Reading some registers end in a system crash ala:
Unhandled fault: external abort on non-linefetch (0x1028) at 0xfe641000
Internal error: : 1028 [#1] PREEMPT ARM
Avoid those by register validation.
Signed-off-by: Christian Gmeiner <christian.gmeiner@xxxxxxxxx>
---
drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c b/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c
index 08f9b3d..4383c0d 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c
@@ -277,6 +277,27 @@ static int submit_reloc(struct etnaviv_gem_submit *submit, void *stream,
return 0;
}
+static int readback_reg_valid(unsigned reg)
+{
+ /*
+ * 0x000..0x200: ok
+ * 0x200..0x400: crash
+ * 0x400..0x800: ok
+ * 0x800..0xa00: crash
+ * 0xa00..0xc00: crash
+ * 0xc00..0xe00: crash
+ * 0xe00..0x1000: crash
+ * everything above: crash
+ */
+ if (reg >= 0x200 && reg < 400)
+ return 0;
+
+ if (reg >= 0x800)
+ return 0;
+
+ return 1;
+}
+
static int submit_readback(struct etnaviv_gem_submit *submit,
struct etnaviv_cmdbuf *cmdbuf,
const struct drm_etnaviv_gem_submit_readback *readbacks,
@@ -303,6 +324,11 @@ static int submit_readback(struct etnaviv_gem_submit *submit,
return -EINVAL;
}
+ if (!readback_reg_valid(r->reg)) {
+ DRM_ERROR("invalid readback reg (would cause crash)");
+ return -EINVAL;
+ }
+
cmdbuf->readbacks[i].bo_vma = etnaviv_gem_vmap(&bo->obj->base);
cmdbuf->readbacks[i].offset = r->readback_offset;
cmdbuf->readbacks[i].reg = r->reg;
--
2.9.3
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