intel/mdb/mdb_amd64util.c

	mdb_amd64util.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (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 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

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

#include <sys/types.h>
#include <sys/reg.h>
#include <sys/privregs.h>
#include <sys/stack.h>
#include <sys/frame.h>

#include <mdb/mdb_target_impl.h>
#include <mdb/mdb_kreg_impl.h>
#include <mdb/mdb_debug.h>
#include <mdb/mdb_modapi.h>
#include <mdb/mdb_amd64util.h>
#include <mdb/mdb_err.h>
#include <mdb/mdb.h>

/*
 * This array is used by the getareg and putareg entry points, and also by our
 * register variable discipline.
 */

const mdb_tgt_regdesc_t mdb_amd64_kregs[] = {
    { "savfp", KREG_SAVFP, MDB_TGT_R_EXPORT },
    { "savpc", KREG_SAVPC, MDB_TGT_R_EXPORT },
    { "rdi", KREG_RDI, MDB_TGT_R_EXPORT },
    { "rsi", KREG_RSI, MDB_TGT_R_EXPORT },
    { "rdx", KREG_RDX, MDB_TGT_R_EXPORT },
    { "rcx", KREG_RCX, MDB_TGT_R_EXPORT },
    { "r8", KREG_R8, MDB_TGT_R_EXPORT },
    { "r9", KREG_R9, MDB_TGT_R_EXPORT },
    { "rax", KREG_RAX, MDB_TGT_R_EXPORT },
    { "rbx", KREG_RBX, MDB_TGT_R_EXPORT },
    { "rbp", KREG_RBP, MDB_TGT_R_EXPORT },
    { "r10", KREG_R10, MDB_TGT_R_EXPORT },
    { "r11", KREG_R11, MDB_TGT_R_EXPORT },
    { "r12", KREG_R12, MDB_TGT_R_EXPORT },
    { "r13", KREG_R13, MDB_TGT_R_EXPORT },
    { "r14", KREG_R14, MDB_TGT_R_EXPORT },
    { "r15", KREG_R15, MDB_TGT_R_EXPORT },
    { "fsbase", KREG_FSBASE, MDB_TGT_R_EXPORT | MDB_TGT_R_PRIV },
    { "gsbase", KREG_GSBASE, MDB_TGT_R_EXPORT | MDB_TGT_R_PRIV },
    { "kgsbase", KREG_KGSBASE, MDB_TGT_R_EXPORT | MDB_TGT_R_PRIV },
    { "ds", KREG_DS, MDB_TGT_R_EXPORT },
    { "es", KREG_ES, MDB_TGT_R_EXPORT },
    { "fs", KREG_FS, MDB_TGT_R_EXPORT },
    { "gs", KREG_GS, MDB_TGT_R_EXPORT },
    { "trapno", KREG_TRAPNO, MDB_TGT_R_EXPORT | MDB_TGT_R_PRIV },
    { "err", KREG_ERR, MDB_TGT_R_EXPORT | MDB_TGT_R_PRIV },
    { "rip", KREG_RIP, MDB_TGT_R_EXPORT },
    { "cs", KREG_CS, MDB_TGT_R_EXPORT },
    { "rflags", KREG_RFLAGS, MDB_TGT_R_EXPORT },
    { "rsp", KREG_RSP, MDB_TGT_R_EXPORT },
    { "ss", KREG_SS, MDB_TGT_R_EXPORT },
    { NULL, 0, 0 }
};

void
mdb_amd64_printregs(const mdb_tgt_gregset_t *gregs)
{
    const kreg_t *kregs = &gregs->kregs[0];
    kreg_t rflags = kregs[KREG_RFLAGS];

#define GETREG2(x) ((uintptr_t)kregs[(x)]), ((uintptr_t)kregs[(x)])

    mdb_printf("%%rax = 0x%0?p %15A %%r9  = 0x%0?p %A\n",
        GETREG2(KREG_RAX), GETREG2(KREG_R9));
    mdb_printf("%%rbx = 0x%0?p %15A %%r10 = 0x%0?p %A\n",
        GETREG2(KREG_RBX), GETREG2(KREG_R10));
    mdb_printf("%%rcx = 0x%0?p %15A %%r11 = 0x%0?p %A\n",
        GETREG2(KREG_RCX), GETREG2(KREG_R11));
    mdb_printf("%%rdx = 0x%0?p %15A %%r12 = 0x%0?p %A\n",
        GETREG2(KREG_RDX), GETREG2(KREG_R12));
    mdb_printf("%%rsi = 0x%0?p %15A %%r13 = 0x%0?p %A\n",
        GETREG2(KREG_RSI), GETREG2(KREG_R13));
    mdb_printf("%%rdi = 0x%0?p %15A %%r14 = 0x%0?p %A\n",
        GETREG2(KREG_RDI), GETREG2(KREG_R14));
    mdb_printf("%%r8  = 0x%0?p %15A %%r15 = 0x%0?p %A\n\n",
        GETREG2(KREG_R8), GETREG2(KREG_R15));

