intel/kmdb/kvm_isadep.c

	kvm_isadep.c revision ae115bc77f6fcde83175c75b4206dc2e50747966
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * isa-dependent portions of the kmdb target
 */

#include <kmdb/kvm.h>
#include <kmdb/kvm_cpu.h>
#include <kmdb/kmdb_kdi.h>
#include <kmdb/kmdb_asmutil.h>
#include <mdb/mdb_debug.h>
#include <mdb/mdb_err.h>
#include <mdb/mdb_list.h>
#include <mdb/mdb_target_impl.h>
#include <mdb/mdb_isautil.h>
#include <mdb/mdb_kreg_impl.h>
#include <mdb/mdb.h>

#include <sys/types.h>
#include <sys/frame.h>
#include <sys/trap.h>
#include <sys/bitmap.h>
#include <sys/pci_impl.h>

/* Higher than the highest trap number for which we have a defined specifier */
#define KMT_MAXTRAPNO   0x20

#define IOPORTLIMIT 0xffff  /* XXX find a new home for this */

const char *
kmt_def_dismode(void)
{
#ifdef  __amd64
    return ("amd64");
#else
    return ("ia32");
#endif
}

int
kmt_step_out_validate(mdb_tgt_t *t, uintptr_t pc)
{
    kmt_data_t *kmt = t->t_data;
    int i;

    for (i = 0; i < sizeof (kmt->kmt_intrsyms) / sizeof (GElf_Sym); i++) {
        GElf_Sym *sym = (GElf_Sym *)&kmt->kmt_intrsyms + i;

        if (pc >= sym->st_value && pc < sym->st_value + sym->st_size)
            return (0);
    }

    return (1);
}

/*
 * Determine the return address for the current frame.
 */
int
kmt_step_out(mdb_tgt_t *t, uintptr_t *p)
{
    mdb_instr_t instr;
    kreg_t pc, sp, fp;

    (void) kmdb_dpi_get_register("pc", &pc);
    (void) kmdb_dpi_get_register("sp", &sp);
    (void) kmdb_dpi_get_register("fp", &fp);

    if (mdb_tgt_vread(t, &instr, sizeof (mdb_instr_t), pc) !=
        sizeof (mdb_instr_t))
        return (-1); /* errno is set for us */

    if (!kmt_step_out_validate(t, pc))
        return (set_errno(EMDB_TGTNOTSUP));

    return (mdb_isa_step_out(t, p, pc, fp, sp, instr));
}

int
kmt_step_branch(mdb_tgt_t *t)
{
    kmt_data_t *kmt = t->t_data;

    return (kmt_cpu_step_branch(t, kmt->kmt_cpu));
}

/*
 * Return the address of the next instruction following a call, or return -1
 * and set errno to EAGAIN if the target should just single-step.
 */
int
kmt_next(mdb_tgt_t *t, uintptr_t *p)
{
    kreg_t pc;
    mdb_instr_t instr;

    (void) kmdb_dpi_get_register("pc", &pc);

    if (mdb_tgt_vread(t, &instr, sizeof (mdb_instr_t), pc) !=
        sizeof (mdb_instr_t))
        return (-1); /* errno is set for us */

    return (mdb_isa_next(t, p, pc, instr));
}

/*
 * Return a flag indicating if the specified %eip is likely to have an
 * interrupt frame on the stack.  We do this by comparing the address to the
 * range of addresses spanned by several well-known routines, and looking
 * to see if the next and previous %ebp values are "far" apart.  Sigh.
 */
int
mdb_kvm_intrframe(mdb_tgt_t *t, uintptr_t pc, uintptr_t fp,
    uintptr_t prevfp)
{
    kmt_data_t *kmt = t->t_data;
    const size_t dist = 0x800 * sizeof (uintptr_t);

    return ((pc >= kmt->kmt_cmnint.st_value &&
        (pc < kmt->kmt_cmnint.st_value + kmt->kmt_cmnint.st_size)) ||
        (pc >= kmt->kmt_cmntrap.st_value &&
        (pc < kmt->kmt_cmntrap.st_value + kmt->kmt_cmntrap.st_size)) ||
        (fp >= prevfp + dist) || (fp <= prevfp - dist));
}

