/*
 *  linux/fs/proc/array.c
 *
 *  Copyright (C) 1992  by Linus Torvalds
 *  based on ideas by Darren Senn
 *
 * Fixes:
 * Michael. K. Johnson: stat,statm extensions.
 *                      <johnsonm@stolaf.edu>
 *
 * Pauline Middelink :  Made cmdline,envline only break at '\0's, to
 *                      make sure SET_PROCTITLE works. Also removed
 *                      bad '!' which forced address recalculation for
 *                      EVERY character on the current page.
 *                      <middelin@polyware.iaf.nl>
 *
 * Danny ter Haar    :  added cpuinfo
 *                      <dth@cistron.nl>
 *
 * Alessandro Rubini :  profile extension.
 *                      <rubini@ipvvis.unipv.it>
 *
 * Jeff Tranter      :  added BogoMips field to cpuinfo
 *                      <Jeff_Tranter@Mitel.COM>
 *
 * Bruno Haible      :  remove 4K limit for the maps file
 *                      <haible@ma2s2.mathematik.uni-karlsruhe.de>
 *
 * Yves Arrouye      :  remove removal of trailing spaces in get_array.
 *                      <Yves.Arrouye@marin.fdn.fr>
 *
 * Jerome Forissier  :  added per-CPU time information to /proc/stat
 *                      and /proc/<pid>/cpu extension
 *                      <forissier@isia.cma.fr>
 *                      - Incorporation and non-SMP safe operation
 *                      of forissier patch in 2.1.78 by
 *                      Hans Marcus <crowbar@concepts.nl>
 *
 * aeb@cwi.nl        :  /proc/partitions
 *
 *
 * Alan Cox          :  security fixes.
 *                      <alan@lxorguk.ukuu.org.uk>
 *
 * Al Viro           :  safe handling of mm_struct
 *
 * Gerhard Wichert   :  added BIGMEM support
 * Siemens AG           <Gerhard.Wichert@pdb.siemens.de>
 *
 * Al Viro & Jeff Garzik :  moved most of the thing into base.c and
 *                       :  proc_misc.c. The rest may eventually go into
 *                       :  base.c too.
 */

#include <linux/types.h>
#include <linux/errno.h>
#include <linux/time.h>
#include <linux/kernel.h>
#include <linux/kernel_stat.h>
#include <linux/tty.h>
#include <linux/string.h>
#include <linux/mman.h>
#include <linux/proc_fs.h>
#include <linux/ioport.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/mm.h>
#include <linux/hugetlb.h>
#include <linux/pagemap.h>
#include <linux/swap.h>
#include <linux/slab.h>
#include <linux/smp.h>
#include <linux/signal.h>
#include <linux/highmem.h>
#include <linux/file.h>
#include <linux/fdtable.h>
#include <linux/times.h>
#include <linux/cpuset.h>
#include <linux/rcupdate.h>
#include <linux/delayacct.h>
#include <linux/seq_file.h>
#include <linux/pid_namespace.h>
#include <linux/ptrace.h>
#include <linux/tracehook.h>
#include <linux/swapops.h>

#include <asm/pgtable.h>
#include <asm/processor.h>
#include "internal.h"

static inline void task_name(struct seq_file *m, struct task_struct *p)
{
        int i;
        char *buf, *end;
        char *name;
        char tcomm[sizeof(p->comm)];

        get_task_comm(tcomm, p);

        seq_printf(m, "Name:\t");
        end = m->buf + m->size;
        buf = m->buf + m->count;
        name = tcomm;
        i = sizeof(tcomm);
        while (i && (buf < end)) {
                unsigned char c = *name;
                name++;
                i--;
                *buf = c;
                if (!c)
                        break;
                if (c == '\\') {
                        buf++;
                        if (buf < end)
                                *buf++ = c;
                        continue;
                }
                if (c == '\n') {
                        *buf++ = '\\';
                        if (buf < end)
                                *buf++ = 'n';
                        continue;
                }
                buf++;
        }
        m->count = buf - m->buf;
        seq_printf(m, "\n");
}

