loader: remove devdesc comments and assertions

[unleashed.git] / kernel / os / dumpsubr.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) 1998, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2014, Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
 * Copyright 2016 Joyent, Inc.
 */

#include <sys/types.h>
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/vm.h>
#include <sys/proc.h>
#include <sys/file.h>
#include <sys/conf.h>
#include <sys/kmem.h>
#include <sys/mem.h>
#include <sys/mman.h>
#include <sys/vnode.h>
#include <sys/errno.h>
#include <sys/memlist.h>
#include <sys/dumphdr.h>
#include <sys/dumpadm.h>
#include <sys/ksyms.h>
#include <sys/compress.h>
#include <sys/stream.h>
#include <sys/strsun.h>
#include <sys/cmn_err.h>
#include <sys/bitmap.h>
#include <sys/modctl.h>
#include <sys/utsname.h>
#include <sys/systeminfo.h>
#include <sys/vmem.h>
#include <sys/log.h>
#include <sys/var.h>
#include <sys/debug.h>
#include <sys/sunddi.h>
#include <sys/fs_subr.h>
#include <sys/fs/snode.h>
#include <sys/ontrap.h>
#include <sys/panic.h>
#include <sys/dkio.h>
#include <sys/vtoc.h>
#include <sys/errorq.h>
#include <sys/fm/util.h>
#include <sys/fs/zfs.h>

#include <vm/hat.h>
#include <vm/as.h>
#include <vm/page.h>
#include <vm/pvn.h>
#include <vm/seg.h>
#include <vm/seg_kmem.h>
#include <sys/clock_impl.h>
#include <sys/hold_page.h>

/*
 * exported vars
 */
kmutex_t        dump_lock;              /* lock for dump configuration */
dumphdr_t       *dumphdr;               /* dump header */
int             dump_conflags = DUMP_KERNEL; /* dump configuration flags */
vnode_t         *dumpvp;                /* dump device vnode pointer */
uoff_t  dumpvp_size;            /* size of dump device, in bytes */
char            *dumppath;              /* pathname of dump device */
int             dump_timeout = 120;     /* timeout for dumping pages */
int             dump_timeleft;          /* portion of dump_timeout remaining */
int             dump_ioerr;             /* dump i/o error */
char            *dump_stack_scratch;    /* scratch area for saving stack summary */

/*
 * Tunables for dump.  These can be set via /etc/system.
 *
 * dump_metrics_on      if set, metrics are collected in the kernel, passed
 *      to savecore via the dump file, and recorded by savecore in
 *      METRICS.txt.
 */

/* tunables for pre-reserved heap */
uint_t dump_kmem_permap = 1024;
uint_t dump_kmem_pages = 8;

/*
 * Compression metrics are accumulated nano-second subtotals. The
 * results are normalized by the number of pages dumped. A report is
 * generated when dumpsys() completes and is saved in the dump image
 * after the trailing dump header.
 *
 * Metrics are always collected. Set the variable dump_metrics_on to
 * cause metrics to be saved in the crash file, where savecore will
 * save it in the file METRICS.txt.
 */
#define PERPAGES \
        PERPAGE(bitmap) PERPAGE(map) PERPAGE(unmap) \
        PERPAGE(compress) \
        PERPAGE(write)

typedef struct perpage {
#define PERPAGE(x) hrtime_t x;
        PERPAGES
#undef PERPAGE
} perpage_t;

/*
 * If dump_metrics_on is set to 1, the timing information is passed to
 * savecore via the crash file, where it is appended to the file
 * dump-dir/METRICS.txt.
 */
uint_t dump_metrics_on = 0;     /* set to 1 to enable recording metrics */

#define HRSTART(v, m)           v##ts.m = gethrtime()
#define HRSTOP(v, m)            v.m += gethrtime() - v##ts.m

static char dump_osimage_uuid[36 + 1];

#define isdigit(ch)     ((ch) >= '0' && (ch) <= '9')
#define isxdigit(ch)    (isdigit(ch) || ((ch) >= 'a' && (ch) <= 'f') || \
                        ((ch) >= 'A' && (ch) <= 'F'))

/*
 * configuration vars for dumpsys
 */
typedef struct dumpcfg {
        char *page;                     /* buffer for page copy */
        char *lzbuf;                    /* lzjb output */

        char *cmap;                     /* array of input (map) buffers */
        ulong_t *bitmap;                /* bitmap for marking pages to dump */
        pgcnt_t bitmapsize;             /* size of bitmap */
        pid_t *pids;                    /* list of process IDs at dump time */

        /*
         * statistics
         */
        perpage_t perpage;              /* per page metrics */
        perpage_t perpagets;            /* per page metrics (timestamps) */
        pgcnt_t npages;                 /* subtotal of pages dumped */
        pgcnt_t pages_mapped;           /* subtotal of pages mapped */
        pgcnt_t pages_used;             /* subtotal of pages used per map */
        size_t nwrite;                  /* subtotal of bytes written */
        hrtime_t elapsed;               /* elapsed time when completed */
        hrtime_t iotime;                /* time spent writing nwrite bytes */
        hrtime_t iowait;                /* time spent waiting for output */
        hrtime_t iowaitts;              /* iowait timestamp */

        /*
         * I/O buffer
         *
         * There is one I/O buffer used by dumpvp_write and dumvp_flush. It
         * is sized according to the optimum device transfer speed.
         */
        struct {
                vnode_t *cdev_vp;       /* VCHR open of the dump device */
                len_t   vp_limit;       /* maximum write offset */
                offset_t vp_off;        /* current dump device offset */
                char    *cur;           /* dump write pointer */
                char    *start;         /* dump buffer address */
                char    *end;           /* dump buffer end */
                size_t  size;           /* size of dump buf in bytes */
                size_t  iosize;         /* best transfer size for device */
        } buf;
} dumpcfg_t;

static dumpcfg_t dumpcfg;       /* config vars */

/*
 * The dump I/O buffer must be at least one page, at most xfer_size bytes,
 * and should scale with physmem in between.  The transfer size passed in
 * will either represent a global default (maxphys) or the best size for the
 * device.  The size of the dump I/O buffer is limited by dumpbuf_limit (8MB
 * by default) because the dump performance saturates beyond a certain size.
 * The default is to select 1/4096 of the memory.
 */
static int      dumpbuf_fraction = 12;  /* memory size scale factor */
static size_t   dumpbuf_limit = 8 << 20;        /* max I/O buf size */

static size_t
dumpbuf_iosize(size_t xfer_size)
{
        size_t iosize = ptob(physmem >> dumpbuf_fraction);

        if (iosize < PAGESIZE)
                iosize = PAGESIZE;
        else if (iosize > xfer_size)
                iosize = xfer_size;
        if (iosize > dumpbuf_limit)
                iosize = dumpbuf_limit;
        return (iosize & PAGEMASK);
}