/*ARGSUSED*/
static int
kmt_stack_common(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv,
    int cpuid, mdb_tgt_stack_f *func)
{
    const mdb_tgt_gregset_t *grp = NULL;
    mdb_tgt_gregset_t gregs;
    void *arg = (void *)(uintptr_t)mdb.m_nargs;

    if (flags & DCMD_ADDRSPEC) {
        bzero(&gregs, sizeof (gregs));
        gregs.kregs[KREG_FP] = addr;
        grp = &gregs;
    } else
        grp = kmdb_dpi_get_gregs(cpuid);

    if (grp == NULL) {
        warn("failed to retrieve registers for cpu %d", cpuid);
        return (DCMD_ERR);
    }

    if (argc != 0) {
        if (argv->a_type == MDB_TYPE_CHAR || argc > 1)
            return (DCMD_USAGE);

        if (argv->a_type == MDB_TYPE_STRING)
            arg = (void *)(uintptr_t)mdb_strtoull(argv->a_un.a_str);
        else
            arg = (void *)(uintptr_t)argv->a_un.a_val;
    }

    (void) mdb_isa_kvm_stack_iter(mdb.m_target, grp, func, arg);

    return (DCMD_OK);
}

int
kmt_cpustack(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv,
    int cpuid, int verbose)
{
    return (kmt_stack_common(addr, flags, argc, argv, cpuid,
        (verbose ? mdb_isa_kvm_framev : mdb_isa_kvm_frame)));
}

int
kmt_stack(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    return (kmt_stack_common(addr, flags, argc, argv, DPI_MASTER_CPUID,
        mdb_isa_kvm_frame));
}

int
kmt_stackv(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    return (kmt_stack_common(addr, flags, argc, argv, DPI_MASTER_CPUID,
        mdb_isa_kvm_framev));
}

int
kmt_stackr(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    return (kmt_stack_common(addr, flags, argc, argv, DPI_MASTER_CPUID,
        mdb_isa_kvm_framev));
}

/*ARGSUSED*/
void
kmt_printregs(const mdb_tgt_gregset_t *gregs)
{
    mdb_isa_printregs(gregs);
}

#define IOCHECK_NOWARN  0
#define IOCHECK_WARN    1

static int
kmt_io_check(uint64_t nbytes, uintptr_t addr, int dowarn)
{
    if (addr > IOPORTLIMIT) {
        if (dowarn)
            warn("port address must be 0-%#x\n", IOPORTLIMIT);
        return (set_errno(EINVAL));
    }

    if (nbytes != 1 && nbytes != 2 && nbytes != 4) {
        if (dowarn)
            warn("port access must be 1, 2, or 4 bytes\n");
        return (set_errno(EINVAL));
    }

    if ((addr & (nbytes - 1)) != 0) {
        if (dowarn) {
            warn("address for %llu-byte access must be %llu-byte "
                "aligned\n", (u_longlong_t)nbytes,
                (u_longlong_t)nbytes);
        }
        return (set_errno(EINVAL));
    }

    return (0);
}

/*ARGSUSED1*/
int
kmt_in_dcmd(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    uint64_t len = 0;
    uint32_t buf;

    if (mdb_getopts(argc, argv,
        'L', MDB_OPT_UINT64, &len,
        NULL) != argc)
        return (DCMD_USAGE);

    if (len == 0)
        len = mdb.m_dcount;

    if (kmt_io_check(len, addr, IOCHECK_WARN) < 0)
        return (DCMD_ERR);

    if (mdb_tgt_ioread(mdb.m_target, &buf, len, addr) < 0) {
        warn("failed to read from port 0x%llx", (u_longlong_t)addr);
        return (DCMD_ERR);
    }

    mdb_printf("%x\n", buf);

    return (DCMD_OK);
}

static uint64_t
kmt_numarg(const mdb_arg_t *arg)
{
    if (arg->a_type == MDB_TYPE_STRING)
        return (mdb_strtoull(arg->a_un.a_str));
    else
        return (arg->a_un.a_val);
}

