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 alocating the 'expect' array.
Signed-off-by: Max Filippov <[email protected]>
---
Changes v1->v2:
- add WARN_ON in case of kmalloc failure
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 dcec1b743c69..a60c561724be 100644
--- a/kernel/kcsan/kcsan_test.c
+++ b/kernel/kcsan/kcsan_test.c
@@ -159,7 +159,7 @@ 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;
@@ -168,6 +168,10 @@ 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 */
@@ -253,6 +257,7 @@ 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;
}
--
2.30.2
On Sat, 31 Dec 2022 at 01:45, Max Filippov <[email protected]> wrote:
>
> 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 alocating the 'expect' array.
>
> Signed-off-by: Max Filippov <[email protected]>
Reviewed-by: Marco Elver <[email protected]>
Tested-by: Marco Elver <[email protected]>
Can you take this through the xtensa tree?
> ---
> Changes v1->v2:
> - add WARN_ON in case of kmalloc failure
>
> 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 dcec1b743c69..a60c561724be 100644
> --- a/kernel/kcsan/kcsan_test.c
> +++ b/kernel/kcsan/kcsan_test.c
> @@ -159,7 +159,7 @@ 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;
> @@ -168,6 +168,10 @@ 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 */
> @@ -253,6 +257,7 @@ 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;
> }
>
> --
> 2.30.2
>
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On Sun, Jan 1, 2023 at 11:00 PM Marco Elver <[email protected]> wrote:
>
> On Sat, 31 Dec 2022 at 01:45, Max Filippov <[email protected]> wrote:
> >
> > 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 alocating the 'expect' array.
> >
> > Signed-off-by: Max Filippov <[email protected]>
>
> Reviewed-by: Marco Elver <[email protected]>
> Tested-by: Marco Elver <[email protected]>
>
> Can you take this through the xtensa tree?
Sure. Thanks for your review and testing.
-- Max