[PATCH AUTOSEL 5.10 03/17] kcsan: test: don't put the expect array on the stack

Sasha Levin
2023-01-16T14:15:16Z

From: Max Filippov <jcmvbkbc@gmail.com>

[ Upstream commit 5b24ac2dfd3eb3e36f794af3aa7f2828b19035bd ]

Size of the 'expect' array in the __report_matches is 1536 bytes, which
is exactly the default frame size warning limit of the xtensa
architecture.
As a result allmodconfig xtensa kernel builds with the gcc that does not
support the compiler plugins (which otherwise would push the said
warning limit to 2K) fail with the following message:

kernel/kcsan/kcsan_test.c:257:1: error: the frame size of 1680 bytes
is larger than 1536 bytes

Fix it by dynamically allocating the 'expect' array.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Marco Elver <elver@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
kernel/kcsan/kcsan-test.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/kernel/kcsan/kcsan-test.c b/kernel/kcsan/kcsan-test.c
index ebe7fd245104..8a8ccaf4f38f 100644
--- a/kernel/kcsan/kcsan-test.c
+++ b/kernel/kcsan/kcsan-test.c
@@ -149,7 +149,7 @@ static bool report_matches(const struct expect_report *r)
const bool is_assert = (r->access[0].type | r->access[1].type) & KCSAN_ACCESS_ASSERT;
bool ret = false;
unsigned long flags;
- typeof(observed.lines) expect;
+ typeof(*observed.lines) *expect;
const char *end;
char *cur;
int i;
@@ -158,6 +158,10 @@ static bool report_matches(const struct expect_report *r)
if (!report_available())
return false;

+ expect = kmalloc(sizeof(observed.lines), GFP_KERNEL);
+ if (WARN_ON(!expect))
+ return false;
+
/* Generate expected report contents. */

/* Title */
@@ -241,6 +245,7 @@ static bool report_matches(const struct expect_report *r)
strstr(observed.lines[2], expect[1])));
out:
spin_unlock_irqrestore(&observed.lock, flags);
+ kfree(expect);
return ret;
}

--
2.35.1