| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| 247 | 59.38% | 4 | 30.77% | |
| 108 | 25.96% | 2 | 15.38% | |
| 37 | 8.89% | 3 | 23.08% | |
| 18 | 4.33% | 1 | 7.69% | |
| 2 | 0.48% | 1 | 7.69% | |
| 2 | 0.48% | 1 | 7.69% | |
| 2 | 0.48% | 1 | 7.69% | |
| Total | 416 | 13 |
| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Mark Rutland | 247 | 59.38% | 4 | 30.77% |
| Alexander Popov | 108 | 25.96% | 2 | 15.38% |
| Kees Cook | 37 | 8.89% | 3 | 23.08% |
| Josh Poimboeuf | 18 | 4.33% | 1 | 7.69% |
| Ankita Garg | 2 | 0.48% | 1 | 7.69% |
| Randy Dunlap | 2 | 0.48% | 1 | 7.69% |
| Linus Torvalds | 2 | 0.48% | 1 | 7.69% |
| Total | 416 | 13 |
// 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), };