/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2017 Dell EMC
 * Copyright (c) 2007 Sandvine Incorporated
 * Copyright (c) 1998 John D. Polstra
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/cdefs.h>
#include <sys/endian.h>
#include <sys/param.h>
#include <sys/procfs.h>
#include <sys/ptrace.h>
#include <sys/queue.h>
#include <sys/linker_set.h>
#include <sys/sbuf.h>
#include <sys/sysctl.h>
#include <sys/user.h>
#include <sys/wait.h>
#include <machine/elf.h>
#include <vm/vm_param.h>
#include <vm/vm.h>
#include <assert.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <libutil.h>

#include "extern.h"

/*
 * Code for generating ELF core dumps.
 */

struct map_entry {
        struct map_entry *next;
        vm_offset_t start;
        vm_offset_t end;
        vm_prot_t protection;
};

typedef void (*segment_callback)(struct map_entry *, void *);

/* Closure for cb_put_phdr(). */
struct phdr_closure {
        Elf_Phdr *phdr;         /* Program header to fill in */
        Elf_Off offset;         /* Offset of segment in core file */
};

/* Closure for cb_size_segment(). */
struct sseg_closure {
        int count;              /* Count of writable segments. */
        size_t size;            /* Total size of all writable segments. */
};

#ifdef ELFCORE_COMPAT_32
typedef struct prpsinfo32 elfcore_prpsinfo_t;
#else
typedef prpsinfo_t elfcore_prpsinfo_t;
#endif

typedef void* (*notefunc_t)(void *, size_t *);

static void cb_put_phdr(struct map_entry *, void *);
static void cb_size_segment(struct map_entry *, void *);
static void each_dumpable_segment(struct map_entry *, segment_callback,
    void *closure);
static void elf_detach(void);   /* atexit() handler. */
static void *elf_note_prpsinfo(void *, size_t *);
#if defined(__i386__) || defined(__amd64__)
static void *elf_note_x86_xstate(void *, size_t *);
#endif
#if defined(__powerpc__)
static void *elf_note_powerpc_vmx(void *, size_t *);
static void *elf_note_powerpc_vsx(void *, size_t *);
#endif
static void *elf_note_procstat_auxv(void *, size_t *);
static void *elf_note_procstat_files(void *, size_t *);
static void *elf_note_procstat_groups(void *, size_t *);
static void *elf_note_procstat_kqueues(void *, size_t *);
static void *elf_note_procstat_osrel(void *, size_t *);
static void *elf_note_procstat_proc(void *, size_t *);
static void *elf_note_procstat_psstrings(void *, size_t *);
static void *elf_note_procstat_rlimit(void *, size_t *);
static void *elf_note_procstat_umask(void *, size_t *);
static void *elf_note_procstat_vmmap(void *, size_t *);
static void elf_puthdr(int, pid_t, struct map_entry *, void *, size_t, size_t,
    size_t, int);
static void elf_putnote(int, notefunc_t, void *, struct sbuf *);
static void elf_putnotes(pid_t, struct sbuf *, size_t *);
static void elf_putregnote(int, lwpid_t, struct sbuf *);
static void freemap(struct map_entry *);
static struct map_entry *readmap(pid_t);
static void *procstat_sysctl(void *, int, size_t, size_t *sizep);

static pid_t g_pid;             /* Pid being dumped, global for elf_detach */
static int g_status;            /* proc status after ptrace attach */

static int
elf_ident(int efd, pid_t pid __unused, char *binfile __unused)
{
        Elf_Ehdr hdr;
        int cnt;
        uint16_t machine;

        cnt = read(efd, &hdr, sizeof(hdr));
        if (cnt != sizeof(hdr))
                return (0);
        if (!IS_ELF(hdr))
                return (0);
        switch (hdr.e_ident[EI_DATA]) {
        case ELFDATA2LSB:
                machine = le16toh(hdr.e_machine);
                break;
        case ELFDATA2MSB:
                machine = be16toh(hdr.e_machine);
                break;
        default:
                return (0);
        }
        if (!ELF_MACHINE_OK(machine))
                return (0);

        /* Looks good. */
        return (1);
}

static void
elf_detach(void)
{
        int sig;

        if (g_pid != 0) {
                /*
                 * Forward any pending signals. SIGSTOP is generated by ptrace
                 * itself, so ignore it.
                 */
                sig = WIFSTOPPED(g_status) ? WSTOPSIG(g_status) : 0;
                if (sig == SIGSTOP)
                        sig = 0;
                ptrace(PT_DETACH, g_pid, (caddr_t)1, sig);
        }
}

