5876 sys/regset.h pollutes name space

[illumos-gate.git] / usr / src / uts / intel / ia32 / os / archdep.c

/*
 * 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 (c) 1992, 2010, Oracle and/or its affiliates. All rights reserved.
 */

/*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*        All Rights Reserved   */
/*
 * Copyright (c) 2012, Joyent, Inc.  All rights reserved.
 * Copyright 2012 Nexenta Systems, Inc.  All rights reserved.
 */

#include <sys/param.h>
#include <sys/types.h>
#include <sys/vmparam.h>
#include <sys/systm.h>
#include <sys/signal.h>
#include <sys/stack.h>
#include <sys/regset.h>
#include <sys/privregs.h>
#include <sys/frame.h>
#include <sys/proc.h>
#include <sys/psw.h>
#include <sys/siginfo.h>
#include <sys/cpuvar.h>
#include <sys/asm_linkage.h>
#include <sys/kmem.h>
#include <sys/errno.h>
#include <sys/bootconf.h>
#include <sys/archsystm.h>
#include <sys/debug.h>
#include <sys/elf.h>
#include <sys/spl.h>
#include <sys/time.h>
#include <sys/atomic.h>
#include <sys/sysmacros.h>
#include <sys/cmn_err.h>
#include <sys/modctl.h>
#include <sys/kobj.h>
#include <sys/panic.h>
#include <sys/reboot.h>
#include <sys/time.h>
#include <sys/fp.h>
#include <sys/x86_archext.h>
#include <sys/auxv.h>
#include <sys/auxv_386.h>
#include <sys/dtrace.h>
#include <sys/brand.h>
#include <sys/machbrand.h>
#include <sys/cmn_err.h>

extern const struct fnsave_state x87_initial;
extern const struct fxsave_state sse_initial;

/*
 * Map an fnsave-formatted save area into an fxsave-formatted save area.
 *
 * Most fields are the same width, content and semantics.  However
 * the tag word is compressed.
 */
static void
fnsave_to_fxsave(const struct fnsave_state *fn, struct fxsave_state *fx)
{
        uint_t i, tagbits;

        fx->fx_fcw = fn->f_fcw;
        fx->fx_fsw = fn->f_fsw;

        /*
         * copy element by element (because of holes)
         */
        for (i = 0; i < 8; i++)
                bcopy(&fn->f_st[i].fpr_16[0], &fx->fx_st[i].fpr_16[0],
                    sizeof (fn->f_st[0].fpr_16)); /* 80-bit x87-style floats */

        /*
         * synthesize compressed tag bits
         */
        fx->fx_fctw = 0;
        for (tagbits = fn->f_ftw, i = 0; i < 8; i++, tagbits >>= 2)
                if ((tagbits & 3) != 3)
                        fx->fx_fctw |= (1 << i);

        fx->fx_fop = fn->f_fop;

#if defined(__amd64)
        fx->fx_rip = (uint64_t)fn->f_eip;
        fx->fx_rdp = (uint64_t)fn->f_dp;
#else
        fx->fx_eip = fn->f_eip;
        fx->fx_cs = fn->f_cs;
        fx->__fx_ign0 = 0;
        fx->fx_dp = fn->f_dp;
        fx->fx_ds = fn->f_ds;
        fx->__fx_ign1 = 0;
#endif
}

/*
 * Map from an fxsave-format save area to an fnsave-format save area.
 */
static void
fxsave_to_fnsave(const struct fxsave_state *fx, struct fnsave_state *fn)
{
        uint_t i, top, tagbits;

        fn->f_fcw = fx->fx_fcw;
        fn->__f_ign0 = 0;
        fn->f_fsw = fx->fx_fsw;
        fn->__f_ign1 = 0;

        top = (fx->fx_fsw & FPS_TOP) >> 11;

        /*
         * copy element by element (because of holes)
         */
        for (i = 0; i < 8; i++)
                bcopy(&fx->fx_st[i].fpr_16[0], &fn->f_st[i].fpr_16[0],
                    sizeof (fn->f_st[0].fpr_16)); /* 80-bit x87-style floats */

        /*
         * synthesize uncompressed tag bits
         */
        fn->f_ftw = 0;
        for (tagbits = fx->fx_fctw, i = 0; i < 8; i++, tagbits >>= 1) {
                uint_t ibit, expo;
                const uint16_t *fpp;
                static const uint16_t zero[5] = { 0, 0, 0, 0, 0 };

                if ((tagbits & 1) == 0) {
                        fn->f_ftw |= 3 << (i << 1);     /* empty */
                        continue;
                }

                /*
                 * (tags refer to *physical* registers)
                 */
                fpp = &fx->fx_st[(i - top + 8) & 7].fpr_16[0];
                ibit = fpp[3] >> 15;
                expo = fpp[4] & 0x7fff;

                if (ibit && expo != 0 && expo != 0x7fff)
                        continue;                       /* valid fp number */

                if (bcmp(fpp, &zero, sizeof (zero)))
                        fn->f_ftw |= 2 << (i << 1);     /* NaN */
                else
                        fn->f_ftw |= 1 << (i << 1);     /* fp zero */
        }

        fn->f_fop = fx->fx_fop;

        fn->__f_ign2 = 0;
#if defined(__amd64)
        fn->f_eip = (uint32_t)fx->fx_rip;
        fn->f_cs = U32CS_SEL;
        fn->f_dp = (uint32_t)fx->fx_rdp;
        fn->f_ds = UDS_SEL;
#else
        fn->f_eip = fx->fx_eip;
        fn->f_cs = fx->fx_cs;
        fn->f_dp = fx->fx_dp;
        fn->f_ds = fx->fx_ds;
#endif
        fn->__f_ign3 = 0;
}

/*
 * Map from an fpregset_t into an fxsave-format save area
 */
static void
fpregset_to_fxsave(const fpregset_t *fp, struct fxsave_state *fx)
{
#if defined(__amd64)
        bcopy(fp, fx, sizeof (*fx));
#else
        const struct _fpchip_state *fc = &fp->fp_reg_set.fpchip_state;

        fnsave_to_fxsave((const struct fnsave_state *)fc, fx);
        fx->fx_mxcsr = fc->mxcsr;
        bcopy(&fc->xmm[0], &fx->fx_xmm[0], sizeof (fc->xmm));
#endif
        /*
         * avoid useless #gp exceptions - mask reserved bits
         */
        fx->fx_mxcsr &= sse_mxcsr_mask;
}

/*
 * Map from an fxsave-format save area into a fpregset_t
 */
static void
fxsave_to_fpregset(const struct fxsave_state *fx, fpregset_t *fp)
{
#if defined(__amd64)
        bcopy(fx, fp, sizeof (*fx));
#else
        struct _fpchip_state *fc = &fp->fp_reg_set.fpchip_state;

        fxsave_to_fnsave(fx, (struct fnsave_state *)fc);
        fc->mxcsr = fx->fx_mxcsr;
        bcopy(&fx->fx_xmm[0], &fc->xmm[0], sizeof (fc->xmm));
#endif
}

