misc/lkdtm/stackleak.c

3  * This code tests that the current task stack is properly erased (filled
16  * Check that stackleak tracks the lowest stack pointer and erases the stack
19  * To prevent the lowest stack pointer changing during the test, IRQs are
21  * compiler will create a fixed-size stack frame for this function.
23  * Any non-inlined function may make further use of the stack, altering the
24  * lowest stack pointer and/or clobbering poison values. To avoid spurious
40 	 * Check that the current and lowest recorded stack pointer values fall  in check_stackleak_irqoff()
41 	 * within the expected task stack boundaries. These tests should never  in check_stackleak_irqoff()
47 		pr_err("FAIL: current_stack_pointer (0x%lx) outside of task stack bounds [0x%lx..0x%lx]\n",  in check_stackleak_irqoff()
54 		pr_err("FAIL: current->lowest_stack (0x%lx) outside of task stack bounds [0x%lx..0x%lx]\n",  in check_stackleak_irqoff()
62 	 * stack pointer could be above or below the current stack pointer.  in check_stackleak_irqoff()
66 	 * stack pointer might not be sufficiently aligned, we must align  in check_stackleak_irqoff()
67 	 * downwards to find the lowest known stack pointer value. This is the  in check_stackleak_irqoff()
68 	 * high boundary for a portion of the stack which may have been used  in check_stackleak_irqoff()
80 	 * Check whether the poisoned portion of the stack (if any) consists  in check_stackleak_irqoff()
99 	pr_info("stackleak stack usage:\n"  in check_stackleak_irqoff()
117 		pr_err("FAIL: the thread stack is NOT properly erased!\n");  in check_stackleak_irqoff()
119 		pr_info("OK: the rest of the thread stack is properly erased\n");  in check_stackleak_irqoff()