/*
 * Write an ELF coredump for the given pid to the given fd.
 */
static void
elf_coredump(int efd, int fd, pid_t pid)
{
        struct map_entry *map;
        struct sseg_closure seginfo;
        struct sbuf *sb;
        void *hdr;
        size_t hdrsize, notesz, segoff;
        ssize_t n, old_len;
        Elf_Phdr *php;
        int i;

        /* Attach to process to dump. */
        g_pid = pid;
        if (atexit(elf_detach) != 0)
                err(1, "atexit");
        errno = 0;
        ptrace(PT_ATTACH, pid, NULL, 0);
        if (errno)
                err(1, "PT_ATTACH");
        if (waitpid(pid, &g_status, 0) == -1)
                err(1, "waitpid");

        /* Get the program's memory map. */
        map = readmap(pid);

        /* Size the program segments. */
        seginfo.count = 0;
        seginfo.size = 0;
        each_dumpable_segment(map, cb_size_segment, &seginfo);

        /*
         * Build the header and the notes using sbuf and write to the file.
         */
        sb = sbuf_new_auto();
        hdrsize = sizeof(Elf_Ehdr) + sizeof(Elf_Phdr) * (1 + seginfo.count);
        if (seginfo.count + 1 >= PN_XNUM)
                hdrsize += sizeof(Elf_Shdr);
        /* Start header + notes section. */
        sbuf_start_section(sb, NULL);
        /* Make empty header subsection. */
        sbuf_start_section(sb, &old_len);
        sbuf_putc(sb, 0);
        sbuf_end_section(sb, old_len, hdrsize, 0);
        /* Put notes. */
        elf_putnotes(pid, sb, &notesz);
        /* Align up to a page boundary for the program segments. */
        sbuf_end_section(sb, -1, getpagesize(), 0);
        if (sbuf_finish(sb) != 0)
                err(1, "sbuf_finish");
        hdr = sbuf_data(sb);
        segoff = sbuf_len(sb);
        /* Fill in the header. */
        elf_puthdr(efd, pid, map, hdr, hdrsize, notesz, segoff, seginfo.count);

        n = write(fd, hdr, segoff);
        if (n == -1)
                err(1, "write");
        if (n < segoff)
              errx(1, "short write");

        /* Write the contents of all of the writable segments. */
        php = (Elf_Phdr *)((char *)hdr + sizeof(Elf_Ehdr)) + 1;
        for (i = 0;  i < seginfo.count;  i++) {
                struct ptrace_io_desc iorequest;
                uintmax_t nleft = php->p_filesz;

                iorequest.piod_op = PIOD_READ_D;
                iorequest.piod_offs = (caddr_t)(uintptr_t)php->p_vaddr;
                while (nleft > 0) {
                        char buf[8*1024];
                        size_t nwant;
                        ssize_t ngot;

                        if (nleft > sizeof(buf))
                                nwant = sizeof buf;
                        else
                                nwant = nleft;
                        iorequest.piod_addr = buf;
                        iorequest.piod_len = nwant;
                        ptrace(PT_IO, pid, (caddr_t)&iorequest, 0);
                        ngot = iorequest.piod_len;
                        if ((size_t)ngot < nwant)
                                errx(1, "short read wanted %zu, got %zd",
                                    nwant, ngot);
                        ngot = write(fd, buf, nwant);
                        if (ngot == -1)
                                err(1, "write of segment %d failed", i);
                        if ((size_t)ngot != nwant)
                                errx(1, "short write");
                        nleft -= nwant;
                        iorequest.piod_offs += ngot;
                }
                php++;
        }
        sbuf_delete(sb);
        freemap(map);
}

