freebsd-dev/sys/powerpc/aim/trap.c
Justin Hibbits c757049235 Implement DTrace for PowerPC. This includes both 32-bit and 64-bit.
There is one known issue:  Some probes will display an error message along the
lines of:  "Invalid address (0)"

I tested this with both a simple dtrace probe and dtruss on a few different
binaries on 32-bit.  I only compiled 64-bit, did not run it, but I don't expect
problems without the modules loaded.  Volunteers are welcome.

MFC after:	1 month
2012-11-07 23:45:09 +00:00

810 lines
18 KiB
C

/*-
* Copyright (C) 1995, 1996 Wolfgang Solfrank.
* Copyright (C) 1995, 1996 TooLs GmbH.
* All rights reserved.
*
* 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 TooLs GmbH.
* 4. The name of TooLs GmbH may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``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 TOOLS GMBH 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.
*
* $NetBSD: trap.c,v 1.58 2002/03/04 04:07:35 dbj Exp $
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_hwpmc_hooks.h"
#include "opt_kdtrace.h"
#include <sys/param.h>
#include <sys/kdb.h>
#include <sys/proc.h>
#include <sys/ktr.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/pioctl.h>
#include <sys/ptrace.h>
#include <sys/reboot.h>
#include <sys/syscall.h>
#include <sys/sysent.h>
#include <sys/systm.h>
#include <sys/uio.h>
#include <sys/signalvar.h>
#include <sys/vmmeter.h>
#ifdef HWPMC_HOOKS
#include <sys/pmckern.h>
#endif
#include <security/audit/audit.h>
#include <vm/vm.h>
#include <vm/pmap.h>
#include <vm/vm_extern.h>
#include <vm/vm_param.h>
#include <vm/vm_kern.h>
#include <vm/vm_map.h>
#include <vm/vm_page.h>
#include <machine/_inttypes.h>
#include <machine/altivec.h>
#include <machine/cpu.h>
#include <machine/db_machdep.h>
#include <machine/fpu.h>
#include <machine/frame.h>
#include <machine/pcb.h>
#include <machine/pmap.h>
#include <machine/psl.h>
#include <machine/trap.h>
#include <machine/spr.h>
#include <machine/sr.h>
static void trap_fatal(struct trapframe *frame);
static void printtrap(u_int vector, struct trapframe *frame, int isfatal,
int user);
static int trap_pfault(struct trapframe *frame, int user);
static int fix_unaligned(struct thread *td, struct trapframe *frame);
static int ppc_instr_emulate(struct trapframe *frame);
static int handle_onfault(struct trapframe *frame);
static void syscall(struct trapframe *frame);
#ifdef __powerpc64__
void handle_kernel_slb_spill(int, register_t, register_t);
static int handle_user_slb_spill(pmap_t pm, vm_offset_t addr);
extern int n_slbs;
#endif
int setfault(faultbuf); /* defined in locore.S */
/* Why are these not defined in a header? */
int badaddr(void *, size_t);
int badaddr_read(void *, size_t, int *);
struct powerpc_exception {
u_int vector;
char *name;
};
#ifdef KDTRACE_HOOKS
#include <sys/dtrace_bsd.h>
/*
* This is a hook which is initialised by the dtrace module
* to handle traps which might occur during DTrace probe
* execution.
*/
dtrace_trap_func_t dtrace_trap_func;
dtrace_doubletrap_func_t dtrace_doubletrap_func;
/*
* This is a hook which is initialised by the systrace module
* when it is loaded. This keeps the DTrace syscall provider
* implementation opaque.
*/
systrace_probe_func_t systrace_probe_func;
/*
* These hooks are necessary for the pid, usdt and fasttrap providers.