/*
 * resize the I/O buffer
 */
static void
dumpbuf_resize(void)
{
        char *old_buf = dumpcfg.buf.start;
        size_t old_size = dumpcfg.buf.size;
        char *new_buf;
        size_t new_size;

        ASSERT(MUTEX_HELD(&dump_lock));

        new_size = dumpbuf_iosize(MAX(dumpcfg.buf.iosize, maxphys));
        if (new_size <= old_size)
                return; /* no need to reallocate buffer */

        new_buf = kmem_alloc(new_size, KM_SLEEP);
        dumpcfg.buf.size = new_size;
        dumpcfg.buf.start = new_buf;
        dumpcfg.buf.end = new_buf + new_size;
        kmem_free(old_buf, old_size);
}

/*
 * dump_update_clevel is called when dumpadm configures the dump device.
 *      Allocate the minimum configuration for now.
 *
 * When the dump file is configured we reserve a minimum amount of
 * memory for use at crash time. But we reserve VA for all the memory
 * we really want in order to do the fastest dump possible. The VA is
 * backed by pages not being dumped, according to the bitmap. If
 * there is insufficient spare memory, however, we fall back to the
 * minimum.
 *
 * Live dump (savecore -L) always uses the minimum config.
 */
static void
dump_update_clevel()
{
        dumpcfg_t *old = &dumpcfg;
        dumpcfg_t newcfg = *old;
        dumpcfg_t *new = &newcfg;

        ASSERT(MUTEX_HELD(&dump_lock));

        /*
         * Free the previously allocated bufs and VM.
         */
        if (old->lzbuf)
                kmem_free(old->lzbuf, PAGESIZE);
        if (old->page)
                kmem_free(old->page, PAGESIZE);

        if (old->cmap)
                /* VM space for mapping pages */
                vmem_xfree(heap_arena, old->cmap, PAGESIZE);

        /*
         * Allocate new data structures and buffers, and also figure the max
         * desired size.
         */
        new->lzbuf = kmem_alloc(PAGESIZE, KM_SLEEP);
        new->page = kmem_alloc(PAGESIZE, KM_SLEEP);

        new->cmap = vmem_xalloc(heap_arena, PAGESIZE, PAGESIZE,
                                0, 0, NULL, NULL, VM_SLEEP);

        /*
         * Reserve memory for kmem allocation calls made during crash
         * dump.  The hat layer allocates memory for each mapping
         * created, and the I/O path allocates buffers and data structs.
         * Add a few pages for safety.
         */
        kmem_dump_init(dump_kmem_permap + (dump_kmem_pages * PAGESIZE));

        /* set new config pointers */
        *old = *new;
}

/*
 * Define a struct memlist walker to optimize bitnum to pfn
 * lookup. The walker maintains the state of the list traversal.
 */
typedef struct dumpmlw {
        struct memlist  *mp;            /* current memlist */
        pgcnt_t         basenum;        /* bitnum base offset */
        pgcnt_t         mppages;        /* current memlist size */
        pgcnt_t         mpleft;         /* size to end of current memlist */
        pfn_t           mpaddr;         /* first pfn in memlist */
} dumpmlw_t;

/* initialize the walker */
static inline void
dump_init_memlist_walker(dumpmlw_t *pw)
{
        pw->mp = phys_install;
        pw->basenum = 0;
        pw->mppages = pw->mp->ml_size >> PAGESHIFT;
        pw->mpleft = pw->mppages;
        pw->mpaddr = pw->mp->ml_address >> PAGESHIFT;
}

/*
 * Lookup pfn given bitnum. The memlist can be quite long on some
 * systems (e.g.: one per board). To optimize sequential lookups, the
 * caller initializes and presents a memlist walker.
 */
static pfn_t
dump_bitnum_to_pfn(pgcnt_t bitnum, dumpmlw_t *pw)
{
        bitnum -= pw->basenum;
        while (pw->mp != NULL) {
                if (bitnum < pw->mppages) {
                        pw->mpleft = pw->mppages - bitnum;
                        return (pw->mpaddr + bitnum);
                }
                bitnum -= pw->mppages;
                pw->basenum += pw->mppages;
                pw->mp = pw->mp->ml_next;
                if (pw->mp != NULL) {
                        pw->mppages = pw->mp->ml_size >> PAGESHIFT;
                        pw->mpleft = pw->mppages;
                        pw->mpaddr = pw->mp->ml_address >> PAGESHIFT;
                }
        }
        return (PFN_INVALID);
}

static pgcnt_t
dump_pfn_to_bitnum(pfn_t pfn)
{
        struct memlist *mp;
        pgcnt_t bitnum = 0;

        for (mp = phys_install; mp != NULL; mp = mp->ml_next) {
                if (pfn >= (mp->ml_address >> PAGESHIFT) &&
                    pfn < ((mp->ml_address + mp->ml_size) >> PAGESHIFT))
                        return (bitnum + pfn - (mp->ml_address >> PAGESHIFT));
                bitnum += mp->ml_size >> PAGESHIFT;
        }
        return ((pgcnt_t)-1);
}

static void
dumphdr_init(void)
{
        pgcnt_t npages;

