The patch titled
kernel core: use helpers for rlimits
has been added to the -mm tree. Its filename is
kernel-core-use-helpers-for-rlimits.patch
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The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: kernel core: use helpers for rlimits
From: Jiri Slaby <jslaby@xxxxxxx>
Make sure compiler won't do weird things with limits. E.g. fetching them
twice may return 2 different values after writable limits are implemented.
I.e. either use rlimit helpers added in
3e10e716abf3c71bdb5d86b8f507f9e72236c9cd ("resource: add helpers for
fetching rlimits") or ACCESS_ONCE if not applicable.
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: john stultz <johnstul@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/fork.c | 2 +-
kernel/perf_event.c | 2 +-
kernel/posix-cpu-timers.c | 10 ++++++----
kernel/sched.c | 4 ++--
kernel/sched_rt.c | 5 +++--
kernel/signal.c | 2 +-
kernel/sys.c | 3 +--
7 files changed, 15 insertions(+), 13 deletions(-)
diff -puN kernel/fork.c~kernel-core-use-helpers-for-rlimits kernel/fork.c
--- a/kernel/fork.c~kernel-core-use-helpers-for-rlimits
+++ a/kernel/fork.c
@@ -1036,7 +1036,7 @@ static struct task_struct *copy_process(
#endif
retval = -EAGAIN;
if (atomic_read(&p->real_cred->user->processes) >=
- p->signal->rlim[RLIMIT_NPROC].rlim_cur) {
+ task_rlimit(p, RLIMIT_NPROC)) {
if (!capable(CAP_SYS_ADMIN) && !capable(CAP_SYS_RESOURCE) &&
p->real_cred->user != INIT_USER)
goto bad_fork_free;
diff -puN kernel/perf_event.c~kernel-core-use-helpers-for-rlimits kernel/perf_event.c
--- a/kernel/perf_event.c~kernel-core-use-helpers-for-rlimits
+++ a/kernel/perf_event.c
@@ -2602,7 +2602,7 @@ static int perf_mmap(struct file *file,
if (user_locked > user_lock_limit)
extra = user_locked - user_lock_limit;
- lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
+ lock_limit = rlimit(RLIMIT_MEMLOCK);
lock_limit >>= PAGE_SHIFT;
locked = vma->vm_mm->locked_vm + extra;
diff -puN kernel/posix-cpu-timers.c~kernel-core-use-helpers-for-rlimits kernel/posix-cpu-timers.c
--- a/kernel/posix-cpu-timers.c~kernel-core-use-helpers-for-rlimits
+++ a/kernel/posix-cpu-timers.c
@@ -966,9 +966,10 @@ static void check_thread_timers(struct t
/*
* Check for the special case thread timers.
*/
- soft = sig->rlim[RLIMIT_RTTIME].rlim_cur;
+ soft = ACCESS_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_cur);
if (soft != RLIM_INFINITY) {
- unsigned long hard = sig->rlim[RLIMIT_RTTIME].rlim_max;
+ unsigned long hard =
+ ACCESS_ONCE(sig->rlim[RLIMIT_RTTIME].rlim_max);
if (hard != RLIM_INFINITY &&
tsk->rt.timeout > DIV_ROUND_UP(hard, USEC_PER_SEC/HZ)) {
@@ -1130,10 +1131,11 @@ static void check_process_timers(struct
SIGPROF);
check_cpu_itimer(tsk, &sig->it[CPUCLOCK_VIRT], &virt_expires, utime,
SIGVTALRM);
- soft = sig->rlim[RLIMIT_CPU].rlim_cur;
+ soft = ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_cur);
if (soft != RLIM_INFINITY) {
