"Aneesh Kumar K.V" writes:
> On fork, we inherit from the parent and on exec, we should switch to
> default_amr values.
>
> Also, avoid changing the AMR register value within the kernel. The kernel now
> runs with
> different AMR values.
>
> Signed-off-by: Aneesh Kumar K.V
> ---
> arch/powerpc/include/asm/book3s/64/kup.h | 2 ++
> arch/powerpc/kernel/process.c| 19 ++-
> arch/powerpc/mm/book3s64/pkeys.c | 18 ++
> 3 files changed, 22 insertions(+), 17 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/book3s/64/kup.h
> b/arch/powerpc/include/asm/book3s/64/kup.h
> index 67320a990f3f..fe1818954e51 100644
> --- a/arch/powerpc/include/asm/book3s/64/kup.h
> +++ b/arch/powerpc/include/asm/book3s/64/kup.h
> @@ -171,6 +171,8 @@
> #include
>
> extern u64 default_uamor;
> +extern u64 default_amr;
> +extern u64 default_iamr;
>
> static inline void kuap_restore_user_amr(struct pt_regs *regs)
> {
> diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
> index 9ef95a1217ef..0ab9a8cf1bcb 100644
> --- a/arch/powerpc/kernel/process.c
> +++ b/arch/powerpc/kernel/process.c
> @@ -1474,7 +1474,25 @@ void arch_setup_new_exec(void)
> current->thread.regs = regs - 1;
> }
>
> +#ifdef CONFIG_PPC_MEM_KEYS
> + current->thread.regs->kuap = default_amr;
> + current->thread.regs->kuep = default_iamr;
> +#endif
> +
> }
> +#else
> +void arch_setup_new_exec(void)
> +{
> + /*
> + * If we exec out of a kernel thread then thread.regs will not be
> + * set. Do it now.
> + */
> + if (!current->thread.regs) {
> + struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE;
> + current->thread.regs = regs - 1;
> + }
> +}
> +
> #endif
>
> #ifdef CONFIG_PPC64
> @@ -1809,7 +1827,6 @@ void start_thread(struct pt_regs *regs, unsigned long
> start, unsigned long sp)
> current->thread.load_tm = 0;
> #endif /* CONFIG_PPC_TRANSACTIONAL_MEM */
>
> - thread_pkey_regs_init(>thread);
> }
> EXPORT_SYMBOL(start_thread);
>
> diff --git a/arch/powerpc/mm/book3s64/pkeys.c
> b/arch/powerpc/mm/book3s64/pkeys.c
> index 976f65f27324..5012b57af808 100644
> --- a/arch/powerpc/mm/book3s64/pkeys.c
> +++ b/arch/powerpc/mm/book3s64/pkeys.c
> @@ -20,8 +20,8 @@ int max_pkey; /* Maximum key value
> supported */
> */
> u32 reserved_allocation_mask;
> static u32 initial_allocation_mask; /* Bits set for the initially
> allocated keys */
> -static u64 default_amr;
> -static u64 default_iamr;
> +u64 default_amr;
> +u64 default_iamr;
> /* Allow all keys to be modified by default */
> u64 default_uamor = ~0x0UL;
> /*
> @@ -387,20 +387,6 @@ void thread_pkey_regs_restore(struct thread_struct
> *new_thread,
> write_uamor(new_thread->uamor);
> }
>
> -void thread_pkey_regs_init(struct thread_struct *thread)
> -{
> - if (!mmu_has_feature(MMU_FTR_PKEY))
> - return;
> -
> - thread->amr = default_amr;
> - thread->iamr = default_iamr;
> - thread->uamor = default_uamor;
> -
> - write_amr(default_amr);
> - write_iamr(default_iamr);
> - write_uamor(default_uamor);
> -}
> -
> int execute_only_pkey(struct mm_struct *mm)
> {
> if (static_branch_likely(_pkey_disabled))
> --
> 2.26.2
Needs this change to fix build error.
---
arch/powerpc/include/asm/thread_info.h | 2 --
1 file changed, 2 deletions(-)
diff --git a/arch/powerpc/include/asm/thread_info.h
b/arch/powerpc/include/asm/thread_info.h
index ca6c97025704..9418dff1cfe1 100644
--- a/arch/powerpc/include/asm/thread_info.h
+++ b/arch/powerpc/include/asm/thread_info.h
@@ -77,10 +77,8 @@ struct thread_info {
/* how to get the thread information struct from C */
extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct
*src);
-#ifdef CONFIG_PPC_BOOK3S_64
void arch_setup_new_exec(void);
#define arch_setup_new_exec arch_setup_new_exec
-#endif
#endif /* __ASSEMBLY__ */
--
2.26.2
