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f06febc96b
kernel-ark/kernel/compat.c
Frank Mayhar f06febc96b timers: fix itimer/many thread hang 
Overview

This patch reworks the handling of POSIX CPU timers, including the
ITIMER_PROF, ITIMER_VIRT timers and rlimit handling.  It was put together
with the help of Roland McGrath, the owner and original writer of this code.

The problem we ran into, and the reason for this rework, has to do with using
a profiling timer in a process with a large number of threads.  It appears
that the performance of the old implementation of run_posix_cpu_timers() was
at least O(n*3) (where "n" is the number of threads in a process) or worse.
Everything is fine with an increasing number of threads until the time taken
for that routine to run becomes the same as or greater than the tick time, at
which point things degrade rather quickly.

This patch fixes bug 9906, "Weird hang with NPTL and SIGPROF."

Code Changes

This rework corrects the implementation of run_posix_cpu_timers() to make it
run in constant time for a particular machine.  (Performance may vary between
one machine and another depending upon whether the kernel is built as single-
or multiprocessor and, in the latter case, depending upon the number of
running processors.)  To do this, at each tick we now update fields in
signal_struct as well as task_struct.  The run_posix_cpu_timers() function
uses those fields to make its decisions.

We define a new structure, "task_cputime," to contain user, system and
scheduler times and use these in appropriate places:

struct task_cputime {
	cputime_t utime;
	cputime_t stime;
	unsigned long long sum_exec_runtime;
};

This is included in the structure "thread_group_cputime," which is a new
substructure of signal_struct and which varies for uniprocessor versus
multiprocessor kernels.  For uniprocessor kernels, it uses "task_cputime" as
a simple substructure, while for multiprocessor kernels it is a pointer:

struct thread_group_cputime {
	struct task_cputime totals;
};

struct thread_group_cputime {
	struct task_cputime *totals;
};

We also add a new task_cputime substructure directly to signal_struct, to
cache the earliest expiration of process-wide timers, and task_cputime also
replaces the it_*_expires fields of task_struct (used for earliest expiration
of thread timers).  The "thread_group_cputime" structure contains process-wide
timers that are updated via account_user_time() and friends.  In the non-SMP
case the structure is a simple aggregator; unfortunately in the SMP case that
simplicity was not achievable due to cache-line contention between CPUs (in
one measured case performance was actually _worse_ on a 16-cpu system than
the same test on a 4-cpu system, due to this contention).  For SMP, the
thread_group_cputime counters are maintained as a per-cpu structure allocated
using alloc_percpu().  The timer functions update only the timer field in
the structure corresponding to the running CPU, obtained using per_cpu_ptr().

We define a set of inline functions in sched.h that we use to maintain the
thread_group_cputime structure and hide the differences between UP and SMP
implementations from the rest of the kernel.  The thread_group_cputime_init()
function initializes the thread_group_cputime structure for the given task.
The thread_group_cputime_alloc() is a no-op for UP; for SMP it calls the
out-of-line function thread_group_cputime_alloc_smp() to allocate and fill
in the per-cpu structures and fields.  The thread_group_cputime_free()
function, also a no-op for UP, in SMP frees the per-cpu structures.  The
thread_group_cputime_clone_thread() function (also a UP no-op) for SMP calls
thread_group_cputime_alloc() if the per-cpu structures haven't yet been
allocated.  The thread_group_cputime() function fills the task_cputime
structure it is passed with the contents of the thread_group_cputime fields;
in UP it's that simple but in SMP it must also safely check that tsk->signal
is non-NULL (if it is it just uses the appropriate fields of task_struct) and,
if so, sums the per-cpu values for each online CPU.  Finally, the three
functions account_group_user_time(), account_group_system_time() and
account_group_exec_runtime() are used by timer functions to update the
respective fields of the thread_group_cputime structure.

Non-SMP operation is trivial and will not be mentioned further.

The per-cpu structure is always allocated when a task creates its first new
thread, via a call to thread_group_cputime_clone_thread() from copy_signal().
It is freed at process exit via a call to thread_group_cputime_free() from
cleanup_signal().

All functions that formerly summed utime/stime/sum_sched_runtime values from
from all threads in the thread group now use thread_group_cputime() to
snapshot the values in the thread_group_cputime structure or the values in
the task structure itself if the per-cpu structure hasn't been allocated.

Finally, the code in kernel/posix-cpu-timers.c has changed quite a bit.
The run_posix_cpu_timers() function has been split into a fast path and a
slow path; the former safely checks whether there are any expired thread
timers and, if not, just returns, while the slow path does the heavy lifting.
With the dedicated thread group fields, timers are no longer "rebalanced" and
the process_timer_rebalance() function and related code has gone away.  All
summing loops are gone and all code that used them now uses the
thread_group_cputime() inline.  When process-wide timers are set, the new
task_cputime structure in signal_struct is used to cache the earliest
expiration; this is checked in the fast path.

Performance

The fix appears not to add significant overhead to existing operations.  It
generally performs the same as the current code except in two cases, one in
which it performs slightly worse (Case 5 below) and one in which it performs
very significantly better (Case 2 below).  Overall it's a wash except in those
two cases.

I've since done somewhat more involved testing on a dual-core Opteron system.