*/
dtrace_fasttrap_probe_ptr_t dtrace_fasttrap_probe_ptr;
dtrace_pid_probe_ptr_t dtrace_pid_probe_ptr;
dtrace_return_probe_ptr_t dtrace_return_probe_ptr;
#endif
static struct powerpc_exception powerpc_exceptions[] = {
{ 0x0100, "system reset" },
{ 0x0200, "machine check" },
{ 0x0300, "data storage interrupt" },
{ 0x0380, "data segment exception" },
{ 0x0400, "instruction storage interrupt" },
{ 0x0480, "instruction segment exception" },
{ 0x0500, "external interrupt" },
{ 0x0600, "alignment" },
{ 0x0700, "program" },
{ 0x0800, "floating-point unavailable" },
{ 0x0900, "decrementer" },
{ 0x0c00, "system call" },
{ 0x0d00, "trace" },
{ 0x0e00, "floating-point assist" },
{ 0x0f00, "performance monitoring" },
{ 0x0f20, "altivec unavailable" },
{ 0x1000, "instruction tlb miss" },
{ 0x1100, "data load tlb miss" },
{ 0x1200, "data store tlb miss" },
{ 0x1300, "instruction breakpoint" },
{ 0x1400, "system management" },
{ 0x1600, "altivec assist" },
{ 0x1700, "thermal management" },
{ 0x2000, "run mode/trace" },
{ 0x3000, NULL }
};
static const char *
trapname(u_int vector)
{
struct powerpc_exception *pe;
for (pe = powerpc_exceptions; pe->vector != 0x3000; pe++) {
if (pe->vector == vector)
return (pe->name);
}
return ("unknown");
}
void
trap(struct trapframe *frame)
{
struct thread *td;
struct proc *p;
int sig, type, user;
u_int ucode;
ksiginfo_t ksi;
PCPU_INC(cnt.v_trap);
td = curthread;
p = td->td_proc;
type = ucode = frame->exc;
sig = 0;
user = frame->srr1 & PSL_PR;
CTR3(KTR_TRAP, "trap: %s type=%s (%s)", td->td_name,
trapname(type), user ? "user" : "kernel");
#ifdef HWPMC_HOOKS
if (type == EXC_PERF && (pmc_intr != NULL)) {
#ifdef notyet
(*pmc_intr)(PCPU_GET(cpuid), frame);
if (!user)
return;
#endif
}
else
#endif
#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.
*/
/*
* XXXDTRACE: add fasttrap and pid probes handlers here (if ever)
*/
if (!user) {
if (dtrace_trap_func != NULL && (*dtrace_trap_func)(frame, type))
return;
}
#endif
if (user) {
td->td_pticks = 0;
td->td_frame = frame;
if (td->td_ucred != p->p_ucred)
cred_update_thread(td);
/* User Mode Traps */
switch (type) {
case EXC_RUNMODETRC:
case EXC_TRC:
frame->srr1 &= ~PSL_SE;
sig = SIGTRAP;
break;
#ifdef __powerpc64__
case EXC_ISE:
case EXC_DSE:
if (handle_user_slb_spill(&p->p_vmspace->vm_pmap,
(type == EXC_ISE) ? frame->srr0 :
frame->cpu.aim.dar) != 0)
sig = SIGSEGV;
break;
#endif
case EXC_DSI:
case EXC_ISI:
sig = trap_pfault(frame, 1);
break;
case EXC_SC:
syscall(frame);
break;
case EXC_FPU:
KASSERT((td->td_pcb->pcb_flags & PCB_FPU) != PCB_FPU,
("FPU already enabled for thread"));
enable_fpu(td);
break;
case EXC_VEC:
KASSERT((td->td_pcb->pcb_flags & PCB_VEC) != PCB_VEC,
("Altivec already enabled for thread"));
enable_vec(td);
break;
case EXC_VECAST_G4:
case EXC_VECAST_G5:
/*
* We get a VPU assist exception for IEEE mode
* vector operations on denormalized floats.
* Emulating this is a giant pain, so for now,
* just switch off IEEE mode and treat them as
* zero.
