[PATCH] drm/komeda: Fix bit check to import to value of proper type
Steven Price
steven.price at arm.com
Wed Jan 27 16:31:04 UTC 2021
NIT: This is the second version of this patch so should have "[PATCH
v2]" in the subject.
On 27/01/2021 12:34, carsten.haitzler at foss.arm.com wrote:
> From: Carsten Haitzler <carsten.haitzler at arm.com>
>
> Another issue found by KASAN. The bit finding is buried inside the
> dp_for_each_set_bit() macro (that passes on to for_each_set_bit() that
> calls the bit stuff. These bit functions want an unsigned long pointer
> as input and just dumbly casting leads to out-of-bounds accesses.
> This fixes that.
>
> Signed-off-by: Carsten Haitzler <carsten.haitzler at arm.com>
> ---
> .../gpu/drm/arm/display/include/malidp_utils.h | 10 ++++++++--
> .../gpu/drm/arm/display/komeda/komeda_pipeline.c | 16 +++++++++++-----
> .../arm/display/komeda/komeda_pipeline_state.c | 13 ++++++++-----
> 3 files changed, 27 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/gpu/drm/arm/display/include/malidp_utils.h b/drivers/gpu/drm/arm/display/include/malidp_utils.h
> index 3bc383d5bf73..8d289cd0b5b8 100644
> --- a/drivers/gpu/drm/arm/display/include/malidp_utils.h
> +++ b/drivers/gpu/drm/arm/display/include/malidp_utils.h
> @@ -12,9 +12,15 @@
>
> #define has_bit(nr, mask) (BIT(nr) & (mask))
> #define has_bits(bits, mask) (((bits) & (mask)) == (bits))
> -
> +/*
> +#define dp_for_each_set_bit(bit, mask) \
> + for_each_set_bit((bit), (&((unsigned long)(mask))), sizeof(mask) * 8)
> +#define dp_for_each_set_bit(bit, mask) \
> + unsigned long __local_mask = mask; \
> + for_each_set_bit((bit), (&__local_mask), sizeof(mask) * 8)
> +*/
Commented out code left in - please remove it.
> #define dp_for_each_set_bit(bit, mask) \
> - for_each_set_bit((bit), ((unsigned long *)&(mask)), sizeof(mask) * 8)
> + for_each_set_bit((bit), &(mask), sizeof(mask) * 8)
I'm not really sure if there's much point in this macro now. In practice
the uses below are now getting the wrong length (because sizeof(mask) ==
sizeof(unsigned long) ) but we actually know the size is smaller in most
cases, so we could pass a more appropriate value in.
Other than that the changes below look correct to me.
Steve
>
> #define dp_wait_cond(__cond, __tries, __min_range, __max_range) \
> ({ \
> diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_pipeline.c b/drivers/gpu/drm/arm/display/komeda/komeda_pipeline.c
> index 719a79728e24..a85c8a806334 100644
> --- a/drivers/gpu/drm/arm/display/komeda/komeda_pipeline.c
> +++ b/drivers/gpu/drm/arm/display/komeda/komeda_pipeline.c
> @@ -46,8 +46,9 @@ void komeda_pipeline_destroy(struct komeda_dev *mdev,
> {
> struct komeda_component *c;
> int i;
> + unsigned long avail_comps = pipe->avail_comps;
>
> - dp_for_each_set_bit(i, pipe->avail_comps) {
> + dp_for_each_set_bit(i, avail_comps) {
> c = komeda_pipeline_get_component(pipe, i);
> komeda_component_destroy(mdev, c);
> }
> @@ -247,6 +248,7 @@ static void komeda_pipeline_dump(struct komeda_pipeline *pipe)
> {
> struct komeda_component *c;
> int id;
> + unsigned long avail_comps = pipe->avail_comps;
>
> DRM_INFO("Pipeline-%d: n_layers: %d, n_scalers: %d, output: %s.\n",
> pipe->id, pipe->n_layers, pipe->n_scalers,
> @@ -258,7 +260,7 @@ static void komeda_pipeline_dump(struct komeda_pipeline *pipe)
> pipe->of_output_links[1] ?