/*
 * The task state array is a strange "bitmap" of
 * reasons to sleep. Thus "running" is zero, and
 * you can test for combinations of others with
 * simple bit tests.
 */
static const char *task_state_array[] = {
        "R (running)",          /*  0 */
        "S (sleeping)",         /*  1 */
        "D (disk sleep)",       /*  2 */
        "T (stopped)",          /*  4 */
        "T (tracing stop)",     /*  8 */
        "Z (zombie)",           /* 16 */
        "X (dead)"              /* 32 */
};

static inline const char *get_task_state(struct task_struct *tsk)
{
        unsigned int state = (tsk->state & TASK_REPORT) | tsk->exit_state;
        const char **p = &task_state_array[0];

        while (state) {
                p++;
                state >>= 1;
        }
        return *p;
}

static inline void task_state(struct seq_file *m, struct pid_namespace *ns,
                                struct pid *pid, struct task_struct *p)
{
        struct group_info *group_info;
        int g;
        struct fdtable *fdt = NULL;
        const struct cred *cred;
        pid_t ppid, tpid;

        rcu_read_lock();
        ppid = pid_alive(p) ?
                task_tgid_nr_ns(rcu_dereference(p->real_parent), ns) : 0;
        tpid = 0;
        if (pid_alive(p)) {
                struct task_struct *tracer = tracehook_tracer_task(p);
                if (tracer)
                        tpid = task_pid_nr_ns(tracer, ns);
        }
        cred = get_cred((struct cred *) __task_cred(p));
        seq_printf(m,
                "State:\t%s\n"
                "Tgid:\t%d\n"
                "Pid:\t%d\n"
                "PPid:\t%d\n"
                "TracerPid:\t%d\n"
                "Uid:\t%d\t%d\t%d\t%d\n"
                "Gid:\t%d\t%d\t%d\t%d\n",
                get_task_state(p),
                task_tgid_nr_ns(p, ns),
                pid_nr_ns(pid, ns),
                ppid, tpid,
                cred->uid, cred->euid, cred->suid, cred->fsuid,
                cred->gid, cred->egid, cred->sgid, cred->fsgid);

        task_lock(p);
        if (p->files)
                fdt = files_fdtable(p->files);
        seq_printf(m,
                "FDSize:\t%d\n"
                "Groups:\t",
                fdt ? fdt->max_fds : 0);
        rcu_read_unlock();

        group_info = cred->group_info;
        task_unlock(p);

        for (g = 0; g < min(group_info->ngroups, NGROUPS_SMALL); g++)
                seq_printf(m, "%d ", GROUP_AT(group_info, g));
        put_cred(cred);

        seq_printf(m, "\n");
}

static void render_sigset_t(struct seq_file *m, const char *header,
                                sigset_t *set)
{
        int i;

        seq_printf(m, "%s", header);

        i = _NSIG;
        do {
                int x = 0;

                i -= 4;
                if (sigismember(set, i+1)) x |= 1;
                if (sigismember(set, i+2)) x |= 2;
                if (sigismember(set, i+3)) x |= 4;
                if (sigismember(set, i+4)) x |= 8;
                seq_printf(m, "%x", x);
        } while (i >= 4);

        seq_printf(m, "\n");
}

static void collect_sigign_sigcatch(struct task_struct *p, sigset_t *ign,
                                    sigset_t *catch)
{
        struct k_sigaction *k;
        int i;

        k = p->sighand->action;
        for (i = 1; i <= _NSIG; ++i, ++k) {
                if (k->sa.sa_handler == SIG_IGN)
                        sigaddset(ign, i);
                else if (k->sa.sa_handler != SIG_DFL)
                        sigaddset(catch, i);
        }
}

static inline void task_sig(struct seq_file *m, struct task_struct *p)
{
        unsigned long flags;
        sigset_t pending, shpending, blocked, ignored, caught;
        int num_threads = 0;
        unsigned long qsize = 0;
        unsigned long qlim = 0;

        sigemptyset(&pending);
        sigemptyset(&shpending);
        sigemptyset(&blocked);
        sigemptyset(&ignored);
        sigemptyset(&caught);

        if (lock_task_sighand(p, &flags)) {
                pending = p->pending.signal;
                shpending = p->signal->shared_pending.signal;
                blocked = p->blocked;
                collect_sigign_sigcatch(p, &ignored, &caught);
                num_threads = atomic_read(&p->signal->count);
                qsize = atomic_read(&__task_cred(p)->user->sigpending);
                qlim = p->signal->rlim[RLIMIT_SIGPENDING].rlim_cur;
                unlock_task_sighand(p, &flags);
        }

        seq_printf(m, "Threads:\t%d\n", num_threads);
        seq_printf(m, "SigQ:\t%lu/%lu\n", qsize, qlim);

