lkdtm: split remaining logic bug tests to separate file
authorKees Cook <keescook@chromium.org>
Mon, 27 Jun 2016 05:17:25 +0000 (22:17 -0700)
committerKees Cook <keescook@chromium.org>
Thu, 7 Jul 2016 18:09:22 +0000 (11:09 -0700)
This splits all the remaining tests from lkdtm_core.c into the new
lkdtm_bugs.c file to help separate things better for readability.

Signed-off-by: Kees Cook <keescook@chromium.org>
drivers/misc/Makefile
drivers/misc/lkdtm.h
drivers/misc/lkdtm_bugs.c [new file with mode: 0644]
drivers/misc/lkdtm_core.c

index d66f657..4387ccb 100644 (file)
@@ -59,6 +59,7 @@ obj-$(CONFIG_CXL_BASE)                += cxl/
 obj-$(CONFIG_PANEL)             += panel.o
 
 lkdtm-$(CONFIG_LKDTM)          += lkdtm_core.o
+lkdtm-$(CONFIG_LKDTM)          += lkdtm_bugs.o
 lkdtm-$(CONFIG_LKDTM)          += lkdtm_heap.o
 lkdtm-$(CONFIG_LKDTM)          += lkdtm_perms.o
 lkdtm-$(CONFIG_LKDTM)          += lkdtm_rodata_objcopy.o
index 9397360..d70a417 100644 (file)
@@ -1,6 +1,23 @@
 #ifndef __LKDTM_H
 #define __LKDTM_H
 
+/* lkdtm_bugs.c */
+void __init lkdtm_bugs_init(int *recur_param);
+void lkdtm_PANIC(void);
+void lkdtm_BUG(void);
+void lkdtm_WARNING(void);
+void lkdtm_EXCEPTION(void);
+void lkdtm_LOOP(void);
+void lkdtm_OVERFLOW(void);
+void lkdtm_CORRUPT_STACK(void);
+void lkdtm_UNALIGNED_LOAD_STORE_WRITE(void);
+void lkdtm_SOFTLOCKUP(void);
+void lkdtm_HARDLOCKUP(void);
+void lkdtm_SPINLOCKUP(void);
+void lkdtm_HUNG_TASK(void);
+void lkdtm_ATOMIC_UNDERFLOW(void);
+void lkdtm_ATOMIC_OVERFLOW(void);
+
 /* lkdtm_heap.c */
 void lkdtm_OVERWRITE_ALLOCATION(void);
 void lkdtm_WRITE_AFTER_FREE(void);
diff --git a/drivers/misc/lkdtm_bugs.c b/drivers/misc/lkdtm_bugs.c
new file mode 100644 (file)
index 0000000..e87071f
--- /dev/null
@@ -0,0 +1,152 @@
+/*
+ * This is for all the tests related to logic bugs (e.g. bad dereferences,
+ * bad alignment, bad loops, bad locking, bad scheduling, deep stacks, and
+ * lockups) along with other things that don't fit well into existing LKDTM
+ * test source files.
+ */
+#define pr_fmt(fmt) "lkdtm: " fmt
+
+#include <linux/kernel.h>
+#include <linux/sched.h>
+
+#include "lkdtm.h"
+
+/*
+ * Make sure our attempts to over run the kernel stack doesn't trigger
+ * a compiler warning when CONFIG_FRAME_WARN is set. Then make sure we
+ * recurse past the end of THREAD_SIZE by default.
+ */
+#if defined(CONFIG_FRAME_WARN) && (CONFIG_FRAME_WARN > 0)
+#define REC_STACK_SIZE (CONFIG_FRAME_WARN / 2)
+#else
+#define REC_STACK_SIZE (THREAD_SIZE / 8)
+#endif
+#define REC_NUM_DEFAULT ((THREAD_SIZE / REC_STACK_SIZE) * 2)
+
+static int recur_count = REC_NUM_DEFAULT;
+
+static DEFINE_SPINLOCK(lock_me_up);
+
+static int recursive_loop(int remaining)
+{
+       char buf[REC_STACK_SIZE];
+
+       /* Make sure compiler does not optimize this away. */
+       memset(buf, (remaining & 0xff) | 0x1, REC_STACK_SIZE);
+       if (!remaining)
+               return 0;
+       else
+               return recursive_loop(remaining - 1);
+}
+
+/* If the depth is negative, use the default, otherwise keep parameter. */
+void __init lkdtm_bugs_init(int *recur_param)
+{
+       if (*recur_param < 0)
+               *recur_param = recur_count;
+       else
+               recur_count = *recur_param;
+}
+
+void lkdtm_PANIC(void)
+{
+       panic("dumptest");
+}
+
+void lkdtm_BUG(void)
+{
+       BUG();
+}
+
+void lkdtm_WARNING(void)
+{
+       WARN_ON(1);
+}
+
+void lkdtm_EXCEPTION(void)
+{
+       *((int *) 0) = 0;
+}
+
+void lkdtm_LOOP(void)
+{
+       for (;;)
+               ;
+}
+
+void lkdtm_OVERFLOW(void)
+{
+       (void) recursive_loop(recur_count);
+}
+
+noinline void lkdtm_CORRUPT_STACK(void)
+{
+       /* Use default char array length that triggers stack protection. */
+       char data[8];
+
+       memset((void *)data, 0, 64);
+}
+
+void lkdtm_UNALIGNED_LOAD_STORE_WRITE(void)
+{
+       static u8 data[5] __attribute__((aligned(4))) = {1, 2, 3, 4, 5};
+       u32 *p;
+       u32 val = 0x12345678;
+
+       p = (u32 *)(data + 1);
+       if (*p == 0)
+               val = 0x87654321;
+       *p = val;
+}
+
+void lkdtm_SOFTLOCKUP(void)
+{
+       preempt_disable();
+       for (;;)
+               cpu_relax();
+}
+
+void lkdtm_HARDLOCKUP(void)
+{
+       local_irq_disable();
+       for (;;)
+               cpu_relax();
+}
+
+void lkdtm_SPINLOCKUP(void)
+{
+       /* Must be called twice to trigger. */
+       spin_lock(&lock_me_up);
+       /* Let sparse know we intended to exit holding the lock. */
+       __release(&lock_me_up);
+}
+
+void lkdtm_HUNG_TASK(void)
+{
+       set_current_state(TASK_UNINTERRUPTIBLE);
+       schedule();
+}
+
+void lkdtm_ATOMIC_UNDERFLOW(void)
+{
+       atomic_t under = ATOMIC_INIT(INT_MIN);
+
+       pr_info("attempting good atomic increment\n");
+       atomic_inc(&under);
+       atomic_dec(&under);
+
+       pr_info("attempting bad atomic underflow\n");
+       atomic_dec(&under);
+}
+
+void lkdtm_ATOMIC_OVERFLOW(void)
+{
+       atomic_t over = ATOMIC_INIT(INT_MAX);
+
+       pr_info("attempting good atomic decrement\n");
+       atomic_dec(&over);
+       atomic_inc(&over);
+
+       pr_info("attempting bad atomic overflow\n");
+       atomic_inc(&over);
+}
index 1c5056c..e0f1013 100644 (file)
 