/*
 * A callback for each_dumpable_segment() to write out the segment's
 * program header entry.
 */
static void
cb_put_phdr(struct map_entry *entry, void *closure)
{
        struct phdr_closure *phc = (struct phdr_closure *)closure;
        Elf_Phdr *phdr = phc->phdr;
        size_t page_size;

        page_size = getpagesize();
        phc->offset = roundup2(phc->offset, page_size);

        phdr->p_type = PT_LOAD;
        phdr->p_offset = phc->offset;
        phdr->p_vaddr = entry->start;
        phdr->p_paddr = 0;
        phdr->p_filesz = phdr->p_memsz = entry->end - entry->start;
        phdr->p_align = page_size;
        phdr->p_flags = 0;
        if (entry->protection & VM_PROT_READ)
                phdr->p_flags |= PF_R;
        if (entry->protection & VM_PROT_WRITE)
                phdr->p_flags |= PF_W;
        if (entry->protection & VM_PROT_EXECUTE)
                phdr->p_flags |= PF_X;

        phc->offset += phdr->p_filesz;
        phc->phdr++;
}

/*
 * A callback for each_dumpable_segment() to gather information about
 * the number of segments and their total size.
 */
static void
cb_size_segment(struct map_entry *entry, void *closure)
{
        struct sseg_closure *ssc = (struct sseg_closure *)closure;

        ssc->count++;
        ssc->size += entry->end - entry->start;
}

/*
 * For each segment in the given memory map, call the given function
 * with a pointer to the map entry and some arbitrary caller-supplied
 * data.
 */
static void
each_dumpable_segment(struct map_entry *map, segment_callback func,
    void *closure)
{
        struct map_entry *entry;

        for (entry = map; entry != NULL; entry = entry->next)
                (*func)(entry, closure);
}

static void
elf_putnotes(pid_t pid, struct sbuf *sb, size_t *sizep)
{
        lwpid_t *tids;
        size_t threads, old_len;
        ssize_t size;
        int i;

        errno = 0;
        threads = ptrace(PT_GETNUMLWPS, pid, NULL, 0);
        if (errno)
                err(1, "PT_GETNUMLWPS");
        tids = malloc(threads * sizeof(*tids));
        if (tids == NULL)
                errx(1, "out of memory");
        errno = 0;
        ptrace(PT_GETLWPLIST, pid, (void *)tids, threads);
        if (errno)
                err(1, "PT_GETLWPLIST");

        sbuf_start_section(sb, &old_len);
        elf_putnote(NT_PRPSINFO, elf_note_prpsinfo, &pid, sb);

        for (i = 0; i < threads; ++i) {
                elf_putregnote(NT_PRSTATUS, tids[i], sb);
                elf_putregnote(NT_FPREGSET, tids[i], sb);
                elf_putregnote(NT_THRMISC, tids[i], sb);
                elf_putregnote(NT_PTLWPINFO, tids[i], sb);
#if defined(__aarch64__) || defined(__arm__)
                elf_putregnote(NT_ARM_TLS, tids[i], sb);
#endif
#if (defined(ELFCORE_COMPAT_32) && defined(__aarch64__)) || defined(__arm__)
                elf_putregnote(NT_ARM_VFP, tids[i], sb);
#endif
#if defined(__i386__) || defined(__amd64__)
                elf_putregnote(NT_X86_SEGBASES, tids[i], sb);
                elf_putnote(NT_X86_XSTATE, elf_note_x86_xstate, tids + i, sb);
#endif
#if defined(__powerpc__)
                elf_putnote(NT_PPC_VMX, elf_note_powerpc_vmx, tids + i, sb);
                elf_putnote(NT_PPC_VSX, elf_note_powerpc_vsx, tids + i, sb);
#endif
        }

#ifndef ELFCORE_COMPAT_32
        elf_putnote(NT_PROCSTAT_PROC, elf_note_procstat_proc, &pid, sb);
        elf_putnote(NT_PROCSTAT_FILES, elf_note_procstat_files, &pid, sb);
        elf_putnote(NT_PROCSTAT_VMMAP, elf_note_procstat_vmmap, &pid, sb);
        elf_putnote(NT_PROCSTAT_GROUPS, elf_note_procstat_groups, &pid, sb);
        elf_putnote(NT_PROCSTAT_UMASK, elf_note_procstat_umask, &pid, sb);
        elf_putnote(NT_PROCSTAT_RLIMIT, elf_note_procstat_rlimit, &pid, sb);
        elf_putnote(NT_PROCSTAT_OSREL, elf_note_procstat_osrel, &pid, sb);
        elf_putnote(NT_PROCSTAT_PSSTRINGS, elf_note_procstat_psstrings, &pid,
            sb);
        elf_putnote(NT_PROCSTAT_AUXV, elf_note_procstat_auxv, &pid, sb);
        elf_putnote(NT_PROCSTAT_KQUEUES, elf_note_procstat_kqueues, &pid, sb);
#endif

        size = sbuf_end_section(sb, old_len, 1, 0);
        if (size == -1)
                err(1, "sbuf_end_section");
        free(tids);
        *sizep = size;
}