#if defined(_SYSCALL32_IMPL)
static void
fpregset32_to_fxsave(const fpregset32_t *fp, struct fxsave_state *fx)
{
        const struct fpchip32_state *fc = &fp->fp_reg_set.fpchip_state;

        fnsave_to_fxsave((const struct fnsave_state *)fc, fx);
        /*
         * avoid useless #gp exceptions - mask reserved bits
         */
        fx->fx_mxcsr = sse_mxcsr_mask & fc->mxcsr;
        bcopy(&fc->xmm[0], &fx->fx_xmm[0], sizeof (fc->xmm));
}

static void
fxsave_to_fpregset32(const struct fxsave_state *fx, fpregset32_t *fp)
{
        struct fpchip32_state *fc = &fp->fp_reg_set.fpchip_state;

        fxsave_to_fnsave(fx, (struct fnsave_state *)fc);
        fc->mxcsr = fx->fx_mxcsr;
        bcopy(&fx->fx_xmm[0], &fc->xmm[0], sizeof (fc->xmm));
}

static void
fpregset_nto32(const fpregset_t *src, fpregset32_t *dst)
{
        fxsave_to_fpregset32((struct fxsave_state *)src, dst);
        dst->fp_reg_set.fpchip_state.status =
            src->fp_reg_set.fpchip_state.status;
        dst->fp_reg_set.fpchip_state.xstatus =
            src->fp_reg_set.fpchip_state.xstatus;
}

static void
fpregset_32ton(const fpregset32_t *src, fpregset_t *dst)
{
        fpregset32_to_fxsave(src, (struct fxsave_state *)dst);
        dst->fp_reg_set.fpchip_state.status =
            src->fp_reg_set.fpchip_state.status;
        dst->fp_reg_set.fpchip_state.xstatus =
            src->fp_reg_set.fpchip_state.xstatus;
}
#endif

/*
 * Set floating-point registers from a native fpregset_t.
 */
void
setfpregs(klwp_t *lwp, fpregset_t *fp)
{
        struct fpu_ctx *fpu = &lwp->lwp_pcb.pcb_fpu;

        if (fpu->fpu_flags & FPU_EN) {
                if (!(fpu->fpu_flags & FPU_VALID)) {
                        /*
                         * FPU context is still active, release the
                         * ownership.
                         */
                        fp_free(fpu, 0);
                }
        }
        /*
         * Else: if we are trying to change the FPU state of a thread which
         * hasn't yet initialized floating point, store the state in
         * the pcb and indicate that the state is valid.  When the
         * thread enables floating point, it will use this state instead
         * of the default state.
         */

        switch (fp_save_mech) {
#if defined(__i386)
        case FP_FNSAVE:
                bcopy(fp, &fpu->fpu_regs.kfpu_u.kfpu_fn,
                    sizeof (fpu->fpu_regs.kfpu_u.kfpu_fn));
                break;
#endif
        case FP_FXSAVE:
                fpregset_to_fxsave(fp, &fpu->fpu_regs.kfpu_u.kfpu_fx);
                fpu->fpu_regs.kfpu_xstatus =
                    fp->fp_reg_set.fpchip_state.xstatus;
                break;

        case FP_XSAVE:
                fpregset_to_fxsave(fp,
                    &fpu->fpu_regs.kfpu_u.kfpu_xs.xs_fxsave);
                fpu->fpu_regs.kfpu_xstatus =
                    fp->fp_reg_set.fpchip_state.xstatus;
                fpu->fpu_regs.kfpu_u.kfpu_xs.xs_xstate_bv |=
                    (XFEATURE_LEGACY_FP | XFEATURE_SSE);
                break;
        default:
                panic("Invalid fp_save_mech");
                /*NOTREACHED*/
        }

        fpu->fpu_regs.kfpu_status = fp->fp_reg_set.fpchip_state.status;
        fpu->fpu_flags |= FPU_VALID;
}

/*
 * Get floating-point registers into a native fpregset_t.
 */
void
getfpregs(klwp_t *lwp, fpregset_t *fp)
{
        struct fpu_ctx *fpu = &lwp->lwp_pcb.pcb_fpu;

        kpreempt_disable();
        if (fpu->fpu_flags & FPU_EN) {
                /*
                 * If we have FPU hw and the thread's pcb doesn't have
                 * a valid FPU state then get the state from the hw.
                 */
                if (fpu_exists && ttolwp(curthread) == lwp &&
                    !(fpu->fpu_flags & FPU_VALID))
                        fp_save(fpu); /* get the current FPU state */
        }

        /*
         * There are 3 possible cases we have to be aware of here:
         *
         * 1. FPU is enabled.  FPU state is stored in the current LWP.
         *
         * 2. FPU is not enabled, and there have been no intervening /proc
         *    modifications.  Return initial FPU state.
         *
         * 3. FPU is not enabled, but a /proc consumer has modified FPU state.
         *    FPU state is stored in the current LWP.
         */
        if ((fpu->fpu_flags & FPU_EN) || (fpu->fpu_flags & FPU_VALID)) {
                /*
                 * Cases 1 and 3.
                 */
                switch (fp_save_mech) {
#if defined(__i386)
                case FP_FNSAVE:
                        bcopy(&fpu->fpu_regs.kfpu_u.kfpu_fn, fp,
                            sizeof (fpu->fpu_regs.kfpu_u.kfpu_fn));
                        break;
#endif
                case FP_FXSAVE:
                        fxsave_to_fpregset(&fpu->fpu_regs.kfpu_u.kfpu_fx, fp);
                        fp->fp_reg_set.fpchip_state.xstatus =
                            fpu->fpu_regs.kfpu_xstatus;
                        break;
                case FP_XSAVE:
                        fxsave_to_fpregset(
                            &fpu->fpu_regs.kfpu_u.kfpu_xs.xs_fxsave, fp);
                        fp->fp_reg_set.fpchip_state.xstatus =
                            fpu->fpu_regs.kfpu_xstatus;
                        break;
                default:
                        panic("Invalid fp_save_mech");
                        /*NOTREACHED*/
                }
                fp->fp_reg_set.fpchip_state.status = fpu->fpu_regs.kfpu_status;
        } else {
                /*
                 * Case 2.
                 */
                switch (fp_save_mech) {
#if defined(__i386)
                case FP_FNSAVE:
                        bcopy(&x87_initial, fp, sizeof (x87_initial));
                        break;
#endif
                case FP_FXSAVE:
                case FP_XSAVE:
                        /*
                         * For now, we don't have any AVX specific field in ABI.
                         * If we add any in the future, we need to initial them
                         * as well.
                         */
                        fxsave_to_fpregset(&sse_initial, fp);
                        fp->fp_reg_set.fpchip_state.xstatus =
                            fpu->fpu_regs.kfpu_xstatus;
                        break;
                default:
                        panic("Invalid fp_save_mech");
                        /*NOTREACHED*/
                }
                fp->fp_reg_set.fpchip_state.status = fpu->fpu_regs.kfpu_status;
        }
        kpreempt_enable();
}