/*ARGSUSED1*/
int
kmt_out_dcmd(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    uint64_t len = 0;
    uint64_t val;

    if (mdb_getopts(argc, argv,
        'L', MDB_OPT_UINT64, &len,
        NULL) != argc - 1)
        return (DCMD_USAGE);

    if (len == 0)
        len = mdb.m_dcount;

    argv += argc - 1;
    val = kmt_numarg(argv);

    if (kmt_io_check(len, addr, IOCHECK_WARN) < 0)
        return (DCMD_ERR);

    if (val > (1ULL << (len * NBBY)) - 1) {
        warn("value is out of range for port size\n");
        return (DCMD_ERR);
    }

    if (mdb_tgt_iowrite(mdb.m_target, &val, len, addr) < 0) {
        warn("failed to write to port %llx", (u_longlong_t)addr);
        return (DCMD_ERR);
    }

    return (DCMD_OK);
}

static int
kmt_rwmsr(uint32_t addr, uint64_t *valp, void (*rw)(uint32_t, uint64_t *))
{
    jmp_buf pcb, *oldpcb = NULL;

    if (setjmp(pcb) != 0) {
        kmdb_dpi_restore_fault_hdlr(oldpcb);
        return (-1); /* errno is set for us */
    }

    oldpcb = kmdb_dpi_set_fault_hdlr(&pcb);
    rw(addr, valp);
    kmdb_dpi_restore_fault_hdlr(oldpcb);

    return (0);
}

/*ARGSUSED*/
int
kmt_rdmsr(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    uint64_t val;

    if (!(flags & DCMD_ADDRSPEC))
        return (DCMD_USAGE);

    if (kmt_rwmsr(addr, &val, rdmsr) < 0) {
        warn("rdmsr failed");
        return (DCMD_ERR);
    }

    mdb_printf("%llx\n", (u_longlong_t)val);

    return (DCMD_OK);
}

/*ARGSUSED*/
int
kmt_wrmsr(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    uint64_t val;

    if (!(flags & DCMD_ADDRSPEC) || argc != 1)
        return (DCMD_USAGE);

    val = kmt_numarg(argv);

    if (kmt_rwmsr(addr, &val, wrmsr)) {
        warn("wrmsr failed");
        return (DCMD_ERR);
    }

    return (DCMD_OK);
}

int
kmt_msr_validate(const kdi_msr_t *msr)
{
    uint64_t val;

    for (/* */; msr->msr_num != 0; msr++) {
        if (kmt_rwmsr(msr->msr_num, &val, rdmsr) < 0)
            return (0);
    }

    return (1);
}

/*ARGSUSED*/
ssize_t
kmt_write(mdb_tgt_t *t, const void *buf, size_t nbytes, uintptr_t addr)
{
    if (!(t->t_flags & MDB_TGT_F_ALLOWIO) &&
        (nbytes = kmdb_kdi_range_is_nontoxic(addr, nbytes, 1)) == 0)
        return (set_errno(EMDB_NOMAP));

    /*
     * No writes to user space are allowed.  If we were to allow it, we'd
     * be in the unfortunate situation where kmdb could place a breakpoint
     * on a userspace executable page; this dirty page would end up being
     * flushed back to disk, incurring sadness when it's next executed.
     * Besides, we can't allow trapping in from userspace anyway.
     */
    if (addr < kmdb_kdi_get_userlimit())
        return (set_errno(EMDB_TGTNOTSUP));

    return (kmt_rw(t, (void *)buf, nbytes, addr, kmt_writer));
}

/*ARGSUSED*/
static ssize_t
kmt_iorw(mdb_tgt_t *t, void *buf, size_t nbytes, uint64_t addr,
    void (*iorw)(void *, size_t, uintptr_t))
{
    jmp_buf pcb, *oldpcb = NULL;

    if (kmt_io_check(nbytes, addr, IOCHECK_NOWARN) < 0)
        return (-1); /* errno is set for us */

    if (setjmp(pcb) != 0) {
        kmdb_dpi_restore_fault_hdlr(oldpcb);
        return (-1); /* errno is set for us */
    }

    oldpcb = kmdb_dpi_set_fault_hdlr(&pcb);
    iorw(buf, nbytes, addr);
    kmdb_dpi_restore_fault_hdlr(oldpcb);

    return (nbytes);
}

/*ARGSUSED*/
ssize_t
kmt_ioread(mdb_tgt_t *t, void *buf, size_t nbytes, uintptr_t addr)
{
    return (kmt_iorw(t, buf, nbytes, addr, kmt_in));
}