        ASSERT(MUTEX_HELD(&dump_lock));

        if (dumphdr == NULL) {
                dumphdr = kmem_zalloc(sizeof (dumphdr_t), KM_SLEEP);
                dumphdr->dump_magic = DUMP_MAGIC;
                dumphdr->dump_version = DUMP_VERSION;
                dumphdr->dump_wordsize = DUMP_WORDSIZE;
                dumphdr->dump_pageshift = PAGESHIFT;
                dumphdr->dump_pagesize = PAGESIZE;
                dumphdr->dump_utsname = utsname;
                (void) strcpy(dumphdr->dump_platform, platform);
                dumpcfg.buf.size = dumpbuf_iosize(maxphys);
                dumpcfg.buf.start = kmem_alloc(dumpcfg.buf.size, KM_SLEEP);
                dumpcfg.buf.end = dumpcfg.buf.start + dumpcfg.buf.size;
                dumpcfg.pids = kmem_alloc(v.v_proc * sizeof (pid_t), KM_SLEEP);
                dump_stack_scratch = kmem_alloc(STACK_BUF_SIZE, KM_SLEEP);
                (void) strncpy(dumphdr->dump_uuid, dump_get_uuid(),
                    sizeof (dumphdr->dump_uuid));
        }

        npages = num_phys_pages();

        if (dumpcfg.bitmapsize != npages) {
                void *map = kmem_alloc(BT_SIZEOFMAP(npages), KM_SLEEP);

                if (dumpcfg.bitmap != NULL)
                        kmem_free(dumpcfg.bitmap, BT_SIZEOFMAP(dumpcfg.
                            bitmapsize));
                dumpcfg.bitmap = map;
                dumpcfg.bitmapsize = npages;
        }
}

/*
 * Establish a new dump device.
 */
int
dumpinit(vnode_t *vp, char *name, int justchecking)
{
        vnode_t *cvp;
        vattr_t vattr;
        vnode_t *cdev_vp;
        int error = 0;

        ASSERT(MUTEX_HELD(&dump_lock));

        dumphdr_init();

        cvp = common_specvp(vp);
        if (cvp == dumpvp)
                return (0);

        /*
         * Determine whether this is a plausible dump device.  We want either:
         * (1) a real device that's not mounted and has a cb_dump routine, or
         * (2) a swapfile on some filesystem that has a vop_dump routine.
         */
        if ((error = fop_open(&cvp, FREAD | FWRITE, kcred, NULL)) != 0)
                return (error);

        vattr.va_mask = AT_SIZE | AT_TYPE | AT_RDEV;
        if ((error = fop_getattr(cvp, &vattr, 0, kcred, NULL)) == 0) {
                if (vattr.va_type == VBLK || vattr.va_type == VCHR) {
                        if (devopsp[getmajor(vattr.va_rdev)]->
                            devo_cb_ops->cb_dump == nodev)
                                error = ENOTSUP;
                        else if (vfs_devismounted(vattr.va_rdev))
                                error = EBUSY;
                        if (strcmp(ddi_driver_name(VTOS(cvp)->s_dip),
                            ZFS_DRIVER) == 0 &&
                            IS_SWAPVP(common_specvp(cvp)))
                                error = EBUSY;
                } else {
                        if (cvp->v_op->vop_dump == fs_nosys ||
                            cvp->v_op->vop_dump == NULL ||
                            !IS_SWAPVP(cvp))
                                error = ENOTSUP;
                }
        }

        if (error == 0 && vattr.va_size < 2 * DUMP_LOGSIZE + DUMP_ERPTSIZE)
                error = ENOSPC;

        if (error || justchecking) {
                (void) fop_close(cvp, FREAD | FWRITE, 1, 0,
                    kcred, NULL);
                return (error);
        }

        VN_HOLD(cvp);

        if (dumpvp != NULL)
                dumpfini();     /* unconfigure the old dump device */

        dumpvp = cvp;
        dumpvp_size = vattr.va_size & -DUMP_OFFSET;
        dumppath = kmem_alloc(strlen(name) + 1, KM_SLEEP);
        (void) strcpy(dumppath, name);
        dumpcfg.buf.iosize = 0;

        /*
         * If the dump device is a block device, attempt to open up the
         * corresponding character device and determine its maximum transfer
         * size.  We use this information to potentially resize dump buffer
         * to a larger and more optimal size for performing i/o to the dump
         * device.
         */
        if (cvp->v_type == VBLK &&
            (cdev_vp = makespecvp(VTOS(cvp)->s_dev, VCHR)) != NULL) {
                if (fop_open(&cdev_vp, FREAD | FWRITE, kcred, NULL) == 0) {
                        size_t blk_size;
                        struct dk_cinfo dki;
                        struct dk_minfo minf;

                        if (fop_ioctl(cdev_vp, DKIOCGMEDIAINFO,
                            (intptr_t)&minf, FKIOCTL, kcred, NULL, NULL)
                            == 0 && minf.dki_lbsize != 0)
                                blk_size = minf.dki_lbsize;
                        else
                                blk_size = DEV_BSIZE;

                        if (fop_ioctl(cdev_vp, DKIOCINFO, (intptr_t)&dki,
                            FKIOCTL, kcred, NULL, NULL) == 0) {
                                dumpcfg.buf.iosize = dki.dki_maxtransfer * blk_size;
                                dumpbuf_resize();
                        }
                        /*
                         * If we are working with a zvol then dumpify it
                         * if it's not being used as swap.
                         */
                        if (strcmp(dki.dki_dname, ZVOL_DRIVER) == 0) {
                                if (IS_SWAPVP(common_specvp(cvp)))
                                        error = EBUSY;
                                else if ((error = fop_ioctl(cdev_vp,
                                    DKIOCDUMPINIT, (intptr_t)NULL, FKIOCTL,
                                    kcred, NULL, NULL)) != 0)
                                        dumpfini();
                        }

                        (void) fop_close(cdev_vp, FREAD | FWRITE, 1, 0,
                            kcred, NULL);
                }

                VN_RELE(cdev_vp);
        }

        cmn_err(CE_CONT, "?dump on %s size %llu MB\n", name, dumpvp_size >> 20);

        dump_update_clevel();

        return (error);
}

void
dumpfini(void)
{
        vattr_t vattr;
        boolean_t is_zfs = B_FALSE;
        vnode_t *cdev_vp;
        ASSERT(MUTEX_HELD(&dump_lock));

        kmem_free(dumppath, strlen(dumppath) + 1);