#if defined(_SYSCALL32_IMPL)

/*
 * Set floating-point registers from an fpregset32_t.
 */
void
setfpregs32(klwp_t *lwp, fpregset32_t *fp)
{
        fpregset_t fpregs;

        fpregset_32ton(fp, &fpregs);
        setfpregs(lwp, &fpregs);
}

/*
 * Get floating-point registers into an fpregset32_t.
 */
void
getfpregs32(klwp_t *lwp, fpregset32_t *fp)
{
        fpregset_t fpregs;

        getfpregs(lwp, &fpregs);
        fpregset_nto32(&fpregs, fp);
}

#endif  /* _SYSCALL32_IMPL */

/*
 * Return the general registers
 */
void
getgregs(klwp_t *lwp, gregset_t grp)
{
        struct regs *rp = lwptoregs(lwp);
#if defined(__amd64)
        struct pcb *pcb = &lwp->lwp_pcb;
        int thisthread = lwptot(lwp) == curthread;

        grp[REG_RDI] = rp->r_rdi;
        grp[REG_RSI] = rp->r_rsi;
        grp[REG_RDX] = rp->r_rdx;
        grp[REG_RCX] = rp->r_rcx;
        grp[REG_R8] = rp->r_r8;
        grp[REG_R9] = rp->r_r9;
        grp[REG_RAX] = rp->r_rax;
        grp[REG_RBX] = rp->r_rbx;
        grp[REG_RBP] = rp->r_rbp;
        grp[REG_R10] = rp->r_r10;
        grp[REG_R11] = rp->r_r11;
        grp[REG_R12] = rp->r_r12;
        grp[REG_R13] = rp->r_r13;
        grp[REG_R14] = rp->r_r14;
        grp[REG_R15] = rp->r_r15;
        grp[REG_FSBASE] = pcb->pcb_fsbase;
        grp[REG_GSBASE] = pcb->pcb_gsbase;
        if (thisthread)
                kpreempt_disable();
        if (pcb->pcb_rupdate == 1) {
                grp[REG_DS] = pcb->pcb_ds;
                grp[REG_ES] = pcb->pcb_es;
                grp[REG_FS] = pcb->pcb_fs;
                grp[REG_GS] = pcb->pcb_gs;
        } else {
                grp[REG_DS] = rp->r_ds;
                grp[REG_ES] = rp->r_es;
                grp[REG_FS] = rp->r_fs;
                grp[REG_GS] = rp->r_gs;
        }
        if (thisthread)
                kpreempt_enable();
        grp[REG_TRAPNO] = rp->r_trapno;
        grp[REG_ERR] = rp->r_err;
        grp[REG_RIP] = rp->r_rip;
        grp[REG_CS] = rp->r_cs;
        grp[REG_SS] = rp->r_ss;
        grp[REG_RFL] = rp->r_rfl;
        grp[REG_RSP] = rp->r_rsp;
#else
        bcopy(&rp->r_gs, grp, sizeof (gregset_t));
#endif
}

#if defined(_SYSCALL32_IMPL)

void
getgregs32(klwp_t *lwp, gregset32_t grp)
{
        struct regs *rp = lwptoregs(lwp);
        struct pcb *pcb = &lwp->lwp_pcb;
        int thisthread = lwptot(lwp) == curthread;

        if (thisthread)
                kpreempt_disable();
        if (pcb->pcb_rupdate == 1) {
                grp[GS] = (uint16_t)pcb->pcb_gs;
                grp[FS] = (uint16_t)pcb->pcb_fs;
                grp[DS] = (uint16_t)pcb->pcb_ds;
                grp[ES] = (uint16_t)pcb->pcb_es;
        } else {
                grp[GS] = (uint16_t)rp->r_gs;
                grp[FS] = (uint16_t)rp->r_fs;
                grp[DS] = (uint16_t)rp->r_ds;
                grp[ES] = (uint16_t)rp->r_es;
        }
        if (thisthread)
                kpreempt_enable();
        grp[EDI] = (greg32_t)rp->r_rdi;
        grp[ESI] = (greg32_t)rp->r_rsi;
        grp[EBP] = (greg32_t)rp->r_rbp;
        grp[ESP] = 0;
        grp[EBX] = (greg32_t)rp->r_rbx;
        grp[EDX] = (greg32_t)rp->r_rdx;
        grp[ECX] = (greg32_t)rp->r_rcx;
        grp[EAX] = (greg32_t)rp->r_rax;
        grp[TRAPNO] = (greg32_t)rp->r_trapno;
        grp[ERR] = (greg32_t)rp->r_err;
        grp[EIP] = (greg32_t)rp->r_rip;
        grp[CS] = (uint16_t)rp->r_cs;
        grp[EFL] = (greg32_t)rp->r_rfl;
        grp[UESP] = (greg32_t)rp->r_rsp;
        grp[SS] = (uint16_t)rp->r_ss;
}

void
ucontext_32ton(const ucontext32_t *src, ucontext_t *dst)
{
        mcontext_t *dmc = &dst->uc_mcontext;
        const mcontext32_t *smc = &src->uc_mcontext;

        bzero(dst, sizeof (*dst));
        dst->uc_flags = src->uc_flags;
        dst->uc_link = (ucontext_t *)(uintptr_t)src->uc_link;

        bcopy(&src->uc_sigmask, &dst->uc_sigmask, sizeof (dst->uc_sigmask));

        dst->uc_stack.ss_sp = (void *)(uintptr_t)src->uc_stack.ss_sp;
        dst->uc_stack.ss_size = (size_t)src->uc_stack.ss_size;
        dst->uc_stack.ss_flags = src->uc_stack.ss_flags;

        dmc->gregs[REG_GS] = (greg_t)(uint32_t)smc->gregs[GS];
        dmc->gregs[REG_FS] = (greg_t)(uint32_t)smc->gregs[FS];
        dmc->gregs[REG_ES] = (greg_t)(uint32_t)smc->gregs[ES];
        dmc->gregs[REG_DS] = (greg_t)(uint32_t)smc->gregs[DS];
        dmc->gregs[REG_RDI] = (greg_t)(uint32_t)smc->gregs[EDI];
        dmc->gregs[REG_RSI] = (greg_t)(uint32_t)smc->gregs[ESI];
        dmc->gregs[REG_RBP] = (greg_t)(uint32_t)smc->gregs[EBP];
        dmc->gregs[REG_RBX] = (greg_t)(uint32_t)smc->gregs[EBX];
        dmc->gregs[REG_RDX] = (greg_t)(uint32_t)smc->gregs[EDX];
        dmc->gregs[REG_RCX] = (greg_t)(uint32_t)smc->gregs[ECX];
        dmc->gregs[REG_RAX] = (greg_t)(uint32_t)smc->gregs[EAX];
        dmc->gregs[REG_TRAPNO] = (greg_t)(uint32_t)smc->gregs[TRAPNO];
        dmc->gregs[REG_ERR] = (greg_t)(uint32_t)smc->gregs[ERR];
        dmc->gregs[REG_RIP] = (greg_t)(uint32_t)smc->gregs[EIP];
        dmc->gregs[REG_CS] = (greg_t)(uint32_t)smc->gregs[CS];
        dmc->gregs[REG_RFL] = (greg_t)(uint32_t)smc->gregs[EFL];
        dmc->gregs[REG_RSP] = (greg_t)(uint32_t)smc->gregs[UESP];
        dmc->gregs[REG_SS] = (greg_t)(uint32_t)smc->gregs[SS];