*/
save_vec(td);
td->td_pcb->pcb_vec.vscr |= ALTIVEC_VSCR_NJ;
enable_vec(td);
break;
case EXC_ALI:
if (fix_unaligned(td, frame) != 0)
sig = SIGBUS;
else
frame->srr0 += 4;
break;
case EXC_PGM:
/* Identify the trap reason */
if (frame->srr1 & EXC_PGM_TRAP)
sig = SIGTRAP;
else if (ppc_instr_emulate(frame) == 0)
frame->srr0 += 4;
else
sig = SIGILL;
break;
default:
trap_fatal(frame);
}
} else {
/* Kernel Mode Traps */
KASSERT(cold || td->td_ucred != NULL,
("kernel trap doesn't have ucred"));
switch (type) {
#ifdef __powerpc64__
case EXC_DSE:
if ((frame->cpu.aim.dar & SEGMENT_MASK) == USER_ADDR) {
__asm __volatile ("slbmte %0, %1" ::
"r"(td->td_pcb->pcb_cpu.aim.usr_vsid),
"r"(USER_SLB_SLBE));
return;
}
break;
#endif
case EXC_DSI:
if (trap_pfault(frame, 0) == 0)
return;
break;
case EXC_MCHK:
if (handle_onfault(frame))
return;
break;
default:
break;
}
trap_fatal(frame);
}
if (sig != 0) {
if (p->p_sysent->sv_transtrap != NULL)
sig = (p->p_sysent->sv_transtrap)(sig, type);
ksiginfo_init_trap(&ksi);
ksi.ksi_signo = sig;
ksi.ksi_code = (int) ucode; /* XXX, not POSIX */
/* ksi.ksi_addr = ? */
ksi.ksi_trapno = type;
trapsignal(td, &ksi);
}
userret(td, frame);
}
static void
trap_fatal(struct trapframe *frame)
{
printtrap(frame->exc, frame, 1, (frame->srr1 & PSL_PR));
#ifdef KDB
if ((debugger_on_panic || kdb_active) &&
kdb_trap(frame->exc, 0, frame))
return;
#endif
panic("%s trap", trapname(frame->exc));
}
static void
printtrap(u_int vector, struct trapframe *frame, int isfatal, int user)
{
printf("\n");
printf("%s %s trap:\n", isfatal ? "fatal" : "handled",
user ? "user" : "kernel");
printf("\n");
printf(" exception = 0x%x (%s)\n", vector, trapname(vector));
switch (vector) {
case EXC_DSE:
case EXC_DSI:
printf(" virtual address = 0x%" PRIxPTR "\n",
frame->cpu.aim.dar);
break;
case EXC_ISE:
case EXC_ISI:
printf(" virtual address = 0x%" PRIxPTR "\n", frame->srr0);
break;
}
printf(" srr0 = 0x%" PRIxPTR "\n", frame->srr0);
printf(" srr1 = 0x%" PRIxPTR "\n", frame->srr1);
printf(" lr = 0x%" PRIxPTR "\n", frame->lr);
printf(" curthread = %p\n", curthread);
if (curthread != NULL)
printf(" pid = %d, comm = %s\n",
curthread->td_proc->p_pid, curthread->td_name);
printf("\n");
}
/*
* Handles a fatal fault when we have onfault state to recover. Returns
* non-zero if there was onfault recovery state available.
*/
static int
handle_onfault(struct trapframe *frame)
{
struct thread *td;
faultbuf *fb;
td = curthread;
fb = td->td_pcb->pcb_onfault;
if (fb != NULL) {
frame->srr0 = (*fb)[0];
frame->fixreg[1] = (*fb)[1];
frame->fixreg[2] = (*fb)[2];
frame->fixreg[3] = 1;
frame->cr = (*fb)[3];
bcopy(&(*fb)[4], &frame->fixreg[13],
19 * sizeof(register_t));
return (1);
}
return (0);
}
int
cpu_fetch_syscall_args(struct thread *td, struct syscall_args *sa)
{
struct proc *p;
struct trapframe *frame;
caddr_t params;
size_t argsz;
int error, n, i;
p = td->td_proc;
frame = td->td_frame;
sa->code = frame->fixreg[0];
params = (caddr_t)(frame->fixreg + FIRSTARG);
n = NARGREG;
if (sa->code == SYS_syscall) {
/*
* code is first argument,
* followed by actual args.
*/
sa->code = *(register_t *) params;
params += sizeof(register_t);
n -= 1;
} else if (sa->code == SYS___syscall) {
/*
* Like syscall, but code is a quad,
* so as to maintain quad alignment
* for the rest of the args.
