@@ -17,6 +17,7 @@
struct page;
struct kmem_cache;
+struct task_struct;
#ifdef CONFIG_KMSAN
@@ -43,6 +44,14 @@ struct kmsan_ctx {
bool allow_reporting;
};
+void kmsan_task_create(struct task_struct *task);
+
+/**
+ * kmsan_task_exit() - Notify KMSAN that a task has exited.
+ * @task: task about to finish.
+ */
+void kmsan_task_exit(struct task_struct *task);
+
/**
* kmsan_alloc_page() - Notify KMSAN about an alloc_pages() call.
* @page: struct page pointer returned by alloc_pages().
@@ -164,6 +173,14 @@ void kmsan_iounmap_page_range(unsigned long start, unsigned long end);
#else
+static inline void kmsan_task_create(struct task_struct *task)
+{
+}
+
+static inline void kmsan_task_exit(struct task_struct *task)
+{
+}
+
static inline int kmsan_alloc_page(struct page *page, unsigned int order,
gfp_t flags)
{
@@ -59,6 +59,7 @@
#include <linux/writeback.h>
#include <linux/shm.h>
#include <linux/kcov.h>
+#include <linux/kmsan.h>
#include <linux/random.h>
#include <linux/rcuwait.h>
#include <linux/compat.h>
@@ -752,6 +753,7 @@ void __noreturn do_exit(long code)
force_uaccess_begin();
kcov_task_exit(tsk);
+ kmsan_task_exit(tsk);
coredump_task_exit(tsk);
ptrace_event(PTRACE_EVENT_EXIT, code);
@@ -37,6 +37,7 @@
#include <linux/fdtable.h>
#include <linux/iocontext.h>
#include <linux/key.h>
+#include <linux/kmsan.h>
#include <linux/binfmts.h>
#include <linux/mman.h>
#include <linux/mmu_notifier.h>
@@ -956,6 +957,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig, int node)
account_kernel_stack(tsk, 1);
kcov_task_init(tsk);
+ kmsan_task_create(tsk);
kmap_local_fork(tsk);
#ifdef CONFIG_FAULT_INJECTION
@@ -44,6 +44,16 @@ bool kmsan_enabled __read_mostly;
*/
DEFINE_PER_CPU(struct kmsan_ctx, kmsan_percpu_ctx);
+void kmsan_internal_task_create(struct task_struct *task)
+{
+ struct kmsan_ctx *ctx = &task->kmsan_ctx;
+
+ __memset(ctx, 0, sizeof(struct kmsan_ctx));
+ ctx->allow_reporting = true;
+ kmsan_internal_unpoison_memory(current_thread_info(),
+ sizeof(struct thread_info), false);
+}
+
void kmsan_internal_poison_memory(void *address, size_t size, gfp_t flags,
unsigned int poison_flags)
{
@@ -26,6 +26,25 @@
* skipping effects of functions like memset() inside instrumented code.
*/
+void kmsan_task_create(struct task_struct *task)
+{
+ kmsan_enter_runtime();
+ kmsan_internal_task_create(task);
+ kmsan_leave_runtime();
+}
+EXPORT_SYMBOL(kmsan_task_create);
+
+void kmsan_task_exit(struct task_struct *task)
+{
+ struct kmsan_ctx *ctx = &task->kmsan_ctx;
+
+ if (!kmsan_enabled || kmsan_in_runtime())
+ return;
+
+ ctx->allow_reporting = false;
+}
+EXPORT_SYMBOL(kmsan_task_exit);
+
void kmsan_slab_alloc(struct kmem_cache *s, void *object, gfp_t flags)
{
if (unlikely(object == NULL))
@@ -172,6 +172,8 @@ void kmsan_internal_set_shadow_origin(void *address, size_t size, int b,
u32 origin, bool checked);
depot_stack_handle_t kmsan_internal_chain_origin(depot_stack_handle_t id);
+void kmsan_internal_task_create(struct task_struct *task);
+
bool kmsan_metadata_is_contiguous(void *addr, size_t size);
void kmsan_internal_check_memory(void *addr, size_t size, const void *user_addr,
int reason);
Tell KMSAN that a new task is created, so the tool creates a backing metadata structure for that task. Signed-off-by: Alexander Potapenko <glider@google.com> --- v2: -- move implementation of kmsan_task_create() and kmsan_task_exit() here Link: https://linux-review.googlesource.com/id/I0f41c3a1c7d66f7e14aabcfdfc7c69addb945805 --- include/linux/kmsan.h | 17 +++++++++++++++++ kernel/exit.c | 2 ++ kernel/fork.c | 2 ++ mm/kmsan/core.c | 10 ++++++++++ mm/kmsan/hooks.c | 19 +++++++++++++++++++ mm/kmsan/kmsan.h | 2 ++ 6 files changed, 52 insertions(+)