        /*
         * Determine if we are using zvols for our dump device
         */
        vattr.va_mask = AT_RDEV;
        if (fop_getattr(dumpvp, &vattr, 0, kcred, NULL) == 0) {
                is_zfs = (getmajor(vattr.va_rdev) ==
                    ddi_name_to_major(ZFS_DRIVER)) ? B_TRUE : B_FALSE;
        }

        /*
         * If we have a zvol dump device then we call into zfs so
         * that it may have a chance to cleanup.
         */
        if (is_zfs &&
            (cdev_vp = makespecvp(VTOS(dumpvp)->s_dev, VCHR)) != NULL) {
                if (fop_open(&cdev_vp, FREAD | FWRITE, kcred, NULL) == 0) {
                        (void) fop_ioctl(cdev_vp, DKIOCDUMPFINI, (intptr_t)NULL,
                            FKIOCTL, kcred, NULL, NULL);
                        (void) fop_close(cdev_vp, FREAD | FWRITE, 1, 0,
                            kcred, NULL);
                }
                VN_RELE(cdev_vp);
        }

        (void) fop_close(dumpvp, FREAD | FWRITE, 1, 0, kcred, NULL);

        VN_RELE(dumpvp);

        dumpvp = NULL;
        dumpvp_size = 0;
        dumppath = NULL;
}

static offset_t
dumpvp_flush(void)
{
        size_t size = P2ROUNDUP(dumpcfg.buf.cur - dumpcfg.buf.start, PAGESIZE);
        hrtime_t iotime;
        int err;

        if (dumpcfg.buf.vp_off + size > dumpcfg.buf.vp_limit) {
                dump_ioerr = ENOSPC;
                dumpcfg.buf.vp_off = dumpcfg.buf.vp_limit;
        } else if (size != 0) {
                iotime = gethrtime();
                dumpcfg.iowait += iotime - dumpcfg.iowaitts;
                if (panicstr)
                        err = fop_dump(dumpvp, dumpcfg.buf.start,
                            lbtodb(dumpcfg.buf.vp_off), btod(size), NULL);
                else
                        err = vn_rdwr(UIO_WRITE, dumpcfg.buf.cdev_vp != NULL ?
                            dumpcfg.buf.cdev_vp : dumpvp, dumpcfg.buf.start, size,
                            dumpcfg.buf.vp_off, UIO_SYSSPACE, 0, dumpcfg.buf.vp_limit,
                            kcred, 0);
                if (err && dump_ioerr == 0)
                        dump_ioerr = err;
                dumpcfg.iowaitts = gethrtime();
                dumpcfg.iotime += dumpcfg.iowaitts - iotime;
                dumpcfg.nwrite += size;
                dumpcfg.buf.vp_off += size;
        }
        dumpcfg.buf.cur = dumpcfg.buf.start;
        dump_timeleft = dump_timeout;
        return (dumpcfg.buf.vp_off);
}

/* maximize write speed by keeping seek offset aligned with size */
void
dumpvp_write(const void *va, size_t size)
{
        size_t len, off, sz;

        while (size != 0) {
                len = MIN(size, dumpcfg.buf.end - dumpcfg.buf.cur);
                if (len == 0) {
                        off = P2PHASE(dumpcfg.buf.vp_off, dumpcfg.buf.size);
                        if (off == 0 || !ISP2(dumpcfg.buf.size)) {
                                (void) dumpvp_flush();
                        } else {
                                sz = dumpcfg.buf.size - off;
                                dumpcfg.buf.cur = dumpcfg.buf.start + sz;
                                (void) dumpvp_flush();
                                ovbcopy(dumpcfg.buf.start + sz, dumpcfg.buf.start, off);
                                dumpcfg.buf.cur += off;
                        }
                } else {
                        bcopy(va, dumpcfg.buf.cur, len);
                        va = (char *)va + len;
                        dumpcfg.buf.cur += len;
                        size -= len;
                }
        }
}

/*ARGSUSED*/
static void
dumpvp_ksyms_write(const void *src, void *dst, size_t size)
{
        dumpvp_write(src, size);
}

/*
 * Mark 'pfn' in the bitmap and dump its translation table entry.
 */
void
dump_addpage(struct as *as, void *va, pfn_t pfn)
{
        mem_vtop_t mem_vtop;
        pgcnt_t bitnum;

        if ((bitnum = dump_pfn_to_bitnum(pfn)) != (pgcnt_t)-1) {
                if (!BT_TEST(dumpcfg.bitmap, bitnum)) {
                        dumphdr->dump_npages++;
                        BT_SET(dumpcfg.bitmap, bitnum);
                }
                dumphdr->dump_nvtop++;
                mem_vtop.m_as = as;
                mem_vtop.m_va = va;
                mem_vtop.m_pfn = pfn;
                dumpvp_write(&mem_vtop, sizeof (mem_vtop_t));
        }
        dump_timeleft = dump_timeout;
}

/*
 * Mark 'pfn' in the bitmap
 */
void
dump_page(pfn_t pfn)
{
        pgcnt_t bitnum;

        if ((bitnum = dump_pfn_to_bitnum(pfn)) != (pgcnt_t)-1) {
                if (!BT_TEST(dumpcfg.bitmap, bitnum)) {
                        dumphdr->dump_npages++;
                        BT_SET(dumpcfg.bitmap, bitnum);
                }
        }
        dump_timeleft = dump_timeout;
}

/*
 * Dump the <as, va, pfn> information for a given address space.
 * segop_dump() will call dump_addpage() for each page in the segment.
 */
static void
dump_as(struct as *as)
{
        struct seg *seg;