unsigned long psecs = cputime_to_secs(ptime);
- unsigned long hard = sig->rlim[RLIMIT_CPU].rlim_max;
+ unsigned long hard =
+ ACCESS_ONCE(sig->rlim[RLIMIT_CPU].rlim_max);
cputime_t x;
if (psecs >= hard) {
/*
diff -puN kernel/sched.c~kernel-core-use-helpers-for-rlimits kernel/sched.c
--- a/kernel/sched.c~kernel-core-use-helpers-for-rlimits
+++ a/kernel/sched.c
@@ -4324,7 +4324,7 @@ int can_nice(const struct task_struct *p
/* convert nice value [19,-20] to rlimit style value [1,40] */
int nice_rlim = 20 - nice;
- return (nice_rlim <= p->signal->rlim[RLIMIT_NICE].rlim_cur ||
+ return (nice_rlim <= task_rlimit(p, RLIMIT_NICE) ||
capable(CAP_SYS_NICE));
}
@@ -4501,7 +4501,7 @@ recheck:
if (!lock_task_sighand(p, &flags))
return -ESRCH;
- rlim_rtprio = p->signal->rlim[RLIMIT_RTPRIO].rlim_cur;
+ rlim_rtprio = task_rlimit(p, RLIMIT_RTPRIO);
unlock_task_sighand(p, &flags);
/* can't set/change the rt policy */
diff -puN kernel/sched_rt.c~kernel-core-use-helpers-for-rlimits kernel/sched_rt.c
--- a/kernel/sched_rt.c~kernel-core-use-helpers-for-rlimits
+++ a/kernel/sched_rt.c
@@ -1656,8 +1656,9 @@ static void watchdog(struct rq *rq, stru
if (!p->signal)
return;
- soft = p->signal->rlim[RLIMIT_RTTIME].rlim_cur;
- hard = p->signal->rlim[RLIMIT_RTTIME].rlim_max;
+ /* max may change after cur was read, this will be fixed next tick */
+ soft = task_rlimit(p, RLIMIT_RTTIME);
+ hard = task_rlimit_max(p, RLIMIT_RTTIME);
if (soft != RLIM_INFINITY) {
unsigned long next;
diff -puN kernel/signal.c~kernel-core-use-helpers-for-rlimits kernel/signal.c
--- a/kernel/signal.c~kernel-core-use-helpers-for-rlimits
+++ a/kernel/signal.c
@@ -228,7 +228,7 @@ __sigqueue_alloc(int sig, struct task_st
if (override_rlimit ||
atomic_read(&user->sigpending) <=
- t->signal->rlim[RLIMIT_SIGPENDING].rlim_cur) {
+ task_rlimit(t, RLIMIT_SIGPENDING)) {
q = kmem_cache_alloc(sigqueue_cachep, flags);
} else {
print_dropped_signal(sig);
diff -puN kernel/sys.c~kernel-core-use-helpers-for-rlimits kernel/sys.c
--- a/kernel/sys.c~kernel-core-use-helpers-for-rlimits
+++ a/kernel/sys.c
@@ -569,8 +569,7 @@ static int set_user(struct cred *new)
if (!new_user)
return -EAGAIN;
- if (atomic_read(&new_user->processes) >=
- current->signal->rlim[RLIMIT_NPROC].rlim_cur &&
+ if (atomic_read(&new_user->processes) >= rlimit(RLIMIT_NPROC) &&
new_user != INIT_USER) {
free_uid(new_user);
return -EAGAIN;
_
Patches currently in -mm which might be from jslaby@xxxxxxx are
linux-next.patch
gpu-drm-i915-fix-potential-null-dereference.patch
infiniband-use-rlimit-helpers.patch
mtd-chips-cfi-remove-unneeded-null-checks.patch
video-backlight-progear-fix-pci-device-refcounting.patch
mm-use-rlimit-helpers.patch
bootmem-avoid-dma32-zone-by-default.patch
fs-use-rlimit-helpers.patch
posix-cpu-timers-cleanup-rlimits-usage.patch
kernel-core-use-helpers-for-rlimits.patch
ipc-use-rlimit-helpers.patch
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