Re: [PATCH] Fix CPU bitmask truncation

[Anton Blanchard]

> Linus, this is the 2.5.x version of the same patch originally by Bjorn
> for 2.4.x. This fixes an entire class of critical 64-bit bugs.
> 
> Against 2.5.52-bk as of 2:25AM 20 Dec 2002. Please apply.

Here's one in 2.5, found when adding 64 CPU support to ppc64.

Anton

===== kernel/module.c 1.31 vs edited =====
--- 1.31/kernel/module.c	Mon Dec  2 17:44:11 2002
+++ edited/kernel/module.c	Tue Dec 17 10:29:27 2002
@@ -210,7 +210,7 @@
 	struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
 	setscheduler(current->pid, SCHED_FIFO, &param);
 #endif
-	set_cpus_allowed(current, 1 << (unsigned long)cpu);
+	set_cpus_allowed(current, 1UL << (unsigned long)cpu);
 
 	/* Ack: we are alive */
 	atomic_inc(&stopref_thread_ack);
@@ -271,7 +271,7 @@
 
 	/* FIXME: racy with set_cpus_allowed. */
 	old_allowed = current->cpus_allowed;
-	set_cpus_allowed(current, 1 << (unsigned long)cpu);
+	set_cpus_allowed(current, 1UL << (unsigned long)cpu);
 
 	atomic_set(&stopref_thread_ack, 0);
 	stopref_num_threads = 0;