shouldn't enable interrupts while holding a
* spin lock or servicing an NMI.
*/
if (type != T_NMI && td->td_md.md_spinlock_count == 0)
enable_intr();
}
}
code = frame->tf_err;
if (type == T_PAGEFLT) {
/*
* If we get a page fault while in a critical section, then
* it is most likely a fatal kernel page fault. The kernel
* is already going to panic trying to get a sleep lock to
* do the VM lookup, so just consider it a fatal trap so the
* kernel can print out a useful trap message and even get
* to the debugger.
*
* If we get a page fault while holding a non-sleepable
* lock, then it is most likely a fatal kernel page fault.
* If WITNESS is enabled, then it's going to whine about
* bogus LORs with various VM locks, so just skip to the
* fatal trap handling directly.
*/
if (td->td_critnest != 0 ||
WITNESS_CHECK(WARN_SLEEPOK | WARN_GIANTOK, NULL,
"Kernel page fault") != 0)
trap_fatal(frame, frame->tf_addr);
}
if (ISPL(frame->tf_cs) == SEL_UPL) {
/* user trap */
td->td_pticks = 0;
td->td_frame = frame;
addr = frame->tf_rip;
if (td->td_ucred != p->p_ucred)
cred_update_thread(td);
switch (type) {
case T_PRIVINFLT: /* privileged instruction fault */
i = SIGILL;
ucode = ILL_PRVOPC;
break;
case T_BPTFLT: /* bpt instruction fault */
case T_TRCTRAP: /* trace trap */
enable_intr();
frame->tf_rflags &= ~PSL_T;
i = SIGTRAP;
ucode = (type == T_TRCTRAP ? TRAP_TRACE : TRAP_BRKPT);
break;
case T_ARITHTRAP: /* arithmetic trap */
ucode = fputrap();
if (ucode == -1)
goto userout;
i = SIGFPE;
break;
case T_PROTFLT: /* general protection fault */
i = SIGBUS;
ucode = BUS_OBJERR;
break;
case T_STKFLT: /* stack fault */
case T_SEGNPFLT: /* segment not present fault */
i = SIGBUS;
ucode = BUS_ADRERR;
break;
case T_TSSFLT: /* invalid TSS fault */
i = SIGBUS;
ucode = BUS_OBJERR;
break;
case T_DOUBLEFLT: /* double fault */
default:
i = SIGBUS;
ucode = BUS_OBJERR;
break;
case T_PAGEFLT: /* page fault */
addr = frame->tf_addr;
#ifdef KSE
if (td->td_pflags & TDP_SA)
thread_user_enter(td);
#endif
i = trap_pfault(frame, TRUE);
if (i == -1)
goto userout;
if (i == 0)
goto user;
if (i == SIGSEGV)
ucode = SEGV_MAPERR;
else {
if (prot_fault_translation == 0) {
/*
* Autodetect.
* This check also covers the images
* without the ABI-tag ELF note.
*/
if ((curproc->p_sysent ==
&elf64_freebsd_sysvec
#ifdef COMPAT_IA32
|| curproc->p_sysent ==
&ia32_freebsd_sysvec
#endif
) && p->p_osrel >= 700004) {
i = SIGSEGV;
ucode = SEGV_ACCERR;
} else {
i = SIGBUS;
ucode = BUS_PAGE_FAULT;
}
} else if (prot_fault_translation == 1) {
/*
* Always compat mode.
*/
i = SIGBUS;
ucode = BUS_PAGE_FAULT;
} else {
/*
* Always SIGSEGV mode.
*/
i = SIGSEGV;
ucode = SEGV_ACCERR;
}
}
break;
case T_DIVIDE: /* integer divide fault */
ucode = FPE_INTDIV;
i = SIGFPE;
break;
#ifdef DEV_ISA
case T_NMI:
/* machine/parity/power fail/"kitchen sink" faults */
/* XXX Giant */
if (isa_nmi(code) == 0) {
#ifdef KDB
/*
* NMI can be hooked up to a pushbutton
* for debugging.