        /*
         * A valid fpregs is only copied in if uc.uc_flags has UC_FPU set
         * otherwise there is no guarantee that anything in fpregs is valid.
         */
        if (src->uc_flags & UC_FPU)
                fpregset_32ton(&src->uc_mcontext.fpregs,
                    &dst->uc_mcontext.fpregs);
}

#endif  /* _SYSCALL32_IMPL */

/*
 * Return the user-level PC.
 * If in a system call, return the address of the syscall trap.
 */
greg_t
getuserpc()
{
        greg_t upc = lwptoregs(ttolwp(curthread))->r_pc;
        uint32_t insn;

        if (curthread->t_sysnum == 0)
                return (upc);

        /*
         * We might've gotten here from sysenter (0xf 0x34),
         * syscall (0xf 0x5) or lcall (0x9a 0 0 0 0 0x27 0).
         *
         * Go peek at the binary to figure it out..
         */
        if (fuword32((void *)(upc - 2), &insn) != -1 &&
            (insn & 0xffff) == 0x340f || (insn & 0xffff) == 0x050f)
                return (upc - 2);
        return (upc - 7);
}

/*
 * Protect segment registers from non-user privilege levels and GDT selectors
 * other than USER_CS, USER_DS and lwp FS and GS values.  If the segment
 * selector is non-null and not USER_CS/USER_DS, we make sure that the
 * TI bit is set to point into the LDT and that the RPL is set to 3.
 *
 * Since struct regs stores each 16-bit segment register as a 32-bit greg_t, we
 * also explicitly zero the top 16 bits since they may be coming from the
 * user's address space via setcontext(2) or /proc.
 *
 * Note about null selector. When running on the hypervisor if we allow a
 * process to set its %cs to null selector with RPL of 0 the hypervisor will
 * crash the domain. If running on bare metal we would get a #gp fault and
 * be able to kill the process and continue on. Therefore we make sure to
 * force RPL to SEL_UPL even for null selector when setting %cs.
 */

#if defined(IS_CS) || defined(IS_NOT_CS)
#error  "IS_CS and IS_NOT_CS already defined"
#endif

#define IS_CS           1
#define IS_NOT_CS       0

/*ARGSUSED*/
static greg_t
fix_segreg(greg_t sr, int iscs, model_t datamodel)
{
        switch (sr &= 0xffff) {

        case 0:
                if (iscs == IS_CS)
                        return (0 | SEL_UPL);
                else
                        return (0);

#if defined(__amd64)
        /*
         * If lwp attempts to switch data model then force their
         * code selector to be null selector.
         */
        case U32CS_SEL:
                if (datamodel == DATAMODEL_NATIVE)
                        return (0 | SEL_UPL);
                else
                        return (sr);

        case UCS_SEL:
                if (datamodel == DATAMODEL_ILP32)
                        return (0 | SEL_UPL);
#elif defined(__i386)
        case UCS_SEL:
#endif
        /*FALLTHROUGH*/
        case UDS_SEL:
        case LWPFS_SEL:
        case LWPGS_SEL:
        case SEL_UPL:
                return (sr);
        default:
                break;
        }

        /*
         * Force it into the LDT in ring 3 for 32-bit processes, which by
         * default do not have an LDT, so that any attempt to use an invalid
         * selector will reference the (non-existant) LDT, and cause a #gp
         * fault for the process.
         *
         * 64-bit processes get the null gdt selector since they
         * are not allowed to have a private LDT.
         */
#if defined(__amd64)
        if (datamodel == DATAMODEL_ILP32) {
                return (sr | SEL_TI_LDT | SEL_UPL);
        } else {
                if (iscs == IS_CS)
                        return (0 | SEL_UPL);
                else
                        return (0);
        }

#elif defined(__i386)
        return (sr | SEL_TI_LDT | SEL_UPL);
#endif
}

/*
 * Set general registers.
 */
void
setgregs(klwp_t *lwp, gregset_t grp)
{
        struct regs *rp = lwptoregs(lwp);
        model_t datamodel = lwp_getdatamodel(lwp);

#if defined(__amd64)
        struct pcb *pcb = &lwp->lwp_pcb;
        int thisthread = lwptot(lwp) == curthread;

        if (datamodel == DATAMODEL_NATIVE) {

                if (thisthread)
                        (void) save_syscall_args();     /* copy the args */

                rp->r_rdi = grp[REG_RDI];
                rp->r_rsi = grp[REG_RSI];
                rp->r_rdx = grp[REG_RDX];
                rp->r_rcx = grp[REG_RCX];
                rp->r_r8 = grp[REG_R8];
                rp->r_r9 = grp[REG_R9];
                rp->r_rax = grp[REG_RAX];
                rp->r_rbx = grp[REG_RBX];
                rp->r_rbp = grp[REG_RBP];
                rp->r_r10 = grp[REG_R10];
                rp->r_r11 = grp[REG_R11];
                rp->r_r12 = grp[REG_R12];
                rp->r_r13 = grp[REG_R13];
                rp->r_r14 = grp[REG_R14];
                rp->r_r15 = grp[REG_R15];
                rp->r_trapno = grp[REG_TRAPNO];
                rp->r_err = grp[REG_ERR];
                rp->r_rip = grp[REG_RIP];
                /*
                 * Setting %cs or %ss to anything else is quietly but
                 * quite definitely forbidden!
                 */
                rp->r_cs = UCS_SEL;
                rp->r_ss = UDS_SEL;
                rp->r_rsp = grp[REG_RSP];

                if (thisthread)
                        kpreempt_disable();

                pcb->pcb_ds = UDS_SEL;
                pcb->pcb_es = UDS_SEL;

                /*
                 * 64-bit processes -are- allowed to set their fsbase/gsbase
                 * values directly, but only if they're using the segment
                 * selectors that allow that semantic.
                 *
                 * (32-bit processes must use lwp_set_private().)
                 */
                pcb->pcb_fsbase = grp[REG_FSBASE];
                pcb->pcb_gsbase = grp[REG_GSBASE];
                pcb->pcb_fs = fix_segreg(grp[REG_FS], IS_NOT_CS, datamodel);
                pcb->pcb_gs = fix_segreg(grp[REG_GS], IS_NOT_CS, datamodel);

