69 lines
2.4 KiB
Diff
69 lines
2.4 KiB
Diff
|
From 1f42fbc79dea3529dd919249ee6e58f157704aaf Mon Sep 17 00:00:00 2001
|
||
|
|
From: Eric Anholt <eric@anholt.net>
|
||
|
|
Date: Thu, 20 Oct 2016 16:48:12 -0700
|
||
|
|
Subject: [PATCH] drm/vc4: Fix termination of the initial scan for branch
|
||
|
|
targets.
|
||
|
|
|
||
|
|
The loop is scanning until the original max_ip (size of the BO), but
|
||
|
|
we want to not examine any code after the PROG_END's delay slots.
|
||
|
|
There was a block trying to do that, except that we had some early
|
||
|
|
continue statements if the signal wasn't a PROG_END or a BRANCH.
|
||
|
|
|
||
|
|
The failure mode would be that a valid shader is rejected because some
|
||
|
|
undefined memory after the PROG_END slots is parsed as a branch and
|
||
|
|
the rest of its setup is illegal. I haven't seen this in the wild,
|
||
|
|
but valgrind was complaining when about this up in the userland
|
||
|
|
simulator mode.
|
||
|
|
|
||
|
|
Signed-off-by: Eric Anholt <eric@anholt.net>
|
||
|
|
(cherry picked from commit 457e67a728696c4f8e6423c64e93def50530db9a)
|
||
|
|
---
|
||
|
|
drivers/gpu/drm/vc4/vc4_validate_shaders.c | 19 ++++++++-----------
|
||
|
|
1 file changed, 8 insertions(+), 11 deletions(-)
|
||
|
|
|
||
|
|
--- a/drivers/gpu/drm/vc4/vc4_validate_shaders.c
|
||
|
|
+++ b/drivers/gpu/drm/vc4/vc4_validate_shaders.c
|
||
|
|
@@ -608,9 +608,7 @@ static bool
|
||
|
|
vc4_validate_branches(struct vc4_shader_validation_state *validation_state)
|
||
|
|
{
|
||
|
|
uint32_t max_branch_target = 0;
|
||
|
|
- bool found_shader_end = false;
|
||
|
|
int ip;
|
||
|
|
- int shader_end_ip = 0;
|
||
|
|
int last_branch = -2;
|
||
|
|
|
||
|
|
for (ip = 0; ip < validation_state->max_ip; ip++) {
|
||
|
|
@@ -621,8 +619,13 @@ vc4_validate_branches(struct vc4_shader_
|
||
|
|
uint32_t branch_target_ip;
|
||
|
|
|
||
|
|
if (sig == QPU_SIG_PROG_END) {
|
||
|
|
- shader_end_ip = ip;
|
||
|
|
- found_shader_end = true;
|
||
|
|
+ /* There are two delay slots after program end is
|
||
|
|
+ * signaled that are still executed, then we're
|
||
|
|
+ * finished. validation_state->max_ip is the
|
||
|
|
+ * instruction after the last valid instruction in the
|
||
|
|
+ * program.
|
||
|
|
+ */
|
||
|
|
+ validation_state->max_ip = ip + 3;
|
||
|
|
continue;
|
||
|
|
}
|
||
|
|
|
||
|
|
@@ -676,15 +679,9 @@ vc4_validate_branches(struct vc4_shader_
|
||
|
|
}
|
||
|
|
set_bit(after_delay_ip, validation_state->branch_targets);
|
||
|
|
max_branch_target = max(max_branch_target, after_delay_ip);
|
||
|
|
-
|
||
|
|
- /* There are two delay slots after program end is signaled
|
||
|
|
- * that are still executed, then we're finished.
|
||
|
|
- */
|
||
|
|
- if (found_shader_end && ip == shader_end_ip + 2)
|
||
|
|
- break;
|
||
|
|
}
|
||
|
|
|
||
|
|
- if (max_branch_target > shader_end_ip) {
|
||
|
|
+ if (max_branch_target > validation_state->max_ip - 3) {
|
||
|
|
DRM_ERROR("Branch landed after QPU_SIG_PROG_END");
|
||
|
|
return false;
|
||
|
|
}
|