diff mbox series

[v13,18/20] tee/optee, arm64: untag user pointers in check_mem_type

Message ID 665632a911273ab537ded9acb78f4bafd91cbc19.1553093421.git.andreyknvl@google.com (mailing list archive)
State New, archived
Headers show
Series arm64: untag user pointers passed to the kernel | expand

Commit Message

Andrey Konovalov March 20, 2019, 2:51 p.m. UTC 
This patch is a part of a series that extends arm64 kernel ABI to allow to
pass tagged user pointers (with the top byte set to something else other
than 0x00) as syscall arguments.

check_mem_type() uses provided user pointers for vma lookups (via
__check_mem_type()), which can only by done with untagged pointers.

Untag user pointers in this function.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
---
 drivers/tee/optee/call.c | 1 +
 1 file changed, 1 insertion(+)
diff mbox series

Patch

diff --git a/drivers/tee/optee/call.c b/drivers/tee/optee/call.c
index a5afbe6dee68..e3be20264092 100644
--- a/drivers/tee/optee/call.c
+++ b/drivers/tee/optee/call.c
@@ -563,6 +563,7 @@  static int check_mem_type(unsigned long start, size_t num_pages)
 	int rc;
 
 	down_read(&mm->mmap_sem);
+	start = untagged_addr(start);
 	rc = __check_mem_type(find_vma(mm, start),
 			      start + num_pages * PAGE_SIZE);
 	up_read(&mm->mmap_sem);