8 files changed, 117 insertions, 30 deletions

diff --git a/kernel/fork.c b/kernel/fork.c
index 9bd91447e052..202a0ba63d3c 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1127,6 +1127,10 @@ static struct task_struct *copy_process(unsigned long clone_flags,
 #ifdef CONFIG_DEBUG_MUTEXES
         p->blocked_on = NULL; /* not blocked yet */
 #endif
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR
+        p->memcg_batch.do_batch = 0;
+        p->memcg_batch.memcg = NULL;
+#endif
 
         p->bts = NULL;
 
@@ -1206,9 +1210,10 @@ static struct task_struct *copy_process(unsigned long clone_flags,
                 p->sas_ss_sp = p->sas_ss_size = 0;
 
         /*
-         * Syscall tracing should be turned off in the child regardless
-         * of CLONE_PTRACE.
+         * Syscall tracing and stepping should be turned off in the
+         * child regardless of CLONE_PTRACE.
          */
+        user_disable_single_step(p);
         clear_tsk_thread_flag(p, TIF_SYSCALL_TRACE);
 #ifdef TIF_SYSCALL_EMU
         clear_tsk_thread_flag(p, TIF_SYSCALL_EMU);
diff --git a/kernel/kexec.c b/kernel/kexec.c
index f336e2107f98..433e9fcc1fc5 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -31,6 +31,7 @@
 #include <linux/cpu.h>
 #include <linux/console.h>
 #include <linux/vmalloc.h>
+#include <linux/swap.h>
 
 #include <asm/page.h>
 #include <asm/uaccess.h>
@@ -1082,6 +1083,64 @@ void crash_kexec(struct pt_regs *regs)
         }
 }
 
+size_t crash_get_memory_size(void)
+{
+        size_t size;
+        mutex_lock(&kexec_mutex);
+        size = crashk_res.end - crashk_res.start + 1;
+        mutex_unlock(&kexec_mutex);
+        return size;
+}
+
+static void free_reserved_phys_range(unsigned long begin, unsigned long end)
+{
+        unsigned long addr;
+
+        for (addr = begin; addr < end; addr += PAGE_SIZE) {
+                ClearPageReserved(pfn_to_page(addr >> PAGE_SHIFT));
+                init_page_count(pfn_to_page(addr >> PAGE_SHIFT));
+                free_page((unsigned long)__va(addr));
+                totalram_pages++;
+        }
+}
+
+int crash_shrink_memory(unsigned long new_size)
+{
+        int ret = 0;
+        unsigned long start, end;
+
+        mutex_lock(&kexec_mutex);
+
+        if (kexec_crash_image) {
+                ret = -ENOENT;
+                goto unlock;
+        }
+        start = crashk_res.start;
+        end = crashk_res.end;
+
+        if (new_size >= end - start + 1) {
+                ret = -EINVAL;
+                if (new_size == end - start + 1)
+                        ret = 0;
+                goto unlock;
+        }
+
+        start = roundup(start, PAGE_SIZE);
+        end = roundup(start + new_size, PAGE_SIZE);
+
+        free_reserved_phys_range(end, crashk_res.end);
+
+        if (start == end) {
+                crashk_res.end = end;
+                release_resource(&crashk_res);
+        } else
+                crashk_res.end = end - 1;
+
+unlock:
+        mutex_unlock(&kexec_mutex);
+        return ret;
+}
+
 static u32 *append_elf_note(u32 *buf, char *name, unsigned type, void *data,
                             size_t data_len)
 {
diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c
index 528dd78e7e7e..3feaf5a74514 100644
--- a/kernel/ksysfs.c
+++ b/kernel/ksysfs.c
@@ -100,6 +100,26 @@ static ssize_t kexec_crash_loaded_show(struct kobject *kobj,
 }
 KERNEL_ATTR_RO(kexec_crash_loaded);
 