        AS_LOCK_ENTER(as, RW_READER);
        for (seg = AS_SEGFIRST(as); seg; seg = AS_SEGNEXT(as, seg)) {
                if (seg->s_as != as)
                        break;
                if (seg->s_ops == NULL)
                        continue;
                segop_dump(seg);
        }
        AS_LOCK_EXIT(as);

        if (seg != NULL)
                cmn_err(CE_WARN, "invalid segment %p in address space %p",
                    (void *)seg, (void *)as);
}

static int
dump_process(pid_t pid)
{
        proc_t *p = sprlock(pid);

        if (p == NULL)
                return (-1);
        if (p->p_as != &kas) {
                mutex_exit(&p->p_lock);
                dump_as(p->p_as);
                mutex_enter(&p->p_lock);
        }

        sprunlock(p);

        return (0);
}

/*
 * The following functions (dump_summary(), dump_ereports(), and
 * dump_messages()), write data to an uncompressed area within the
 * crashdump. The layout of these is
 *
 * +------------------------------------------------------------+
 * |     compressed pages       | summary | ereports | messages |
 * +------------------------------------------------------------+
 *
 * With the advent of saving a compressed crash dump by default, we
 * need to save a little more data to describe the failure mode in
 * an uncompressed buffer available before savecore uncompresses
 * the dump. Initially this is a copy of the stack trace. Additional
 * summary information should be added here.
 */

void
dump_summary(void)
{
        uoff_t dumpvp_start;
        summary_dump_t sd;

        if (dumpvp == NULL || dumphdr == NULL)
                return;

        dumpcfg.buf.cur = dumpcfg.buf.start;

        dumpcfg.buf.vp_limit = dumpvp_size - (DUMP_OFFSET + DUMP_LOGSIZE +
            DUMP_ERPTSIZE);
        dumpvp_start = dumpcfg.buf.vp_limit - DUMP_SUMMARYSIZE;
        dumpcfg.buf.vp_off = dumpvp_start;

        sd.sd_magic = SUMMARY_MAGIC;
        sd.sd_ssum = checksum32(dump_stack_scratch, STACK_BUF_SIZE);
        dumpvp_write(&sd, sizeof (sd));
        dumpvp_write(dump_stack_scratch, STACK_BUF_SIZE);

        sd.sd_magic = 0; /* indicate end of summary */
        dumpvp_write(&sd, sizeof (sd));
        (void) dumpvp_flush();
}

void
dump_ereports(void)
{
        uoff_t dumpvp_start;
        erpt_dump_t ed;

        if (dumpvp == NULL || dumphdr == NULL)
                return;

        dumpcfg.buf.cur = dumpcfg.buf.start;
        dumpcfg.buf.vp_limit = dumpvp_size - (DUMP_OFFSET + DUMP_LOGSIZE);
        dumpvp_start = dumpcfg.buf.vp_limit - DUMP_ERPTSIZE;
        dumpcfg.buf.vp_off = dumpvp_start;

        fm_ereport_dump();
        if (panicstr)
                errorq_dump();

        bzero(&ed, sizeof (ed)); /* indicate end of ereports */
        dumpvp_write(&ed, sizeof (ed));
        (void) dumpvp_flush();

        if (!panicstr) {
                (void) fop_putpage(dumpvp, dumpvp_start,
                    (size_t)(dumpcfg.buf.vp_off - dumpvp_start),
                    B_INVAL | B_FORCE, kcred, NULL);
        }
}

void
dump_messages(void)
{
        log_dump_t ld;
        mblk_t *mctl, *mdata;
        queue_t *q, *qlast;
        uoff_t dumpvp_start;

        if (dumpvp == NULL || dumphdr == NULL || log_consq == NULL)
                return;

        dumpcfg.buf.cur = dumpcfg.buf.start;
        dumpcfg.buf.vp_limit = dumpvp_size - DUMP_OFFSET;
        dumpvp_start = dumpcfg.buf.vp_limit - DUMP_LOGSIZE;
        dumpcfg.buf.vp_off = dumpvp_start;

        qlast = NULL;
        do {
                for (q = log_consq; q->q_next != qlast; q = q->q_next)
                        continue;
                for (mctl = q->q_first; mctl != NULL; mctl = mctl->b_next) {
                        dump_timeleft = dump_timeout;
                        mdata = mctl->b_cont;
                        ld.ld_magic = LOG_MAGIC;
                        ld.ld_msgsize = MBLKL(mctl->b_cont);
                        ld.ld_csum = checksum32(mctl->b_rptr, MBLKL(mctl));
                        ld.ld_msum = checksum32(mdata->b_rptr, MBLKL(mdata));
                        dumpvp_write(&ld, sizeof (ld));
                        dumpvp_write(mctl->b_rptr, MBLKL(mctl));
                        dumpvp_write(mdata->b_rptr, MBLKL(mdata));
                }
        } while ((qlast = q) != log_consq);

        ld.ld_magic = 0;                /* indicate end of messages */
        dumpvp_write(&ld, sizeof (ld));
        (void) dumpvp_flush();
        if (!panicstr) {
                (void) fop_putpage(dumpvp, dumpvp_start,
                    (size_t)(dumpcfg.buf.vp_off - dumpvp_start),
                    B_INVAL | B_FORCE, kcred, NULL);
        }
}

/*
 * Copy pages, trapping ECC errors. Also, for robustness, trap data
 * access in case something goes wrong in the hat layer and the
 * mapping is broken.
 */
static void
dump_pagecopy(void *src, void *dst)
{
        long *wsrc = (long *)src;
        long *wdst = (long *)dst;
        const ulong_t ncopies = PAGESIZE / sizeof (long);
        volatile int w = 0;
        volatile int ueoff = -1;
        on_trap_data_t otd;

        if (on_trap(&otd, OT_DATA_EC | OT_DATA_ACCESS)) {
                if (ueoff == -1)
                        ueoff = w * sizeof (long);
                /* report "bad ECC" or "bad address" */
#ifdef _LP64
                if (otd.ot_trap & OT_DATA_EC)
                        wdst[w++] = 0x00badecc00badecc;
                else
                        wdst[w++] = 0x00badadd00badadd;
#else
                if (otd.ot_trap & OT_DATA_EC)
                        wdst[w++] = 0x00badecc;
                else
                        wdst[w++] = 0x00badadd;
#endif
        }
        while (w < ncopies) {
                wdst[w] = wsrc[w];
                w++;
        }
        no_trap();
}

size_t
dumpsys_metrics(char *buf, size_t size)
{
        dumpcfg_t *cfg = &dumpcfg;
        int compress_ratio;
        int sec, iorate;
        char *e = buf + size;
        char *p = buf;

        sec = cfg->elapsed / (1000 * 1000 * 1000ULL);
        if (sec < 1)
                sec = 1;

        if (cfg->iotime < 1)
                cfg->iotime = 1;
        iorate = (cfg->nwrite * 100000ULL) / cfg->iotime;

        compress_ratio = 100LL * cfg->npages / btopr(cfg->nwrite + 1);