Case 1: With no itimer running, for a test with 100,000 threads, the fixed
	kernel took 1428.5 seconds, 513 seconds more than the unfixed system,
	all of which was spent in the system.  There were twice as many
	voluntary context switches with the fix as without it.

Case 2: With an itimer running at .01 second ticks and 4000 threads (the most
	an unmodified kernel can handle), the fixed kernel ran the test in
	eight percent of the time (5.8 seconds as opposed to 70 seconds) and
	had better tick accuracy (.012 seconds per tick as opposed to .023
	seconds per tick).

Case 3: A 4000-thread test with an initial timer tick of .01 second and an
	interval of 10,000 seconds (i.e. a timer that ticks only once) had
	very nearly the same performance in both cases:  6.3 seconds elapsed
	for the fixed kernel versus 5.5 seconds for the unfixed kernel.

With fewer threads (eight in these tests), the Case 1 test ran in essentially
the same time on both the modified and unmodified kernels (5.2 seconds versus
5.8 seconds).  The Case 2 test ran in about the same time as well, 5.9 seconds
versus 5.4 seconds but again with much better tick accuracy, .013 seconds per
tick versus .025 seconds per tick for the unmodified kernel.

Since the fix affected the rlimit code, I also tested soft and hard CPU limits.

Case 4: With a hard CPU limit of 20 seconds and eight threads (and an itimer
	running), the modified kernel was very slightly favored in that while
	it killed the process in 19.997 seconds of CPU time (5.002 seconds of
	wall time), only .003 seconds of that was system time, the rest was
	user time.  The unmodified kernel killed the process in 20.001 seconds
	of CPU (5.014 seconds of wall time) of which .016 seconds was system
	time.  Really, though, the results were too close to call.  The results
	were essentially the same with no itimer running.

Case 5: With a soft limit of 20 seconds and a hard limit of 2000 seconds
	(where the hard limit would never be reached) and an itimer running,
	the modified kernel exhibited worse tick accuracy than the unmodified
	kernel: .050 seconds/tick versus .028 seconds/tick.  Otherwise,
	performance was almost indistinguishable.  With no itimer running this
	test exhibited virtually identical behavior and times in both cases.

In times past I did some limited performance testing.  those results are below.

On a four-cpu Opteron system without this fix, a sixteen-thread test executed
in 3569.991 seconds, of which user was 3568.435s and system was 1.556s.  On
the same system with the fix, user and elapsed time were about the same, but
system time dropped to 0.007 seconds.  Performance with eight, four and one
thread were comparable.  Interestingly, the timer ticks with the fix seemed
more accurate:  The sixteen-thread test with the fix received 149543 ticks
for 0.024 seconds per tick, while the same test without the fix received 58720
for 0.061 seconds per tick.  Both cases were configured for an interval of
0.01 seconds.  Again, the other tests were comparable.  Each thread in this
test computed the primes up to 25,000,000.

I also did a test with a large number of threads, 100,000 threads, which is
impossible without the fix.  In this case each thread computed the primes only
up to 10,000 (to make the runtime manageable).  System time dominated, at
1546.968 seconds out of a total 2176.906 seconds (giving a user time of
629.938s).  It received 147651 ticks for 0.015 seconds per tick, still quite
accurate.  There is obviously no comparable test without the fix.

Signed-off-by: Frank Mayhar <fmayhar@google.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-14 16:25:35 +02:00

