maccess: unify the probe kernel arch hooks

Currently architectures have to override every routine that probes
kernel memory, which includes a pure read and strcpy, both in strict
and not strict variants.  Just provide a single arch hooks instead to
make sure all architectures cover all the cases.

[[email protected]: fix !CONFIG_X86_64 build]

Signed-off-by: Christoph Hellwig <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Linus Torvalds <[email protected]>

1 files changed, 4 insertions, 6 deletions

diff --git a/arch/um/kernel/maccess.c b/arch/um/kernel/maccess.c
index 67b2e0fa92bb..ad2c538ce497 100644
--- a/arch/um/kernel/maccess.c
+++ b/arch/um/kernel/maccess.c
@@ -7,15 +7,13 @@
 #include <linux/kernel.h>
 #include <os.h>
 
-long probe_kernel_read(void *dst, const void *src, size_t size)
+bool probe_kernel_read_allowed(const void *src, size_t size, bool strict)
 {
 	void *psrc = (void *)rounddown((unsigned long)src, PAGE_SIZE);
 
 	if ((unsigned long)src < PAGE_SIZE || size <= 0)
-		return -EFAULT;
-
+		return false;
 	if (os_mincore(psrc, size + src - psrc) <= 0)
-		return -EFAULT;
-
-	return __probe_kernel_read(dst, src, size);
+		return false;
+	return true;
 }