#define P(...) (p += p < e ? snprintf(p, e - p, __VA_ARGS__) : 0)

        P("Master cpu_seqid,%d\n", CPU->cpu_seqid);
        P("Master cpu_id,%d\n", CPU->cpu_id);
        P("dump_flags,0x%x\n", dumphdr->dump_flags);
        P("dump_ioerr,%d\n", dump_ioerr);

        P("Compression type,serial lzjb\n");
        P("Compression ratio,%d.%02d\n", compress_ratio / 100, compress_ratio %
            100);

        P("Dump I/O rate MBS,%d.%02d\n", iorate / 100, iorate % 100);
        P("..total bytes,%lld\n", (u_longlong_t)cfg->nwrite);
        P("..total nsec,%lld\n", (u_longlong_t)cfg->iotime);
        P("dumpbuf.iosize,%ld\n", dumpcfg.buf.iosize);
        P("dumpbuf.size,%ld\n", dumpcfg.buf.size);

        P("Dump pages/sec,%llu\n", (u_longlong_t)cfg->npages / sec);
        P("Dump pages,%llu\n", (u_longlong_t)cfg->npages);
        P("Dump time,%d\n", sec);

        if (cfg->pages_mapped > 0)
                P("per-cent map utilization,%d\n", (int)((100 * cfg->pages_used)
                    / cfg->pages_mapped));

        P("\nPer-page metrics:\n");
        if (cfg->npages > 0) {
#define PERPAGE(x) \
                P("%s nsec/page,%d\n", #x, (int)(cfg->perpage.x / cfg->npages));
                PERPAGES;
#undef PERPAGE

                P("I/O wait nsec/page,%llu\n", (u_longlong_t)(cfg->iowait /
                    cfg->npages));
        }
#undef P
        if (p < e)
                bzero(p, e - p);
        return (p - buf);
}

/*
 * Dump the system.
 */
void
dumpsys(void)
{
        dumpcfg_t *cfg = &dumpcfg;
        uint_t percent_done;            /* dump progress reported */
        int sec_done;
        hrtime_t start;                 /* start time */
        pfn_t pfn;
        pgcnt_t bitnum;
        proc_t *p;
        pid_t npids, pidx;
        char *content;
        char *buf;
        size_t size;
        dumpmlw_t mlw;
        dumpcsize_t datatag;
        dumpdatahdr_t datahdr;

        if (dumpvp == NULL || dumphdr == NULL) {
                uprintf("skipping system dump - no dump device configured\n");
                return;
        }
        dumpcfg.buf.cur = dumpcfg.buf.start;

        /* clear the sync variables */
        cfg->npages = 0;
        cfg->pages_mapped = 0;
        cfg->pages_used = 0;
        cfg->nwrite = 0;
        cfg->elapsed = 0;
        cfg->iotime = 0;
        cfg->iowait = 0;
        cfg->iowaitts = 0;

        /*
         * Calculate the starting block for dump.  If we're dumping on a
         * swap device, start 1/5 of the way in; otherwise, start at the
         * beginning.  And never use the first page -- it may be a disk label.
         */
        if (dumpvp->v_flag & VISSWAP)
                dumphdr->dump_start = P2ROUNDUP(dumpvp_size / 5, DUMP_OFFSET);
        else
                dumphdr->dump_start = DUMP_OFFSET;

        dumphdr->dump_flags = DF_VALID | DF_COMPLETE | DF_LIVE | DF_COMPRESSED;
        dumphdr->dump_crashtime = gethrestime_sec();
        dumphdr->dump_npages = 0;
        dumphdr->dump_nvtop = 0;
        bzero(dumpcfg.bitmap, BT_SIZEOFMAP(dumpcfg.bitmapsize));
        dump_timeleft = dump_timeout;

        if (panicstr) {
                dumphdr->dump_flags &= ~DF_LIVE;
                (void) fop_dumpctl(dumpvp, DUMP_FREE, NULL, NULL);
                (void) fop_dumpctl(dumpvp, DUMP_ALLOC, NULL, NULL);
                (void) vsnprintf(dumphdr->dump_panicstring, DUMP_PANICSIZE,
                    panicstr, panicargs);
        }

        if (dump_conflags & DUMP_ALL)
                content = "all";
        else if (dump_conflags & DUMP_CURPROC)
                content = "kernel + curproc";
        else
                content = "kernel";
        uprintf("dumping to %s, offset %lld, content: %s\n", dumppath,
            dumphdr->dump_start, content);

        /* Make sure nodename is current */
        bcopy(utsname.nodename, dumphdr->dump_utsname.nodename, SYS_NMLN);

        /*
         * If this is a live dump, try to open a VCHR vnode for better
         * performance. We must take care to flush the buffer cache
         * first.
         */
        if (!panicstr) {
                vnode_t *cdev_vp, *cmn_cdev_vp;

                ASSERT(dumpcfg.buf.cdev_vp == NULL);
                cdev_vp = makespecvp(VTOS(dumpvp)->s_dev, VCHR);
                if (cdev_vp != NULL) {
                        cmn_cdev_vp = common_specvp(cdev_vp);
                        if (fop_open(&cmn_cdev_vp, FREAD | FWRITE, kcred, NULL)
                            == 0) {
                                if (vn_has_cached_data(dumpvp))
                                        (void) pvn_vplist_dirty(dumpvp, 0, NULL,
                                            B_INVAL | B_TRUNC, kcred);
                                dumpcfg.buf.cdev_vp = cmn_cdev_vp;
                        } else {
                                VN_RELE(cdev_vp);
                        }
                }
        }

        /*
         * Store a hires timestamp so we can look it up during debugging.
         */
        lbolt_debug_entry();

        /*
         * Leave room for the message and ereport save areas and terminal dump
         * header.
         */
        dumpcfg.buf.vp_limit = dumpvp_size - DUMP_LOGSIZE - DUMP_OFFSET -
            DUMP_ERPTSIZE;