1059 lines
26 KiB
C
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/*
* linux/kernel/compat.c
*
* Kernel compatibililty routines for e.g. 32 bit syscall support
* on 64 bit kernels.
*
* Copyright (C) 2002-2003 Stephen Rothwell, IBM Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/linkage.h>
#include <linux/compat.h>
#include <linux/errno.h>
#include <linux/time.h>
#include <linux/signal.h>
#include <linux/sched.h> /* for MAX_SCHEDULE_TIMEOUT */
#include <linux/syscalls.h>
#include <linux/unistd.h>
#include <linux/security.h>
#include <linux/timex.h>
#include <linux/migrate.h>
#include <linux/posix-timers.h>
#include <linux/times.h>
#include <asm/uaccess.h>
int get_compat_timespec(struct timespec *ts, const struct compat_timespec __user *cts)
{
return (!access_ok(VERIFY_READ, cts, sizeof(*cts)) ||
__get_user(ts->tv_sec, &cts->tv_sec) ||
__get_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
}
int put_compat_timespec(const struct timespec *ts, struct compat_timespec __user *cts)
{
return (!access_ok(VERIFY_WRITE, cts, sizeof(*cts)) ||
__put_user(ts->tv_sec, &cts->tv_sec) ||
__put_user(ts->tv_nsec, &cts->tv_nsec)) ? -EFAULT : 0;
}
static long compat_nanosleep_restart(struct restart_block *restart)
{
struct compat_timespec __user *rmtp;
struct timespec rmt;
mm_segment_t oldfs;
long ret;
restart->nanosleep.rmtp = (struct timespec __user *) &rmt;
oldfs = get_fs();
set_fs(KERNEL_DS);
ret = hrtimer_nanosleep_restart(restart);
set_fs(oldfs);
if (ret) {
rmtp = restart->nanosleep.compat_rmtp;
if (rmtp && put_compat_timespec(&rmt, rmtp))
return -EFAULT;
}
return ret;
}
asmlinkage long compat_sys_nanosleep(struct compat_timespec __user *rqtp,
struct compat_timespec __user *rmtp)
{
struct timespec tu, rmt;
mm_segment_t oldfs;
long ret;
if (get_compat_timespec(&tu, rqtp))
return -EFAULT;
if (!timespec_valid(&tu))
return -EINVAL;
oldfs = get_fs();
set_fs(KERNEL_DS);
ret = hrtimer_nanosleep(&tu,
rmtp ? (struct timespec __user *)&rmt : NULL,
HRTIMER_MODE_REL, CLOCK_MONOTONIC);
set_fs(oldfs);
if (ret) {
struct restart_block *restart
= &current_thread_info()->restart_block;
restart->fn = compat_nanosleep_restart;
restart->nanosleep.compat_rmtp = rmtp;
if (rmtp && put_compat_timespec(&rmt, rmtp))
return -EFAULT;
}
return ret;
}
static inline long get_compat_itimerval(struct itimerval *o,
struct compat_itimerval __user *i)
{
return (!access_ok(VERIFY_READ, i, sizeof(*i)) ||
(__get_user(o->it_interval.tv_sec, &i->it_interval.tv_sec) |
__get_user(o->it_interval.tv_usec, &i->it_interval.tv_usec) |
__get_user(o->it_value.tv_sec, &i->it_value.tv_sec) |
__get_user(o->it_value.tv_usec, &i->it_value.tv_usec)));
}
static inline long put_compat_itimerval(struct compat_itimerval __user *o,
struct itimerval *i)
{
return (!access_ok(VERIFY_WRITE, o, sizeof(*o)) ||
(__put_user(i->it_interval.tv_sec, &o->it_interval.tv_sec) |
__put_user(i->it_interval.tv_usec, &o->it_interval.tv_usec) |
__put_user(i->it_value.tv_sec, &o->it_value.tv_sec) |
__put_user(i->it_value.tv_usec, &o->it_value.tv_usec)));
}
asmlinkage long compat_sys_getitimer(int which,
struct compat_itimerval __user *it)
{
struct itimerval kit;
int error;
error = do_getitimer(which, &kit);
if (!error && put_compat_itimerval(it, &kit))
error = -EFAULT;
return error;
}
asmlinkage long compat_sys_setitimer(int which,
struct compat_itimerval __user *in,
struct compat_itimerval __user *out)
{
struct itimerval kin, kout;
int error;
if (in) {
if (get_compat_itimerval(&kin, in))
return -EFAULT;
} else
memset(&kin, 0, sizeof(kin));
error = do_setitimer(which, &kin, out ? &kout : NULL);
if (error || !out)
return error;
if (put_compat_itimerval(out, &kout))
return -EFAULT;
return 0;
}
static compat_clock_t clock_t_to_compat_clock_t(clock_t x)
{
return compat_jiffies_to_clock_t(clock_t_to_jiffies(x));
}
asmlinkage long compat_sys_times(struct compat_tms __user *tbuf)
{
if (tbuf) {
struct tms tms;
struct compat_tms tmp;
do_sys_times(&tms);
/* Convert our struct tms to the compat version. */
tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime);
tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime);
tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime);
tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime);
