[PATCH] prctl: implement PR_GET_ENDIAN for all architectures

From: Helge Deller
Date: Sat Jan 28 2017 - 06:21:06 EST


The prctl(PR_GET_ENDIAN) syscall was added to Kernel 2.6.18, but
implemented for PowerPC only.
This trivial patch adds support for this syscall for all other architectures.

Signed-off-by: Helge Deller <deller@xxxxxx>

diff --git a/kernel/sys.c b/kernel/sys.c
index 842914e..5818e5e 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -79,9 +79,6 @@
#ifndef GET_FPEXC_CTL
# define GET_FPEXC_CTL(a, b) (-EINVAL)
#endif
-#ifndef GET_ENDIAN
-# define GET_ENDIAN(a, b) (-EINVAL)
-#endif
#ifndef SET_ENDIAN
# define SET_ENDIAN(a, b) (-EINVAL)
#endif
@@ -2136,7 +2133,13 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
return -EFAULT;
break;
case PR_GET_ENDIAN:
+#ifdef GET_ENDIAN
error = GET_ENDIAN(me, arg2);
+#elif defined(__BIG_ENDIAN)
+ error = put_user(PR_ENDIAN_BIG, (unsigned int __user *)arg2);
+#else
+ error = put_user(PR_ENDIAN_LITTLE, (unsigned int __user *)arg2);
+#endif
break;
case PR_SET_ENDIAN:
error = SET_ENDIAN(me, arg2);