/*
 * Emit one register set note section to sbuf.
 */
static void
elf_putregnote(int type, lwpid_t tid, struct sbuf *sb)
{
        Elf_Note note;
        struct iovec iov;
        ssize_t old_len;

        iov.iov_base = NULL;
        iov.iov_len = 0;
        if (ptrace(PT_GETREGSET, tid, (void *)&iov, type) != 0)
                return;
        iov.iov_base = calloc(1, iov.iov_len);
        if (iov.iov_base == NULL)
                errx(1, "out of memory");
        if (ptrace(PT_GETREGSET, tid, (void *)&iov, type) != 0)
                errx(1, "failed to fetch register set %d", type);

        note.n_namesz = 8; /* strlen("FreeBSD") + 1 */
        note.n_descsz = iov.iov_len;
        note.n_type = type;

        sbuf_bcat(sb, &note, sizeof(note));
        sbuf_start_section(sb, &old_len);
        sbuf_bcat(sb, "FreeBSD", note.n_namesz);
        sbuf_end_section(sb, old_len, sizeof(Elf32_Size), 0);
        sbuf_start_section(sb, &old_len);
        sbuf_bcat(sb, iov.iov_base, iov.iov_len);
        sbuf_end_section(sb, old_len, sizeof(Elf32_Size), 0);
        free(iov.iov_base);
}

/*
 * Emit one note section to sbuf.
 */
static void
elf_putnote(int type, notefunc_t notefunc, void *arg, struct sbuf *sb)
{
        Elf_Note note;
        size_t descsz;
        ssize_t old_len;
        void *desc;

        desc = notefunc(arg, &descsz);
        note.n_namesz = 8; /* strlen("FreeBSD") + 1 */
        note.n_descsz = descsz;
        note.n_type = type;

        sbuf_bcat(sb, &note, sizeof(note));
        sbuf_start_section(sb, &old_len);
        sbuf_bcat(sb, "FreeBSD", note.n_namesz);
        sbuf_end_section(sb, old_len, sizeof(Elf32_Size), 0);
        if (descsz == 0)
                return;
        sbuf_start_section(sb, &old_len);
        sbuf_bcat(sb, desc, descsz);
        sbuf_end_section(sb, old_len, sizeof(Elf32_Size), 0);
        free(desc);
}

/*
 * Generate the ELF coredump header.
 */
static void
elf_puthdr(int efd, pid_t pid, struct map_entry *map, void *hdr, size_t hdrsize,
    size_t notesz, size_t segoff, int numsegs)
{
        Elf_Ehdr *ehdr, binhdr;
        Elf_Phdr *phdr;
        Elf_Shdr *shdr;
        struct phdr_closure phc;
        ssize_t cnt;

        cnt = read(efd, &binhdr, sizeof(binhdr));
        if (cnt < 0)
                err(1, "Failed to re-read ELF header");
        else if (cnt != sizeof(binhdr))
                errx(1, "Failed to re-read ELF header");

        ehdr = (Elf_Ehdr *)hdr;

        ehdr->e_ident[EI_MAG0] = ELFMAG0;
        ehdr->e_ident[EI_MAG1] = ELFMAG1;
        ehdr->e_ident[EI_MAG2] = ELFMAG2;
        ehdr->e_ident[EI_MAG3] = ELFMAG3;
        ehdr->e_ident[EI_CLASS] = ELF_CLASS;
        ehdr->e_ident[EI_DATA] = ELF_DATA;
        ehdr->e_ident[EI_VERSION] = EV_CURRENT;
        ehdr->e_ident[EI_OSABI] = ELFOSABI_FREEBSD;
        ehdr->e_ident[EI_ABIVERSION] = 0;
        ehdr->e_ident[EI_PAD] = 0;
        ehdr->e_type = ET_CORE;
        ehdr->e_machine = binhdr.e_machine;
        ehdr->e_version = EV_CURRENT;
        ehdr->e_entry = 0;
        ehdr->e_phoff = sizeof(Elf_Ehdr);
        ehdr->e_flags = binhdr.e_flags;
        ehdr->e_ehsize = sizeof(Elf_Ehdr);
        ehdr->e_phentsize = sizeof(Elf_Phdr);
        ehdr->e_shentsize = sizeof(Elf_Shdr);
        ehdr->e_shstrndx = SHN_UNDEF;
        if (numsegs + 1 < PN_XNUM) {
                ehdr->e_phnum = numsegs + 1;
                ehdr->e_shnum = 0;
        } else {
                ehdr->e_phnum = PN_XNUM;
                ehdr->e_shnum = 1;

