[PATCH v4 26/41] powerpc/book3s64/pkeys: Inherit correctly on fork.

[Aneesh Kumar K.V]

Child thread.kuap value is inherited from the parent in copy_thread_tls. We still
need to make sure when the child returns from a fork in the kernel we start with the kernel
default AMR value.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar at linux.ibm.com>
---
 arch/powerpc/kernel/process.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 14599c7e4a37..dbce0b1daf2f 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1705,6 +1705,15 @@ int copy_thread_tls(unsigned long clone_flags, unsigned long usp,
 		childregs->ppr = DEFAULT_PPR;
 
 	p->thread.tidr = 0;
+#endif
+	/*
+	 * Run with the current AMR value of the kernel
+	 */
+#if defined(CONFIG_PPC_MEM_KEYS)
+	if (mmu_has_feature(MMU_FTR_KUAP))
+		kregs->kuap = AMR_KUAP_BLOCKED;
+	if (mmu_has_feature(MMU_FTR_KUEP))
+		kregs->kuep = AMR_KUEP_BLOCKED;
 #endif
 	kregs->nip = ppc_function_entry(f);
 	return 0;
-- 
2.26.2