        /*
         * Write out the symbol table.  It's no longer compressed,
         * so its 'size' and 'csize' are equal.
         */
        dumpcfg.buf.vp_off = dumphdr->dump_ksyms = dumphdr->dump_start + PAGESIZE;
        dumphdr->dump_ksyms_size = dumphdr->dump_ksyms_csize =
            ksyms_snapshot(dumpvp_ksyms_write, NULL, LONG_MAX);

        /*
         * Write out the translation map.
         */
        dumphdr->dump_map = dumpvp_flush();
        dump_as(&kas);
        dumphdr->dump_nvtop += dump_plat_addr();

        /*
         * call into hat, which may have unmapped pages that also need to
         * be in the dump
         */
        hat_dump();

        if (dump_conflags & DUMP_ALL) {
                mutex_enter(&pidlock);

                for (npids = 0, p = practive; p != NULL; p = p->p_next)
                        dumpcfg.pids[npids++] = p->p_pid;

                mutex_exit(&pidlock);

                for (pidx = 0; pidx < npids; pidx++)
                        (void) dump_process(dumpcfg.pids[pidx]);

                dump_init_memlist_walker(&mlw);
                for (bitnum = 0; bitnum < dumpcfg.bitmapsize; bitnum++) {
                        dump_timeleft = dump_timeout;
                        pfn = dump_bitnum_to_pfn(bitnum, &mlw);
                        /*
                         * Some hypervisors do not have all pages available to
                         * be accessed by the guest OS.  Check for page
                         * accessibility.
                         */
                        if (plat_hold_page(pfn, PLAT_HOLD_NO_LOCK, NULL) !=
                            PLAT_HOLD_OK)
                                continue;
                        BT_SET(dumpcfg.bitmap, bitnum);
                }
                dumphdr->dump_npages = dumpcfg.bitmapsize;
                dumphdr->dump_flags |= DF_ALL;

        } else if (dump_conflags & DUMP_CURPROC) {
                /*
                 * Determine which pid is to be dumped.  If we're panicking, we
                 * dump the process associated with panic_thread (if any).  If
                 * this is a live dump, we dump the process associated with
                 * curthread.
                 */
                npids = 0;
                if (panicstr) {
                        if (panic_thread != NULL &&
                            panic_thread->t_procp != NULL &&
                            panic_thread->t_procp != &p0) {
                                dumpcfg.pids[npids++] =
                                    panic_thread->t_procp->p_pid;
                        }
                } else {
                        dumpcfg.pids[npids++] = curthread->t_procp->p_pid;
                }

                if (npids && dump_process(dumpcfg.pids[0]) == 0)
                        dumphdr->dump_flags |= DF_CURPROC;
                else
                        dumphdr->dump_flags |= DF_KERNEL;

        } else {
                dumphdr->dump_flags |= DF_KERNEL;
        }

        dumphdr->dump_hashmask = (1 << highbit(dumphdr->dump_nvtop - 1)) - 1;

        /*
         * Write out the pfn table.
         */
        dumphdr->dump_pfn = dumpvp_flush();
        dump_init_memlist_walker(&mlw);
        for (bitnum = 0; bitnum < dumpcfg.bitmapsize; bitnum++) {
                dump_timeleft = dump_timeout;
                if (!BT_TEST(dumpcfg.bitmap, bitnum))
                        continue;
                pfn = dump_bitnum_to_pfn(bitnum, &mlw);
                ASSERT(pfn != PFN_INVALID);
                dumpvp_write(&pfn, sizeof (pfn_t));
        }
        dump_plat_pfn();

        /*
         * Write out all the pages.
         * Map pages, copy them handling UEs, compress, and write them out.
         */
        dumphdr->dump_data = dumpvp_flush();

        ASSERT(dumpcfg.page);
        bzero(&dumpcfg.perpage, sizeof (dumpcfg.perpage));

        start = gethrtime();
        cfg->iowaitts = start;

        if (panicstr)
                kmem_dump_begin();

        percent_done = 0;
        sec_done = 0;

        dump_init_memlist_walker(&mlw);
        for (bitnum = 0; bitnum < dumpcfg.bitmapsize; bitnum++) {
                dumpcsize_t csize;
                uint_t percent;
                int sec;

                dump_timeleft = dump_timeout;
                HRSTART(cfg->perpage, bitmap);
                if (!BT_TEST(dumpcfg.bitmap, bitnum)) {
                        HRSTOP(cfg->perpage, bitmap);
                        continue;
                }
                HRSTOP(cfg->perpage, bitmap);

                pfn = dump_bitnum_to_pfn(bitnum, &mlw);
                ASSERT(pfn != PFN_INVALID);

                HRSTART(cfg->perpage, map);
                hat_devload(kas.a_hat, dumpcfg.cmap, PAGESIZE, pfn, PROT_READ,
                            HAT_LOAD_NOCONSIST);
                HRSTOP(cfg->perpage, map);

                dump_pagecopy(dumpcfg.cmap, dumpcfg.page);

                HRSTART(cfg->perpage, unmap);
                hat_unload(kas.a_hat, dumpcfg.cmap, PAGESIZE, HAT_UNLOAD);
                HRSTOP(cfg->perpage, unmap);

                HRSTART(dumpcfg.perpage, compress);
                csize = compress(dumpcfg.page, dumpcfg.lzbuf, PAGESIZE);
                HRSTOP(dumpcfg.perpage, compress);

                HRSTART(dumpcfg.perpage, write);
                dumpvp_write(&csize, sizeof (csize));
                dumpvp_write(dumpcfg.lzbuf, csize);
                HRSTOP(dumpcfg.perpage, write);

                if (dump_ioerr) {
                        dumphdr->dump_flags &= ~DF_COMPLETE;
                        dumphdr->dump_npages = cfg->npages;
                        break;
                }

                sec = (gethrtime() - start) / NANOSEC;
                percent = ++cfg->npages * 100LL / dumphdr->dump_npages;

                /*
                 * Render a simple progress display on the system console to
                 * make clear to the operator that the system has not hung.
                 * Emit an update when dump progress has advanced by one
                 * percent, or when no update has been drawn in the last
                 * second.
                 */
                if (percent > percent_done || sec > sec_done) {
                        percent_done = percent;
                        sec_done = sec;