    mdb_printf("%%rip = 0x%0?p %A\n", GETREG2(KREG_RIP));
    mdb_printf("%%rbp = 0x%0?p\n", kregs[KREG_RBP]);
    mdb_printf("%%rsp = 0x%0?p\n", kregs[KREG_RSP]);

    mdb_printf("%%rflags = 0x%08x\n", rflags);

    mdb_printf("  id=%u vip=%u vif=%u ac=%u vm=%u rf=%u nt=%u iopl=0x%x\n",
        (rflags & KREG_EFLAGS_ID_MASK) >> KREG_EFLAGS_ID_SHIFT,
        (rflags & KREG_EFLAGS_VIP_MASK) >> KREG_EFLAGS_VIP_SHIFT,
        (rflags & KREG_EFLAGS_VIF_MASK) >> KREG_EFLAGS_VIF_SHIFT,
        (rflags & KREG_EFLAGS_AC_MASK) >> KREG_EFLAGS_AC_SHIFT,
        (rflags & KREG_EFLAGS_VM_MASK) >> KREG_EFLAGS_VM_SHIFT,
        (rflags & KREG_EFLAGS_RF_MASK) >> KREG_EFLAGS_RF_SHIFT,
        (rflags & KREG_EFLAGS_NT_MASK) >> KREG_EFLAGS_NT_SHIFT,
        (rflags & KREG_EFLAGS_IOPL_MASK) >> KREG_EFLAGS_IOPL_SHIFT);

    mdb_printf("  status=<%s,%s,%s,%s,%s,%s,%s,%s,%s>\n\n",
        (rflags & KREG_EFLAGS_OF_MASK) ? "OF" : "of",
        (rflags & KREG_EFLAGS_DF_MASK) ? "DF" : "df",
        (rflags & KREG_EFLAGS_IF_MASK) ? "IF" : "if",
        (rflags & KREG_EFLAGS_TF_MASK) ? "TF" : "tf",
        (rflags & KREG_EFLAGS_SF_MASK) ? "SF" : "sf",
        (rflags & KREG_EFLAGS_ZF_MASK) ? "ZF" : "zf",
        (rflags & KREG_EFLAGS_AF_MASK) ? "AF" : "af",
        (rflags & KREG_EFLAGS_PF_MASK) ? "PF" : "pf",
        (rflags & KREG_EFLAGS_CF_MASK) ? "CF" : "cf");

    mdb_printf("%24s%%cs = 0x%04x\t%%ds = 0x%04x\t%%es = 0x%04x\n",
        " ", kregs[KREG_CS], kregs[KREG_DS], kregs[KREG_ES]);

    mdb_printf("%%trapno = 0x%x\t\t%%fs = 0x%04x\tfsbase = 0x%0?p\n",
        kregs[KREG_TRAPNO], (kregs[KREG_FS] & 0xffff), kregs[KREG_FSBASE]);
    mdb_printf("   %%err = 0x%x\t\t%%gs = 0x%04x\tgsbase = 0x%0?p\n",
        kregs[KREG_ERR], (kregs[KREG_GS] & 0xffff), kregs[KREG_GSBASE]);
}

int
mdb_amd64_kvm_stack_iter(mdb_tgt_t *t, const mdb_tgt_gregset_t *gsp,
    mdb_tgt_stack_f *func, void *arg)
{
    mdb_tgt_gregset_t gregs;
    kreg_t *kregs = &gregs.kregs[0];
    int got_pc = (gsp->kregs[KREG_RIP] != 0);

    struct {
        uintptr_t fr_savfp;
        uintptr_t fr_savpc;
    } fr;

    uintptr_t fp = gsp->kregs[KREG_RBP];
    uintptr_t pc = gsp->kregs[KREG_RIP];

    bcopy(gsp, &gregs, sizeof (gregs));

    while (fp != 0) {

        if (fp & (STACK_ALIGN - 1))
            return (set_errno(EMDB_STKALIGN));

