[PATCH 2/2] drm/i915/selftests: Exercise cross-process context isolation
Chris Wilson
chris at chris-wilson.co.uk
Thu Jan 14 08:31:23 UTC 2021
Verify that one context running on engine A cannot manipulate another
client's context concurrently running on engine B using unprivileged
access.
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
drivers/gpu/drm/i915/gt/selftest_lrc.c | 235 ++++++++++++++++++++++---
1 file changed, 211 insertions(+), 24 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/selftest_lrc.c b/drivers/gpu/drm/i915/gt/selftest_lrc.c
index a55cbf524692..ef86f5e6385e 100644
--- a/drivers/gpu/drm/i915/gt/selftest_lrc.c
+++ b/drivers/gpu/drm/i915/gt/selftest_lrc.c
@@ -912,6 +912,7 @@ create_user_vma(struct i915_address_space *vm, unsigned long size)
static struct i915_vma *
store_context(struct intel_context *ce,
+ struct file *state,
struct i915_vma *scratch,
bool relative)
{
@@ -929,7 +930,7 @@ store_context(struct intel_context *ce,
return ERR_CAST(cs);
}
- defaults = shmem_pin_map(ce->engine->default_state);
+ defaults = shmem_pin_map(state);
if (!defaults) {
i915_gem_object_unpin_map(batch->obj);
i915_vma_put(batch);
@@ -980,7 +981,7 @@ store_context(struct intel_context *ce,
*cs++ = MI_BATCH_BUFFER_END;
- shmem_unpin_map(ce->engine->default_state, defaults);
+ shmem_unpin_map(state, defaults);
i915_gem_object_flush_map(batch->obj);
i915_gem_object_unpin_map(batch->obj);
@@ -1003,23 +1004,40 @@ static int move_to_active(struct i915_request *rq,
return err;
}
+struct hwsp_semaphore {
+ u32 ggtt;
+ u32 *va;
+};
+
+static struct hwsp_semaphore hwsp_semaphore(struct intel_engine_cs *engine)
+{
+ struct hwsp_semaphore s;
+
+ s.va = memset32(engine->status_page.addr + 1000, 0, 1);
+ s.ggtt = (i915_ggtt_offset(engine->status_page.vma) +
+ offset_in_page(s.va));
+
+ return s;
+}
+
static struct i915_request *
record_registers(struct intel_context *ce,
+ struct file *state,
struct i915_vma *before,
struct i915_vma *after,
bool relative,
- u32 *sema)
+ const struct hwsp_semaphore *sema)
{
struct i915_vma *b_before, *b_after;
struct i915_request *rq;
u32 *cs;
int err;
- b_before = store_context(ce, before, relative);
+ b_before = store_context(ce, state, before, relative);
if (IS_ERR(b_before))
return ERR_CAST(b_before);
- b_after = store_context(ce, after, relative);
+ b_after = store_context(ce, state, after, relative);
if (IS_ERR(b_after)) {
rq = ERR_CAST(b_after);
goto err_before;
@@ -1062,8 +1080,7 @@ record_registers(struct intel_context *ce,
MI_SEMAPHORE_POLL |
MI_SEMAPHORE_SAD_NEQ_SDD;
*cs++ = 0;
- *cs++ = i915_ggtt_offset(ce->engine->status_page.vma) +
- offset_in_page(sema);
+ *cs++ = sema->ggtt;
*cs++ = 0;
*cs++ = MI_NOOP;
@@ -1074,7 +1091,7 @@ record_registers(struct intel_context *ce,
intel_ring_advance(rq, cs);
- WRITE_ONCE(*sema, 0);
+ WRITE_ONCE(*sema->va, 0);
i915_request_get(rq);
i915_request_add(rq);
err_after:
@@ -1090,7 +1107,9 @@ record_registers(struct intel_context *ce,
}
static struct i915_vma *
-load_context(struct intel_context *ce, u32 poison, bool relative)
+load_context(struct intel_context *ce,
+ struct file *state,
+ u32 poison, bool relative)
{
struct i915_vma *batch;
u32 dw, *cs, *hw;
@@ -1106,7 +1125,7 @@ load_context(struct intel_context *ce, u32 poison, bool relative)
return ERR_CAST(cs);
}
- defaults = shmem_pin_map(ce->engine->default_state);
+ defaults = shmem_pin_map(state);
if (!defaults) {
i915_gem_object_unpin_map(batch->obj);
i915_vma_put(batch);
@@ -1153,7 +1172,7 @@ load_context(struct intel_context *ce, u32 poison, bool relative)
