tick/broadcast: Prevent NULL pointer dereference

[uclinux-h8/linux.git] / kernel / cpuset.c

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index fc7f474..ee14e3a 100644 (file)
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -622,6 +622,7 @@ static int generate_sched_domains(cpumask_var_t **domains,
        int csn;                /* how many cpuset ptrs in csa so far */
        int i, j, k;            /* indices for partition finding loops */
        cpumask_var_t *doms;    /* resulting partition; i.e. sched domains */
+       cpumask_var_t non_isolated_cpus;  /* load balanced CPUs */
        struct sched_domain_attr *dattr;  /* attributes for custom domains */
        int ndoms = 0;          /* number of sched domains in result */
        int nslot;              /* next empty doms[] struct cpumask slot */
@@ -631,6 +632,10 @@ static int generate_sched_domains(cpumask_var_t **domains,
        dattr = NULL;
        csa = NULL;
 
+       if (!alloc_cpumask_var(&non_isolated_cpus, GFP_KERNEL))
+               goto done;
+       cpumask_andnot(non_isolated_cpus, cpu_possible_mask, cpu_isolated_map);
+
        /* Special case for the 99% of systems with one, full, sched domain */
        if (is_sched_load_balance(&top_cpuset)) {
                ndoms = 1;
@@ -643,7 +648,8 @@ static int generate_sched_domains(cpumask_var_t **domains,
                        *dattr = SD_ATTR_INIT;
                        update_domain_attr_tree(dattr, &top_cpuset);
                }
-               cpumask_copy(doms[0], top_cpuset.effective_cpus);
+               cpumask_and(doms[0], top_cpuset.effective_cpus,
+                                    non_isolated_cpus);
 
                goto done;
        }
@@ -666,7 +672,8 @@ static int generate_sched_domains(cpumask_var_t **domains,
                 * the corresponding sched domain.
                 */
                if (!cpumask_empty(cp->cpus_allowed) &&
-                   !is_sched_load_balance(cp))
+                   !(is_sched_load_balance(cp) &&
+                     cpumask_intersects(cp->cpus_allowed, non_isolated_cpus)))
                        continue;
 
                if (is_sched_load_balance(cp))
@@ -748,6 +755,7 @@ restart:
 
                        if (apn == b->pn) {
                                cpumask_or(dp, dp, b->effective_cpus);
+                               cpumask_and(dp, dp, non_isolated_cpus);
                                if (dattr)
                                        update_domain_attr_tree(dattr + nslot, b);
 
@@ -760,6 +768,7 @@ restart:
        BUG_ON(nslot != ndoms);
 
 done:
+       free_cpumask_var(non_isolated_cpus);
        kfree(csa);
 
        /*
@@ -2444,20 +2453,12 @@ static struct cpuset *nearest_hardwall_ancestor(struct cpuset *cs)
  * @node: is this an allowed node?
  * @gfp_mask: memory allocation flags
  *
- * If we're in interrupt, yes, we can always allocate.  If __GFP_THISNODE is
- * set, yes, we can always allocate.  If node is in our task's mems_allowed,
- * yes.  If it's not a __GFP_HARDWALL request and this node is in the nearest
- * hardwalled cpuset ancestor to this task's cpuset, yes.  If the task has been
- * OOM killed and has access to memory reserves as specified by the TIF_MEMDIE
- * flag, yes.
+ * If we're in interrupt, yes, we can always allocate.  If @node is set in
+ * current's mems_allowed, yes.  If it's not a __GFP_HARDWALL request and this
+ * node is set in the nearest hardwalled cpuset ancestor to current's cpuset,
+ * yes.  If current has access to memory reserves due to TIF_MEMDIE, yes.
  * Otherwise, no.
  *
- * The __GFP_THISNODE placement logic is really handled elsewhere,
- * by forcibly using a zonelist starting at a specified node, and by
- * (in get_page_from_freelist()) refusing to consider the zones for
- * any node on the zonelist except the first.  By the time any such
- * calls get to this routine, we should just shut up and say 'yes'.
- *
  * GFP_USER allocations are marked with the __GFP_HARDWALL bit,
  * and do not allow allocations outside the current tasks cpuset
  * unless the task has been OOM killed as is marked TIF_MEMDIE.
@@ -2493,7 +2494,7 @@ int __cpuset_node_allowed(int node, gfp_t gfp_mask)
        int allowed;                    /* is allocation in zone z allowed? */
        unsigned long flags;
 
-       if (in_interrupt() || (gfp_mask & __GFP_THISNODE))
+       if (in_interrupt())
                return 1;
        if (node_isset(node, current->mems_allowed))
                return 1;