[PATCH] Define vsyscall cache as blob to make clearer that user space shouldn't use it

[linux-drm-fsl-dcu.git] / kernel / sys.c

diff --git a/kernel/sys.c b/kernel/sys.c
index 2d5179c67cec727f40476e2f9e75fbb9eeeb8d8c..b88806c66244b2df825f6bb43bbb20b251cce21c 100644 (file)
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -4,7 +4,6 @@
  *  Copyright (C) 1991, 1992  Linus Torvalds
  */
 
-#include <linux/config.h>
 #include <linux/module.h>
 #include <linux/mm.h>
 #include <linux/utsname.h>
@@ -29,6 +28,7 @@
 #include <linux/tty.h>
 #include <linux/signal.h>
 #include <linux/cn_proc.h>
+#include <linux/getcpu.h>
 
 #include <linux/compat.h>
 #include <linux/syscalls.h>
@@ -612,7 +612,6 @@ void kernel_restart(char *cmd)
        } else {
                printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd);
        }
-       printk(".\n");
        machine_restart(cmd);
 }
 EXPORT_SYMBOL_GPL(kernel_restart);
@@ -1984,7 +1983,7 @@ asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
                        error = current->mm->dumpable;
                        break;
                case PR_SET_DUMPABLE:
-                       if (arg2 < 0 || arg2 > 2) {
+                       if (arg2 < 0 || arg2 > 1) {
                                error = -EINVAL;
                                break;
                        }
@@ -2063,3 +2062,33 @@ asmlinkage long sys_prctl(int option, unsigned long arg2, unsigned long arg3,
        }
        return error;
 }
+
+asmlinkage long sys_getcpu(unsigned __user *cpup, unsigned __user *nodep,
+                          struct getcpu_cache __user *cache)
+{
+       int err = 0;
+       int cpu = raw_smp_processor_id();
+       if (cpup)
+               err |= put_user(cpu, cpup);
+       if (nodep)
+               err |= put_user(cpu_to_node(cpu), nodep);
+       if (cache) {
+               /*
+                * The cache is not needed for this implementation,
+                * but make sure user programs pass something
+                * valid. vsyscall implementations can instead make
+                * good use of the cache. Only use t0 and t1 because
+                * these are available in both 32bit and 64bit ABI (no
+                * need for a compat_getcpu). 32bit has enough
+                * padding
+                */
+               unsigned long t0, t1;
+               get_user(t0, &cache->blob[0]);
+               get_user(t1, &cache->blob[1]);
+               t0++;
+               t1++;
+               put_user(t0, &cache->blob[0]);
+               put_user(t1, &cache->blob[1]);
+       }
+       return err ? -EFAULT : 0;
+}