                /*
                 * Ensure that we go out via update_sregs
                 */
                pcb->pcb_rupdate = 1;
                lwptot(lwp)->t_post_sys = 1;
                if (thisthread)
                        kpreempt_enable();
#if defined(_SYSCALL32_IMPL)
        } else {
                rp->r_rdi = (uint32_t)grp[REG_RDI];
                rp->r_rsi = (uint32_t)grp[REG_RSI];
                rp->r_rdx = (uint32_t)grp[REG_RDX];
                rp->r_rcx = (uint32_t)grp[REG_RCX];
                rp->r_rax = (uint32_t)grp[REG_RAX];
                rp->r_rbx = (uint32_t)grp[REG_RBX];
                rp->r_rbp = (uint32_t)grp[REG_RBP];
                rp->r_trapno = (uint32_t)grp[REG_TRAPNO];
                rp->r_err = (uint32_t)grp[REG_ERR];
                rp->r_rip = (uint32_t)grp[REG_RIP];

                rp->r_cs = fix_segreg(grp[REG_CS], IS_CS, datamodel);
                rp->r_ss = fix_segreg(grp[REG_DS], IS_NOT_CS, datamodel);

                rp->r_rsp = (uint32_t)grp[REG_RSP];

                if (thisthread)
                        kpreempt_disable();

                pcb->pcb_ds = fix_segreg(grp[REG_DS], IS_NOT_CS, datamodel);
                pcb->pcb_es = fix_segreg(grp[REG_ES], IS_NOT_CS, datamodel);

                /*
                 * (See fsbase/gsbase commentary above)
                 */
                pcb->pcb_fs = fix_segreg(grp[REG_FS], IS_NOT_CS, datamodel);
                pcb->pcb_gs = fix_segreg(grp[REG_GS], IS_NOT_CS, datamodel);

                /*
                 * Ensure that we go out via update_sregs
                 */
                pcb->pcb_rupdate = 1;
                lwptot(lwp)->t_post_sys = 1;
                if (thisthread)
                        kpreempt_enable();
#endif
        }

        /*
         * Only certain bits of the flags register can be modified.
         */
        rp->r_rfl = (rp->r_rfl & ~PSL_USERMASK) |
            (grp[REG_RFL] & PSL_USERMASK);

#elif defined(__i386)

        /*
         * Only certain bits of the flags register can be modified.
         */
        grp[EFL] = (rp->r_efl & ~PSL_USERMASK) | (grp[EFL] & PSL_USERMASK);

        /*
         * Copy saved registers from user stack.
         */
        bcopy(grp, &rp->r_gs, sizeof (gregset_t));

        rp->r_cs = fix_segreg(rp->r_cs, IS_CS, datamodel);
        rp->r_ss = fix_segreg(rp->r_ss, IS_NOT_CS, datamodel);
        rp->r_ds = fix_segreg(rp->r_ds, IS_NOT_CS, datamodel);
        rp->r_es = fix_segreg(rp->r_es, IS_NOT_CS, datamodel);
        rp->r_fs = fix_segreg(rp->r_fs, IS_NOT_CS, datamodel);
        rp->r_gs = fix_segreg(rp->r_gs, IS_NOT_CS, datamodel);

#endif  /* __i386 */
}

/*
 * Determine whether 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.
 */
extern void _interrupt();
extern void _allsyscalls();
extern void _cmntrap();
extern void fakesoftint();

extern size_t _interrupt_size;
extern size_t _allsyscalls_size;
extern size_t _cmntrap_size;
extern size_t _fakesoftint_size;

/*
 * Get a pc-only stacktrace.  Used for kmem_alloc() buffer ownership tracking.
 * Returns MIN(current stack depth, pcstack_limit).
 */
int
getpcstack(pc_t *pcstack, int pcstack_limit)
{
        struct frame *fp = (struct frame *)getfp();
        struct frame *nextfp, *minfp, *stacktop;
        int depth = 0;
        int on_intr;
        uintptr_t pc;

        if ((on_intr = CPU_ON_INTR(CPU)) != 0)
                stacktop = (struct frame *)(CPU->cpu_intr_stack + SA(MINFRAME));
        else
                stacktop = (struct frame *)curthread->t_stk;
        minfp = fp;

        pc = ((struct regs *)fp)->r_pc;

        while (depth < pcstack_limit) {
                nextfp = (struct frame *)fp->fr_savfp;
                pc = fp->fr_savpc;
                if (nextfp <= minfp || nextfp >= stacktop) {
                        if (on_intr) {
                                /*
                                 * Hop from interrupt stack to thread stack.
                                 */
                                stacktop = (struct frame *)curthread->t_stk;
                                minfp = (struct frame *)curthread->t_stkbase;
                                on_intr = 0;
                                continue;
                        }
                        break;
                }
                pcstack[depth++] = (pc_t)pc;
                fp = nextfp;
                minfp = fp;
        }
        return (depth);
}

/*
 * The following ELF header fields are defined as processor-specific
 * in the V8 ABI:
 *
 *      e_ident[EI_DATA]        encoding of the processor-specific
 *                              data in the object file
 *      e_machine               processor identification
 *      e_flags                 processor-specific flags associated
 *                              with the file
 */

/*
 * The value of at_flags reflects a platform's cpu module support.
 * at_flags is used to check for allowing a binary to execute and
 * is passed as the value of the AT_FLAGS auxiliary vector.
 */
int at_flags = 0;

/*
 * Check the processor-specific fields of an ELF header.
 *
 * returns 1 if the fields are valid, 0 otherwise
 */
/*ARGSUSED2*/
int
elfheadcheck(
        unsigned char e_data,
        Elf32_Half e_machine,
        Elf32_Word e_flags)
{
        if (e_data != ELFDATA2LSB)
                return (0);
#if defined(__amd64)
        if (e_machine == EM_AMD64)
                return (1);
#endif
        return (e_machine == EM_386);
}

uint_t auxv_hwcap_include = 0;  /* patch to enable unrecognized features */
uint_t auxv_hwcap_include_2 = 0;        /* second word */
uint_t auxv_hwcap_exclude = 0;  /* patch for broken cpus, debugging */
uint_t auxv_hwcap_exclude_2 = 0;        /* second word */
#if defined(_SYSCALL32_IMPL)
uint_t auxv_hwcap32_include = 0;        /* ditto for 32-bit apps */
uint_t auxv_hwcap32_include_2 = 0;      /* ditto for 32-bit apps */
uint_t auxv_hwcap32_exclude = 0;        /* ditto for 32-bit apps */
uint_t auxv_hwcap32_exclude_2 = 0;      /* ditto for 32-bit apps */
#endif

/*
 * Gather information about the processor and place it into auxv_hwcap
 * so that it can be exported to the linker via the aux vector.
 *
 * We use this seemingly complicated mechanism so that we can ensure
 * that /etc/system can be used to override what the system can or
 * cannot discover for itself.
 */
void
bind_hwcap(void)
{
        uint_t cpu_hwcap_flags[2];
        cpuid_pass4(NULL, cpu_hwcap_flags);

        auxv_hwcap = (auxv_hwcap_include | cpu_hwcap_flags[0]) &
            ~auxv_hwcap_exclude;
        auxv_hwcap_2 = (auxv_hwcap_include_2 | cpu_hwcap_flags[1]) &
            ~auxv_hwcap_exclude_2;