*/
if (kdb_on_nmi) {
printf ("NMI ... going to debugger\n");
kdb_trap(type, 0, frame);
}
#endif /* KDB */
goto userout;
} else if (panic_on_nmi)
panic("NMI indicates hardware failure");
break;
#endif /* DEV_ISA */
case T_OFLOW: /* integer overflow fault */
ucode = FPE_INTOVF;
i = SIGFPE;
break;
case T_BOUND: /* bounds check fault */
ucode = FPE_FLTSUB;
i = SIGFPE;
break;
case T_DNA:
/* transparent fault (due to context switch "late") */
fpudna();
goto userout;
case T_FPOPFLT: /* FPU operand fetch fault */
ucode = ILL_COPROC;
i = SIGILL;
break;
case T_XMMFLT: /* SIMD floating-point exception */
ucode = 0; /* XXX */
i = SIGFPE;
break;
}
} else {
/* kernel trap */
KASSERT(cold || td->td_ucred != NULL,
("kernel trap doesn't have ucred"));
switch (type) {
case T_PAGEFLT: /* page fault */
(void) trap_pfault(frame, FALSE);
goto out;
case T_DNA:
/*
* The kernel is apparently using fpu for copying.
* XXX this should be fatal unless the kernel has
* registered such use.
*/
fpudna();
printf("fpudna in kernel mode!\n");
goto out;
case T_STKFLT: /* stack fault */
break;
case T_PROTFLT: /* general protection fault */
case T_SEGNPFLT: /* segment not present fault */
if (td->td_intr_nesting_level != 0)
break;
/*
* Invalid segment selectors and out of bounds
* %rip's and %rsp'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.
*/
if (frame->tf_rip == (long)doreti_iret) {
frame->tf_rip = (long)doreti_iret_fault;
goto out;
}
if (PCPU_GET(curpcb)->pcb_onfault != NULL) {
frame->tf_rip =
(long)PCPU_GET(curpcb)->pcb_onfault;
goto out;
}
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_rflags & PSL_NT) {
frame->tf_rflags &= ~PSL_NT;
goto out;
}
break;
case T_TRCTRAP: /* trace trap */
/*
* Ignore debug register trace traps due to
* accesses in the user's address space, which
* can happen under several conditions such as
* if a user sets a watchpoint on a buffer and
* then passes that buffer to a system call.
* We still want to get TRCTRAPS for addresses
* in kernel space because that is useful when
* debugging the kernel.
*/
if (user_dbreg_trap()) {
/*
* Reset breakpoint bits because the
* processor doesn't
*/
/* XXX check upper bits here */
load_dr6(rdr6() & 0xfffffff0);
goto out;
}
/*
* FALLTHROUGH (TRCTRAP kernel mode, kernel address)
*/
case T_BPTFLT:
/*
* If KDB is enabled, let it handle the debugger trap.
* Otherwise, debugger traps "can't happen".
*/
#ifdef KDB
if (kdb_trap(type, 0, frame))
goto out;
#endif
break;
#ifdef DEV_ISA
case T_NMI:
/* XXX Giant */
/* machine/parity/power fail/"kitchen sink" faults */
if (isa_nmi(code) == 0) {
#ifdef KDB
/*
* NMI can be hooked up to a pushbutton
* for debugging.