        /* render them all */
        render_sigset_t(m, "SigPnd:\t", &pending);
        render_sigset_t(m, "ShdPnd:\t", &shpending);
        render_sigset_t(m, "SigBlk:\t", &blocked);
        render_sigset_t(m, "SigIgn:\t", &ignored);
        render_sigset_t(m, "SigCgt:\t", &caught);
}

static void render_cap_t(struct seq_file *m, const char *header,
                        kernel_cap_t *a)
{
        unsigned __capi;

        seq_printf(m, "%s", header);
        CAP_FOR_EACH_U32(__capi) {
                seq_printf(m, "%08x",
                           a->cap[(_KERNEL_CAPABILITY_U32S-1) - __capi]);
        }
        seq_printf(m, "\n");
}

static inline void task_cap(struct seq_file *m, struct task_struct *p)
{
        const struct cred *cred;
        kernel_cap_t cap_inheritable, cap_permitted, cap_effective, cap_bset;

        rcu_read_lock();
        cred = __task_cred(p);
        cap_inheritable = cred->cap_inheritable;
        cap_permitted   = cred->cap_permitted;
        cap_effective   = cred->cap_effective;
        cap_bset        = cred->cap_bset;
        rcu_read_unlock();

        render_cap_t(m, "CapInh:\t", &cap_inheritable);
        render_cap_t(m, "CapPrm:\t", &cap_permitted);
        render_cap_t(m, "CapEff:\t", &cap_effective);
        render_cap_t(m, "CapBnd:\t", &cap_bset);
}

static inline void task_context_switch_counts(struct seq_file *m,
                                                struct task_struct *p)
{
        seq_printf(m,   "voluntary_ctxt_switches:\t%lu\n"
                        "nonvoluntary_ctxt_switches:\t%lu\n",
                        p->nvcsw,
                        p->nivcsw);
}

#ifdef CONFIG_MMU

struct stack_stats {
        struct vm_area_struct *vma;
        unsigned long   startpage;
        unsigned long   usage;
};

static int stack_usage_pte_range(pmd_t *pmd, unsigned long addr,
                                unsigned long end, struct mm_walk *walk)
{
        struct stack_stats *ss = walk->private;
        struct vm_area_struct *vma = ss->vma;
        pte_t *pte, ptent;
        spinlock_t *ptl;
        int ret = 0;

        pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
        for (; addr != end; pte++, addr += PAGE_SIZE) {
                ptent = *pte;

#ifdef CONFIG_STACK_GROWSUP
                if (pte_present(ptent) || is_swap_pte(ptent))
                        ss->usage = addr - ss->startpage + PAGE_SIZE;
#else
                if (pte_present(ptent) || is_swap_pte(ptent)) {
                        ss->usage = ss->startpage - addr + PAGE_SIZE;
                        pte++;
                        ret = 1;
                        break;
                }
#endif
        }
        pte_unmap_unlock(pte - 1, ptl);
        cond_resched();
        return ret;
}

static inline unsigned long get_stack_usage_in_bytes(struct vm_area_struct *vma,
                                struct task_struct *task)
{
        struct stack_stats ss;
        struct mm_walk stack_walk = {
                .pmd_entry = stack_usage_pte_range,
                .mm = vma->vm_mm,
                .private = &ss,
        };

        if (!vma->vm_mm || is_vm_hugetlb_page(vma))
                return 0;

        ss.vma = vma;
        ss.startpage = task->stack_start & PAGE_MASK;
        ss.usage = 0;