if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
return -EFAULT;
}
return compat_jiffies_to_clock_t(jiffies);
}
/*
* Assumption: old_sigset_t and compat_old_sigset_t are both
* types that can be passed to put_user()/get_user().
*/
asmlinkage long compat_sys_sigpending(compat_old_sigset_t __user *set)
{
old_sigset_t s;
long ret;
mm_segment_t old_fs = get_fs();
set_fs(KERNEL_DS);
ret = sys_sigpending((old_sigset_t __user *) &s);
set_fs(old_fs);
if (ret == 0)
ret = put_user(s, set);
return ret;
}
asmlinkage long compat_sys_sigprocmask(int how, compat_old_sigset_t __user *set,
compat_old_sigset_t __user *oset)
{
old_sigset_t s;
long ret;
mm_segment_t old_fs;
if (set && get_user(s, set))
return -EFAULT;
old_fs = get_fs();
set_fs(KERNEL_DS);
ret = sys_sigprocmask(how,
set ? (old_sigset_t __user *) &s : NULL,
oset ? (old_sigset_t __user *) &s : NULL);
set_fs(old_fs);
if (ret == 0)
if (oset)
ret = put_user(s, oset);
return ret;
}
asmlinkage long compat_sys_setrlimit(unsigned int resource,
struct compat_rlimit __user *rlim)
{
struct rlimit r;
int ret;
mm_segment_t old_fs = get_fs ();
if (resource >= RLIM_NLIMITS)
return -EINVAL;
if (!access_ok(VERIFY_READ, rlim, sizeof(*rlim)) ||
__get_user(r.rlim_cur, &rlim->rlim_cur) ||
__get_user(r.rlim_max, &rlim->rlim_max))
return -EFAULT;
if (r.rlim_cur == COMPAT_RLIM_INFINITY)
r.rlim_cur = RLIM_INFINITY;
if (r.rlim_max == COMPAT_RLIM_INFINITY)
r.rlim_max = RLIM_INFINITY;
set_fs(KERNEL_DS);
ret = sys_setrlimit(resource, (struct rlimit __user *) &r);
set_fs(old_fs);
return ret;
}
#ifdef COMPAT_RLIM_OLD_INFINITY
asmlinkage long compat_sys_old_getrlimit(unsigned int resource,
struct compat_rlimit __user *rlim)
{
struct rlimit r;
int ret;
mm_segment_t old_fs = get_fs();
set_fs(KERNEL_DS);
ret = sys_old_getrlimit(resource, &r);
set_fs(old_fs);
if (!ret) {
if (r.rlim_cur > COMPAT_RLIM_OLD_INFINITY)
r.rlim_cur = COMPAT_RLIM_INFINITY;
if (r.rlim_max > COMPAT_RLIM_OLD_INFINITY)
r.rlim_max = COMPAT_RLIM_INFINITY;
if (!access_ok(VERIFY_WRITE, rlim, sizeof(*rlim)) ||
__put_user(r.rlim_cur, &rlim->rlim_cur) ||
__put_user(r.rlim_max, &rlim->rlim_max))
return -EFAULT;
}
return ret;
}
#endif
asmlinkage long compat_sys_getrlimit (unsigned int resource,
struct compat_rlimit __user *rlim)
{
struct rlimit r;
int ret;
mm_segment_t old_fs = get_fs();
set_fs(KERNEL_DS);
ret = sys_getrlimit(resource, (struct rlimit __user *) &r);
set_fs(old_fs);
if (!ret) {
if (r.rlim_cur > COMPAT_RLIM_INFINITY)
r.rlim_cur = COMPAT_RLIM_INFINITY;
if (r.rlim_max > COMPAT_RLIM_INFINITY)
r.rlim_max = COMPAT_RLIM_INFINITY;
if (!access_ok(VERIFY_WRITE, rlim, sizeof(*rlim)) ||
__put_user(r.rlim_cur, &rlim->rlim_cur) ||
__put_user(r.rlim_max, &rlim->rlim_max))
return -EFAULT;
}
return ret;
}
int put_compat_rusage(const struct rusage *r, struct compat_rusage __user *ru)
{
if (!access_ok(VERIFY_WRITE, ru, sizeof(*ru)) ||
__put_user(r->ru_utime.tv_sec, &ru->ru_utime.tv_sec) ||
__put_user(r->ru_utime.tv_usec, &ru->ru_utime.tv_usec) ||
__put_user(r->ru_stime.tv_sec, &ru->ru_stime.tv_sec) ||
__put_user(r->ru_stime.tv_usec, &ru->ru_stime.tv_usec) ||
__put_user(r->ru_maxrss, &ru->ru_maxrss) ||
__put_user(r->ru_ixrss, &ru->ru_ixrss) ||
__put_user(r->ru_idrss, &ru->ru_idrss) ||
__put_user(r->ru_isrss, &ru->ru_isrss) ||
__put_user(r->ru_minflt, &ru->ru_minflt) ||
__put_user(r->ru_majflt, &ru->ru_majflt) ||
__put_user(r->ru_nswap, &ru->ru_nswap) ||
__put_user(r->ru_inblock, &ru->ru_inblock) ||
__put_user(r->ru_oublock, &ru->ru_oublock) ||
__put_user(r->ru_msgsnd, &ru->ru_msgsnd) ||
__put_user(r->ru_msgrcv, &ru->ru_msgrcv) ||
__put_user(r->ru_nsignals, &ru->ru_nsignals) ||
__put_user(r->ru_nvcsw, &ru->ru_nvcsw) ||
__put_user(r->ru_nivcsw, &ru->ru_nivcsw))
return -EFAULT;
return 0;
}
asmlinkage long compat_sys_getrusage(int who, struct compat_rusage __user *ru)
{
struct rusage r;
int ret;
mm_segment_t old_fs = get_fs();
set_fs(KERNEL_DS);
ret = sys_getrusage(who, (struct rusage __user *) &r);
set_fs(old_fs);
if (ret)
return ret;
if (put_compat_rusage(&r, ru))
return -EFAULT;
return 0;
}
asmlinkage long
compat_sys_wait4(compat_pid_t pid, compat_uint_t __user *stat_addr, int options,
struct compat_rusage __user *ru)
{
if (!ru) {
return sys_wait4(pid, stat_addr, options, NULL);
