The use of kmap() and kmap_atomic() are being deprecated in favor of
kmap_local_page().
With kmap_local_page(), the mappings are per thread, CPU local and not
globally visible. Furthermore, the mappings can be acquired from any
context (including interrupts).
Therefore, use kmap_local_page() in exec.c because these mappings are per
thread, CPU local, and not globally visible.
Tested with xfstests on a QEMU + KVM 32-bits VM booting a kernel with
HIGHMEM64GB enabled.
Suggested-by: Ira Weiny <ira.weiny@xxxxxxxxx>
Signed-off-by: Fabio M. De Francesco <fmdefrancesco@xxxxxxxxx>
---
fs/exec.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)
diff --git a/fs/exec.c b/fs/exec.c
index 0989fb8472a1..4a2129c0d422 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -583,11 +583,11 @@ static int copy_strings(int argc, struct user_arg_ptr argv,
if (kmapped_page) {
flush_dcache_page(kmapped_page);
- kunmap(kmapped_page);
+ kunmap_local(kaddr);
put_arg_page(kmapped_page);
}
kmapped_page = page;
- kaddr = kmap(kmapped_page);
+ kaddr = kmap_local_page(kmapped_page);
kpos = pos & PAGE_MASK;
flush_arg_page(bprm, kpos, kmapped_page);
}
@@ -601,7 +601,7 @@ static int copy_strings(int argc, struct user_arg_ptr argv,
out:
if (kmapped_page) {
flush_dcache_page(kmapped_page);
- kunmap(kmapped_page);
+ kunmap_local(kaddr);
put_arg_page(kmapped_page);
}
return ret;
@@ -883,11 +883,11 @@ int transfer_args_to_stack(struct linux_binprm *bprm,
for (index = MAX_ARG_PAGES - 1; index >= stop; index--) {
unsigned int offset = index == stop ? bprm->p & ~PAGE_MASK : 0;
- char *src = kmap(bprm->page[index]) + offset;
+ char *src = kmap_local_page(bprm->page[index]) + offset;
sp -= PAGE_SIZE - offset;
if (copy_to_user((void *) sp, src, PAGE_SIZE - offset) != 0)
ret = -EFAULT;
- kunmap(bprm->page[index]);
+ kunmap_local(src);
if (ret)
goto out;
}
@@ -1680,13 +1680,13 @@ int remove_arg_zero(struct linux_binprm *bprm)
ret = -EFAULT;
goto out;
}
- kaddr = kmap_atomic(page);
+ kaddr = kmap_local_page(page);
for (; offset < PAGE_SIZE && kaddr[offset];
offset++, bprm->p++)
;
- kunmap_atomic(kaddr);
+ kunmap_local(kaddr);
put_arg_page(page);
} while (offset == PAGE_SIZE);
--
2.36.1