#ifdef CONFIG_STACK_GROWSUP
        walk_page_range(KSTK_ESP(task) & PAGE_MASK, vma->vm_end,
                &stack_walk);
#else
        walk_page_range(vma->vm_start, (KSTK_ESP(task) & PAGE_MASK) + PAGE_SIZE,
                &stack_walk);
#endif
        return ss.usage;
}

static inline void task_show_stack_usage(struct seq_file *m,
                                                struct task_struct *task)
{
        struct vm_area_struct   *vma;
        struct mm_struct        *mm = get_task_mm(task);

        if (mm) {
                down_read(&mm->mmap_sem);
                vma = find_vma(mm, task->stack_start);
                if (vma)
                        seq_printf(m, "Stack usage:\t%lu kB\n",
                                get_stack_usage_in_bytes(vma, task) >> 10);

                up_read(&mm->mmap_sem);
                mmput(mm);
        }
}
#else
static void task_show_stack_usage(struct seq_file *m, struct task_struct *task)
{
}
#endif          /* CONFIG_MMU */

int proc_pid_status(struct seq_file *m, struct pid_namespace *ns,
                        struct pid *pid, struct task_struct *task)
{
        struct mm_struct *mm = get_task_mm(task);

        task_name(m, task);
        task_state(m, ns, pid, task);

        if (mm) {
                task_mem(m, mm);
                mmput(mm);
        }
        task_sig(m, task);
        task_cap(m, task);
        cpuset_task_status_allowed(m, task);
#if defined(CONFIG_S390)
        task_show_regs(m, task);
#endif
        task_context_switch_counts(m, task);
        task_show_stack_usage(m, task);
        return 0;
}

static int do_task_stat(struct seq_file *m, struct pid_namespace *ns,
                        struct pid *pid, struct task_struct *task, int whole)
{
        unsigned long vsize, eip, esp, wchan = ~0UL;
        long priority, nice;
        int tty_pgrp = -1, tty_nr = 0;
        sigset_t sigign, sigcatch;
        char state;
        pid_t ppid = 0, pgid = -1, sid = -1;
        int num_threads = 0;
        int permitted;
        struct mm_struct *mm;
        unsigned long long start_time;
        unsigned long cmin_flt = 0, cmaj_flt = 0;
        unsigned long  min_flt = 0,  maj_flt = 0;
        cputime_t cutime, cstime, utime, stime;
        cputime_t cgtime, gtime;
        unsigned long rsslim = 0;
        char tcomm[sizeof(task->comm)];
        unsigned long flags;

        state = *get_task_state(task);
        vsize = eip = esp = 0;
        permitted = ptrace_may_access(task, PTRACE_MODE_READ);
        mm = get_task_mm(task);
        if (mm) {
                vsize = task_vsize(mm);
                if (permitted) {
                        eip = KSTK_EIP(task);
                        esp = KSTK_ESP(task);
                }
        }

        get_task_comm(tcomm, task);

        sigemptyset(&sigign);
        sigemptyset(&sigcatch);
        cutime = cstime = utime = stime = cputime_zero;
        cgtime = gtime = cputime_zero;

        if (lock_task_sighand(task, &flags)) {
                struct signal_struct *sig = task->signal;

                if (sig->tty) {
                        struct pid *pgrp = tty_get_pgrp(sig->tty);
                        tty_pgrp = pid_nr_ns(pgrp, ns);
                        put_pid(pgrp);
                        tty_nr = new_encode_dev(tty_devnum(sig->tty));
                }

                num_threads = atomic_read(&sig->count);
                collect_sigign_sigcatch(task, &sigign, &sigcatch);

                cmin_flt = sig->cmin_flt;
                cmaj_flt = sig->cmaj_flt;
                cutime = sig->cutime;
                cstime = sig->cstime;
                cgtime = sig->cgtime;
                rsslim = sig->rlim[RLIMIT_RSS].rlim_cur;

                /* add up live thread stats at the group level */
                if (whole) {
                        struct task_cputime cputime;
                        struct task_struct *t = task;
                        do {
                                min_flt += t->min_flt;
                                maj_flt += t->maj_flt;
                                gtime = cputime_add(gtime, task_gtime(t));
                                t = next_thread(t);
                        } while (t != task);

