From: Jani Nikula Date: Mon, 21 Dec 2015 13:10:59 +0000 (+0200) Subject: drm/i915/dsi: be defensive about out of bounds operation byte X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=28c72840a787559851aa8d70a18bb5ac41b73b53;p=linux-beck.git drm/i915/dsi: be defensive about out of bounds operation byte Untie the VBT based generic panel driver from the VBT parsing, so that the two don't have to be updated in lockstep. Reviewed-by: Daniel Vetter Signed-off-by: Jani Nikula Link: http://patchwork.freedesktop.org/patch/msgid/01c71ac89a9db8bc7b8ae0fb05c50a5fae362dc4.1450702954.git.jani.nikula@intel.com --- diff --git a/drivers/gpu/drm/i915/intel_dsi_panel_vbt.c b/drivers/gpu/drm/i915/intel_dsi_panel_vbt.c index c6aea69230e8..9bd920809697 100644 --- a/drivers/gpu/drm/i915/intel_dsi_panel_vbt.c +++ b/drivers/gpu/drm/i915/intel_dsi_panel_vbt.c @@ -232,11 +232,9 @@ static const u8 *mipi_exec_gpio(struct intel_dsi *intel_dsi, const u8 *data) typedef const u8 * (*fn_mipi_elem_exec)(struct intel_dsi *intel_dsi, const u8 *data); static const fn_mipi_elem_exec exec_elem[] = { - NULL, /* reserved */ - mipi_exec_send_packet, - mipi_exec_delay, - mipi_exec_gpio, - NULL, /* status read; later */ + [MIPI_SEQ_ELEM_SEND_PKT] = mipi_exec_send_packet, + [MIPI_SEQ_ELEM_DELAY] = mipi_exec_delay, + [MIPI_SEQ_ELEM_GPIO] = mipi_exec_gpio, }; /* @@ -264,7 +262,6 @@ static const char *sequence_name(enum mipi_seq seq_id) static void generic_exec_sequence(struct intel_dsi *intel_dsi, const u8 *data) { fn_mipi_elem_exec mipi_elem_exec; - int index; if (!data) return; @@ -277,15 +274,14 @@ static void generic_exec_sequence(struct intel_dsi *intel_dsi, const u8 *data) /* parse each byte till we reach end of sequence byte - 0x00 */ while (1) { - index = *data; - mipi_elem_exec = exec_elem[index]; - if (!mipi_elem_exec) { - DRM_ERROR("Unsupported MIPI element, skipping sequence execution\n"); + u8 operation_byte = *data++; + if (operation_byte >= ARRAY_SIZE(exec_elem) || + !exec_elem[operation_byte]) { + DRM_ERROR("Unsupported MIPI operation byte %u\n", + operation_byte); return; } - - /* goto element payload */ - data++; + mipi_elem_exec = exec_elem[operation_byte]; /* execute the element specific rotines */ data = mipi_elem_exec(intel_dsi, data);