} else {
struct rusage r;
int ret;
unsigned int status;
mm_segment_t old_fs = get_fs();
set_fs (KERNEL_DS);
ret = sys_wait4(pid,
(stat_addr ?
(unsigned int __user *) &status : NULL),
options, (struct rusage __user *) &r);
set_fs (old_fs);
if (ret > 0) {
if (put_compat_rusage(&r, ru))
return -EFAULT;
if (stat_addr && put_user(status, stat_addr))
return -EFAULT;
}
return ret;
}
}
asmlinkage long compat_sys_waitid(int which, compat_pid_t pid,
struct compat_siginfo __user *uinfo, int options,
struct compat_rusage __user *uru)
{
siginfo_t info;
struct rusage ru;
long ret;
mm_segment_t old_fs = get_fs();
memset(&info, 0, sizeof(info));
set_fs(KERNEL_DS);
ret = sys_waitid(which, pid, (siginfo_t __user *)&info, options,
uru ? (struct rusage __user *)&ru : NULL);
set_fs(old_fs);
if ((ret < 0) || (info.si_signo == 0))
return ret;
if (uru) {
ret = put_compat_rusage(&ru, uru);
if (ret)
return ret;
}
BUG_ON(info.si_code & __SI_MASK);
info.si_code |= __SI_CHLD;
return copy_siginfo_to_user32(uinfo, &info);
}
static int compat_get_user_cpu_mask(compat_ulong_t __user *user_mask_ptr,
unsigned len, cpumask_t *new_mask)
{
unsigned long *k;
if (len < sizeof(cpumask_t))
memset(new_mask, 0, sizeof(cpumask_t));
else if (len > sizeof(cpumask_t))
len = sizeof(cpumask_t);
k = cpus_addr(*new_mask);
return compat_get_bitmap(k, user_mask_ptr, len * 8);
}
asmlinkage long compat_sys_sched_setaffinity(compat_pid_t pid,
unsigned int len,
compat_ulong_t __user *user_mask_ptr)
{
cpumask_t new_mask;
int retval;
retval = compat_get_user_cpu_mask(user_mask_ptr, len, &new_mask);
if (retval)
return retval;
return sched_setaffinity(pid, &new_mask);
}
asmlinkage long compat_sys_sched_getaffinity(compat_pid_t pid, unsigned int len,
compat_ulong_t __user *user_mask_ptr)
{
int ret;
cpumask_t mask;
unsigned long *k;
unsigned int min_length = sizeof(cpumask_t);
if (NR_CPUS <= BITS_PER_COMPAT_LONG)
min_length = sizeof(compat_ulong_t);
if (len < min_length)
return -EINVAL;
ret = sched_getaffinity(pid, &mask);
if (ret < 0)
return ret;
k = cpus_addr(mask);
ret = compat_put_bitmap(user_mask_ptr, k, min_length * 8);
if (ret)
return ret;
return min_length;
}
int get_compat_itimerspec(struct itimerspec *dst,
const struct compat_itimerspec __user *src)
{
if (get_compat_timespec(&dst->it_interval, &src->it_interval) ||
get_compat_timespec(&dst->it_value, &src->it_value))
return -EFAULT;
return 0;
}
int put_compat_itimerspec(struct compat_itimerspec __user *dst,
const struct itimerspec *src)
{
if (put_compat_timespec(&src->it_interval, &dst->it_interval) ||
put_compat_timespec(&src->it_value, &dst->it_value))
return -EFAULT;
return 0;
}
long compat_sys_timer_create(clockid_t which_clock,
struct compat_sigevent __user *timer_event_spec,
timer_t __user *created_timer_id)
{
struct sigevent __user *event = NULL;
if (timer_event_spec) {
struct sigevent kevent;
event = compat_alloc_user_space(sizeof(*event));
if (get_compat_sigevent(&kevent, timer_event_spec) ||
copy_to_user(event, &kevent, sizeof(*event)))
return -EFAULT;
}
return sys_timer_create(which_clock, event, created_timer_id);
}
long compat_sys_timer_settime(timer_t timer_id, int flags,
struct compat_itimerspec __user *new,
struct compat_itimerspec __user *old)
{
long err;
mm_segment_t oldfs;
struct itimerspec newts, oldts;
if (!new)
return -EINVAL;
if (get_compat_itimerspec(&newts, new))
return -EFAULT;
oldfs = get_fs();
set_fs(KERNEL_DS);
err = sys_timer_settime(timer_id, flags,
(struct itimerspec __user *) &newts,
(struct itimerspec __user *) &oldts);
set_fs(oldfs);
if (!err && old && put_compat_itimerspec(old, &oldts))
return -EFAULT;
return err;
}
long compat_sys_timer_gettime(timer_t timer_id,
struct compat_itimerspec __user *setting)
{
long err;
mm_segment_t oldfs;
struct itimerspec ts;
oldfs = get_fs();
set_fs(KERNEL_DS);
err = sys_timer_gettime(timer_id,
(struct itimerspec __user *) &ts);
set_fs(oldfs);
if (!err && put_compat_itimerspec(setting, &ts))
return -EFAULT;
return err;
}
long compat_sys_clock_settime(clockid_t which_clock,
struct compat_timespec __user *tp)
{
long err;
mm_segment_t oldfs;
struct timespec ts;
if (get_compat_timespec(&ts, tp))
return -EFAULT;
oldfs = get_fs();
set_fs(KERNEL_DS);
err = sys_clock_settime(which_clock,
