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drm/xe/rtp: Don't short-circuit to false in or-yes case

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While RTP processing evaluates true on the "yes-or" case (i.e. a
conjunction of rules that evaluate to true followed by an "OR" without
the right hand operand), it does not on the "or-yes" one.

Both cases are considered malformed and could be a result of someone
dropping checks deemed not necessary anymore and forgetting to drop the
superfluous "OR".  Nevertheless, we should aim for consistency, and
having the "or-yes" case also evaluating to true while also causing a
warning seems reasonable.  So let's do that.

The "or-yes" pattern being evaluated to false comes from the fact that
that we unconditionally short-circuit upon finding XE_RTP_MATCH_OR on
the outer loop.  We should only do that if the preceding conjunction of
rules evaluated to true (meaning that rcount must be non-zero) and
continue the evaluation otherwise.

Do that and also add extra test cases to validate the short-circuiting
behavior.

Notice that some of the new test cases have a "FIXME" comment, which
comes from the fact that we are unable to detect syntax errors after the
short-circuit point.  That is going to be fixed in a follow-up change.

Link: https://lore.kernel.org/intel-xe/871pfw4lo9.fsf@intel.com/
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Reviewed-by: Violet Monti <violet.monti@intel.com>
Link: https://patch.msgid.link/20260522-rtp-rule-parser-v3-3-0c51039899f4@intel.com
Signed-off-by: Gustavo Sousa <gustavo.sousa@intel.com>
This commit is contained in:
Gustavo Sousa 2026-05-22 05:45:18 -03:00
parent ff7746336b
commit f6d460e33e
2 changed files with 50 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

42
drivers/gpu/drm/xe/tests/xe_rtp_test.c
View File

@ -195,11 +195,49 @@ static const struct rtp_rules_test_case rtp_rules_cases[] = {
XE_RTP_RULES(OR),
},
{
.name = "or-anything",
.expected_match = false,
.name = "or-yes",
.expected_match = true,
.expected_err = -EINVAL,
XE_RTP_RULES(OR, FUNC(match_yes)),
},
{
.name = "or-no",
.expected_match = false,
.expected_err = -EINVAL,
XE_RTP_RULES(OR, FUNC(match_no)),
},
{
.name = "yes-or",
.expected_match = true,
/* FIXME: The parser should raise an error here. */
.expected_err = 0,
XE_RTP_RULES(FUNC(match_yes), OR),
},
{
.name = "no-or",
.expected_match = false,
.expected_err = -EINVAL,
XE_RTP_RULES(FUNC(match_no), OR),
},
{
.name = "no-or-or-yes",
.expected_match = true,
.expected_err = -EINVAL,
XE_RTP_RULES(FUNC(match_no), OR, OR, FUNC(match_yes)),
},
{
.name = "yes-or-or-no",
.expected_match = true,
/* FIXME: The parser should raise an error here. */
.expected_err = 0,
XE_RTP_RULES(FUNC(match_yes), OR, OR, FUNC(match_no)),
},
{
.name = "no-or-or-no",
.expected_match = false,
.expected_err = -EINVAL,
XE_RTP_RULES(FUNC(match_no), OR, OR, FUNC(match_no)),
},
};
static void xe_rtp_rules_tests(struct kunit *test)

15
drivers/gpu/drm/xe/xe_rtp.c
View File

@ -47,12 +47,18 @@ static bool rule_matches_with_err(const struct xe_device *xe,
for (r = rules, i = 0; i < n_rules; r = &rules[++i]) {
switch (r->match_type) {
case XE_RTP_MATCH_OR:
if (drm_WARN_ON(&xe->drm, !rcount)) {
if (err)
*err = -EINVAL;
continue;
}
/*
* This is only reached if a complete set of
* rules passed or none were evaluated. For both cases,
* shortcut the other rules and return the proper value.
* This is only reached if a complete conjunction of
* rules passed, in which case we shortcut the other
* rules and return true.
*/
goto done;
return true;
case XE_RTP_MATCH_PLATFORM:
match = xe->info.platform == r->platform;
break;
@ -169,7 +175,6 @@ static bool rule_matches_with_err(const struct xe_device *xe,
}
}
done:
if (drm_WARN_ON(&xe->drm, !rcount))
goto error;