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authorJohannes Berg <johannes.berg@intel.com>2021-01-10 21:05:09 +0300
committerRichard Weinberger <richard@nod.at>2021-01-27 00:11:38 +0300
commita31e9c4e7247d182192e9b85abbea498d63dd850 (patch)
tree35c289fd8b81c74b8d49177566eb35f552e2ebe6 /arch/um/kernel/tlb.c
parent2fcb4090cd7352665ecb756990a3087bfd86a295 (diff)
downloadlinux-a31e9c4e7247d182192e9b85abbea498d63dd850.tar.xz
Revert "um: support some of ARCH_HAS_SET_MEMORY"
This reverts commit 963285b0b47a ("um: support some of ARCH_HAS_SET_MEMORY"), as it turns out that it's not only not working (due to um never using the protection bits in the page tables) but also corrupts the page tables if used on a non-vmalloc page, since um never allocates proper page tables for the 'physmem' in the first place. Fixing all this will take more effort, so for now revert it. Reported-by: Benjamin Berg <benjamin@sipsolutions.net> Fixes: 963285b0b47a ("um: support some of ARCH_HAS_SET_MEMORY") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch/um/kernel/tlb.c')
-rw-r--r--arch/um/kernel/tlb.c54
1 files changed, 0 insertions, 54 deletions
diff --git a/arch/um/kernel/tlb.c b/arch/um/kernel/tlb.c
index 437d1f1cc5ec..61776790cd67 100644
--- a/arch/um/kernel/tlb.c
+++ b/arch/um/kernel/tlb.c
@@ -608,57 +608,3 @@ void force_flush_all(void)
vma = vma->vm_next;
}
}
-
-struct page_change_data {
- unsigned int set_mask, clear_mask;
-};
-
-static int change_page_range(pte_t *ptep, unsigned long addr, void *data)
-{
- struct page_change_data *cdata = data;
- pte_t pte = READ_ONCE(*ptep);
-
- pte_clear_bits(pte, cdata->clear_mask);
- pte_set_bits(pte, cdata->set_mask);
-
- set_pte(ptep, pte);
- return 0;
-}
-
-static int change_memory(unsigned long start, unsigned long pages,
- unsigned int set_mask, unsigned int clear_mask)
-{
- unsigned long size = pages * PAGE_SIZE;
- struct page_change_data data;
- int ret;
-
- data.set_mask = set_mask;
- data.clear_mask = clear_mask;
-
- ret = apply_to_page_range(&init_mm, start, size, change_page_range,
- &data);
-
- flush_tlb_kernel_range(start, start + size);
-
- return ret;
-}
-
-int set_memory_ro(unsigned long addr, int numpages)
-{
- return change_memory(addr, numpages, 0, _PAGE_RW);
-}
-
-int set_memory_rw(unsigned long addr, int numpages)
-{
- return change_memory(addr, numpages, _PAGE_RW, 0);
-}
-
-int set_memory_nx(unsigned long addr, int numpages)
-{
- return -EOPNOTSUPP;
-}
-
-int set_memory_x(unsigned long addr, int numpages)
-{
- return -EOPNOTSUPP;
-}