Adds more code comments. We also remove an unnecessary pkey check
after we check for pkey error in this patch.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
if (unlikely(!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE))))
return true;
if (unlikely(!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE))))
return true;
+ /*
+ * We should ideally do the vma pkey access check here. But in the
+ * fault path, handle_mm_fault() also does the same check. To avoid
+ * these multiple checks, we skip it here and handle access error due
+ * to pkeys later.
+ */
#ifdef CONFIG_PPC_MEM_KEYS
/*
#ifdef CONFIG_PPC_MEM_KEYS
/*
- * if the HPTE is not hashed, hardware will not detect
- * a key fault. Lets check if we failed because of a
- * software detected key fault.
+ * we skipped checking for access error due to key earlier.
+ * Check that using handle_mm_fault error return.
*/
if (unlikely(fault & VM_FAULT_SIGSEGV) &&
*/
if (unlikely(fault & VM_FAULT_SIGSEGV) &&
- !arch_vma_access_permitted(vma, flags & FAULT_FLAG_WRITE,
- is_exec, 0)) {
- /*
- * The PGD-PDT...PMD-PTE tree may not have been fully setup.
- * Hence we cannot walk the tree to locate the PTE, to locate
- * the key. Hence let's use vma_pkey() to get the key; instead
- * of get_mm_addr_key().
- */
+ !arch_vma_access_permitted(vma, is_write, is_exec, 0)) {
+
int pkey = vma_pkey(vma);
int pkey = vma_pkey(vma);
- if (likely(pkey)) {
- up_read(&mm->mmap_sem);
- return bad_key_fault_exception(regs, address, pkey);
- }
+ up_read(&mm->mmap_sem);
+ return bad_key_fault_exception(regs, address, pkey);
}
#endif /* CONFIG_PPC_MEM_KEYS */
}
#endif /* CONFIG_PPC_MEM_KEYS */
#else
os_reserved = 0;
#endif
#else
os_reserved = 0;
#endif
+ initial_allocation_mask = ~0x0;
+ pkey_amr_uamor_mask = ~0x0ul;
+ pkey_iamr_mask = ~0x0ul;
- * Bits are in LE format. NOTE: 1, 0 are reserved.
+ * key 0, 1 are reserved.
* key 0 is the default key, which allows read/write/execute.
* key 1 is recommended not to be used. PowerISA(3.0) page 1015,
* programming note.
*/
* key 0 is the default key, which allows read/write/execute.
* key 1 is recommended not to be used. PowerISA(3.0) page 1015,
* programming note.
*/
- initial_allocation_mask = ~0x0;
-
- /* register mask is in BE format */
- pkey_amr_uamor_mask = ~0x0ul;
- pkey_iamr_mask = ~0x0ul;
-
for (i = 2; i < (pkeys_total - os_reserved); i++) {
initial_allocation_mask &= ~(0x1 << i);
pkey_amr_uamor_mask &= ~(0x3ul << pkeyshift(i));
for (i = 2; i < (pkeys_total - os_reserved); i++) {
initial_allocation_mask &= ~(0x1 << i);
pkey_amr_uamor_mask &= ~(0x3ul << pkeyshift(i));