tmakin/ack-tegra
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

kunit: split out part of kunit_assert into a static const

Browse Source 
This is per Linus's suggestion in [1].

The issue there is that every KUNIT_EXPECT/KUNIT_ASSERT puts a
kunit_assert object onto the stack. Normally we rely on compilers to
elide this, but when that doesn't work out, this blows up the stack
usage of kunit test functions.

We can move some data off the stack by making it static.
This change introduces a new `struct kunit_loc` to hold the file and
line number and then just passing assert_type (EXPECT or ASSERT) as an
argument.

In [1], it was suggested to also move out the format string as well, but
users could theoretically craft a format string at runtime, so we can't.

This change leaves a copy of `assert_type` in kunit_assert for now
because cleaning up all the macros to not pass it around is a bit more
involved.

Here's an example of the expanded code for KUNIT_FAIL():
if (__builtin_expect(!!(!(false)), 0)) {
  static const struct kunit_loc loc = { .file = ... };
  struct kunit_fail_assert __assertion = { .assert = { .type ...  };
  kunit_do_failed_assertion(test, &loc, KUNIT_EXPECTATION, &__assertion.assert, ...);
};

[1] https://groups.google.com/g/kunit-dev/c/i3fZXgvBrfA/m/VULQg1z6BAAJ

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
This commit is contained in:
Daniel Latypov
2022-01-13 08:59:30 -08:00
committed by Shuah Khan
parent dd640d7087
commit 21957f90b2
4 changed files with 42 additions and 19 deletions
Download Patch File Download Diff File Expand all files Collapse all files
lib/kunit/assert.c
+5 -4
View File
@@ -10,12 +10,13 @@
#include "string-stream.h"
void kunit_base_assert_format(const struct kunit_assert *assert,
void kunit_assert_prologue(const struct kunit_loc *loc,
enum kunit_assert_type type,
struct string_stream *stream)
{
const char *expect_or_assert = NULL;
switch (assert->type) {
switch (type) {
case KUNIT_EXPECTATION:
expect_or_assert = "EXPECTATION";
break;
@@ -25,9 +26,9 @@ void kunit_base_assert_format(const struct kunit_assert *assert,
}
string_stream_add(stream, "%s FAILED at %s:%d\n",
expect_or_assert, assert->file, assert->line);
expect_or_assert, loc->file, loc->line);
}
EXPORT_SYMBOL_GPL(kunit_base_assert_format);
EXPORT_SYMBOL_GPL(kunit_assert_prologue);
void kunit_assert_print_msg(const struct kunit_assert *assert,
struct string_stream *stream)