+static ssize_t kexec_crash_size_show(struct kobject *kobj,
+                                       struct kobj_attribute *attr, char *buf)
+{
+        return sprintf(buf, "%zu\n", crash_get_memory_size());
+}
+static ssize_t kexec_crash_size_store(struct kobject *kobj,
+                                   struct kobj_attribute *attr,
+                                   const char *buf, size_t count)
+{
+        unsigned long cnt;
+        int ret;
+
+        if (strict_strtoul(buf, 0, &cnt))
+                return -EINVAL;
+
+        ret = crash_shrink_memory(cnt);
+        return ret < 0 ? ret : count;
+}
+KERNEL_ATTR_RW(kexec_crash_size);
+
 static ssize_t vmcoreinfo_show(struct kobject *kobj,
                                struct kobj_attribute *attr, char *buf)
 {
@@ -147,6 +167,7 @@ static struct attribute * kernel_attrs[] = {
 #ifdef CONFIG_KEXEC
         &kexec_loaded_attr.attr,
         &kexec_crash_loaded_attr.attr,
+        &kexec_crash_size_attr.attr,
         &vmcoreinfo_attr.attr,
 #endif
         NULL
diff --git a/kernel/pid.c b/kernel/pid.c
index d3f722d20f9c..2e17c9c92cbe 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -141,11 +141,12 @@ static int alloc_pidmap(struct pid_namespace *pid_ns)
                          * installing it:
                          */
                         spin_lock_irq(&pidmap_lock);
-                        if (map->page)
-                                kfree(page);
-                        else
+                        if (!map->page) {
                                 map->page = page;
+                                page = NULL;
+                        }
                         spin_unlock_irq(&pidmap_lock);
+                        kfree(page);
                         if (unlikely(!map->page))
                                 break;
                 }
@@ -268,12 +269,11 @@ struct pid *alloc_pid(struct pid_namespace *ns)
         for (type = 0; type < PIDTYPE_MAX; ++type)
                 INIT_HLIST_HEAD(&pid->tasks[type]);
 
+        upid = pid->numbers + ns->level;
         spin_lock_irq(&pidmap_lock);
-        for (i = ns->level; i >= 0; i--) {
-                upid = &pid->numbers[i];
+        for ( ; upid >= pid->numbers; --upid)
                 hlist_add_head_rcu(&upid->pid_chain,
                                 &pid_hash[pid_hashfn(upid->nr, upid->ns)]);
-        }
         spin_unlock_irq(&pidmap_lock);
 
 out:
diff --git a/kernel/relay.c b/kernel/relay.c
index 760c26209a3c..c705a41b4ba3 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -1198,7 +1198,7 @@ static void relay_pipe_buf_release(struct pipe_inode_info *pipe,
         relay_consume_bytes(rbuf, buf->private);
 }
 
-static struct pipe_buf_operations relay_pipe_buf_ops = {
+static const struct pipe_buf_operations relay_pipe_buf_ops = {
         .can_merge = 0,
         .map = generic_pipe_buf_map,
         .unmap = generic_pipe_buf_unmap,
diff --git a/kernel/signal.c b/kernel/signal.c
index 6b982f2cf524..1814e68e4de3 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -423,7 +423,7 @@ still_pending:
                  */
                 info->si_signo = sig;
                 info->si_errno = 0;
-                info->si_code = 0;
+                info->si_code = SI_USER;
                 info->si_pid = 0;
                 info->si_uid = 0;
         }
@@ -607,6 +607,17 @@ static int rm_from_queue(unsigned long mask, struct sigpending *s)
         return 1;
 }
 
+static inline int is_si_special(const struct siginfo *info)
+{
+        return info <= SEND_SIG_FORCED;
+}
+
+static inline bool si_fromuser(const struct siginfo *info)
+{
+        return info == SEND_SIG_NOINFO ||
+                (!is_si_special(info) && SI_FROMUSER(info));
+}
+
 /*
  * Bad permissions for sending the signal
  * - the caller must hold at least the RCU read lock
@@ -621,7 +632,7 @@ static int check_kill_permission(int sig, struct siginfo *info,
         if (!valid_signal(sig))
                 return -EINVAL;
 