 #include "lkdtm.h"
 
-/*
- * Make sure our attempts to over run the kernel stack doesn't trigger
- * a compiler warning when CONFIG_FRAME_WARN is set. Then make sure we
- * recurse past the end of THREAD_SIZE by default.
- */
-#if defined(CONFIG_FRAME_WARN) && (CONFIG_FRAME_WARN > 0)
-#define REC_STACK_SIZE (CONFIG_FRAME_WARN / 2)
-#else
-#define REC_STACK_SIZE (THREAD_SIZE / 8)
-#endif
-#define REC_NUM_DEFAULT ((THREAD_SIZE / REC_STACK_SIZE) * 2)
-
 #define DEFAULT_COUNT 10
 
+static int count = DEFAULT_COUNT;
+static DEFINE_SPINLOCK(count_lock);
+
 enum cname {
        CN_INVALID,
        CN_INT_HARDWARE_ENTRY,
@@ -179,13 +170,10 @@ static void lkdtm_handler(void);
 static char* cpoint_name;
 static char* cpoint_type;
 static int cpoint_count = DEFAULT_COUNT;
-static int recur_count = REC_NUM_DEFAULT;
+static int recur_count = -1;
 
 static enum cname cpoint = CN_INVALID;
 static enum ctype cptype = CT_NONE;
-static int count = DEFAULT_COUNT;
-static DEFINE_SPINLOCK(count_lock);
-static DEFINE_SPINLOCK(lock_me_up);
 
 module_param(recur_count, int, 0644);
 MODULE_PARM_DESC(recur_count, " Recursion level for the stack overflow test");
@@ -327,63 +315,33 @@ static int lkdtm_parse_commandline(void)
        return -EINVAL;
 }
 