> pipe->of_output_links[1]->full_name : "none");
>
> - dp_for_each_set_bit(id, pipe->avail_comps) {
> + dp_for_each_set_bit(id, avail_comps) {
> c = komeda_pipeline_get_component(pipe, id);
>
> komeda_component_dump(c);
> @@ -270,8 +272,9 @@ static void komeda_component_verify_inputs(struct komeda_component *c)
> struct komeda_pipeline *pipe = c->pipeline;
> struct komeda_component *input;
> int id;
> + unsigned long supported_inputs = c->supported_inputs;
>
> - dp_for_each_set_bit(id, c->supported_inputs) {
> + dp_for_each_set_bit(id, supported_inputs) {
> input = komeda_pipeline_get_component(pipe, id);
> if (!input) {
> c->supported_inputs &= ~(BIT(id));
> @@ -302,8 +305,9 @@ static void komeda_pipeline_assemble(struct komeda_pipeline *pipe)
> struct komeda_component *c;
> struct komeda_layer *layer;
> int i, id;
> + unsigned long avail_comps = pipe->avail_comps;
>
> - dp_for_each_set_bit(id, pipe->avail_comps) {
> + dp_for_each_set_bit(id, avail_comps) {
> c = komeda_pipeline_get_component(pipe, id);
> komeda_component_verify_inputs(c);
> }
> @@ -355,13 +359,15 @@ void komeda_pipeline_dump_register(struct komeda_pipeline *pipe,
> {
> struct komeda_component *c;
> u32 id;
> + unsigned long avail_comps;
>
> seq_printf(sf, "\n======== Pipeline-%d ==========\n", pipe->id);
>
> if (pipe->funcs && pipe->funcs->dump_register)
> pipe->funcs->dump_register(pipe, sf);
>
> - dp_for_each_set_bit(id, pipe->avail_comps) {
> + avail_comps = pipe->avail_comps;
> + dp_for_each_set_bit(id, avail_comps) {
> c = komeda_pipeline_get_component(pipe, id);
>
> seq_printf(sf, "\n------%s------\n", c->name);
> diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_pipeline_state.c b/drivers/gpu/drm/arm/display/komeda/komeda_pipeline_state.c
> index e8b1e15312d8..7640dae7f4bf 100644
> --- a/drivers/gpu/drm/arm/display/komeda/komeda_pipeline_state.c
> +++ b/drivers/gpu/drm/arm/display/komeda/komeda_pipeline_state.c
> @@ -1232,7 +1232,8 @@ komeda_pipeline_unbound_components(struct komeda_pipeline *pipe,
> struct komeda_pipeline_state *old = priv_to_pipe_st(pipe->obj.state);
> struct komeda_component_state *c_st;
> struct komeda_component *c;
> - u32 disabling_comps, id;
> + u32 id;
> + unsigned long disabling_comps;
>
> WARN_ON(!old);
>
> @@ -1287,7 +1288,8 @@ bool komeda_pipeline_disable(struct komeda_pipeline *pipe,
> struct komeda_pipeline_state *old;
> struct komeda_component *c;
> struct komeda_component_state *c_st;
> - u32 id, disabling_comps = 0;
> + u32 id;
> + unsigned long disabling_comps;
>
> old = komeda_pipeline_get_old_state(pipe, old_state);
>
> @@ -1297,7 +1299,7 @@ bool komeda_pipeline_disable(struct komeda_pipeline *pipe,
> disabling_comps = old->active_comps &
> pipe->standalone_disabled_comps;
>
> - DRM_DEBUG_ATOMIC("PIPE%d: active_comps: 0x%x, disabling_comps: 0x%x.\n",
> + DRM_DEBUG_ATOMIC("PIPE%d: active_comps: 0x%x, disabling_comps: 0x%lx.\n",
> pipe->id, old->active_comps, disabling_comps);
>
> dp_for_each_set_bit(id, disabling_comps) {
> @@ -1331,13 +1333,14 @@ void komeda_pipeline_update(struct komeda_pipeline *pipe,
> struct komeda_pipeline_state *new = priv_to_pipe_st(pipe->obj.state);
> struct komeda_pipeline_state *old;
> struct komeda_component *c;
> - u32 id, changed_comps = 0;
> + u32 id;
> + unsigned long changed_comps;
>
> old = komeda_pipeline_get_old_state(pipe, old_state);
>
> changed_comps = new->active_comps | old->active_comps;
>
> - DRM_DEBUG_ATOMIC("PIPE%d: active_comps: 0x%x, changed: 0x%x.\n",
> + DRM_DEBUG_ATOMIC("PIPE%d: active_comps: 0x%x, changed: 0x%lx.\n",
> pipe->id, new->active_comps, changed_comps);
>
> dp_for_each_set_bit(id, changed_comps) {
>
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