-        if (info != SEND_SIG_NOINFO && (is_si_special(info) || SI_FROMKERNEL(info)))
+        if (!si_fromuser(info))
                 return 0;
 
         error = audit_signal_info(sig, t); /* Let audit system see the signal */
@@ -949,9 +960,8 @@ static int send_signal(int sig, struct siginfo *info, struct task_struct *t,
         int from_ancestor_ns = 0;
 
 #ifdef CONFIG_PID_NS
-        if (!is_si_special(info) && SI_FROMUSER(info) &&
-                        task_pid_nr_ns(current, task_active_pid_ns(t)) <= 0)
-                from_ancestor_ns = 1;
+        from_ancestor_ns = si_fromuser(info) &&
+                           !task_pid_nr_ns(current, task_active_pid_ns(t));
 #endif
 
         return __send_signal(sig, info, t, group, from_ancestor_ns);
@@ -1052,12 +1062,6 @@ force_sig_info(int sig, struct siginfo *info, struct task_struct *t)
         return ret;
 }
 
-void
-force_sig_specific(int sig, struct task_struct *t)
-{
-        force_sig_info(sig, SEND_SIG_FORCED, t);
-}
-
 /*
  * Nuke all other threads in the group.
  */
@@ -1186,8 +1190,7 @@ int kill_pid_info_as_uid(int sig, struct siginfo *info, struct pid *pid,
                 goto out_unlock;
         }
         pcred = __task_cred(p);
-        if ((info == SEND_SIG_NOINFO ||
-             (!is_si_special(info) && SI_FROMUSER(info))) &&
+        if (si_fromuser(info) &&
             euid != pcred->suid && euid != pcred->uid &&
             uid  != pcred->suid && uid  != pcred->uid) {
                 ret = -EPERM;
@@ -1837,11 +1840,6 @@ relock:
 
         for (;;) {
                 struct k_sigaction *ka;
-
-                if (unlikely(signal->group_stop_count > 0) &&
-                    do_signal_stop(0))
-                        goto relock;
-
                 /*
                  * Tracing can induce an artifical signal and choose sigaction.
                  * The return value in @signr determines the default action,
@@ -1853,6 +1851,10 @@ relock:
                 if (unlikely(signr != 0))
                         ka = return_ka;
                 else {
+                        if (unlikely(signal->group_stop_count > 0) &&
+                            do_signal_stop(0))
+                                goto relock;
+
                         signr = dequeue_signal(current, &current->blocked,
                                                info);
 
diff --git a/kernel/time/timecompare.c b/kernel/time/timecompare.c
index 96ff643a5a59..12f5c55090be 100644
--- a/kernel/time/timecompare.c
+++ b/kernel/time/timecompare.c
@@ -89,7 +89,7 @@ int timecompare_offset(struct timecompare *sync,
                          * source time
                          */
                         sample.offset =
-                                ktime_to_ns(ktime_add(end, start)) / 2 -
+                                (ktime_to_ns(end) + ktime_to_ns(start)) / 2 -
                                 ts;
 
                         /* simple insertion sort based on duration */
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index bb6b5e7fa2a2..31118ae16f03 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3133,7 +3133,7 @@ static void tracing_spd_release_pipe(struct splice_pipe_desc *spd,
         __free_page(spd->pages[idx]);
 }
 
-static struct pipe_buf_operations tracing_pipe_buf_ops = {
+static const struct pipe_buf_operations tracing_pipe_buf_ops = {
         .can_merge              = 0,
         .map                    = generic_pipe_buf_map,
         .unmap                  = generic_pipe_buf_unmap,
@@ -3617,7 +3617,7 @@ static void buffer_pipe_buf_get(struct pipe_inode_info *pipe,
 }
 
 /* Pipe buffer operations for a buffer. */
-static struct pipe_buf_operations buffer_pipe_buf_ops = {
+static const struct pipe_buf_operations buffer_pipe_buf_ops = {
         .can_merge              = 0,
         .map                    = generic_pipe_buf_map,
         .unmap                  = generic_pipe_buf_unmap,