[PATCH AUTOSEL 6.3 3/7] lkdtm/stackleak: Fix noinstr violation

Sasha Levin
2023-05-09T03:55:13Z

From: Josh Poimboeuf <jpoimboe@kernel.org>

[ Upstream commit f571da059f86fd9d432aea32c9c7e5aaa53245d8 ]

Fixes the following warning:

vmlinux.o: warning: objtool: check_stackleak_irqoff+0x2b6: call to _printk() leaves .noinstr.text section

Signed-off-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/ee5209f53aa0a62aea58be18f2b78b17606779a6.1681320026.git.jpoimboe@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/misc/lkdtm/stackleak.c | 6 ++++++
1 file changed, 6 insertions(+)

diff --git a/drivers/misc/lkdtm/stackleak.c b/drivers/misc/lkdtm/stackleak.c
index 025b133297a6b..f1d0221609138 100644
--- a/drivers/misc/lkdtm/stackleak.c
+++ b/drivers/misc/lkdtm/stackleak.c
@@ -43,12 +43,14 @@ static void noinstr check_stackleak_irqoff(void)
* 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;
@@ -86,11 +88,14 @@ static void noinstr check_stackleak_irqoff(void)
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"
@@ -113,6 +118,7 @@ static void noinstr check_stackleak_irqoff(void)
} else {
pr_info("OK: the rest of the thread stack is properly erased\n");
}
+ instrumentation_end();
}

static void lkdtm_STACKLEAK_ERASING(void)
--
2.39.2