[PATCH 9/9] vdso: Modify getrandom to include the correct namespace

Vincenzo Frascino
2024-09-03T15:15:23Z

The VDSO implementation includes headers from outside of the
vdso/ namespace.

Modify getrandom to take advantage of the refactoring done in the
previous patches and to include only the vdso/ namespace.

Cc: Andy Lutomirski <luto@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
lib/vdso/getrandom.c | 22 ++++++++--------------
1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/lib/vdso/getrandom.c b/lib/vdso/getrandom.c
index 938ca539aaa6..9c26b738e4a1 100644
--- a/lib/vdso/getrandom.c
+++ b/lib/vdso/getrandom.c
@@ -3,19 +3,13 @@
* Copyright (C) 2022-2024 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*/

-#include <linux/array_size.h>
-#include <linux/minmax.h>
#include <vdso/datapage.h>
#include <vdso/getrandom.h>
#include <vdso/unaligned.h>
-#include <asm/vdso/getrandom.h>
-#include <uapi/linux/mman.h>
-#include <uapi/linux/random.h>
-
-#undef PAGE_SIZE
-#undef PAGE_MASK
-#define PAGE_SIZE (1UL << CONFIG_PAGE_SHIFT)
-#define PAGE_MASK (~(PAGE_SIZE - 1))
+#include <vdso/mman.h>
+#include <vdso/page.h>
+#include <vdso/array_size.h>
+#include <vdso/minmax.h>

#define MEMCPY_AND_ZERO_SRC(type, dst, src, len) do { \
while (len >= sizeof(type)) { \
@@ -68,7 +62,7 @@ static __always_inline ssize_t
__cvdso_getrandom_data(const struct vdso_rng_data *rng_info, void *buffer, size_t len,
unsigned int flags, void *opaque_state, size_t opaque_len)
{
- ssize_t ret = min_t(size_t, INT_MAX & PAGE_MASK /* = MAX_RW_COUNT */, len);
+ ssize_t ret = min_t(size_t, INT_MAX & VDSO_PAGE_MASK /* = MAX_RW_COUNT */, len);
struct vgetrandom_state *state = opaque_state;
size_t batch_len, nblocks, orig_len = len;
bool in_use, have_retried = false;
@@ -79,15 +73,15 @@ __cvdso_getrandom_data(const struct vdso_rng_data *rng_info, void *buffer, size_
if (unlikely(opaque_len == ~0UL && !buffer && !len && !flags)) {
struct vgetrandom_opaque_params *params = opaque_state;
params->size_of_opaque_state = sizeof(*state);
- params->mmap_prot = PROT_READ | PROT_WRITE;
- params->mmap_flags = MAP_DROPPABLE | MAP_ANONYMOUS;
+ params->mmap_prot = VDSO_MMAP_PROT;
+ params->mmap_flags = VDSO_MMAP_FLAGS;
for (size_t i = 0; i < ARRAY_SIZE(params->reserved); ++i)
params->reserved[i] = 0;
return 0;
}

/* The state must not straddle a page, since pages can be zeroed at any time. */
- if (unlikely(((unsigned long)opaque_state & ~PAGE_MASK) + sizeof(*state) > PAGE_SIZE))
+ if (unlikely(((unsigned long)opaque_state & ~VDSO_PAGE_MASK) + sizeof(*state) > VDSO_PAGE_SIZE))
return -EFAULT;

/* Handle unexpected flags by falling back to the kernel. */
--
2.34.1