*/
if (kdb_on_nmi) {
printf ("NMI ... going to debugger\n");
kdb_trap(type, 0, frame);
}
#endif /* KDB */
goto out;
} else if (panic_on_nmi == 0)
goto out;
/* FALLTHROUGH */
#endif /* DEV_ISA */
}
trap_fatal(frame, 0);
goto out;
}
/* Translate fault for emulators (e.g. Linux) */
if (*p->p_sysent->sv_transtrap)
i = (*p->p_sysent->sv_transtrap)(i, type);
ksiginfo_init_trap(&ksi);
ksi.ksi_signo = i;
ksi.ksi_code = ucode;
ksi.ksi_trapno = type;
ksi.ksi_addr = (void *)addr;
trapsignal(td, &ksi);
#ifdef DEBUG
if (type <= MAX_TRAP_MSG) {
uprintf("fatal process exception: %s",
trap_msg[type]);
if ((type == T_PAGEFLT) || (type == T_PROTFLT))
uprintf(", fault VA = 0x%lx", frame->tf_addr);
uprintf("\n");
}
#endif
user:
userret(td, frame);
mtx_assert(&Giant, MA_NOTOWNED);
userout:
out:
return;
}
void
kern_trap(struct trapframe *frame)
{
struct globaldata *gd = mycpu;
struct thread *td = gd->gd_curthread;
struct lwp *lp;
struct proc *p;
int i = 0, ucode = 0, type, code;
int have_mplock = 0;
#ifdef INVARIANTS
int crit_count = td->td_critcount;
lwkt_tokref_t curstop = td->td_toks_stop;
#endif
vm_offset_t eva;
lp = td->td_lwp;
p = td->td_proc;
if (frame->tf_trapno == T_PAGEFLT)
eva = frame->tf_err;
else
eva = 0;
#ifdef DDB
if (db_active) {
++gd->gd_trap_nesting_level;
MAKEMPSAFE(have_mplock);
trap_fatal(frame, FALSE, eva);
--gd->gd_trap_nesting_level;
goto out2;
}
#endif
type = frame->tf_trapno;
code = frame->tf_err;
#if 0
kernel_trap:
#endif
/* kernel trap */
switch (type) {
case T_PAGEFLT: /* page fault */
MAKEMPSAFE(have_mplock);
trap_pfault(frame, FALSE, eva);
goto out2;
case T_DNA:
#if NNPX > 0
/*
* The kernel may be using npx for copying or other
* purposes.
*/
panic("kernel NPX should not happen");
if (npxdna(frame))
goto out2;
#endif
break;
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.
*/
if (mycpu->gd_intr_nesting_level == 0) {
if (td->td_pcb->pcb_onfault) {
frame->tf_eip =
(register_t)td->td_pcb->pcb_onfault;
goto out2;
}
}
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;
goto out2;
}
break;
case T_TRCTRAP: /* trace trap */
#if 0
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.
*/
goto out2;
}
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;
goto out2;
}
#endif
#if 0
/*
* Ignore debug register trace traps due to
* accesses in the user's address space, which
* can happen under several conditions such as
* if a user sets a watchpoint on a buffer and
* then passes that buffer to a system call.
* We still want to get TRCTRAPS for addresses
* in kernel space because that is useful when
* debugging the kernel.
*/
if (user_dbreg_trap()) {
/*
* Reset breakpoint bits because the
* processor doesn't
*/
load_dr6(rdr6() & 0xfffffff0);
goto out2;
}
#endif
/*
* FALLTHROUGH (TRCTRAP kernel mode, kernel address)
*/
case T_BPTFLT:
/*
* If DDB is enabled, let it handle the debugger trap.
* Otherwise, debugger traps "can't happen".
*/
#ifdef DDB
MAKEMPSAFE(have_mplock);
if (kdb_trap (type, 0, frame))
goto out2;
#endif
break;
case T_DIVIDE:
MAKEMPSAFE(have_mplock);
trap_fatal(frame, FALSE, eva);
goto out2;
case T_NMI:
MAKEMPSAFE(have_mplock);
trap_fatal(frame, FALSE, eva);
goto out2;
case T_SYSCALL80:
/*
* Ignore this trap generated from a spurious SIGTRAP.
*
* single stepping in / syscalls leads to spurious / SIGTRAP
* so ignore
*
* Haiku (c) 2007 Simon 'corecode' Schubert
*/
goto out2;
}
/*
* Translate fault for emulators (e.g. Linux)
*/
if (*p->p_sysent->sv_transtrap)
i = (*p->p_sysent->sv_transtrap)(i, type);
MAKEMPSAFE(have_mplock);
trapsignal(lp, i, ucode);
#ifdef DEBUG
if (type <= MAX_TRAP_MSG) {
uprintf("fatal process exception: %s",
trap_msg[type]);
if ((type == T_PAGEFLT) || (type == T_PROTFLT))
uprintf(", fault VA = 0x%lx", (u_long)eva);
uprintf("\n");
}
#endif
out2:
;
if (have_mplock)
rel_mplock();
#ifdef INVARIANTS
KASSERT(crit_count == td->td_critcount,
("trap: critical section count mismatch! %d/%d",
crit_count, td->td_pri));
KASSERT(curstop == td->td_toks_stop,
("trap: extra tokens held after trap! %zd/%zd",
curstop - &td->td_toks_base,
td->td_toks_stop - &td->td_toks_base));
#endif
}