*cs++ = MI_BATCH_BUFFER_END;
- shmem_unpin_map(ce->engine->default_state, defaults);
+ shmem_unpin_map(state, defaults);
i915_gem_object_flush_map(batch->obj);
i915_gem_object_unpin_map(batch->obj);
@@ -1163,16 +1182,17 @@ load_context(struct intel_context *ce, u32 poison, bool relative)
static int
poison_registers(struct intel_context *ce,
+ struct file *state,
u32 poison,
bool relative,
- u32 *sema)
+ const struct hwsp_semaphore *sema)
{
struct i915_request *rq;
struct i915_vma *batch;
u32 *cs;
int err;
- batch = load_context(ce, poison, relative);
+ batch = load_context(ce, state, poison, relative);
if (IS_ERR(batch))
return PTR_ERR(batch);
@@ -1198,8 +1218,7 @@ poison_registers(struct intel_context *ce,
*cs++ = upper_32_bits(batch->node.start);
*cs++ = MI_STORE_DWORD_IMM_GEN4 | MI_USE_GGTT;
- *cs++ = i915_ggtt_offset(ce->engine->status_page.vma) +
- offset_in_page(sema);
+ *cs++ = sema->ggtt;
*cs++ = 0;
*cs++ = 1;
@@ -1219,6 +1238,7 @@ static bool is_moving(u32 a, u32 b)
}
static int compare_isolation(struct intel_engine_cs *engine,
+ struct file *state,
struct i915_vma *ref[2],
struct i915_vma *result[2],
struct intel_context *ce,
@@ -1259,7 +1279,7 @@ static int compare_isolation(struct intel_engine_cs *engine,
}
lrc += LRC_STATE_OFFSET / sizeof(*hw);
- defaults = shmem_pin_map(ce->engine->default_state);
+ defaults = shmem_pin_map(state);
if (!defaults) {
err = -ENOMEM;
goto err_lrc;
@@ -1312,7 +1332,7 @@ static int compare_isolation(struct intel_engine_cs *engine,
} while (dw < PAGE_SIZE / sizeof(u32) &&
(hw[dw] & ~BIT(0)) != MI_BATCH_BUFFER_END);
- shmem_unpin_map(ce->engine->default_state, defaults);
+ shmem_unpin_map(state, defaults);
err_lrc:
i915_gem_object_unpin_map(ce->state->obj);
err_B1:
@@ -1329,7 +1349,7 @@ static int compare_isolation(struct intel_engine_cs *engine,
static int
__lrc_isolation(struct intel_engine_cs *engine, u32 poison, bool relative)
{
- u32 *sema = memset32(engine->status_page.addr + 1000, 0, 1);
+ struct hwsp_semaphore sema = hwsp_semaphore(engine);
struct i915_vma *ref[2], *result[2];
struct intel_context *A, *B;
struct i915_request *rq;
@@ -1357,13 +1377,14 @@ __lrc_isolation(struct intel_engine_cs *engine, u32 poison, bool relative)
goto err_ref0;
}
- rq = record_registers(A, ref[0], ref[1], relative, sema);
+ rq = record_registers(A, engine->default_state,
+ ref[0], ref[1], relative, &sema);
if (IS_ERR(rq)) {
err = PTR_ERR(rq);
goto err_ref1;
}
- WRITE_ONCE(*sema, 1);
+ WRITE_ONCE(*sema.va, 1);
wmb();
if (i915_request_wait(rq, 0, HZ / 2) < 0) {
@@ -1385,15 +1406,17 @@ __lrc_isolation(struct intel_engine_cs *engine, u32 poison, bool relative)
goto err_result0;
}
- rq = record_registers(A, result[0], result[1], relative, sema);
+ rq = record_registers(A, engine->default_state,
+ result[0], result[1], relative, &sema);
if (IS_ERR(rq)) {
err = PTR_ERR(rq);
goto err_result1;
}
- err = poison_registers(B, poison, relative, sema);
+ err = poison_registers(B, engine->default_state,
+ poison, relative, &sema);
if (err) {
- WRITE_ONCE(*sema, -1);
+ WRITE_ONCE(*sema.va, -1);
i915_request_put(rq);
goto err_result1;
}
@@ -1405,7 +1428,8 @@ __lrc_isolation(struct intel_engine_cs *engine, u32 poison, bool relative)
}
i915_request_put(rq);
- err = compare_isolation(engine, ref, result, A, poison, relative);
+ err = compare_isolation(engine, engine->default_state,
+ ref, result, A, poison, relative);
err_result1:
i915_vma_put(result[1]);
@@ -1495,6 +1519,168 @@ static int live_lrc_isolation(void *arg)