*/
if (SV_PROC_FLAG(p, SV_ILP32)) {
params += sizeof(register_t);
sa->code = *(register_t *) params;
params += sizeof(register_t);
n -= 2;
} else {
sa->code = *(register_t *) params;
params += sizeof(register_t);
n -= 1;
}
}
if (p->p_sysent->sv_mask)
sa->code &= p->p_sysent->sv_mask;
if (sa->code >= p->p_sysent->sv_size)
sa->callp = &p->p_sysent->sv_table[0];
else
sa->callp = &p->p_sysent->sv_table[sa->code];
sa->narg = sa->callp->sy_narg;
if (SV_PROC_FLAG(p, SV_ILP32)) {
argsz = sizeof(uint32_t);
for (i = 0; i < n; i++)
sa->args[i] = ((u_register_t *)(params))[i] &
0xffffffff;
} else {
argsz = sizeof(uint64_t);
for (i = 0; i < n; i++)
sa->args[i] = ((u_register_t *)(params))[i];
}
if (sa->narg > n)
error = copyin(MOREARGS(frame->fixreg[1]), sa->args + n,
(sa->narg - n) * argsz);
else
error = 0;
#ifdef __powerpc64__
if (SV_PROC_FLAG(p, SV_ILP32) && sa->narg > n) {
/* Expand the size of arguments copied from the stack */
for (i = sa->narg; i >= n; i--)
sa->args[i] = ((uint32_t *)(&sa->args[n]))[i-n];
}
#endif
if (error == 0) {
td->td_retval[0] = 0;
td->td_retval[1] = frame->fixreg[FIRSTARG + 1];
}
return (error);
}
#include "../../kern/subr_syscall.c"
void
syscall(struct trapframe *frame)
{
struct thread *td;
struct syscall_args sa;
int error;
td = curthread;
td->td_frame = frame;
#ifdef __powerpc64__
/*
* Speculatively restore last user SLB segment, which we know is
* invalid already, since we are likely to do copyin()/copyout().
*/
__asm __volatile ("slbmte %0, %1; isync" ::
"r"(td->td_pcb->pcb_cpu.aim.usr_vsid), "r"(USER_SLB_SLBE));
#endif
error = syscallenter(td, &sa);
syscallret(td, error, &sa);
}
#ifdef __powerpc64__
/* Handle kernel SLB faults -- runs in real mode, all seat belts off */
void
handle_kernel_slb_spill(int type, register_t dar, register_t srr0)
{
struct slb *slbcache;
uint64_t slbe, slbv;
uint64_t esid, addr;
int i;
addr = (type == EXC_ISE) ? srr0 : dar;
slbcache = PCPU_GET(slb);
esid = (uintptr_t)addr >> ADDR_SR_SHFT;
slbe = (esid << SLBE_ESID_SHIFT) | SLBE_VALID;
/* See if the hardware flushed this somehow (can happen in LPARs) */
for (i = 0; i < n_slbs; i++)
if (slbcache[i].slbe == (slbe | (uint64_t)i))
return;
/* Not in the map, needs to actually be added */
slbv = kernel_va_to_slbv(addr);
if (slbcache[USER_SLB_SLOT].slbe == 0) {
for (i = 0; i < n_slbs; i++) {
if (i == USER_SLB_SLOT)
continue;
if (!(slbcache[i].slbe & SLBE_VALID))
goto fillkernslb;
}
if (i == n_slbs)
slbcache[USER_SLB_SLOT].slbe = 1;
}
/* Sacrifice a random SLB entry that is not the user entry */
i = mftb() % n_slbs;
if (i == USER_SLB_SLOT)
i = (i+1) % n_slbs;
fillkernslb:
/* Write new entry */
slbcache[i].slbv = slbv;
slbcache[i].slbe = slbe | (uint64_t)i;
/* Trap handler will restore from cache on exit */
}
static int
handle_user_slb_spill(pmap_t pm, vm_offset_t addr)
{
struct slb *user_entry;
uint64_t esid;
int i;
esid = (uintptr_t)addr >> ADDR_SR_SHFT;
PMAP_LOCK(pm);
user_entry = user_va_to_slb_entry(pm, addr);
if (user_entry == NULL) {
/* allocate_vsid auto-spills it */
(void)allocate_user_vsid(pm, esid, 0);
} else {
/*
* Check that another CPU has not already mapped this.
* XXX: Per-thread SLB caches would be better.
