Subject: [PATCH] powerpc/le: fix endianness of the arguments passed to the ppc_rtas() syscall

From: Greg Kurz <[email-masked]>
Date: Wed, 05 Mar 2014 18:20:06 +0100

RTAS manipulates its input and output arguments in big endian order.

I have looked at factoring some lines with rtas_call() but it is not really
worth it because of the variable arguments.

Signed-off-by: Greg Kurz <[email-masked]>
---
 arch/powerpc/kernel/rtas.c |   15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index 4cf674d..00dbe36 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -1020,6 +1020,7 @@ asmlinkage int ppc_rtas(struct rtas_args __user *uargs)
 	char *buff_copy, *errbuf = NULL;
 	int nargs;
 	int rc;
+	int i;
 
 	if (!capable(CAP_SYS_ADMIN))
 		return -EPERM;
@@ -1056,9 +1057,19 @@ asmlinkage int ppc_rtas(struct rtas_args __user *uargs)
 
 	flags = lock_rtas();
 
-	rtas.args = args;
+	rtas.args.token = cpu_to_be32(args.token);
+	rtas.args.nargs = cpu_to_be32(args.nargs);
+	rtas.args.nret  = cpu_to_be32(args.nret);
+	for (i = 0; i < nargs; ++i)
+		rtas.args.args[i] = cpu_to_be32(args.args[i]);
+	rtas.args.rets  = &rtas.args.args[nargs];
+	for (i = 0; i < args.nret; ++i)
+		rtas.args.rets[i] = 0;
+
 	enter_rtas(__pa(&rtas.args));
-	args = rtas.args;
+
+	for (i = 0; i < args.nret; ++i)
+		args.rets[i] = be32_to_cpu(rtas.args.rets[i]);
 
 	/* A -1 return code indicates that the last command couldn't
 	   be completed due to a hardware error. */