#if defined(__amd64)
        /*
         * On AMD processors, sysenter just doesn't work at all
         * when the kernel is in long mode.  On IA-32e processors
         * it does, but there's no real point in all the alternate
         * mechanism when syscall works on both.
         *
         * Besides, the kernel's sysenter handler is expecting a
         * 32-bit lwp ...
         */
        auxv_hwcap &= ~AV_386_SEP;
#else
        /*
         * 32-bit processes can -always- use the lahf/sahf instructions
         */
        auxv_hwcap |= AV_386_AHF;
#endif

        if (auxv_hwcap_include || auxv_hwcap_exclude || auxv_hwcap_include_2 ||
            auxv_hwcap_exclude_2) {
                /*
                 * The below assignment is regrettably required to get lint
                 * to accept the validity of our format string.  The format
                 * string is in fact valid, but whatever intelligence in lint
                 * understands the cmn_err()-specific %b appears to have an
                 * off-by-one error:  it (mistakenly) complains about bit
                 * number 32 (even though this is explicitly permitted).
                 * Normally, one would will away such warnings with a "LINTED"
                 * directive, but for reasons unclear and unknown, lint
                 * refuses to be assuaged in this case.  Fortunately, lint
                 * doesn't pretend to have solved the Halting Problem --
                 * and as soon as the format string is programmatic, it
                 * knows enough to shut up.
                 */
                char *fmt = "?user ABI extensions: %b\n";
                cmn_err(CE_CONT, fmt, auxv_hwcap, FMT_AV_386);
                fmt = "?user ABI extensions (word 2): %b\n";
                cmn_err(CE_CONT, fmt, auxv_hwcap_2, FMT_AV_386_2);
        }

#if defined(_SYSCALL32_IMPL)
        auxv_hwcap32 = (auxv_hwcap32_include | cpu_hwcap_flags[0]) &
            ~auxv_hwcap32_exclude;
        auxv_hwcap32_2 = (auxv_hwcap32_include_2 | cpu_hwcap_flags[1]) &
            ~auxv_hwcap32_exclude_2;

#if defined(__amd64)
        /*
         * If this is an amd64 architecture machine from Intel, then
         * syscall -doesn't- work in compatibility mode, only sysenter does.
         *
         * Sigh.
         */
        if (!cpuid_syscall32_insn(NULL))
                auxv_hwcap32 &= ~AV_386_AMD_SYSC;

        /*
         * 32-bit processes can -always- use the lahf/sahf instructions
         */
        auxv_hwcap32 |= AV_386_AHF;
#endif

        if (auxv_hwcap32_include || auxv_hwcap32_exclude ||
            auxv_hwcap32_include_2 || auxv_hwcap32_exclude_2) {
                /*
                 * See the block comment in the cmn_err() of auxv_hwcap, above.
                 */
                char *fmt = "?32-bit user ABI extensions: %b\n";
                cmn_err(CE_CONT, fmt, auxv_hwcap32, FMT_AV_386);
                fmt = "?32-bit user ABI extensions (word 2): %b\n";
                cmn_err(CE_CONT, fmt, auxv_hwcap32_2, FMT_AV_386_2);
        }
#endif
}

/*
 *      sync_icache() - this is called
 *      in proc/fs/prusrio.c. x86 has an unified cache and therefore
 *      this is a nop.
 */
/* ARGSUSED */
void
sync_icache(caddr_t addr, uint_t len)
{
        /* Do nothing for now */
}

/*ARGSUSED*/
void
sync_data_memory(caddr_t va, size_t len)
{
        /* Not implemented for this platform */
}

int
__ipltospl(int ipl)
{
        return (ipltospl(ipl));
}

/*
 * The panic code invokes panic_saveregs() to record the contents of a
 * regs structure into the specified panic_data structure for debuggers.
 */
void
panic_saveregs(panic_data_t *pdp, struct regs *rp)
{
        panic_nv_t *pnv = PANICNVGET(pdp);

        struct cregs    creg;

        getcregs(&creg);

#if defined(__amd64)
        PANICNVADD(pnv, "rdi", rp->r_rdi);
        PANICNVADD(pnv, "rsi", rp->r_rsi);
        PANICNVADD(pnv, "rdx", rp->r_rdx);
        PANICNVADD(pnv, "rcx", rp->r_rcx);
        PANICNVADD(pnv, "r8", rp->r_r8);
        PANICNVADD(pnv, "r9", rp->r_r9);
        PANICNVADD(pnv, "rax", rp->r_rax);
        PANICNVADD(pnv, "rbx", rp->r_rbx);
        PANICNVADD(pnv, "rbp", rp->r_rbp);
        PANICNVADD(pnv, "r10", rp->r_r10);
        PANICNVADD(pnv, "r11", rp->r_r11);
        PANICNVADD(pnv, "r12", rp->r_r12);
        PANICNVADD(pnv, "r13", rp->r_r13);
        PANICNVADD(pnv, "r14", rp->r_r14);
        PANICNVADD(pnv, "r15", rp->r_r15);
        PANICNVADD(pnv, "fsbase", rdmsr(MSR_AMD_FSBASE));
        PANICNVADD(pnv, "gsbase", rdmsr(MSR_AMD_GSBASE));
        PANICNVADD(pnv, "ds", rp->r_ds);
        PANICNVADD(pnv, "es", rp->r_es);
        PANICNVADD(pnv, "fs", rp->r_fs);
        PANICNVADD(pnv, "gs", rp->r_gs);
        PANICNVADD(pnv, "trapno", rp->r_trapno);
        PANICNVADD(pnv, "err", rp->r_err);
        PANICNVADD(pnv, "rip", rp->r_rip);
        PANICNVADD(pnv, "cs", rp->r_cs);
        PANICNVADD(pnv, "rflags", rp->r_rfl);
        PANICNVADD(pnv, "rsp", rp->r_rsp);
        PANICNVADD(pnv, "ss", rp->r_ss);
        PANICNVADD(pnv, "gdt_hi", (uint64_t)(creg.cr_gdt._l[3]));
        PANICNVADD(pnv, "gdt_lo", (uint64_t)(creg.cr_gdt._l[0]));
        PANICNVADD(pnv, "idt_hi", (uint64_t)(creg.cr_idt._l[3]));
        PANICNVADD(pnv, "idt_lo", (uint64_t)(creg.cr_idt._l[0]));
#elif defined(__i386)
        PANICNVADD(pnv, "gs", (uint32_t)rp->r_gs);
        PANICNVADD(pnv, "fs", (uint32_t)rp->r_fs);
        PANICNVADD(pnv, "es", (uint32_t)rp->r_es);
        PANICNVADD(pnv, "ds", (uint32_t)rp->r_ds);
        PANICNVADD(pnv, "edi", (uint32_t)rp->r_edi);
        PANICNVADD(pnv, "esi", (uint32_t)rp->r_esi);
        PANICNVADD(pnv, "ebp", (uint32_t)rp->r_ebp);
        PANICNVADD(pnv, "esp", (uint32_t)rp->r_esp);
        PANICNVADD(pnv, "ebx", (uint32_t)rp->r_ebx);
        PANICNVADD(pnv, "edx", (uint32_t)rp->r_edx);
        PANICNVADD(pnv, "ecx", (uint32_t)rp->r_ecx);
        PANICNVADD(pnv, "eax", (uint32_t)rp->r_eax);
        PANICNVADD(pnv, "trapno", (uint32_t)rp->r_trapno);
        PANICNVADD(pnv, "err", (uint32_t)rp->r_err);
        PANICNVADD(pnv, "eip", (uint32_t)rp->r_eip);
        PANICNVADD(pnv, "cs", (uint32_t)rp->r_cs);
        PANICNVADD(pnv, "eflags", (uint32_t)rp->r_efl);
        PANICNVADD(pnv, "uesp", (uint32_t)rp->r_uesp);
        PANICNVADD(pnv, "ss", (uint32_t)rp->r_ss);
        PANICNVADD(pnv, "gdt", creg.cr_gdt);
        PANICNVADD(pnv, "idt", creg.cr_idt);
#endif  /* __i386 */