*/
for (i = 0; i < pm->pm_slb_len; i++)
if (pm->pm_slb[i] == user_entry)
break;
if (i == pm->pm_slb_len)
slb_insert_user(pm, user_entry);
}
PMAP_UNLOCK(pm);
return (0);
}
#endif
static int
trap_pfault(struct trapframe *frame, int user)
{
vm_offset_t eva, va;
struct thread *td;
struct proc *p;
vm_map_t map;
vm_prot_t ftype;
int rv;
register_t user_sr;
td = curthread;
p = td->td_proc;
if (frame->exc == EXC_ISI) {
eva = frame->srr0;
ftype = VM_PROT_EXECUTE;
if (frame->srr1 & SRR1_ISI_PFAULT)
ftype |= VM_PROT_READ;
} else {
eva = frame->cpu.aim.dar;
if (frame->cpu.aim.dsisr & DSISR_STORE)
ftype = VM_PROT_WRITE;
else
ftype = VM_PROT_READ;
}
if (user) {
map = &p->p_vmspace->vm_map;
} else {
if ((eva >> ADDR_SR_SHFT) == (USER_ADDR >> ADDR_SR_SHFT)) {
if (p->p_vmspace == NULL)
return (SIGSEGV);
map = &p->p_vmspace->vm_map;
user_sr = td->td_pcb->pcb_cpu.aim.usr_segm;
eva &= ADDR_PIDX | ADDR_POFF;
eva |= user_sr << ADDR_SR_SHFT;
} else {
map = kernel_map;
}
}
va = trunc_page(eva);
if (map != kernel_map) {
/*
* Keep swapout from messing with us during this
* critical time.
*/
PROC_LOCK(p);
++p->p_lock;
PROC_UNLOCK(p);
/* Fault in the user page: */
rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
PROC_LOCK(p);
--p->p_lock;
PROC_UNLOCK(p);
/*
* XXXDTRACE: add dtrace_doubletrap_func here?
*/
} else {
/*
* Don't have to worry about process locking or stacks in the
* kernel.
*/
rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL);
}
if (rv == KERN_SUCCESS)
return (0);
if (!user && handle_onfault(frame))
return (0);
return (SIGSEGV);
}
int
badaddr(void *addr, size_t size)
{
return (badaddr_read(addr, size, NULL));
}
int
badaddr_read(void *addr, size_t size, int *rptr)
{
struct thread *td;
faultbuf env;
int x;
/* Get rid of any stale machine checks that have been waiting. */
__asm __volatile ("sync; isync");
td = curthread;
if (setfault(env)) {
td->td_pcb->pcb_onfault = 0;
__asm __volatile ("sync");
return 1;
}
__asm __volatile ("sync");
switch (size) {
case 1:
x = *(volatile int8_t *)addr;
break;
case 2:
x = *(volatile int16_t *)addr;
break;
case 4:
x = *(volatile int32_t *)addr;
break;
default:
panic("badaddr: invalid size (%zd)", size);
}
/* Make sure we took the machine check, if we caused one. */
__asm __volatile ("sync; isync");
td->td_pcb->pcb_onfault = 0;
__asm __volatile ("sync"); /* To be sure. */
/* Use the value to avoid reorder. */
if (rptr)
*rptr = x;
return (0);
}
/*
* For now, this only deals with the particular unaligned access case
* that gcc tends to generate. Eventually it should handle all of the
* possibilities that can happen on a 32-bit PowerPC in big-endian mode.
*/
static int
fix_unaligned(struct thread *td, struct trapframe *frame)
{
struct thread *fputhread;
int indicator, reg;
double *fpr;
indicator = EXC_ALI_OPCODE_INDICATOR(frame->cpu.aim.dsisr);
switch (indicator) {
case EXC_ALI_LFD:
case EXC_ALI_STFD:
reg = EXC_ALI_RST(frame->cpu.aim.dsisr);
fpr = &td->td_pcb->pcb_fpu.fpr[reg];
fputhread = PCPU_GET(fputhread);
/* Juggle the FPU to ensure that we've initialized
* the FPRs, and that their current state is in
* the PCB.
*/
if (fputhread != td) {
if (fputhread)
save_fpu(fputhread);
enable_fpu(td);
}
save_fpu(td);
if (indicator == EXC_ALI_LFD) {
if (copyin((void *)frame->cpu.aim.dar, fpr,
sizeof(double)) != 0)
return -1;
enable_fpu(td);
} else {
if (copyout(fpr, (void *)frame->cpu.aim.dar,
sizeof(double)) != 0)
return -1;
}
return 0;
break;
}
return -1;
}
static int
ppc_instr_emulate(struct trapframe *frame)
{
uint32_t instr;
int reg;
instr = fuword32((void *)frame->srr0);
if ((instr & 0xfc1fffff) == 0x7c1f42a6) { /* mfpvr */
reg = (instr & ~0xfc1fffff) >> 21;
frame->fixreg[reg] = mfpvr();
return (0);
}
return (-1);
}