(struct timespec __user *) &ts);
set_fs(oldfs);
return err;
}
long compat_sys_clock_gettime(clockid_t which_clock,
struct compat_timespec __user *tp)
{
long err;
mm_segment_t oldfs;
struct timespec ts;
oldfs = get_fs();
set_fs(KERNEL_DS);
err = sys_clock_gettime(which_clock,
(struct timespec __user *) &ts);
set_fs(oldfs);
if (!err && put_compat_timespec(&ts, tp))
return -EFAULT;
return err;
}
long compat_sys_clock_getres(clockid_t which_clock,
struct compat_timespec __user *tp)
{
long err;
mm_segment_t oldfs;
struct timespec ts;
oldfs = get_fs();
set_fs(KERNEL_DS);
err = sys_clock_getres(which_clock,
(struct timespec __user *) &ts);
set_fs(oldfs);
if (!err && tp && put_compat_timespec(&ts, tp))
return -EFAULT;
return err;
}
static long compat_clock_nanosleep_restart(struct restart_block *restart)
{
long err;
mm_segment_t oldfs;
struct timespec tu;
struct compat_timespec *rmtp = restart->nanosleep.compat_rmtp;
restart->nanosleep.rmtp = (struct timespec __user *) &tu;
oldfs = get_fs();
set_fs(KERNEL_DS);
err = clock_nanosleep_restart(restart);
set_fs(oldfs);
if ((err == -ERESTART_RESTARTBLOCK) && rmtp &&
put_compat_timespec(&tu, rmtp))
return -EFAULT;
if (err == -ERESTART_RESTARTBLOCK) {
restart->fn = compat_clock_nanosleep_restart;
restart->nanosleep.compat_rmtp = rmtp;
}
return err;
}
long compat_sys_clock_nanosleep(clockid_t which_clock, int flags,
struct compat_timespec __user *rqtp,
struct compat_timespec __user *rmtp)
{
long err;
mm_segment_t oldfs;
struct timespec in, out;
struct restart_block *restart;
if (get_compat_timespec(&in, rqtp))
return -EFAULT;
oldfs = get_fs();
set_fs(KERNEL_DS);
err = sys_clock_nanosleep(which_clock, flags,
(struct timespec __user *) &in,
(struct timespec __user *) &out);
set_fs(oldfs);
if ((err == -ERESTART_RESTARTBLOCK) && rmtp &&
put_compat_timespec(&out, rmtp))
return -EFAULT;
if (err == -ERESTART_RESTARTBLOCK) {
restart = &current_thread_info()->restart_block;
restart->fn = compat_clock_nanosleep_restart;
restart->nanosleep.compat_rmtp = rmtp;
}
return err;
}
/*
* We currently only need the following fields from the sigevent
* structure: sigev_value, sigev_signo, sig_notify and (sometimes
* sigev_notify_thread_id). The others are handled in user mode.
* We also assume that copying sigev_value.sival_int is sufficient
* to keep all the bits of sigev_value.sival_ptr intact.
*/
int get_compat_sigevent(struct sigevent *event,
const struct compat_sigevent __user *u_event)
{
memset(event, 0, sizeof(*event));
return (!access_ok(VERIFY_READ, u_event, sizeof(*u_event)) ||
__get_user(event->sigev_value.sival_int,
&u_event->sigev_value.sival_int) ||
__get_user(event->sigev_signo, &u_event->sigev_signo) ||
__get_user(event->sigev_notify, &u_event->sigev_notify) ||
__get_user(event->sigev_notify_thread_id,
&u_event->sigev_notify_thread_id))
? -EFAULT : 0;
}
long compat_get_bitmap(unsigned long *mask, const compat_ulong_t __user *umask,
unsigned long bitmap_size)
{
int i, j;
unsigned long m;
compat_ulong_t um;
unsigned long nr_compat_longs;
/* align bitmap up to nearest compat_long_t boundary */
bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
if (!access_ok(VERIFY_READ, umask, bitmap_size / 8))
return -EFAULT;
nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
for (i = 0; i < BITS_TO_LONGS(bitmap_size); i++) {
m = 0;
for (j = 0; j < sizeof(m)/sizeof(um); j++) {
/*
* We dont want to read past the end of the userspace
* bitmap. We must however ensure the end of the
* kernel bitmap is zeroed.
*/
if (nr_compat_longs-- > 0) {
if (__get_user(um, umask))
return -EFAULT;
} else {
um = 0;
}
umask++;
m |= (long)um << (j * BITS_PER_COMPAT_LONG);
}
*mask++ = m;
}
return 0;
}
long compat_put_bitmap(compat_ulong_t __user *umask, unsigned long *mask,
unsigned long bitmap_size)
{
int i, j;
unsigned long m;
compat_ulong_t um;
unsigned long nr_compat_longs;
/* align bitmap up to nearest compat_long_t boundary */
bitmap_size = ALIGN(bitmap_size, BITS_PER_COMPAT_LONG);
if (!access_ok(VERIFY_WRITE, umask, bitmap_size / 8))
return -EFAULT;
nr_compat_longs = BITS_TO_COMPAT_LONGS(bitmap_size);
for (i = 0; i < BITS_TO_LONGS(bitmap_size); i++) {
m = *mask++;
for (j = 0; j < sizeof(m)/sizeof(um); j++) {
um = m;
/*
