drm/radeon/kms/atom: make sure tables are valid (v2)

[safe/jmp/linux-2.6] / drivers / gpu / drm / radeon / atom.c

diff --git a/drivers/gpu/drm/radeon/atom.c b/drivers/gpu/drm/radeon/atom.c
index b7fe660..247f8ee 100644 (file)
--- a/drivers/gpu/drm/radeon/atom.c
+++ b/drivers/gpu/drm/radeon/atom.c
@@ -1295,12 +1295,16 @@ void atom_destroy(struct atom_context *ctx)
        kfree(ctx);
 }
 
-void atom_parse_data_header(struct atom_context *ctx, int index,
+bool atom_parse_data_header(struct atom_context *ctx, int index,
                            uint16_t * size, uint8_t * frev, uint8_t * crev,
                            uint16_t * data_start)
 {
        int offset = index * 2 + 4;
        int idx = CU16(ctx->data_table + offset);
+       u16 *mdt = (u16 *)(ctx->bios + ctx->data_table + 4);
+
+       if (!mdt[index])
+               return false;
 
        if (size)
                *size = CU16(idx);
@@ -1309,38 +1313,42 @@ void atom_parse_data_header(struct atom_context *ctx, int index,
        if (crev)
                *crev = CU8(idx + 3);
        *data_start = idx;
-       return;
+       return true;
 }
 
-void atom_parse_cmd_header(struct atom_context *ctx, int index, uint8_t * frev,
+bool atom_parse_cmd_header(struct atom_context *ctx, int index, uint8_t * frev,
                           uint8_t * crev)
 {
        int offset = index * 2 + 4;
        int idx = CU16(ctx->cmd_table + offset);
+       u16 *mct = (u16 *)(ctx->bios + ctx->cmd_table + 4);
+
+       if (!mct[index])
+               return false;
 
        if (frev)
                *frev = CU8(idx + 2);
        if (crev)
                *crev = CU8(idx + 3);
-       return;
+       return true;
 }
 
 int atom_allocate_fb_scratch(struct atom_context *ctx)
 {
        int index = GetIndexIntoMasterTable(DATA, VRAM_UsageByFirmware);
        uint16_t data_offset;
-       int usage_bytes;
+       int usage_bytes = 0;
        struct _ATOM_VRAM_USAGE_BY_FIRMWARE *firmware_usage;
 
-       atom_parse_data_header(ctx, index, NULL, NULL, NULL, &data_offset);
+       if (atom_parse_data_header(ctx, index, NULL, NULL, NULL, &data_offset)) {
+               firmware_usage = (struct _ATOM_VRAM_USAGE_BY_FIRMWARE *)(ctx->bios + data_offset);
 
-       firmware_usage = (struct _ATOM_VRAM_USAGE_BY_FIRMWARE *)(ctx->bios + data_offset);
+               DRM_DEBUG("atom firmware requested %08x %dkb\n",
+                         firmware_usage->asFirmwareVramReserveInfo[0].ulStartAddrUsedByFirmware,
+                         firmware_usage->asFirmwareVramReserveInfo[0].usFirmwareUseInKb);
 
-       DRM_DEBUG("atom firmware requested %08x %dkb\n",
-                 firmware_usage->asFirmwareVramReserveInfo[0].ulStartAddrUsedByFirmware,
-                 firmware_usage->asFirmwareVramReserveInfo[0].usFirmwareUseInKb);
-
-       usage_bytes = firmware_usage->asFirmwareVramReserveInfo[0].usFirmwareUseInKb * 1024;
+               usage_bytes = firmware_usage->asFirmwareVramReserveInfo[0].usFirmwareUseInKb * 1024;
+       }
        if (usage_bytes == 0)
                usage_bytes = 20 * 1024;
        /* allocate some scratch memory */