        bzero(&fr, sizeof (fr));
        (void) mdb_tgt_vread(t, &fr, sizeof (fr), fp);

        if (got_pc && func(arg, pc, 0, NULL, &gregs) != 0)
            break;

        kregs[KREG_RSP] = kregs[KREG_RBP];

        kregs[KREG_RBP] = fp = fr.fr_savfp;
        kregs[KREG_RIP] = pc = fr.fr_savpc;

        got_pc = (pc != 0);
    }

    return (0);
}

/*
 * Determine the return address for the current frame.  Typically this is the
 * fr_savpc value from the current frame, but we also perform some special
 * handling to see if we are stopped on one of the first two instructions of
 * a typical function prologue, in which case %rbp will not be set up yet.
 */
int
mdb_amd64_step_out(mdb_tgt_t *t, uintptr_t *p, kreg_t pc, kreg_t fp, kreg_t sp,
    mdb_instr_t curinstr)
{
    struct frame fr;
    GElf_Sym s;
    char buf[1];

    enum {
        M_PUSHQ_RBP = 0x55, /* pushq %rbp */
        M_REX_W     = 0x48, /* REX prefix with only W set */
        M_MOVL_RBP  = 0x8b  /* movq %rsp, %rbp with prefix */
    };

    if (mdb_tgt_lookup_by_addr(t, pc, MDB_TGT_SYM_FUZZY,
        buf, 0, &s, NULL) == 0) {
        if (pc == s.st_value && curinstr == M_PUSHQ_RBP)
            fp = sp - 8;
        else if (pc == s.st_value + 1 && curinstr == M_REX_W) {
            if (mdb_tgt_vread(t, &curinstr, sizeof (curinstr),
                pc + 1) == sizeof (curinstr) && curinstr ==
                M_MOVL_RBP)
                fp = sp;
        }
    }

    if (mdb_tgt_vread(t, &fr, sizeof (fr), fp) == sizeof (fr)) {
        *p = fr.fr_savpc;
        return (0);
    }

    return (-1); /* errno is set for us */
}

/*ARGSUSED*/
int
mdb_amd64_next(mdb_tgt_t *t, uintptr_t *p, kreg_t pc, mdb_instr_t curinstr)
{
    mdb_tgt_addr_t npc;

    enum {
        M_CALL_REL = 0xe8, /* call near with relative displacement */
        M_CALL_REG = 0xff, /* call near indirect or call far register */

        M_REX_LO = 0x40,
        M_REX_HI = 0x4f
    };

    /*
     * If the opcode is a near call with relative displacement, assume the
     * displacement is a rel32 from the next instruction.
     */
    if (curinstr == M_CALL_REL) {
        *p = pc + sizeof (mdb_instr_t) + sizeof (uint32_t);
        return (0);
    }

    /* Skip the rex prefix, if any */
    if (curinstr >= M_REX_LO && curinstr <= M_REX_HI &&
        mdb_tgt_vread(t, &curinstr, sizeof (curinstr), pc) !=
        sizeof (curinstr))
        return (-1); /* errno is set for us */

    if (curinstr != M_CALL_REG) {
        /* It's not a call */
        return (set_errno(EAGAIN));
    }

    if ((npc = mdb_dis_nextins(mdb.m_disasm, t, MDB_TGT_AS_VIRT, pc)) == pc)
        return (-1); /* errno is set for us */

    *p = npc;
    return (0);
}

/*ARGSUSED*/
int
mdb_amd64_kvm_frame(void *arglim, uintptr_t pc, uint_t argc, const long *argv,
    const mdb_tgt_gregset_t *gregs)
{
    argc = MIN(argc, (uintptr_t)arglim);
    mdb_printf("%a(", pc);

    if (argc != 0) {
        mdb_printf("%lr", *argv++);
        for (argc--; argc != 0; argc--)
            mdb_printf(", %lr", *argv++);
    }

    mdb_printf(")\n");
    return (0);
}

int
mdb_amd64_kvm_framev(void *arglim, uintptr_t pc, uint_t argc, const long *argv,
    const mdb_tgt_gregset_t *gregs)
{
    argc = MIN(argc, (uintptr_t)arglim);
    mdb_printf("%0?lr %a(", gregs->kregs[KREG_RBP], pc);

    if (argc != 0) {
        mdb_printf("%lr", *argv++);
        for (argc--; argc != 0; argc--)
            mdb_printf(", %lr", *argv++);
    }

    mdb_printf(")\n");
    return (0);
}