                ehdr->e_shoff = ehdr->e_phoff +
                    (numsegs + 1) * ehdr->e_phentsize;

                shdr = (Elf_Shdr *)((char *)hdr + ehdr->e_shoff);
                memset(shdr, 0, sizeof(*shdr));
                /*
                 * A special first section is used to hold large segment and
                 * section counts.  This was proposed by Sun Microsystems in
                 * Solaris and has been adopted by Linux; the standard ELF
                 * tools are already familiar with the technique.
                 *
                 * See table 7-7 of the Solaris "Linker and Libraries Guide"
                 * (or 12-7 depending on the version of the document) for more
                 * details.
                 */
                shdr->sh_type = SHT_NULL;
                shdr->sh_size = ehdr->e_shnum;
                shdr->sh_link = ehdr->e_shstrndx;
                shdr->sh_info = numsegs + 1;
        }

        /*
         * Fill in the program header entries.
         */
        phdr = (Elf_Phdr *)((char *)hdr + ehdr->e_phoff);

        /* The note segment. */
        phdr->p_type = PT_NOTE;
        phdr->p_offset = hdrsize;
        phdr->p_vaddr = 0;
        phdr->p_paddr = 0;
        phdr->p_filesz = notesz;
        phdr->p_memsz = 0;
        phdr->p_flags = PF_R;
        phdr->p_align = sizeof(Elf32_Size);
        phdr++;

        /* All the writable segments from the program. */
        phc.phdr = phdr;
        phc.offset = segoff;
        each_dumpable_segment(map, cb_put_phdr, &phc);
}

/*
 * Free the memory map.
 */
static void
freemap(struct map_entry *map)
{
        struct map_entry *next;

        while (map != NULL) {
                next = map->next;
                free(map);
                map = next;
        }
}

/*
 * Read the process's memory map using kinfo_getvmmap(), and return a list of
 * VM map entries.  Only the non-device read/writable segments are
 * returned.  The map entries in the list aren't fully filled in; only
 * the items we need are present.
 */
static struct map_entry *
readmap(pid_t pid)
{
        struct map_entry *ent, **linkp, *map;
        struct kinfo_vmentry *vmentl, *kve;
        int i, nitems;

        vmentl = kinfo_getvmmap(pid, &nitems);
        if (vmentl == NULL)
                err(1, "cannot retrieve mappings for %u process", pid);

        map = NULL;
        linkp = &map;
        for (i = 0; i < nitems; i++) {
                kve = &vmentl[i];

                /*
                 * Ignore 'malformed' segments or ones representing memory
                 * mapping with MAP_NOCORE on.
                 * If the 'full' support is disabled, just dump the most
                 * meaningful data segments.
                 */
                if ((kve->kve_protection & KVME_PROT_READ) == 0 ||
                    (kve->kve_flags & KVME_FLAG_NOCOREDUMP) != 0 ||
                    kve->kve_type == KVME_TYPE_DEAD ||
                    kve->kve_type == KVME_TYPE_UNKNOWN ||
                    ((pflags & PFLAGS_FULL) == 0 &&
                    kve->kve_type != KVME_TYPE_DEFAULT &&
                    kve->kve_type != KVME_TYPE_VNODE &&
                    kve->kve_type != KVME_TYPE_SWAP &&
                    kve->kve_type != KVME_TYPE_PHYS))
                        continue;

                ent = calloc(1, sizeof(*ent));
                if (ent == NULL)
                        errx(1, "out of memory");
                ent->start = (vm_offset_t)kve->kve_start;
                ent->end = (vm_offset_t)kve->kve_end;
                ent->protection = VM_PROT_READ;
                if ((kve->kve_protection & KVME_PROT_WRITE) != 0)
                        ent->protection |= VM_PROT_WRITE;
                if ((kve->kve_protection & KVME_PROT_EXEC) != 0)
                        ent->protection |= VM_PROT_EXECUTE;

