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. Reviewed-by: Sandipan Das <sandi...@linux.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com> --- arch/powerpc/include/asm/book3s/64/pkeys.h | 2 ++ arch/powerpc/kernel/process.c | 6 +++++- arch/powerpc/mm/book3s64/pkeys.c | 16 ++-------------- 3 files changed, 9 insertions(+), 15 deletions(-) diff --git a/arch/powerpc/include/asm/book3s/64/pkeys.h b/arch/powerpc/include/asm/book3s/64/pkeys.h index b7d9f4267bcd..3b8640498f5b 100644 --- a/arch/powerpc/include/asm/book3s/64/pkeys.h +++ b/arch/powerpc/include/asm/book3s/64/pkeys.h @@ -6,6 +6,8 @@ #include <asm/book3s/64/hash-pkey.h> extern u64 __ro_after_init default_uamor; +extern u64 __ro_after_init default_amr; +extern u64 __ro_after_init default_iamr; static inline u64 vmflag_to_pte_pkey_bits(u64 vm_flags) { diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 9acb6166012d..7ea53aac0478 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -1542,6 +1542,11 @@ void arch_setup_new_exec(void) struct pt_regs *regs = task_stack_page(current) + THREAD_SIZE; current->thread.regs = regs - 1; } + +#ifdef CONFIG_PPC_MEM_KEYS + current->thread.regs->amr = default_amr; + current->thread.regs->iamr = default_iamr; +#endif } #ifdef CONFIG_PPC64 @@ -1887,7 +1892,6 @@ 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(¤t->thread); } EXPORT_SYMBOL(start_thread); diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c index e434c0a2ee5d..355d001fa155 100644 --- a/arch/powerpc/mm/book3s64/pkeys.c +++ b/arch/powerpc/mm/book3s64/pkeys.c @@ -28,8 +28,8 @@ static u32 initial_allocation_mask __ro_after_init; * Even if we allocate keys with sys_pkey_alloc(), we need to make sure * other thread still find the access denied using the same keys. */ -static u64 default_amr = ~0x0UL; -static u64 default_iamr = 0x5555555555555555UL; +u64 default_amr __ro_after_init = ~0x0UL; +u64 default_iamr __ro_after_init = 0x5555555555555555UL; u64 default_uamor __ro_after_init; /* * Key used to implement PROT_EXEC mmap. Denies READ/WRITE @@ -396,18 +396,6 @@ void thread_pkey_regs_restore(struct thread_struct *new_thread, write_iamr(new_thread->iamr); } -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; - - write_amr(default_amr); - write_iamr(default_iamr); -} - int execute_only_pkey(struct mm_struct *mm) { return mm->context.execute_only_pkey; -- 2.28.0