Re: [Intel-gfx] [PATCH v2 05/22] drm/i915/bios: Trust the LFP data pointers
On Tue, 05 Apr 2022, Ville Syrjala wrote:
> From: Ville Syrjälä
>
> Now that we've sufficiently validated the LFP data pointers we
> can trust them.
>
> Signed-off-by: Ville Syrjälä
Reviewed-by: Jani Nikula
> ---
> drivers/gpu/drm/i915/display/intel_bios.c | 60 ++-
> 1 file changed, 16 insertions(+), 44 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_bios.c
> b/drivers/gpu/drm/i915/display/intel_bios.c
> index cd82ea4de8e1..925f521f1f84 100644
> --- a/drivers/gpu/drm/i915/display/intel_bios.c
> +++ b/drivers/gpu/drm/i915/display/intel_bios.c
> @@ -397,44 +397,19 @@ fill_detail_timing_data(struct drm_display_mode
> *panel_fixed_mode,
> }
>
> static const struct lvds_dvo_timing *
> -get_lvds_dvo_timing(const struct bdb_lvds_lfp_data *lvds_lfp_data,
> - const struct bdb_lvds_lfp_data_ptrs *lvds_lfp_data_ptrs,
> +get_lvds_dvo_timing(const struct bdb_lvds_lfp_data *data,
> + const struct bdb_lvds_lfp_data_ptrs *ptrs,
> int index)
> {
> - /*
> - * the size of fp_timing varies on the different platform.
> - * So calculate the DVO timing relative offset in LVDS data
> - * entry to get the DVO timing entry
> - */
> -
> - int lfp_data_size =
> - lvds_lfp_data_ptrs->ptr[1].dvo_timing.offset -
> - lvds_lfp_data_ptrs->ptr[0].dvo_timing.offset;
> - int dvo_timing_offset =
> - lvds_lfp_data_ptrs->ptr[0].dvo_timing.offset -
> - lvds_lfp_data_ptrs->ptr[0].fp_timing.offset;
> - char *entry = (char *)lvds_lfp_data->data + lfp_data_size * index;
> -
> - return (struct lvds_dvo_timing *)(entry + dvo_timing_offset);
> + return (const void *)data + ptrs->ptr[index].dvo_timing.offset;
> }
>
> -/* get lvds_fp_timing entry
> - * this function may return NULL if the corresponding entry is invalid
> - */
> static const struct lvds_fp_timing *
> get_lvds_fp_timing(const struct bdb_lvds_lfp_data *data,
> const struct bdb_lvds_lfp_data_ptrs *ptrs,
> int index)
> {
> - u16 data_size = ((const u16 *)data)[-1]; /* stored in header */
> - size_t ofs;
> -
> - if (index >= ARRAY_SIZE(ptrs->ptr))
> - return NULL;
> - ofs = ptrs->ptr[index].fp_timing.offset;
> - if (ofs + sizeof(struct lvds_fp_timing) > data_size)
> - return NULL;
> - return (const struct lvds_fp_timing *)((const u8 *)data + ofs);
> + return (const void *)data + ptrs->ptr[index].fp_timing.offset;
> }
>
> /* Parse general panel options */
> @@ -499,8 +474,7 @@ parse_panel_options(struct drm_i915_private *i915)
>
> /* Try to find integrated panel timing data */
> static void
> -parse_lfp_panel_dtd(struct drm_i915_private *i915,
> - const struct bdb_header *bdb)
> +parse_lfp_panel_dtd(struct drm_i915_private *i915)
> {
> const struct bdb_lvds_lfp_data *lvds_lfp_data;
> const struct bdb_lvds_lfp_data_ptrs *lvds_lfp_data_ptrs;
> @@ -536,15 +510,14 @@ parse_lfp_panel_dtd(struct drm_i915_private *i915,
> fp_timing = get_lvds_fp_timing(lvds_lfp_data,
> lvds_lfp_data_ptrs,
> panel_type);
> - if (fp_timing) {
> - /* check the resolution, just to be sure */
> - if (fp_timing->x_res == panel_fixed_mode->hdisplay &&
> - fp_timing->y_res == panel_fixed_mode->vdisplay) {
> - i915->vbt.bios_lvds_val = fp_timing->lvds_reg_val;
> - drm_dbg_kms(&i915->drm,
> - "VBT initial LVDS value %x\n",
> - i915->vbt.bios_lvds_val);
> - }
> +
> + /* check the resolution, just to be sure */
> + if (fp_timing->x_res == panel_fixed_mode->hdisplay &&
> + fp_timing->y_res == panel_fixed_mode->vdisplay) {
> + i915->vbt.bios_lvds_val = fp_timing->lvds_reg_val;
> + drm_dbg_kms(&i915->drm,
> + "VBT initial LVDS value %x\n",
> + i915->vbt.bios_lvds_val);
> }
> }
>
> @@ -627,8 +600,7 @@ parse_generic_dtd(struct drm_i915_private *i915)
> }
>
> static void
> -parse_panel_dtd(struct drm_i915_private *i915,
> - const struct bdb_header *bdb)
> +parse_panel_dtd(struct drm_i915_private *i915)
> {
> /*
>* Older VBTs provided provided DTD information for internal displays
> @@ -641,7 +613,7 @@ parse_panel_dtd(struct drm_i915_private *i915,
> if (i915->vbt.version >= 229)
> parse_generic_dtd(i915);
> if (!i915->vbt.lfp_lvds_vbt_mode)
> - parse_lfp_panel_dtd(i915, bdb);
> + parse_lfp_panel_dtd(i915);
> }
>
> static void
> @@ -2720,7 +2692,7 @@ void intel_bios_init(struct drm_i915_private *i915)
> parse_general_features(i915);
> parse_general_definitions(i915);
> parse_panel_options
[Intel-gfx] [PATCH v2 05/22] drm/i915/bios: Trust the LFP data pointers
From: Ville Syrjälä
Now that we've sufficiently validated the LFP data pointers we
can trust them.