        PANICNVADD(pnv, "ldt", creg.cr_ldt);
        PANICNVADD(pnv, "task", creg.cr_task);
        PANICNVADD(pnv, "cr0", creg.cr_cr0);
        PANICNVADD(pnv, "cr2", creg.cr_cr2);
        PANICNVADD(pnv, "cr3", creg.cr_cr3);
        if (creg.cr_cr4)
                PANICNVADD(pnv, "cr4", creg.cr_cr4);

        PANICNVSET(pdp, pnv);
}

#define TR_ARG_MAX 6    /* Max args to print, same as SPARC */

#if !defined(__amd64)

/*
 * Given a return address (%eip), determine the likely number of arguments
 * that were pushed on the stack prior to its execution.  We do this by
 * expecting that a typical call sequence consists of pushing arguments on
 * the stack, executing a call instruction, and then performing an add
 * on %esp to restore it to the value prior to pushing the arguments for
 * the call.  We attempt to detect such an add, and divide the addend
 * by the size of a word to determine the number of pushed arguments.
 *
 * If we do not find such an add, we punt and return TR_ARG_MAX. It is not
 * possible to reliably determine if a function took no arguments (i.e. was
 * void) because assembler routines do not reliably perform an add on %esp
 * immediately upon returning (eg. _sys_call()), so returning TR_ARG_MAX is
 * safer than returning 0.
 */
static ulong_t
argcount(uintptr_t eip)
{
        const uint8_t *ins = (const uint8_t *)eip;
        ulong_t n;

        enum {
                M_MODRM_ESP = 0xc4,     /* Mod/RM byte indicates %esp */
                M_ADD_IMM32 = 0x81,     /* ADD imm32 to r/m32 */
                M_ADD_IMM8  = 0x83      /* ADD imm8 to r/m32 */
        };

        if (eip < KERNELBASE || ins[1] != M_MODRM_ESP)
                return (TR_ARG_MAX);

        switch (ins[0]) {
        case M_ADD_IMM32:
                n = ins[2] + (ins[3] << 8) + (ins[4] << 16) + (ins[5] << 24);
                break;

        case M_ADD_IMM8:
                n = ins[2];
                break;

        default:
                return (TR_ARG_MAX);
        }

        n /= sizeof (long);
        return (MIN(n, TR_ARG_MAX));
}

#endif  /* !__amd64 */

/*
 * Print a stack backtrace using the specified frame pointer.  We delay two
 * seconds before continuing, unless this is the panic traceback.
 * If we are in the process of panicking, we also attempt to write the
 * stack backtrace to a staticly assigned buffer, to allow the panic
 * code to find it and write it in to uncompressed pages within the
 * system crash dump.
 * Note that the frame for the starting stack pointer value is omitted because
 * the corresponding %eip is not known.
 */

extern char *dump_stack_scratch;

#if defined(__amd64)

void
traceback(caddr_t fpreg)
{
        struct frame    *fp = (struct frame *)fpreg;
        struct frame    *nextfp;
        uintptr_t       pc, nextpc;
        ulong_t         off;
        char            args[TR_ARG_MAX * 2 + 16], *sym;
        uint_t    offset = 0;
        uint_t    next_offset = 0;
        char        stack_buffer[1024];

        if (!panicstr)
                printf("traceback: %%fp = %p\n", (void *)fp);

        if (panicstr && !dump_stack_scratch) {
                printf("Warning - stack not written to the dump buffer\n");
        }

        fp = (struct frame *)plat_traceback(fpreg);
        if ((uintptr_t)fp < KERNELBASE)
                goto out;

        pc = fp->fr_savpc;
        fp = (struct frame *)fp->fr_savfp;

        while ((uintptr_t)fp >= KERNELBASE) {
                /*
                 * XX64 Until port is complete tolerate 8-byte aligned
                 * frame pointers but flag with a warning so they can
                 * be fixed.
                 */
                if (((uintptr_t)fp & (STACK_ALIGN - 1)) != 0) {
                        if (((uintptr_t)fp & (8 - 1)) == 0) {
                                printf("  >> warning! 8-byte"
                                    " aligned %%fp = %p\n", (void *)fp);
                        } else {
                                printf(
                                    "  >> mis-aligned %%fp = %p\n", (void *)fp);
                                break;
                        }
                }

                args[0] = '\0';
                nextpc = (uintptr_t)fp->fr_savpc;
                nextfp = (struct frame *)fp->fr_savfp;
                if ((sym = kobj_getsymname(pc, &off)) != NULL) {
                        printf("%016lx %s:%s+%lx (%s)\n", (uintptr_t)fp,
                            mod_containing_pc((caddr_t)pc), sym, off, args);
                        (void) snprintf(stack_buffer, sizeof (stack_buffer),
                            "%s:%s+%lx (%s) | ",
                            mod_containing_pc((caddr_t)pc), sym, off, args);
                } else {
                        printf("%016lx %lx (%s)\n",
                            (uintptr_t)fp, pc, args);
                        (void) snprintf(stack_buffer, sizeof (stack_buffer),
                            "%lx (%s) | ", pc, args);
                }

                if (panicstr && dump_stack_scratch) {
                        next_offset = offset + strlen(stack_buffer);
                        if (next_offset < STACK_BUF_SIZE) {
                                bcopy(stack_buffer, dump_stack_scratch + offset,
                                    strlen(stack_buffer));
                                offset = next_offset;
                        } else {
                                /*
                                 * In attempting to save the panic stack
                                 * to the dumpbuf we have overflowed that area.
                                 * Print a warning and continue to printf the
                                 * stack to the msgbuf
                                 */
                                printf("Warning: stack in the dump buffer"
                                    " may be incomplete\n");
                                offset = next_offset;
                        }
                }

                pc = nextpc;
                fp = nextfp;
        }
out:
        if (!panicstr) {
                printf("end of traceback\n");
                DELAY(2 * MICROSEC);
        } else if (dump_stack_scratch) {
                dump_stack_scratch[offset] = '\0';
        }
}