                *linkp = ent;
                linkp = &ent->next;
        }
        free(vmentl);
        return (map);
}

/*
 * Miscellaneous note out functions.
 */

static void *
elf_note_prpsinfo(void *arg, size_t *sizep)
{
        char *cp, *end;
        pid_t pid;
        elfcore_prpsinfo_t *psinfo;
        struct kinfo_proc kip;
        size_t len;
        int name[4];

        pid = *(pid_t *)arg;
        psinfo = calloc(1, sizeof(*psinfo));
        if (psinfo == NULL)
                errx(1, "out of memory");
        psinfo->pr_version = PRPSINFO_VERSION;
        psinfo->pr_psinfosz = sizeof(*psinfo);

        name[0] = CTL_KERN;
        name[1] = KERN_PROC;
        name[2] = KERN_PROC_PID;
        name[3] = pid;
        len = sizeof(kip);
        if (sysctl(name, 4, &kip, &len, NULL, 0) == -1)
                err(1, "kern.proc.pid.%u", pid);
        if (kip.ki_pid != pid)
                err(1, "kern.proc.pid.%u", pid);
        strlcpy(psinfo->pr_fname, kip.ki_comm, sizeof(psinfo->pr_fname));
        name[2] = KERN_PROC_ARGS;
        len = sizeof(psinfo->pr_psargs) - 1;
        if (sysctl(name, 4, psinfo->pr_psargs, &len, NULL, 0) == 0 && len > 0) {
                cp = psinfo->pr_psargs;
                end = cp + len - 1;
                for (;;) {
                        cp = memchr(cp, '\0', end - cp);
                        if (cp == NULL)
                                break;
                        *cp = ' ';
                }
        } else
                strlcpy(psinfo->pr_psargs, kip.ki_comm,
                    sizeof(psinfo->pr_psargs));
        psinfo->pr_pid = pid;

        *sizep = sizeof(*psinfo);
        return (psinfo);
}

#if defined(__i386__) || defined(__amd64__)
static void *
elf_note_x86_xstate(void *arg, size_t *sizep)
{
        lwpid_t tid;
        char *xstate;
        static bool xsave_checked = false;
        static struct ptrace_xstate_info info;

        tid = *(lwpid_t *)arg;
        if (!xsave_checked) {
                if (ptrace(PT_GETXSTATE_INFO, tid, (void *)&info,
                    sizeof(info)) != 0)
                        info.xsave_len = 0;
                xsave_checked = true;
        }
        if (info.xsave_len == 0) {
                *sizep = 0;
                return (NULL);
        }
        xstate = calloc(1, info.xsave_len);
        ptrace(PT_GETXSTATE, tid, xstate, 0);
        *(uint64_t *)(xstate + X86_XSTATE_XCR0_OFFSET) = info.xsave_mask;
        *sizep = info.xsave_len;
        return (xstate);
}
#endif

#if defined(__powerpc__)
static void *
elf_note_powerpc_vmx(void *arg, size_t *sizep)
{
        lwpid_t tid;
        struct vmxreg *vmx;
        static bool has_vmx = true;
        struct vmxreg info;

        tid = *(lwpid_t *)arg;
        if (has_vmx) {
                if (ptrace(PT_GETVRREGS, tid, (void *)&info,
                    sizeof(info)) != 0)
                        has_vmx = false;
        }
        if (!has_vmx) {
                *sizep = 0;
                return (NULL);
        }
        vmx = calloc(1, sizeof(*vmx));
        memcpy(vmx, &info, sizeof(*vmx));
        *sizep = sizeof(*vmx);
        return (vmx);
}

static void *
elf_note_powerpc_vsx(void *arg, size_t *sizep)
{
        lwpid_t tid;
        char *vshr_data;
        static bool has_vsx = true;
        uint64_t vshr[32];

        tid = *(lwpid_t *)arg;
        if (has_vsx) {
                if (ptrace(PT_GETVSRREGS, tid, (void *)vshr,
                    sizeof(vshr)) != 0)
                        has_vsx = false;
        }
        if (!has_vsx) {
                *sizep = 0;
                return (NULL);
        }
        vshr_data = calloc(1, sizeof(vshr));
        memcpy(vshr_data, vshr, sizeof(vshr));
        *sizep = sizeof(vshr);
        return (vshr_data);
}
#endif