/*ARGSUSED*/
ssize_t
kmt_iowrite(mdb_tgt_t *t, const void *buf, size_t nbytes, uintptr_t addr)
{
    return (kmt_iorw(t, (void *)buf, nbytes, addr, kmt_out));
}

static int
kmt_pcicfg_common(uintptr_t off, uint32_t *valp, const mdb_arg_t *argv,
    void (*rw)(void *, size_t, uintptr_t))
{
    uint32_t bus, dev, func;
    uint32_t addr;

    bus = kmt_numarg(&argv[0]);
    dev = kmt_numarg(&argv[1]);
    func = kmt_numarg(&argv[2]);

    if ((bus & 0xffff) != bus) {
        warn("invalid bus number (must be 0-0xffff)\n");
        return (DCMD_ERR);
    }

    if ((dev & 0x1f) != dev) {
        warn("invalid device number (must be 0-0x1f)\n");
        return (DCMD_ERR);
    }

    if ((func & 0x7) != func) {
        warn("invalid function number (must be 0-7)\n");
        return (DCMD_ERR);
    }

    if ((off & 0xfc) != off) {
        warn("invalid register number (must be 0-0xff, and 4-byte "
            "aligned\n");
        return (DCMD_ERR);
    }

    addr = PCI_CADDR1(bus, dev, func, off);

    if (kmt_iowrite(mdb.m_target, &addr, sizeof (addr), PCI_CONFADD) !=
        sizeof (addr)) {
        warn("write of PCI_CONFADD failed");
        return (DCMD_ERR);
    }

    if (kmt_iorw(mdb.m_target, valp, sizeof (*valp), PCI_CONFDATA, rw) !=
        sizeof (*valp)) {
        warn("access to PCI_CONFDATA failed");
        return (DCMD_ERR);
    }

    return (DCMD_OK);
}

/*ARGSUSED*/
int
kmt_rdpcicfg(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    uint32_t val;

    if (argc != 3 || !(flags & DCMD_ADDRSPEC))
        return (DCMD_USAGE);

    if (kmt_pcicfg_common(addr, &val, argv, kmt_in) != DCMD_OK)
        return (DCMD_ERR);

    mdb_printf("%llx\n", (u_longlong_t)val);

    return (DCMD_OK);
}

/*ARGSUSED*/
int
kmt_wrpcicfg(uintptr_t addr, uint_t flags, int argc, const mdb_arg_t *argv)
{
    uint32_t val;

    if (argc != 4 || !(flags & DCMD_ADDRSPEC))
        return (DCMD_USAGE);

    val = (uint32_t)kmt_numarg(&argv[3]);

    if (kmt_pcicfg_common(addr, &val, argv, kmt_out) != DCMD_OK)
        return (DCMD_ERR);

    return (DCMD_OK);
}

const char *
kmt_trapname(int trapnum)
{
    static char trapname[11];

    switch (trapnum) {
    case T_ZERODIV:
        return ("division by zero (#de) trap");
    case T_SGLSTP:
        return ("single-step (#db) trap");
    case T_NMIFLT:
        return ("NMI");
    case T_BPTFLT:
        return ("breakpoint (#bp) trap");
    case T_ILLINST:
        return ("illegal instruction (#ud) trap");
    case T_SEGFLT:
        return ("segment not present (#np) trap");
    case T_STKFLT:
        return ("stack (#ss) trap");
    case T_GPFLT:
        return ("general protection (#gp) trap");
    case T_PGFLT:
        return ("page fault (#pf) trap");
    case T_ALIGNMENT:
        return ("alignment check (#ac) trap");
    case T_MCE:
        return ("machine check (#mc) trap");
    case T_SIMDFPE:
        return ("SSE/SSE2 (#xm) trap");
    case T_DBGENTR:
        return ("debugger entry trap");
    default:
        (void) mdb_snprintf(trapname, sizeof (trapname), "trap %#x",
            trapnum);
        return (trapname);
    }
}

void
kmt_init_isadep(mdb_tgt_t *t)
{
    kmt_data_t *kmt = t->t_data;

    kmt->kmt_rds = mdb_isa_kregs;

    kmt->kmt_trapmax = KMT_MAXTRAPNO;
    kmt->kmt_trapmap = mdb_zalloc(BT_SIZEOFMAP(kmt->kmt_trapmax), UM_SLEEP);

