diff options
| author | Eric Anholt <eric@anholt.net> | 2016-10-20 23:48:12 (GMT) |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-03-26 11:05:56 (GMT) |
| commit | dd0b0e22a58875e0ea9f41fc177f2286dddc95ab (patch) | |
| tree | b814dfb5663564aa10a76760b3d0b82ea0492010 /drivers/gpu | |
| parent | c3825da143fc419e2639e602f62d793ed0de4657 (diff) | |
| download | linux-dd0b0e22a58875e0ea9f41fc177f2286dddc95ab.tar.xz | |
drm/vc4: Fix termination of the initial scan for branch targets.
commit 457e67a728696c4f8e6423c64e93def50530db9a upstream.
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>
Cc: Amit Pundir <amit.pundir@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/vc4/vc4_validate_shaders.c | 19 |
1 files changed, 8 insertions, 11 deletions
diff --git a/drivers/gpu/drm/vc4/vc4_validate_shaders.c b/drivers/gpu/drm/vc4/vc4_validate_shaders.c index 2543cf5..917321c 100644 --- 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_validation_state *validation_state) 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_validation_state *validation_state) } 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; } |