kcsan: test: don't put the expect array on the stack

[ 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>

diff --git a/kernel/kcsan/kcsan_test.c b/kernel/kcsan/kcsan_test.c
index dc55fd5..8b176ae 100644 (file)
--- a/kernel/kcsan/kcsan_test.c
+++ b/kernel/kcsan/kcsan_test.c
@@ -151,7 +151,7 @@ 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;
@@ -160,6 +160,10 @@ 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 */
@@ -243,6 +247,7 @@ 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;
 }