commit 06bb53b33804613627c7ca1eda246459a7be2803
author Ram Pai <linuxram@us.ibm.com> Thu Jan 18 17:50:31 2018 -0800
committer Michael Ellerman <mpe@ellerman.id.au> Sat Jan 20 22:59:00 2018 +1100
tree 61428a22fe89565f607bf32480a6173255fb8c7b
parent dcf872956d444bbbd46f601024ea989ced03f8a7

powerpc: store and restore the pkey state across context switches

Store and restore the AMR, IAMR and UAMOR register state of the task
before scheduling out and after scheduling in, respectively.

Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/kernel/process.c

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 9eb78ec..755fd7e 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -42,6 +42,7 @@
 #include <linux/hw_breakpoint.h>
 #include <linux/uaccess.h>
 #include <linux/elf-randomize.h>
+#include <linux/pkeys.h>
 
 #include <asm/pgtable.h>
 #include <asm/io.h>
@@ -1103,6 +1104,8 @@ static inline void save_sprs(struct thread_struct *t)
 		t->tar = mfspr(SPRN_TAR);
 	}
 #endif
+
+	thread_pkey_regs_save(t);
 }
 
 static inline void restore_sprs(struct thread_struct *old_thread,
@@ -1142,6 +1145,8 @@ static inline void restore_sprs(struct thread_struct *old_thread,
 	    old_thread->tidr != new_thread->tidr)
 		mtspr(SPRN_TIDR, new_thread->tidr);
 #endif
+
+	thread_pkey_regs_restore(new_thread, old_thread);
 }
 
 #ifdef CONFIG_PPC_BOOK3S_64
@@ -1867,6 +1872,8 @@ void start_thread(struct pt_regs *regs, unsigned long start, unsigned long sp)
 	current->thread.tm_tfiar = 0;
 	current->thread.load_tm = 0;
 #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
+
+	thread_pkey_regs_init(&current->thread);
 }
 EXPORT_SYMBOL(start_thread);