#elif defined(__i386)

void
traceback(caddr_t fpreg)
{
        struct frame *fp = (struct frame *)fpreg;
        struct frame *nextfp, *minfp, *stacktop;
        uintptr_t pc, nextpc;
        uint_t    offset = 0;
        uint_t    next_offset = 0;
        char        stack_buffer[1024];

        cpu_t *cpu;

        /*
         * args[] holds TR_ARG_MAX hex long args, plus ", " or '\0'.
         */
        char args[TR_ARG_MAX * 2 + 8], *p;

        int on_intr;
        ulong_t off;
        char *sym;

        if (!panicstr)
                printf("traceback: %%fp = %p\n", (void *)fp);

        if (panicstr && !dump_stack_scratch) {
                printf("Warning - stack not written to the dumpbuf\n");
        }

        /*
         * If we are panicking, all high-level interrupt information in
         * CPU was overwritten.  panic_cpu has the correct values.
         */
        kpreempt_disable();                     /* prevent migration */

        cpu = (panicstr && CPU->cpu_id == panic_cpu.cpu_id)? &panic_cpu : CPU;

        if ((on_intr = CPU_ON_INTR(cpu)) != 0)
                stacktop = (struct frame *)(cpu->cpu_intr_stack + SA(MINFRAME));
        else
                stacktop = (struct frame *)curthread->t_stk;

        kpreempt_enable();

        fp = (struct frame *)plat_traceback(fpreg);
        if ((uintptr_t)fp < KERNELBASE)
                goto out;

        minfp = fp;     /* Baseline minimum frame pointer */
        pc = fp->fr_savpc;
        fp = (struct frame *)fp->fr_savfp;

        while ((uintptr_t)fp >= KERNELBASE) {
                ulong_t argc;
                long *argv;

                if (fp <= minfp || fp >= stacktop) {
                        if (on_intr) {
                                /*
                                 * Hop from interrupt stack to thread stack.
                                 */
                                stacktop = (struct frame *)curthread->t_stk;
                                minfp = (struct frame *)curthread->t_stkbase;
                                on_intr = 0;
                                continue;
                        }
                        break; /* we're outside of the expected range */
                }

                if ((uintptr_t)fp & (STACK_ALIGN - 1)) {
                        printf("  >> mis-aligned %%fp = %p\n", (void *)fp);
                        break;
                }

                nextpc = fp->fr_savpc;
                nextfp = (struct frame *)fp->fr_savfp;
                argc = argcount(nextpc);
                argv = (long *)((char *)fp + sizeof (struct frame));

                args[0] = '\0';
                p = args;
                while (argc-- > 0 && argv < (long *)stacktop) {
                        p += snprintf(p, args + sizeof (args) - p,
                            "%s%lx", (p == args) ? "" : ", ", *argv++);
                }

                if ((sym = kobj_getsymname(pc, &off)) != NULL) {
                        printf("%08lx %s:%s+%lx (%s)\n", (uintptr_t)fp,
                            mod_containing_pc((caddr_t)pc), sym, off, args);
                        (void) snprintf(stack_buffer, sizeof (stack_buffer),
                            "%s:%s+%lx (%s) | ",
                            mod_containing_pc((caddr_t)pc), sym, off, args);

                } else {
                        printf("%08lx %lx (%s)\n",
                            (uintptr_t)fp, pc, args);
                        (void) snprintf(stack_buffer, sizeof (stack_buffer),
                            "%lx (%s) | ", pc, args);

                }

                if (panicstr && dump_stack_scratch) {
                        next_offset = offset + strlen(stack_buffer);
                        if (next_offset < STACK_BUF_SIZE) {
                                bcopy(stack_buffer, dump_stack_scratch + offset,
                                    strlen(stack_buffer));
                                offset = next_offset;
                        } else {
                                /*
                                 * In attempting to save the panic stack
                                 * to the dumpbuf we have overflowed that area.
                                 * Print a warning and continue to printf the
                                 * stack to the msgbuf
                                 */
                                printf("Warning: stack in the dumpbuf"
                                    " may be incomplete\n");
                                offset = next_offset;
                        }
                }

                minfp = fp;
                pc = nextpc;
                fp = nextfp;
        }
out:
        if (!panicstr) {
                printf("end of traceback\n");
                DELAY(2 * MICROSEC);
        } else if (dump_stack_scratch) {
                dump_stack_scratch[offset] = '\0';
        }

}

#endif  /* __i386 */

/*
 * Generate a stack backtrace from a saved register set.
 */
void
traceregs(struct regs *rp)
{
        traceback((caddr_t)rp->r_fp);
}

void
exec_set_sp(size_t stksize)
{
        klwp_t *lwp = ttolwp(curthread);

        lwptoregs(lwp)->r_sp = (uintptr_t)curproc->p_usrstack - stksize;
}

hrtime_t
gethrtime_waitfree(void)
{
        return (dtrace_gethrtime());
}

hrtime_t
gethrtime(void)
{
        return (gethrtimef());
}

hrtime_t
gethrtime_unscaled(void)
{
        return (gethrtimeunscaledf());
}

void
scalehrtime(hrtime_t *hrt)
{
        scalehrtimef(hrt);
}

uint64_t
unscalehrtime(hrtime_t nsecs)
{
        return (unscalehrtimef(nsecs));
}

void
gethrestime(timespec_t *tp)
{
        gethrestimef(tp);
}

#if defined(__amd64)
/*
 * Part of the implementation of hres_tick(); this routine is
 * easier in C than assembler .. called with the hres_lock held.
 *
 * XX64 Many of these timekeeping variables need to be extern'ed in a header
 */

#include <sys/time.h>
#include <sys/machlock.h>

extern int one_sec;
extern int max_hres_adj;

void
__adj_hrestime(void)
{
        long long adj;

        if (hrestime_adj == 0)
                adj = 0;
        else if (hrestime_adj > 0) {
                if (hrestime_adj < max_hres_adj)
                        adj = hrestime_adj;
                else
                        adj = max_hres_adj;
        } else {
                if (hrestime_adj < -max_hres_adj)
                        adj = -max_hres_adj;
                else
                        adj = hrestime_adj;
        }

        timedelta -= adj;
        hrestime_adj = timedelta;
        hrestime.tv_nsec += adj;

        while (hrestime.tv_nsec >= NANOSEC) {
                one_sec++;
                hrestime.tv_sec++;
                hrestime.tv_nsec -= NANOSEC;
        }
}
#endif

/*
 * Wrapper functions to maintain backwards compability
 */
int
xcopyin(const void *uaddr, void *kaddr, size_t count)
{
        return (xcopyin_nta(uaddr, kaddr, count, UIO_COPY_CACHED));
}

int
xcopyout(const void *kaddr, void *uaddr, size_t count)
{
        return (xcopyout_nta(kaddr, uaddr, count, UIO_COPY_CACHED));
}