> case PR_GET_FP_MODE:
> error = GET_FP_MODE(me);
> break;
> +#ifdef CONFIG_TASK_ISOLATION
> + case PR_SET_TASK_ISOLATION:
> + error = task_isolation_set(arg2);
> + break;
> + case PR_GET_TASK_ISOLATION:
> + error = me->task_isolation_flags;
> + break;
> +#endif
> default:
> error = -EINVAL;
> break;
It is not a very good idea to ignore the values of unused arguments; it
prevents future their usage, as user space can pass some garbage values
here. Check out the code for newer prctl handlers, like
PR_SET_NO_NEW_PRIVS, PR_SET_THP_DISABLE, or PR_MPX_ENABLE_MANAGEMENT
(PR_[SG]_FP_MODE is an unfortunate recent omission).
The other thing is the usage of #ifdef's, which is generally avoided
there. Also, the patch for man-pages, describing the new prctl calls, is
missing.
Please take a look at the following patch, which is made in an
attempt to fix aforementioned issues (it is assumed it can be squashed
with the current one).
---
include/linux/isolation.h | 12 ++++++++++++
kernel/sys.c | 16 ++++++++++++----
2 files changed, 24 insertions(+), 4 deletions(-)
diff --git a/include/linux/isolation.h b/include/linux/isolation.h
index 02728b1..ae24cad 100644
--- a/include/linux/isolation.h
+++ b/include/linux/isolation.h
@@ -9,6 +9,13 @@
#ifdef CONFIG_TASK_ISOLATION
+#ifndef GET_TASK_ISOLATION
+# define GET_TASK_ISOLATION(me) task_isolation_get(me)
+#endif
+#ifndef SET_TASK_ISOLATION
+# define SET_TASK_ISOLATION(me, a) task_isolation_set(a)
+#endif
+
/* cpus that are configured to support task isolation */
extern cpumask_var_t task_isolation_map;
@@ -22,6 +29,11 @@ static inline bool task_isolation_possible(int cpu)
extern int task_isolation_set(unsigned int flags);
+static inline unsigned int task_isolation_get(struct task_struct *ts)
+{
+ return ts->task_isolation_flags;
+}
+
extern bool task_isolation_ready(void);
extern void task_isolation_enter(void);
diff --git a/kernel/sys.c b/kernel/sys.c
index 3de863f..96e0873 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -104,6 +104,12 @@
#ifndef SET_FP_MODE
# define SET_FP_MODE(a,b) (-EINVAL)
#endif
+#ifndef GET_TASK_ISOLATION
+# define GET_TASK_ISOLATION(me) (-EINVAL)
+#endif
+#ifndef SET_TASK_ISOLATION
+# define SET_TASK_ISOLATION(me, a) (-EINVAL)
+#endif
/*
* this is where the system-wide overflow UID and GID are defined, for
@@ -2262,14 +2268,16 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long,
arg2, unsigned long, arg3,
case PR_GET_FP_MODE:
error = GET_FP_MODE(me);
break;
-#ifdef CONFIG_TASK_ISOLATION
case PR_SET_TASK_ISOLATION:
- error = task_isolation_set(arg2);
+ if (arg3 || arg4 || arg5)
+ return -EINVAL;
+ error = SET_TASK_ISOLATION(me, arg2);
break;
case PR_GET_TASK_ISOLATION:
- error = me->task_isolation_flags;
+ if (arg2 || arg3 || arg4 || arg5)
+ return -EINVAL;
+ error = GET_TASK_ISOLATION(me);
break;
-#endif
default:
error = -EINVAL;
break;
--
2.9.3