-static int recursive_loop(int remaining)
-{
-       char buf[REC_STACK_SIZE];
-
-       /* Make sure compiler does not optimize this away. */
-       memset(buf, (remaining & 0xff) | 0x1, REC_STACK_SIZE);
-       if (!remaining)
-               return 0;
-       else
-               return recursive_loop(remaining - 1);
-}
-
-static noinline void corrupt_stack(void)
-{
-       /* Use default char array length that triggers stack protection. */
-       char data[8];
-
-       memset((void *)data, 0, 64);
-}
-
 static void lkdtm_do_action(enum ctype which)
 {
        switch (which) {
        case CT_PANIC:
-               panic("dumptest");
+               lkdtm_PANIC();
                break;
        case CT_BUG:
-               BUG();
+               lkdtm_BUG();
                break;
        case CT_WARNING:
-               WARN_ON(1);
+               lkdtm_WARNING();
                break;
        case CT_EXCEPTION:
-               *((int *) 0) = 0;
+               lkdtm_EXCEPTION();
                break;
        case CT_LOOP:
-               for (;;)
-                       ;
+               lkdtm_LOOP();
                break;
        case CT_OVERFLOW:
-               (void) recursive_loop(recur_count);
+               lkdtm_OVERFLOW();
                break;
        case CT_CORRUPT_STACK:
-               corrupt_stack();
-               break;
-       case CT_UNALIGNED_LOAD_STORE_WRITE: {
-               static u8 data[5] __attribute__((aligned(4))) = {1, 2,
-                               3, 4, 5};
-               u32 *p;
-               u32 val = 0x12345678;
-
-               p = (u32 *)(data + 1);
-               if (*p == 0)
-                       val = 0x87654321;
-               *p = val;
-                break;
-       }
+               lkdtm_CORRUPT_STACK();
+               break;
+       case CT_UNALIGNED_LOAD_STORE_WRITE:
+               lkdtm_UNALIGNED_LOAD_STORE_WRITE();
+               break;
        case CT_OVERWRITE_ALLOCATION:
                lkdtm_OVERWRITE_ALLOCATION();
                break;
@@ -400,24 +358,16 @@ static void lkdtm_do_action(enum ctype which)
                lkdtm_READ_BUDDY_AFTER_FREE();
                break;
        case CT_SOFTLOCKUP:
-               preempt_disable();
-               for (;;)
-                       cpu_relax();
+               lkdtm_SOFTLOCKUP();
                break;
        case CT_HARDLOCKUP:
-               local_irq_disable();
-               for (;;)
-                       cpu_relax();
+               lkdtm_HARDLOCKUP();
                break;
        case CT_SPINLOCKUP:
-               /* Must be called twice to trigger. */
-               spin_lock(&lock_me_up);
-               /* Let sparse know we intended to exit holding the lock. */
-               __release(&lock_me_up);
+               lkdtm_SPINLOCKUP();
                break;
        case CT_HUNG_TASK:
-               set_current_state(TASK_UNINTERRUPTIBLE);
-               schedule();
+               lkdtm_HUNG_TASK();
                break;
        case CT_EXEC_DATA:
                lkdtm_EXEC_DATA();
@@ -449,29 +399,12 @@ static void lkdtm_do_action(enum ctype which)
        case CT_WRITE_KERN:
                lkdtm_WRITE_KERN();
                break;
-       case CT_ATOMIC_UNDERFLOW: {
-               atomic_t under = ATOMIC_INIT(INT_MIN);
-
-               pr_info("attempting good atomic increment\n");
-               atomic_inc(&under);
-               atomic_dec(&under);
-
-               pr_info("attempting bad atomic underflow\n");
-               atomic_dec(&under);
+       case CT_ATOMIC_UNDERFLOW:
+               lkdtm_ATOMIC_UNDERFLOW();
+               break;
+       case CT_ATOMIC_OVERFLOW:
+               lkdtm_ATOMIC_OVERFLOW();
                break;
-       }
-       case CT_ATOMIC_OVERFLOW: {
-               atomic_t over = ATOMIC_INIT(INT_MAX);
-
-               pr_info("attempting good atomic decrement\n");
-               atomic_dec(&over);
-               atomic_inc(&over);
-
-               pr_info("attempting bad atomic overflow\n");
-               atomic_inc(&over);
-
-               return;
-       }
        case CT_USERCOPY_HEAP_SIZE_TO:
                lkdtm_USERCOPY_HEAP_SIZE_TO();
                break;
@@ -786,6 +719,7 @@ static int __init lkdtm_module_init(void)
        int i;
 
        /* Handle test-specific initialization. */
+       lkdtm_bugs_init(&recur_count);
        lkdtm_perms_init();
        lkdtm_usercopy_init();