On Tue, 11 Jun 2024 at 05:33, Kees Cook kees@kernel.org wrote:
For tests that need to allocate using vm_mmap() (e.g. usercopy and execve), provide the interface to have the allocation tracked by KUnit itself. This requires bringing up a placeholder userspace mm.
This combines my earlier attempt at this with Mark Rutland's version[1].
Link: https://lore.kernel.org/lkml/20230321122514.1743889-2-mark.rutland@arm.com/ [1] Co-developed-by: Mark Rutland mark.rutland@arm.com Signed-off-by: Mark Rutland mark.rutland@arm.com Signed-off-by: Kees Cook kees@kernel.org
Thanks: this looks good to me, at least on the KUnit side of things.
Reviewed-by: David Gow davidgow@google.com
Cheers, -- David
include/kunit/test.h | 17 +++++++ lib/kunit/Makefile | 1 + lib/kunit/user_alloc.c | 111 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 129 insertions(+) create mode 100644 lib/kunit/user_alloc.c
diff --git a/include/kunit/test.h b/include/kunit/test.h index e32b4cb7afa2..ec61cad6b71d 100644 --- a/include/kunit/test.h +++ b/include/kunit/test.h @@ -480,6 +480,23 @@ static inline void *kunit_kcalloc(struct kunit *test, size_t n, size_t size, gfp return kunit_kmalloc_array(test, n, size, gfp | __GFP_ZERO); }
+/**
- kunit_vm_mmap() - Allocate KUnit-tracked vm_mmap() area
- @test: The test context object.
- @file: struct file pointer to map from, if any
- @addr: desired address, if any
- @len: how many bytes to allocate
- @prot: mmap PROT_* bits
- @flag: mmap flags
- @offset: offset into @file to start mapping from.
- See vm_mmap() for more information.
- */
+unsigned long kunit_vm_mmap(struct kunit *test, struct file *file,
unsigned long addr, unsigned long len,unsigned long prot, unsigned long flag,unsigned long offset);void kunit_cleanup(struct kunit *test);
void __printf(2, 3) kunit_log_append(struct string_stream *log, const char *fmt, ...); diff --git a/lib/kunit/Makefile b/lib/kunit/Makefile index 309659a32a78..56dd67dc6e57 100644 --- a/lib/kunit/Makefile +++ b/lib/kunit/Makefile @@ -2,6 +2,7 @@ obj-$(CONFIG_KUNIT) += kunit.o
kunit-objs += test.o \ resource.o \
user_alloc.o \ static_stub.o \ string-stream.o \ assert.o \diff --git a/lib/kunit/user_alloc.c b/lib/kunit/user_alloc.c new file mode 100644 index 000000000000..d66f42282f43 --- /dev/null +++ b/lib/kunit/user_alloc.c @@ -0,0 +1,111 @@ +// SPDX-License-Identifier: GPL-2.0 +/*
- KUnit userspace memory allocation resource management.
- */
+#include <kunit/resource.h> +#include <kunit/test.h> +#include <linux/kthread.h> +#include <linux/mm.h>
+struct kunit_vm_mmap_resource {
unsigned long addr;size_t size;+};
+/* vm_mmap() arguments */ +struct kunit_vm_mmap_params {
struct file *file;unsigned long addr;unsigned long len;unsigned long prot;unsigned long flag;unsigned long offset;+};
+/* Create and attach a new mm if it doesn't already exist. */ +static int kunit_attach_mm(void) +{
struct mm_struct *mm;if (current->mm)return 0;mm = mm_alloc();if (!mm)return -ENOMEM;/* Define the task size. */mm->task_size = TASK_SIZE;/* Make sure we can allocate new VMAs. */arch_pick_mmap_layout(mm, ¤t->signal->rlim[RLIMIT_STACK]);/* Attach the mm. It will be cleaned up when the process dies. */kthread_use_mm(mm);return 0;+}
+static int kunit_vm_mmap_init(struct kunit_resource *res, void *context) +{
struct kunit_vm_mmap_params *p = context;struct kunit_vm_mmap_resource vres;int ret;ret = kunit_attach_mm();if (ret)return ret;vres.size = p->len;vres.addr = vm_mmap(p->file, p->addr, p->len, p->prot, p->flag, p->offset);if (!vres.addr)return -ENOMEM;res->data = kmemdup(&vres, sizeof(vres), GFP_KERNEL);if (!res->data) {vm_munmap(vres.addr, vres.size);return -ENOMEM;}return 0;+}
+static void kunit_vm_mmap_free(struct kunit_resource *res) +{
struct kunit_vm_mmap_resource *vres = res->data;/** Since this is executed from the test monitoring process,* the test's mm has already been torn down. We don't need* to run vm_munmap(vres->addr, vres->size), only clean up* the vres.*/kfree(vres);res->data = NULL;+}
+unsigned long kunit_vm_mmap(struct kunit *test, struct file *file,
unsigned long addr, unsigned long len,unsigned long prot, unsigned long flag,unsigned long offset)+{
struct kunit_vm_mmap_params params = {.file = file,.addr = addr,.len = len,.prot = prot,.flag = flag,.offset = offset,};struct kunit_vm_mmap_resource *vres;vres = kunit_alloc_resource(test,kunit_vm_mmap_init,kunit_vm_mmap_free,GFP_KERNEL,¶ms);if (vres)return vres->addr;return 0;+}
+EXPORT_SYMBOL_GPL(kunit_vm_mmap);
2.34.1