On 11/25/20 7:24 PM, Christophe Leroy wrote:
Le 25/11/2020 à 06:16, Aneesh Kumar K.V a écrit :
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.
Reviewed-by: Sandipan Das <sandi...@linux.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com>
---
arch/powerpc/kernel/process.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/arch/powerpc/kernel/process.c
b/arch/powerpc/kernel/process.c
index b6b8a845e454..733680de0ba4 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -1768,6 +1768,17 @@ int copy_thread(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
+ */
+#ifdef CONFIG_PPC_KUAP
+ if (mmu_has_feature(MMU_FTR_KUAP))
+ kregs->kuap = AMR_KUAP_BLOCKED;
+#endif
Do we need that ifdef at all ?
Shouldn't mmu_has_feature(MMU_FTR_KUAP) be always false and get
optimised out when CONFIG_PPC_KUAP is not defined ?
+#ifdef CONFIG_PPC_KUEP
+ if (mmu_has_feature(MMU_FTR_KUEP))
+ kregs->iamr = AMR_KUEP_BLOCKED;
Same ?
#endif
kregs->nip = ppc_function_entry(f);
return 0;
Not really. I did hit a compile error with this patch on
mpc885_ads_defconfig and that required me to do
modified arch/powerpc/kernel/process.c
@@ -1772,11 +1772,10 @@ int copy_thread(unsigned long clone_flags,
unsigned long usp,
/*
* Run with the current AMR value of the kernel
*/
-#ifdef CONFIG_PPC_KUAP
+#ifdef CONFIG_PPC_PKEY
if (mmu_has_feature(MMU_FTR_KUAP))
- kregs->kuap = AMR_KUAP_BLOCKED;
-#endif
-#ifdef CONFIG_PPC_KUEP
+ kregs->amr = AMR_KUAP_BLOCKED;
+
if (mmu_has_feature(MMU_FTR_KUEP))
kregs->iamr = AMR_KUEP_BLOCKED;
#endif