return err;
}
+static int __lrc_cross(struct intel_engine_cs *a,
+ struct intel_engine_cs *b,
+ u32 poison)
+{
+ struct hwsp_semaphore sema = hwsp_semaphore(a);
+ struct i915_vma *ref[2], *result[2];
+ struct intel_context *A, *B;
+ struct i915_request *rq;
+ int err;
+
+ GEM_BUG_ON(a->gt->ggtt != b->gt->ggtt);
+
+ A = intel_context_create(a);
+ if (IS_ERR(A))
+ return PTR_ERR(A);
+
+ B = intel_context_create(b);
+ if (IS_ERR(B)) {
+ err = PTR_ERR(B);
+ goto err_A;
+ }
+
+ ref[0] = create_user_vma(A->vm, SZ_64K);
+ if (IS_ERR(ref[0])) {
+ err = PTR_ERR(ref[0]);
+ goto err_B;
+ }
+
+ ref[1] = create_user_vma(A->vm, SZ_64K);
+ if (IS_ERR(ref[1])) {
+ err = PTR_ERR(ref[1]);
+ goto err_ref0;
+ }
+
+ rq = record_registers(A, a->default_state,
+ ref[0], ref[1], false, &sema);
+ if (IS_ERR(rq)) {
+ err = PTR_ERR(rq);
+ goto err_ref1;
+ }
+
+ WRITE_ONCE(*sema.va, 1);
+ wmb();
+
+ if (i915_request_wait(rq, 0, HZ / 2) < 0) {
+ i915_request_put(rq);
+ err = -ETIME;
+ goto err_ref1;
+ }
+ i915_request_put(rq);
+
+ result[0] = create_user_vma(A->vm, SZ_64K);
+ if (IS_ERR(result[0])) {
+ err = PTR_ERR(result[0]);
+ goto err_ref1;
+ }
+
+ result[1] = create_user_vma(A->vm, SZ_64K);
+ if (IS_ERR(result[1])) {
+ err = PTR_ERR(result[1]);
+ goto err_result0;
+ }
+
+ rq = record_registers(A, a->default_state,
+ result[0], result[1], false, &sema);
+ if (IS_ERR(rq)) {
+ err = PTR_ERR(rq);
+ goto err_result1;
+ }
+
+ err = poison_registers(B, a->default_state, poison, false, &sema);
+ if (err) {
+ WRITE_ONCE(*sema.va, -1);
+ i915_request_put(rq);
+ goto err_result1;
+ }
+
+ if (i915_request_wait(rq, 0, HZ / 2) < 0) {
+ i915_request_put(rq);
+ err = -ETIME;
+ goto err_result1;
+ }
+ i915_request_put(rq);
+
+ err = compare_isolation(a, a->default_state,
+ ref, result, A, poison, false);
+
+err_result1:
+ i915_vma_put(result[1]);
+err_result0:
+ i915_vma_put(result[0]);
+err_ref1:
+ i915_vma_put(ref[1]);
+err_ref0:
+ i915_vma_put(ref[0]);
+err_B:
+ intel_context_put(B);
+err_A:
+ intel_context_put(A);
+ return err;
+}
+
+static int live_lrc_cross(void *arg)
+{
+ struct intel_gt *gt = arg;
+ struct intel_engine_cs *a, *b;
+ enum intel_engine_id id;
+ const u32 poison[] = {
+ STACK_MAGIC,
+ 0x3a3a3a3a,
+ 0x5c5c5c5c,
+ 0xffffffff,
+ 0xffff0000,
+ };
+ int err = 0;
+ int i;
+
+ /*
+ * Our goal is to try and tamper with another client's context
+ * running concurrently.
+ */
+
+ for_each_engine(a, gt, id) {
+ /* Just don't even ask */
+ if (!IS_ENABLED(CONFIG_DRM_I915_SELFTEST_BROKEN) &&
+ skip_isolation(a))
+ continue;
+
+ intel_engine_pm_get(a);
+
+ for_each_engine(b, gt, id) {
+ if (a == b)
+ continue;
+
+ if (!IS_ENABLED(CONFIG_DRM_I915_SELFTEST_BROKEN) &&
+ skip_isolation(b))
+ continue;
+
+ intel_engine_pm_get(b);
+ for (i = 0; i < ARRAY_SIZE(poison); i++) {
+ int result;
+
+ result = __lrc_cross(a, b, poison[i]);
+ if (result && !err)
+ err = result;
+
+ result = __lrc_cross(a, b, ~poison[i]);
+ if (result && !err)
+ err = result;
+ }
+ intel_engine_pm_put(b);
+ }
+ intel_engine_pm_put(a);
+ if (igt_flush_test(gt->i915)) {
+ err = -EIO;
+ break;
+ }
+ }
+
+ return err;
+}
+
static int indirect_ctx_submit_req(struct intel_context *ce)
{
struct i915_request *rq;
@@ -1885,6 +2071,7 @@ int intel_lrc_live_selftests(struct drm_i915_private *i915)
SUBTEST(live_lrc_isolation),
SUBTEST(live_lrc_timestamp),
SUBTEST(live_lrc_garbage),
+ SUBTEST(live_lrc_cross),
SUBTEST(live_pphwsp_runtime),
SUBTEST(live_lrc_indirect_ctx_bb),
};
--
2.20.1
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