                        uprintf("^\r%2d:%02d %3d%% done", sec / 60, sec % 60,
                            percent_done);
                        if (!panicstr)
                                delay(1);       /* let the output be sent */
                }
        }

        cfg->elapsed = gethrtime() - start;
        if (cfg->elapsed < 1)
                cfg->elapsed = 1;

        /* record actual pages dumped */
        dumphdr->dump_npages = cfg->npages;

        /* platform-specific data */
        dumphdr->dump_npages += dump_plat_data(dumpcfg.page);

        /* note any errors by clearing DF_COMPLETE */
        if (dump_ioerr || cfg->npages < dumphdr->dump_npages)
                dumphdr->dump_flags &= ~DF_COMPLETE;

        /* end of stream blocks */
        datatag = 0;
        dumpvp_write(&datatag, sizeof (datatag));

        bzero(&datahdr, sizeof (datahdr));

        /* buffer for metrics */
        buf = dumpcfg.page;
        size = MIN(PAGESIZE, DUMP_OFFSET - sizeof (dumphdr_t) -
            sizeof (dumpdatahdr_t));

        /* finish the kmem intercepts, collect kmem verbose info */
        if (panicstr) {
                datahdr.dump_metrics = kmem_dump_finish(buf, size);
                buf += datahdr.dump_metrics;
                size -= datahdr.dump_metrics;
        }

        /* record in the header whether this is a fault-management panic */
        if (panicstr)
                dumphdr->dump_fm_panic = is_fm_panic();

        /* compression info in data header */
        datahdr.dump_datahdr_magic = DUMP_DATAHDR_MAGIC;
        datahdr.dump_datahdr_version = DUMP_DATAHDR_VERSION;
        datahdr.dump_maxcsize = PAGESIZE;
        datahdr.dump_maxrange = 1;
        datahdr.dump_nstreams = 1;
        datahdr.dump_clevel = 0;

        if (dump_metrics_on)
                datahdr.dump_metrics += dumpsys_metrics(buf, size);

        datahdr.dump_data_csize = dumpvp_flush() - dumphdr->dump_data;

        /*
         * Write out the initial and terminal dump headers.
         */
        dumpcfg.buf.vp_off = dumphdr->dump_start;
        dumpvp_write(dumphdr, sizeof (dumphdr_t));
        (void) dumpvp_flush();

        dumpcfg.buf.vp_limit = dumpvp_size;
        dumpcfg.buf.vp_off = dumpcfg.buf.vp_limit - DUMP_OFFSET;
        dumpvp_write(dumphdr, sizeof (dumphdr_t));
        dumpvp_write(&datahdr, sizeof (dumpdatahdr_t));
        dumpvp_write(dumpcfg.page, datahdr.dump_metrics);

        (void) dumpvp_flush();

        uprintf("\r%3d%% done: %llu pages dumped, ",
            percent_done, (u_longlong_t)cfg->npages);

        if (dump_ioerr == 0) {
                uprintf("dump succeeded\n");
        } else {
                uprintf("dump failed: error %d\n", dump_ioerr);
#ifdef DEBUG
                if (panicstr)
                        debug_enter("dump failed");
#endif
        }

        /*
         * Write out all undelivered messages.  This has to be the *last*
         * thing we do because the dump process itself emits messages.
         */
        if (panicstr) {
                dump_summary();
                dump_ereports();
                dump_messages();
        }

        ddi_sleep(2);   /* let people see the 'done' message */
        dump_timeleft = 0;
        dump_ioerr = 0;

        /* restore settings after live dump completes */
        if (!panicstr) {
                /* release any VCHR open of the dump device */
                if (dumpcfg.buf.cdev_vp != NULL) {
                        (void) fop_close(dumpcfg.buf.cdev_vp, FREAD | FWRITE, 1, 0,
                            kcred, NULL);
                        VN_RELE(dumpcfg.buf.cdev_vp);
                        dumpcfg.buf.cdev_vp = NULL;
                }
        }
}

/*
 * This function is called whenever the memory size, as represented
 * by the phys_install list, changes.
 */
void
dump_resize()
{
        mutex_enter(&dump_lock);
        dumphdr_init();
        dumpbuf_resize();
        dump_update_clevel();
        mutex_exit(&dump_lock);
}

/*
 * This function allows for dynamic resizing of a dump area. It assumes that
 * the underlying device has update its appropriate size(9P).
 */
int
dumpvp_resize()
{
        int error;
        vattr_t vattr;

        mutex_enter(&dump_lock);
        vattr.va_mask = AT_SIZE;
        if ((error = fop_getattr(dumpvp, &vattr, 0, kcred, NULL)) != 0) {
                mutex_exit(&dump_lock);
                return (error);
        }

        if (error == 0 && vattr.va_size < 2 * DUMP_LOGSIZE + DUMP_ERPTSIZE) {
                mutex_exit(&dump_lock);
                return (ENOSPC);
        }

        dumpvp_size = vattr.va_size & -DUMP_OFFSET;
        mutex_exit(&dump_lock);
        return (0);
}

int
dump_set_uuid(const char *uuidstr)
{
        const char *ptr;
        int i;

        if (uuidstr == NULL || strnlen(uuidstr, 36 + 1) != 36)
                return (EINVAL);

        /* uuid_parse is not common code so check manually */
        for (i = 0, ptr = uuidstr; i < 36; i++, ptr++) {
                switch (i) {
                case 8:
                case 13:
                case 18:
                case 23:
                        if (*ptr != '-')
                                return (EINVAL);
                        break;

                default:
                        if (!isxdigit(*ptr))
                                return (EINVAL);
                        break;
                }
        }

        if (dump_osimage_uuid[0] != '\0')
                return (EALREADY);

        (void) strncpy(dump_osimage_uuid, uuidstr, 36 + 1);

        cmn_err(CE_CONT, "?This Solaris instance has UUID %s\n",
            dump_osimage_uuid);

        return (0);
}

const char *
dump_get_uuid(void)
{
        return (dump_osimage_uuid[0] != '\0' ? dump_osimage_uuid : "");
}