                        min_flt += sig->min_flt;
                        maj_flt += sig->maj_flt;
                        thread_group_cputime(task, &cputime);
                        utime = cputime.utime;
                        stime = cputime.stime;
                        gtime = cputime_add(gtime, sig->gtime);
                }

                sid = task_session_nr_ns(task, ns);
                ppid = task_tgid_nr_ns(task->real_parent, ns);
                pgid = task_pgrp_nr_ns(task, ns);

                unlock_task_sighand(task, &flags);
        }

        if (permitted && (!whole || num_threads < 2))
                wchan = get_wchan(task);
        if (!whole) {
                min_flt = task->min_flt;
                maj_flt = task->maj_flt;
                utime = task_utime(task);
                stime = task_stime(task);
                gtime = task_gtime(task);
        }

        /* scale priority and nice values from timeslices to -20..20 */
        /* to make it look like a "normal" Unix priority/nice value  */
        priority = task_prio(task);
        nice = task_nice(task);

        /* Temporary variable needed for gcc-2.96 */
        /* convert timespec -> nsec*/
        start_time =
                (unsigned long long)task->real_start_time.tv_sec * NSEC_PER_SEC
                                + task->real_start_time.tv_nsec;
        /* convert nsec -> ticks */
        start_time = nsec_to_clock_t(start_time);

        seq_printf(m, "%d (%s) %c %d %d %d %d %d %u %lu \
%lu %lu %lu %lu %lu %ld %ld %ld %ld %d 0 %llu %lu %ld %lu %lu %lu %lu %lu \
%lu %lu %lu %lu %lu %lu %lu %lu %d %d %u %u %llu %lu %ld\n",
                pid_nr_ns(pid, ns),
                tcomm,
                state,
                ppid,
                pgid,
                sid,
                tty_nr,
                tty_pgrp,
                task->flags,
                min_flt,
                cmin_flt,
                maj_flt,
                cmaj_flt,
                cputime_to_clock_t(utime),
                cputime_to_clock_t(stime),
                cputime_to_clock_t(cutime),
                cputime_to_clock_t(cstime),
                priority,
                nice,
                num_threads,
                start_time,
                vsize,
                mm ? get_mm_rss(mm) : 0,
                rsslim,
                mm ? mm->start_code : 0,
                mm ? mm->end_code : 0,
                (permitted && mm) ? task->stack_start : 0,
                esp,
                eip,
                /* The signal information here is obsolete.
                 * It must be decimal for Linux 2.0 compatibility.
                 * Use /proc/#/status for real-time signals.
                 */
                task->pending.signal.sig[0] & 0x7fffffffUL,
                task->blocked.sig[0] & 0x7fffffffUL,
                sigign      .sig[0] & 0x7fffffffUL,
                sigcatch    .sig[0] & 0x7fffffffUL,
                wchan,
                0UL,
                0UL,
                task->exit_signal,
                task_cpu(task),
                task->rt_priority,
                task->policy,
                (unsigned long long)delayacct_blkio_ticks(task),
                cputime_to_clock_t(gtime),
                cputime_to_clock_t(cgtime));
        if (mm)
                mmput(mm);
        return 0;
}

int proc_tid_stat(struct seq_file *m, struct pid_namespace *ns,
                        struct pid *pid, struct task_struct *task)
{
        return do_task_stat(m, ns, pid, task, 0);
}

int proc_tgid_stat(struct seq_file *m, struct pid_namespace *ns,
                        struct pid *pid, struct task_struct *task)
{
        return do_task_stat(m, ns, pid, task, 1);
}

int proc_pid_statm(struct seq_file *m, struct pid_namespace *ns,
                        struct pid *pid, struct task_struct *task)
{
        int size = 0, resident = 0, shared = 0, text = 0, lib = 0, data = 0;
        struct mm_struct *mm = get_task_mm(task);

        if (mm) {
                size = task_statm(mm, &shared, &text, &data, &resident);
                mmput(mm);
        }
        seq_printf(m, "%d %d %d %d %d %d %d\n",
                        size, resident, shared, text, lib, data, 0);

        return 0;
}