powerpc/book3s64/pkeys: Inherit correctly on fork.

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@linux.ibm.com>
Reviewed-by: Sandipan Das <sandipan@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201127044424.40686-12-aneesh.kumar@linux.ibm.com
This commit is contained in:
Aneesh Kumar K.V 2020-11-27 10:14:13 +05:30 committed by Michael Ellerman
parent 8e560921b5
commit f643fcab74
1 changed files with 10 additions and 0 deletions

View File

@ -1760,6 +1760,16 @@ 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_PKEY
if (mmu_has_feature(MMU_FTR_BOOK3S_KUAP))
kregs->amr = AMR_KUAP_BLOCKED;
if (mmu_has_feature(MMU_FTR_BOOK3S_KUEP))
kregs->iamr = AMR_KUEP_BLOCKED;
#endif
kregs->nip = ppc_function_entry(f);
return 0;