[PATCH v2 01/16] compat: Add in_compat_syscall to ask whether we're in a compat syscall

Andy Lutomirski
2016-01-25T22:24:15Z

A lot of code currently abuses is_compat_task to determine this.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
---
include/linux/compat.h | 15 +++++++++++++++
1 file changed, 15 insertions(+)

diff --git a/include/linux/compat.h b/include/linux/compat.h
index a76c9172b2eb..f911bcec618f 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -5,6 +5,8 @@
* syscall compatibility layer.
*/

+#include <linux/types.h>
+
#ifdef CONFIG_COMPAT

#include <linux/stat.h>
@@ -713,9 +715,22 @@ asmlinkage long compat_sys_sched_rr_get_interval(compat_pid_t pid,

asmlinkage long compat_sys_fanotify_mark(int, unsigned int, __u32, __u32,
int, const char __user *);
+
+/*
+ * For most but not all architectures, "am I in a compat syscall?" and
+ * "am I a compat task?" are the same question. For architectures on which
+ * they aren't the same question, arch code can override in_compat_syscall.
+ */
+
+#ifndef in_compat_syscall
+static inline bool in_compat_syscall(void) { return is_compat_task(); }
+#endif
+
#else

#define is_compat_task() (0)
+static inline bool in_compat_syscall(void) { return false; }

#endif /* CONFIG_COMPAT */
+
#endif /* _LINUX_COMPAT_H */
--
2.5.0