Revert "ANDROID: powerpc/mm: protect vm_file during speculative page fault handling"

This reverts commit 6551a55c4d.

File refcounting implemented in this patch is broken and needs to be
redone.

Bug: 258731892
Change-Id: I425517a07d1fdcf5cd1842733a4c6c70ef0608b4
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
This commit is contained in:
Suren Baghdasaryan
2022-11-11 12:48:58 -08:00
parent 4288911d5e
commit e9a7e9f2ff

View File

@@ -395,7 +395,6 @@ static int ___do_page_fault(struct pt_regs *regs, unsigned long address,
vm_fault_t fault, major = 0;
bool kprobe_fault = kprobe_page_fault(regs, 11);
#ifdef CONFIG_SPECULATIVE_PAGE_FAULT
struct vm_area_struct *orig_vma = NULL;
struct vm_area_struct pvma;
unsigned long seq;
#endif
@@ -481,37 +480,24 @@ static int ___do_page_fault(struct pt_regs *regs, unsigned long address,
count_vm_spf_event(SPF_ABORT_NO_SPECULATE);
goto spf_abort;
}
if (vma->vm_file) {
if (!vma_get_file_ref(vma)) {
rcu_read_unlock();
count_vm_spf_event(SPF_ABORT_UNMAPPED);
goto spf_abort;
}
orig_vma = vma;
}
pvma = *vma;
rcu_read_unlock();
if (!mmap_seq_read_check(mm, seq, SPF_ABORT_VMA_COPY)) {
vma_put_file_ref(orig_vma);
if (!mmap_seq_read_check(mm, seq, SPF_ABORT_VMA_COPY))
goto spf_abort;
}
vma = &pvma;
#ifdef CONFIG_PPC_MEM_KEYS
if (unlikely(access_pkey_error(is_write, is_exec,
(error_code & DSISR_KEYFAULT), vma))) {
count_vm_spf_event(SPF_ABORT_ACCESS_ERROR);
vma_put_file_ref(orig_vma);
goto spf_abort;
}
#endif /* CONFIG_PPC_MEM_KEYS */
if (unlikely(access_error(is_write, is_exec, vma))) {
count_vm_spf_event(SPF_ABORT_ACCESS_ERROR);
vma_put_file_ref(orig_vma);
goto spf_abort;
}
fault = do_handle_mm_fault(vma, address,
flags | FAULT_FLAG_SPECULATIVE, seq, regs);
vma_put_file_ref(orig_vma);
major |= fault & VM_FAULT_MAJOR;
if (fault_signal_pending(fault, regs))