static void *
procstat_sysctl(void *arg, int what, size_t structsz, size_t *sizep)
{
        size_t len;
        pid_t pid;
        int name[5], structsize;
        void *buf, *p;

        pid = *(pid_t *)arg;
        structsize = structsz;
        name[0] = CTL_KERN;
        name[1] = KERN_PROC;
        name[2] = what;
        name[3] = pid;
        len = 0;
        if (sysctl(name, 4, NULL, &len, NULL, 0) == -1)
                err(1, "kern.proc.%d.%u", what, pid);
        buf = calloc(1, sizeof(structsize) + len * 4 / 3);
        if (buf == NULL)
                errx(1, "out of memory");
        bcopy(&structsize, buf, sizeof(structsize));
        p = (char *)buf + sizeof(structsize);
        if (sysctl(name, 4, p, &len, NULL, 0) == -1)
                err(1, "kern.proc.%d.%u", what, pid);

        *sizep = sizeof(structsize) + len;
        return (buf);
}

static void *
elf_note_procstat_proc(void *arg, size_t *sizep)
{

        return (procstat_sysctl(arg, KERN_PROC_PID | KERN_PROC_INC_THREAD,
            sizeof(struct kinfo_proc), sizep));
}

static void *
elf_note_procstat_files(void *arg, size_t *sizep)
{

        return (procstat_sysctl(arg, KERN_PROC_FILEDESC,
            sizeof(struct kinfo_file), sizep));
}

static void *
elf_note_procstat_vmmap(void *arg, size_t *sizep)
{

        return (procstat_sysctl(arg, KERN_PROC_VMMAP,
            sizeof(struct kinfo_vmentry), sizep));
}

static void *
elf_note_procstat_groups(void *arg, size_t *sizep)
{

        return (procstat_sysctl(arg, KERN_PROC_GROUPS, sizeof(gid_t), sizep));
}

static void *
elf_note_procstat_umask(void *arg, size_t *sizep)
{

        return (procstat_sysctl(arg, KERN_PROC_UMASK, sizeof(u_short), sizep));
}

static void *
elf_note_procstat_osrel(void *arg, size_t *sizep)
{

        return (procstat_sysctl(arg, KERN_PROC_OSREL, sizeof(int), sizep));
}

static void *
elf_note_procstat_psstrings(void *arg, size_t *sizep)
{

        return (procstat_sysctl(arg, KERN_PROC_PS_STRINGS,
            sizeof(vm_offset_t), sizep));
}

static void *
elf_note_procstat_auxv(void *arg, size_t *sizep)
{

        return (procstat_sysctl(arg, KERN_PROC_AUXV,
            sizeof(Elf_Auxinfo), sizep));
}

static void *
elf_note_procstat_kqueues(void *arg, size_t *sizep)
{

        return (procstat_sysctl(arg, KERN_PROC_KQUEUE,
            sizeof(struct kinfo_knote), sizep));
}

static void *
elf_note_procstat_rlimit(void *arg, size_t *sizep)
{
        pid_t pid;
        size_t len;
        int i, name[5], structsize;
        void *buf, *p;

        pid = *(pid_t *)arg;
        structsize = sizeof(struct rlimit) * RLIM_NLIMITS;
        buf = calloc(1, sizeof(structsize) + structsize);
        if (buf == NULL)
                errx(1, "out of memory");
        bcopy(&structsize, buf, sizeof(structsize));
        p = (char *)buf + sizeof(structsize);
        name[0] = CTL_KERN;
        name[1] = KERN_PROC;
        name[2] = KERN_PROC_RLIMIT;
        name[3] = pid;
        len = sizeof(struct rlimit);
        for (i = 0; i < RLIM_NLIMITS; i++) {
                name[4] = i;
                if (sysctl(name, 5, p, &len, NULL, 0) == -1)
                        err(1, "kern.proc.rlimit.%u", pid);
                if (len != sizeof(struct rlimit))
                        errx(1, "kern.proc.rlimit.%u: short read", pid);
                p += len;
        }

        *sizep = sizeof(structsize) + structsize;
        return (buf);
}

struct dumpers __elfN(dump) = { elf_ident, elf_coredump };
TEXT_SET(dumpset, __elfN(dump));