    /* Traps for which we want to provide an explicit message */
    (void) mdb_tgt_add_fault(t, T_ZERODIV, MDB_TGT_SPEC_INTERNAL,
        no_se_f, NULL);
    (void) mdb_tgt_add_fault(t, T_ILLINST, MDB_TGT_SPEC_INTERNAL,
        no_se_f, NULL);
    (void) mdb_tgt_add_fault(t, T_SEGFLT, MDB_TGT_SPEC_INTERNAL,
        no_se_f, NULL);
    (void) mdb_tgt_add_fault(t, T_STKFLT, MDB_TGT_SPEC_INTERNAL,
        no_se_f, NULL);
    (void) mdb_tgt_add_fault(t, T_GPFLT, MDB_TGT_SPEC_INTERNAL,
        no_se_f, NULL);
    (void) mdb_tgt_add_fault(t, T_PGFLT, MDB_TGT_SPEC_INTERNAL,
        no_se_f, NULL);
    (void) mdb_tgt_add_fault(t, T_ALIGNMENT, MDB_TGT_SPEC_INTERNAL,
        no_se_f, NULL);
    (void) mdb_tgt_add_fault(t, T_MCE, MDB_TGT_SPEC_INTERNAL,
        no_se_f, NULL);
    (void) mdb_tgt_add_fault(t, T_SIMDFPE, MDB_TGT_SPEC_INTERNAL,
        no_se_f, NULL);

    /*
     * Traps which will be handled elsewhere, and which therefore don't
     * need the trap-based message.
     */
    BT_SET(kmt->kmt_trapmap, T_SGLSTP);
    BT_SET(kmt->kmt_trapmap, T_BPTFLT);
    BT_SET(kmt->kmt_trapmap, T_DBGENTR);

    /* Catch-all for traps not explicitly listed here */
    (void) mdb_tgt_add_fault(t, KMT_TRAP_NOTENUM, MDB_TGT_SPEC_INTERNAL,
        no_se_f, NULL);
}

void
kmt_startup_isadep(mdb_tgt_t *t)
{
    kmt_data_t *kmt = t->t_data;

    /*
     * The stack trace and ::step out code need to detect "interrupt"
     * frames.  The heuristic they use to detect said frames requires the
     * addresses of routines that can generate them.
     */
    (void) mdb_tgt_lookup_by_name(t, MDB_TGT_OBJ_EXEC,
        "cmnint", &kmt->kmt_intrsyms._kmt_cmnint, NULL);
    (void) mdb_tgt_lookup_by_name(t, MDB_TGT_OBJ_EXEC,
        "cmntrap", &kmt->kmt_intrsyms._kmt_cmntrap, NULL);
    (void) mdb_tgt_lookup_by_name(t, MDB_TGT_OBJ_EXEC,
        "sys_sysenter", &kmt->kmt_intrsyms._kmt_sysenter, NULL);
    (void) mdb_tgt_lookup_by_name(t, MDB_TGT_OBJ_EXEC,
        "brand_sys_sysenter", &kmt->kmt_intrsyms._kmt_brand_sysenter, NULL);
#if defined(__amd64)
    (void) mdb_tgt_lookup_by_name(t, MDB_TGT_OBJ_EXEC,
        "sys_syscall", &kmt->kmt_intrsyms._kmt_syscall, NULL);
    (void) mdb_tgt_lookup_by_name(t, MDB_TGT_OBJ_EXEC,
        "brand_sys_syscall", &kmt->kmt_intrsyms._kmt_brand_syscall, NULL);
#endif
}