Signed-off-by: Ville Syrjälä
---
drivers/gpu/drm/i915/display/intel_bios.c | 60 ++-
1 file changed, 16 insertions(+), 44 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_bios.c
b/drivers/gpu/drm/i915/display/intel_bios.c
index cd82ea4de8e1..925f521f1f84 100644
--- a/drivers/gpu/drm/i915/display/intel_bios.c
+++ b/drivers/gpu/drm/i915/display/intel_bios.c
@@ -397,44 +397,19 @@ fill_detail_timing_data(struct drm_display_mode
*panel_fixed_mode,
}
static const struct lvds_dvo_timing *
-get_lvds_dvo_timing(const struct bdb_lvds_lfp_data *lvds_lfp_data,
- const struct bdb_lvds_lfp_data_ptrs *lvds_lfp_data_ptrs,
+get_lvds_dvo_timing(const struct bdb_lvds_lfp_data *data,
+ const struct bdb_lvds_lfp_data_ptrs *ptrs,
int index)
{
- /*
-* the size of fp_timing varies on the different platform.
-* So calculate the DVO timing relative offset in LVDS data
-* entry to get the DVO timing entry
-*/
-
- int lfp_data_size =
- lvds_lfp_data_ptrs->ptr[1].dvo_timing.offset -
- lvds_lfp_data_ptrs->ptr[0].dvo_timing.offset;
- int dvo_timing_offset =
- lvds_lfp_data_ptrs->ptr[0].dvo_timing.offset -
- lvds_lfp_data_ptrs->ptr[0].fp_timing.offset;
- char *entry = (char *)lvds_lfp_data->data + lfp_data_size * index;
-
- return (struct lvds_dvo_timing *)(entry + dvo_timing_offset);
+ return (const void *)data + ptrs->ptr[index].dvo_timing.offset;
}
-/* get lvds_fp_timing entry
- * this function may return NULL if the corresponding entry is invalid
- */
static const struct lvds_fp_timing *
get_lvds_fp_timing(const struct bdb_lvds_lfp_data *data,
const struct bdb_lvds_lfp_data_ptrs *ptrs,
int index)
{
- u16 data_size = ((const u16 *)data)[-1]; /* stored in header */
- size_t ofs;
-
- if (index >= ARRAY_SIZE(ptrs->ptr))
- return NULL;
- ofs = ptrs->ptr[index].fp_timing.offset;
- if (ofs + sizeof(struct lvds_fp_timing) > data_size)
- return NULL;
- return (const struct lvds_fp_timing *)((const u8 *)data + ofs);
+ return (const void *)data + ptrs->ptr[index].fp_timing.offset;
}
/* Parse general panel options */
@@ -499,8 +474,7 @@ parse_panel_options(struct drm_i915_private *i915)
/* Try to find integrated panel timing data */
static void
-parse_lfp_panel_dtd(struct drm_i915_private *i915,
- const struct bdb_header *bdb)
+parse_lfp_panel_dtd(struct drm_i915_private *i915)
{
const struct bdb_lvds_lfp_data *lvds_lfp_data;
const struct bdb_lvds_lfp_data_ptrs *lvds_lfp_data_ptrs;
@@ -536,15 +510,14 @@ parse_lfp_panel_dtd(struct drm_i915_private *i915,
fp_timing = get_lvds_fp_timing(lvds_lfp_data,
lvds_lfp_data_ptrs,
panel_type);
- if (fp_timing) {
- /* check the resolution, just to be sure */
- if (fp_timing->x_res == panel_fixed_mode->hdisplay &&
- fp_timing->y_res == panel_fixed_mode->vdisplay) {
- i915->vbt.bios_lvds_val = fp_timing->lvds_reg_val;
- drm_dbg_kms(&i915->drm,
- "VBT initial LVDS value %x\n",
- i915->vbt.bios_lvds_val);
- }
+
+ /* check the resolution, just to be sure */
+ if (fp_timing->x_res == panel_fixed_mode->hdisplay &&
+ fp_timing->y_res == panel_fixed_mode->vdisplay) {
+ i915->vbt.bios_lvds_val = fp_timing->lvds_reg_val;
+ drm_dbg_kms(&i915->drm,
+ "VBT initial LVDS value %x\n",
+ i915->vbt.bios_lvds_val);
}
}
@@ -627,8 +600,7 @@ parse_generic_dtd(struct drm_i915_private *i915)
}
static void
-parse_panel_dtd(struct drm_i915_private *i915,
- const struct bdb_header *bdb)
+parse_panel_dtd(struct drm_i915_private *i915)
{
/*
* Older VBTs provided provided DTD information for internal displays
@@ -641,7 +613,7 @@ parse_panel_dtd(struct drm_i915_private *i915,
if (i915->vbt.version >= 229)
parse_generic_dtd(i915);
if (!i915->vbt.lfp_lvds_vbt_mode)
- parse_lfp_panel_dtd(i915, bdb);
+ parse_lfp_panel_dtd(i915);
}
static void
@@ -2720,7 +2692,7 @@ void intel_bios_init(struct drm_i915_private *i915)
parse_general_features(i915);
parse_general_definitions(i915);
parse_panel_options(i915);
- parse_panel_dtd(i915, bdb);
+ parse_panel_dtd(i915);
parse_lfp_backlight(i915);
parse_sdvo_panel_data(i915);
parse_driver_features(i915);
--
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