* We dont want to write past the end of the userspace
* bitmap.
*/
if (nr_compat_longs-- > 0) {
if (__put_user(um, umask))
return -EFAULT;
}
umask++;
m >>= 4*sizeof(um);
m >>= 4*sizeof(um);
}
}
return 0;
}
void
sigset_from_compat (sigset_t *set, compat_sigset_t *compat)
{
switch (_NSIG_WORDS) {
case 4: set->sig[3] = compat->sig[6] | (((long)compat->sig[7]) << 32 );
case 3: set->sig[2] = compat->sig[4] | (((long)compat->sig[5]) << 32 );
case 2: set->sig[1] = compat->sig[2] | (((long)compat->sig[3]) << 32 );
case 1: set->sig[0] = compat->sig[0] | (((long)compat->sig[1]) << 32 );
}
}
asmlinkage long
compat_sys_rt_sigtimedwait (compat_sigset_t __user *uthese,
struct compat_siginfo __user *uinfo,
struct compat_timespec __user *uts, compat_size_t sigsetsize)
{
compat_sigset_t s32;
sigset_t s;
int sig;
struct timespec t;
siginfo_t info;
long ret, timeout = 0;
if (sigsetsize != sizeof(sigset_t))
return -EINVAL;
if (copy_from_user(&s32, uthese, sizeof(compat_sigset_t)))
return -EFAULT;
sigset_from_compat(&s, &s32);
sigdelsetmask(&s,sigmask(SIGKILL)|sigmask(SIGSTOP));
signotset(&s);
if (uts) {
if (get_compat_timespec (&t, uts))
return -EFAULT;
if (t.tv_nsec >= 1000000000L || t.tv_nsec < 0
|| t.tv_sec < 0)
return -EINVAL;
}
spin_lock_irq(&current->sighand->siglock);
sig = dequeue_signal(current, &s, &info);
if (!sig) {
timeout = MAX_SCHEDULE_TIMEOUT;
if (uts)
timeout = timespec_to_jiffies(&t)
+(t.tv_sec || t.tv_nsec);
if (timeout) {
current->real_blocked = current->blocked;
sigandsets(&current->blocked, &current->blocked, &s);
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
timeout = schedule_timeout_interruptible(timeout);
spin_lock_irq(&current->sighand->siglock);
sig = dequeue_signal(current, &s, &info);
current->blocked = current->real_blocked;
siginitset(&current->real_blocked, 0);
recalc_sigpending();
}
}
spin_unlock_irq(&current->sighand->siglock);
if (sig) {
ret = sig;
if (uinfo) {
if (copy_siginfo_to_user32(uinfo, &info))
ret = -EFAULT;
}
}else {
ret = timeout?-EINTR:-EAGAIN;
}
return ret;
}
#ifdef __ARCH_WANT_COMPAT_SYS_TIME
/* compat_time_t is a 32 bit "long" and needs to get converted. */
asmlinkage long compat_sys_time(compat_time_t __user * tloc)
{
compat_time_t i;
struct timeval tv;
do_gettimeofday(&tv);
i = tv.tv_sec;
if (tloc) {
if (put_user(i,tloc))
i = -EFAULT;
}
return i;
}
asmlinkage long compat_sys_stime(compat_time_t __user *tptr)
{
struct timespec tv;
int err;
if (get_user(tv.tv_sec, tptr))
return -EFAULT;
tv.tv_nsec = 0;
err = security_settime(&tv, NULL);
if (err)
return err;
do_settimeofday(&tv);
return 0;
}
#endif /* __ARCH_WANT_COMPAT_SYS_TIME */
#ifdef __ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND
asmlinkage long compat_sys_rt_sigsuspend(compat_sigset_t __user *unewset, compat_size_t sigsetsize)
{
sigset_t newset;
compat_sigset_t newset32;
/* XXX: Don't preclude handling different sized sigset_t's. */
if (sigsetsize != sizeof(sigset_t))
return -EINVAL;
if (copy_from_user(&newset32, unewset, sizeof(compat_sigset_t)))
return -EFAULT;
sigset_from_compat(&newset, &newset32);
sigdelsetmask(&newset, sigmask(SIGKILL)|sigmask(SIGSTOP));
spin_lock_irq(&current->sighand->siglock);
current->saved_sigmask = current->blocked;
current->blocked = newset;
recalc_sigpending();
spin_unlock_irq(&current->sighand->siglock);
current->state = TASK_INTERRUPTIBLE;
schedule();
set_restore_sigmask();
return -ERESTARTNOHAND;
}
#endif /* __ARCH_WANT_COMPAT_SYS_RT_SIGSUSPEND */
asmlinkage long compat_sys_adjtimex(struct compat_timex __user *utp)
{
struct timex txc;
int ret;
memset(&txc, 0, sizeof(struct timex));
if (!access_ok(VERIFY_READ, utp, sizeof(struct compat_timex)) ||
__get_user(txc.modes, &utp->modes) ||
__get_user(txc.offset, &utp->offset) ||
__get_user(txc.freq, &utp->freq) ||
__get_user(txc.maxerror, &utp->maxerror) ||
__get_user(txc.esterror, &utp->esterror) ||
__get_user(txc.status, &utp->status) ||
__get_user(txc.constant, &utp->constant) ||
__get_user(txc.precision, &utp->precision) ||
__get_user(txc.tolerance, &utp->tolerance) ||
__get_user(txc.time.tv_sec, &utp->time.tv_sec) ||
__get_user(txc.time.tv_usec, &utp->time.tv_usec) ||
__get_user(txc.tick, &utp->tick) ||
__get_user(txc.ppsfreq, &utp->ppsfreq) ||
__get_user(txc.jitter, &utp->jitter) ||
__get_user(txc.shift, &utp->shift) ||
__get_user(txc.stabil, &utp->stabil) ||
__get_user(txc.jitcnt, &utp->jitcnt) ||
__get_user(txc.calcnt, &utp->calcnt) ||
__get_user(txc.errcnt, &utp->errcnt) ||
__get_user(txc.stbcnt, &utp->stbcnt))
return -EFAULT;
