1 files changed, 0 insertions, 150 deletions
diff --git a/drivers/misc/lkdtm/stackleak.c b/drivers/misc/lkdtm/stackleak.c
deleted file mode 100644
index f1d022160913..000000000000
--- a/drivers/misc/lkdtm/stackleak.c
+++ /dev/null
@@ -1,150 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * This code tests that the current task stack is properly erased (filled
- * with STACKLEAK_POISON).
- *
- * Authors:
- *   Alexander Popov <alex.popov@linux.com>
- *   Tycho Andersen <tycho@tycho.ws>
- */
-
-#include "lkdtm.h"
-#include <linux/stackleak.h>
-
-#if defined(CONFIG_GCC_PLUGIN_STACKLEAK)
-/*
- * Check that stackleak tracks the lowest stack pointer and erases the stack
- * below this as expected.
- *
- * To prevent the lowest stack pointer changing during the test, IRQs are
- * masked and instrumentation of this function is disabled. We assume that the
- * compiler will create a fixed-size stack frame for this function.
- *
- * Any non-inlined function may make further use of the stack, altering the
- * lowest stack pointer and/or clobbering poison values. To avoid spurious
- * failures we must avoid printing until the end of the test or have already
- * encountered a failure condition.
- */
-static void noinstr check_stackleak_irqoff(void)
-{
-	const unsigned long task_stack_base = (unsigned long)task_stack_page(current);
-	const unsigned long task_stack_low = stackleak_task_low_bound(current);
-	const unsigned long task_stack_high = stackleak_task_high_bound(current);
-	const unsigned long current_sp = current_stack_pointer;
-	const unsigned long lowest_sp = current->lowest_stack;
-	unsigned long untracked_high;
-	unsigned long poison_high, poison_low;
-	bool test_failed = false;
-
-	/*
-	 * Check that the current and lowest recorded stack pointer values fall
-	 * within the expected task stack boundaries. These tests should never
-	 * fail unless the boundaries are incorrect or we're clobbering the
-	 * STACK_END_MAGIC, and in either casee something is seriously wrong.
-	 */
-	if (current_sp < task_stack_low || current_sp >= task_stack_high) {
-		instrumentation_begin();
-		pr_err("FAIL: current_stack_pointer (0x%lx) outside of task stack bounds [0x%lx..0x%lx]\n",
-		       current_sp, task_stack_low, task_stack_high - 1);
-		test_failed = true;
-		goto out;
-	}
-	if (lowest_sp < task_stack_low || lowest_sp >= task_stack_high) {
-		instrumentation_begin();
-		pr_err("FAIL: current->lowest_stack (0x%lx) outside of task stack bounds [0x%lx..0x%lx]\n",
-		       lowest_sp, task_stack_low, task_stack_high - 1);
-		test_failed = true;
-		goto out;
-	}
-
-	/*
-	 * Depending on what has run prior to this test, the lowest recorded
-	 * stack pointer could be above or below the current stack pointer.
-	 * Start from the lowest of the two.
-	 *
-	 * Poison values are naturally-aligned unsigned longs. As the current
-	 * stack pointer might not be sufficiently aligned, we must align
-	 * downwards to find the lowest known stack pointer value. This is the
-	 * high boundary for a portion of the stack which may have been used
-	 * without being tracked, and has to be scanned for poison.
-	 */
-	untracked_high = min(current_sp, lowest_sp);
-	untracked_high = ALIGN_DOWN(untracked_high, sizeof(unsigned long));
-
-	/*
-	 * Find the top of the poison in the same way as the erasing code.
-	 */
-	poison_high = stackleak_find_top_of_poison(task_stack_low, untracked_high);
-
-	/*
-	 * Check whether the poisoned portion of the stack (if any) consists
-	 * entirely of poison. This verifies the entries that
-	 * stackleak_find_top_of_poison() should have checked.
-	 */
-	poison_low = poison_high;
-	while (poison_low > task_stack_low) {
-		poison_low -= sizeof(unsigned long);
-
-		if (*(unsigned long *)poison_low == STACKLEAK_POISON)
-			continue;
-
-		instrumentation_begin();
-		pr_err("FAIL: non-poison value %lu bytes below poison boundary: 0x%lx\n",
-		       poison_high - poison_low, *(unsigned long *)poison_low);
-		test_failed = true;
-		goto out;
-	}
-
-	instrumentation_begin();
-	pr_info("stackleak stack usage:\n"
-		"  high offset: %lu bytes\n"
-		"  current:     %lu bytes\n"
-		"  lowest:      %lu bytes\n"
-		"  tracked:     %lu bytes\n"
-		"  untracked:   %lu bytes\n"
-		"  poisoned:    %lu bytes\n"
-		"  low offset:  %lu bytes\n",
-		task_stack_base + THREAD_SIZE - task_stack_high,
-		task_stack_high - current_sp,
-		task_stack_high - lowest_sp,
-		task_stack_high - untracked_high,
-		untracked_high - poison_high,
-		poison_high - task_stack_low,
-		task_stack_low - task_stack_base);
-
-out:
-	if (test_failed) {
-		pr_err("FAIL: the thread stack is NOT properly erased!\n");
-	} else {
-		pr_info("OK: the rest of the thread stack is properly erased\n");
-	}
-	instrumentation_end();
-}
-
-static void lkdtm_STACKLEAK_ERASING(void)
-{
-	unsigned long flags;
-
-	local_irq_save(flags);
-	check_stackleak_irqoff();
-	local_irq_restore(flags);
-}
-#else /* defined(CONFIG_GCC_PLUGIN_STACKLEAK) */
-static void lkdtm_STACKLEAK_ERASING(void)
-{
-	if (IS_ENABLED(CONFIG_HAVE_ARCH_STACKLEAK)) {
-		pr_err("XFAIL: stackleak is not enabled (CONFIG_GCC_PLUGIN_STACKLEAK=n)\n");
-	} else {
-		pr_err("XFAIL: stackleak is not supported on this arch (HAVE_ARCH_STACKLEAK=n)\n");
-	}
-}
-#endif /* defined(CONFIG_GCC_PLUGIN_STACKLEAK) */
-
-static struct crashtype crashtypes[] = {
-	CRASHTYPE(STACKLEAK_ERASING),
-};
-
-struct crashtype_category stackleak_crashtypes = {
-	.crashtypes = crashtypes,
-	.len	    = ARRAY_SIZE(crashtypes),
-};