[PATCH v3 4/9] powerpc/pkeys: Save the pkey registers before fork

[Ram Pai]

When a thread forks the contents of AMR, IAMR, UAMOR registers in the
newly forked thread are not inherited.

Save the registers before forking, for content of those
registers to be automatically copied into the new thread.

Cc: Michael Ellerman <mpe at ellerman.id.au>
Cc: Florian Weimer <fweimer at redhat.com>
Cc: Andy Lutomirski <luto at kernel.org>
Cc: Thiago Jung Bauermann <bauerman at linux.ibm.com>
Fixes: cf43d3b26452 ("powerpc: Enable pkey subsystem")
Cc: stable at vger.kernel.org # v4.16+
Signed-off-by: Ram Pai <linuxram at us.ibm.com>
---
 arch/powerpc/kernel/process.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 9ef4aea..991d097 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -583,6 +583,7 @@ static void save_all(struct task_struct *tsk)
 		__giveup_spe(tsk);
 
 	msr_check_and_clear(msr_all_available);
+	thread_pkey_regs_save(&tsk->thread);
 }
 
 void flush_all_to_thread(struct task_struct *tsk)
-- 
1.7.1