ret = do_adjtimex(&txc);
if (!access_ok(VERIFY_WRITE, utp, sizeof(struct compat_timex)) ||
__put_user(txc.modes, &utp->modes) ||
__put_user(txc.offset, &utp->offset) ||
__put_user(txc.freq, &utp->freq) ||
__put_user(txc.maxerror, &utp->maxerror) ||
__put_user(txc.esterror, &utp->esterror) ||
__put_user(txc.status, &utp->status) ||
__put_user(txc.constant, &utp->constant) ||
__put_user(txc.precision, &utp->precision) ||
__put_user(txc.tolerance, &utp->tolerance) ||
__put_user(txc.time.tv_sec, &utp->time.tv_sec) ||
__put_user(txc.time.tv_usec, &utp->time.tv_usec) ||
__put_user(txc.tick, &utp->tick) ||
__put_user(txc.ppsfreq, &utp->ppsfreq) ||
__put_user(txc.jitter, &utp->jitter) ||
__put_user(txc.shift, &utp->shift) ||
__put_user(txc.stabil, &utp->stabil) ||
__put_user(txc.jitcnt, &utp->jitcnt) ||
__put_user(txc.calcnt, &utp->calcnt) ||
__put_user(txc.errcnt, &utp->errcnt) ||
__put_user(txc.stbcnt, &utp->stbcnt) ||
__put_user(txc.tai, &utp->tai))
ret = -EFAULT;
return ret;
}
#ifdef CONFIG_NUMA
asmlinkage long compat_sys_move_pages(pid_t pid, unsigned long nr_pages,
compat_uptr_t __user *pages32,
const int __user *nodes,
int __user *status,
int flags)
{
const void __user * __user *pages;
int i;
pages = compat_alloc_user_space(nr_pages * sizeof(void *));
for (i = 0; i < nr_pages; i++) {
compat_uptr_t p;
if (get_user(p, pages32 + i) ||
put_user(compat_ptr(p), pages + i))
return -EFAULT;
}
return sys_move_pages(pid, nr_pages, pages, nodes, status, flags);
}
asmlinkage long compat_sys_migrate_pages(compat_pid_t pid,
compat_ulong_t maxnode,
const compat_ulong_t __user *old_nodes,
const compat_ulong_t __user *new_nodes)
{
unsigned long __user *old = NULL;
unsigned long __user *new = NULL;
nodemask_t tmp_mask;
unsigned long nr_bits;
unsigned long size;
nr_bits = min_t(unsigned long, maxnode - 1, MAX_NUMNODES);
size = ALIGN(nr_bits, BITS_PER_LONG) / 8;
if (old_nodes) {
if (compat_get_bitmap(nodes_addr(tmp_mask), old_nodes, nr_bits))
return -EFAULT;
old = compat_alloc_user_space(new_nodes ? size * 2 : size);
if (new_nodes)
new = old + size / sizeof(unsigned long);
if (copy_to_user(old, nodes_addr(tmp_mask), size))
return -EFAULT;
}
if (new_nodes) {
if (compat_get_bitmap(nodes_addr(tmp_mask), new_nodes, nr_bits))
return -EFAULT;
if (new == NULL)
new = compat_alloc_user_space(size);
if (copy_to_user(new, nodes_addr(tmp_mask), size))
return -EFAULT;
}
return sys_migrate_pages(pid, nr_bits + 1, old, new);
}
#endif
struct compat_sysinfo {
s32 uptime;
u32 loads[3];
u32 totalram;
u32 freeram;
u32 sharedram;
u32 bufferram;
u32 totalswap;
u32 freeswap;
u16 procs;
u16 pad;
u32 totalhigh;
u32 freehigh;
u32 mem_unit;
char _f[20-2*sizeof(u32)-sizeof(int)];
};
asmlinkage long
compat_sys_sysinfo(struct compat_sysinfo __user *info)
{
struct sysinfo s;
do_sysinfo(&s);
/* Check to see if any memory value is too large for 32-bit and scale
* down if needed
*/
if ((s.totalram >> 32) || (s.totalswap >> 32)) {
int bitcount = 0;
while (s.mem_unit < PAGE_SIZE) {
s.mem_unit <<= 1;
bitcount++;
}
s.totalram >>= bitcount;
s.freeram >>= bitcount;
s.sharedram >>= bitcount;
s.bufferram >>= bitcount;
s.totalswap >>= bitcount;
s.freeswap >>= bitcount;
s.totalhigh >>= bitcount;
s.freehigh >>= bitcount;
}
if (!access_ok(VERIFY_WRITE, info, sizeof(struct compat_sysinfo)) ||
__put_user (s.uptime, &info->uptime) ||
__put_user (s.loads[0], &info->loads[0]) ||
__put_user (s.loads[1], &info->loads[1]) ||
__put_user (s.loads[2], &info->loads[2]) ||
__put_user (s.totalram, &info->totalram) ||
__put_user (s.freeram, &info->freeram) ||
__put_user (s.sharedram, &info->sharedram) ||
__put_user (s.bufferram, &info->bufferram) ||
__put_user (s.totalswap, &info->totalswap) ||
__put_user (s.freeswap, &info->freeswap) ||
__put_user (s.procs, &info->procs) ||
__put_user (s.totalhigh, &info->totalhigh) ||
__put_user (s.freehigh, &info->freehigh) ||
__put_user (s.mem_unit, &info->mem_unit))
return -EFAULT;
return 0;
}
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