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| author | Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> | 2020-11-27 05:44:14 +0100 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2020-12-03 15:01:26 +0100 |
| commit | d5fa30e6993ffcdd1859d8dab1a07a6f6c6e7c3f (patch) | |
| tree | 69bb6b2eb8e0488a5228288cc2073d47ac706191 | |
| parent | powerpc/book3s64/pkeys: Inherit correctly on fork. (diff) | |
| download | linux-d5fa30e6993ffcdd1859d8dab1a07a6f6c6e7c3f.tar.xz linux-d5fa30e6993ffcdd1859d8dab1a07a6f6c6e7c3f.zip | |
powerpc/book3s64/pkeys: Reset userspace AMR correctly on exec
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 <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/20201127044424.40686-13-aneesh.kumar@linux.ibm.com
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/pkeys.h | 2 | ||||
| -rw-r--r-- | arch/powerpc/kernel/process.c | 6 | ||||
| -rw-r--r-- | 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 2ec907a6f9af..0538e0f1790c 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -1546,6 +1546,11 @@ 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 @@ -1895,7 +1900,6 @@ 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; |