cbfs: Remove prog_locate() for stages and rmodules

This patch removes the prog_locate() step for stages and rmodules.
Instead, the stage and rmodule loading functions will now perform the
locate step directly together with the actual loading. The long-term
goal of this is to eliminate prog_locate() (and the rdev member in
struct prog that it fills) completely in order to make CBFS verification
code safer and its security guarantees easier to follow. prog_locate()
is the main remaining use case where a raw rdev of CBFS file data
"leaks" out of cbfs.c into other code, and that other code needs to
manually make sure that the contents of the rdev get verified during
loading. By eliminating this step and moving all code that directly
deals with file data into cbfs.c, we can concentrate the code that needs
to worry about file data hashing (and needs access to cbfs_private.h
APIs) into one file, making it easier to keep track of and reason about.

This patch is the first step of this move, later patches will do the
same for SELFs and other program types.

Signed-off-by: Julius Werner <jwerner@chromium.org>
Change-Id: Ia600e55f77c2549a00e2606f09befc1f92594a3a
Reviewed-on: https://review.coreboot.org/c/coreboot/+/49335
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/arch/arm64/bl31.c

@@ -87,9 +87,6 @@ void run_bl31(u64 payload_entry, u64 payload_arg0, u64 payload_spsr)
 		struct prog bl32 = PROG_INIT(PROG_BL32,
 					     CONFIG_CBFS_PREFIX"/secure_os");
 
-		if (prog_locate(&bl32))
-			die("BL32 not found");
-
 		if (cbfs_prog_stage_load(&bl32))
 			die("BL32 load failed");
 

src/arch/x86/bootblock_normal.c

@@ -12,7 +12,7 @@ static const char *get_fallback(const char *stagelist)
 	return ++stagelist;
 }
 
-int legacy_romstage_selector(struct prog *romstage)
+int legacy_romstage_select_and_load(struct prog *romstage)
 {
 	static const char *default_filenames = "normal/romstage\0fallback/romstage";
 	const char *boot_candidate;
@@ -24,10 +24,10 @@ int legacy_romstage_selector(struct prog *romstage)
 
 	if (do_normal_boot()) {
 		romstage->name = boot_candidate;
-		if (!prog_locate(romstage))
+		if (!cbfs_prog_stage_load(romstage))
 			return 0;
 	}
 
 	romstage->name = get_fallback(boot_candidate);
-	return prog_locate(romstage);
+	return cbfs_prog_stage_load(romstage);
 }

src/arch/x86/postcar_loader.c

@@ -135,9 +135,6 @@ static void load_postcar_cbfs(struct prog *prog, struct postcar_frame *pcf)
 
 	vboot_run_logic();
 
-	if (prog_locate(prog))
-		die_with_post_code(POST_INVALID_ROM,
-				   "Failed to locate after CAR program.\n");
 	if (rmodule_stage_load(&rsl))
 		die_with_post_code(POST_INVALID_ROM,
 				   "Failed to load after CAR program.\n");

src/include/program_loading.h

@@ -165,7 +165,7 @@ struct prog_loader_ops {
 void run_romstage(void);
 
 /* Runtime selector for CBFS_PREFIX of romstage. */
-int legacy_romstage_selector(struct prog *romstage);
+int legacy_romstage_select_and_load(struct prog *romstage);
 
 /************************
  *   RAMSTAGE LOADING   *

src/lib/cbfs.c

@@ -382,19 +382,29 @@ void *_cbfs_cbmem_allocator(void *arg, size_t size, union cbfs_mdata *unused)
 	return cbmem_add((uintptr_t)arg, size);
 }
 
-int cbfs_prog_stage_load(struct prog *pstage)
+cb_err_t cbfs_prog_stage_load(struct prog *pstage)
 {
+	union cbfs_mdata mdata;
+	struct region_device rdev;
 	struct cbfs_stage stage;
 	uint8_t *load;
 	void *entry;
 	size_t fsize;
 	size_t foffset;
-	const struct region_device *fh = prog_rdev(pstage);
+	cb_err_t err;
 
-	if (rdev_readat(fh, &stage, 0, sizeof(stage)) != sizeof(stage))
-		return -1;
+	prog_locate_hook(pstage);
 
-	fsize = region_device_sz(fh);
+	if ((err = cbfs_boot_lookup(prog_name(pstage), false, &mdata, &rdev)))
+		return err;
+
+	assert(be32toh(mdata.h.type) == CBFS_TYPE_STAGE);
+	pstage->cbfs_type = CBFS_TYPE_STAGE;
+
+	if (rdev_readat(&rdev, &stage, 0, sizeof(stage)) != sizeof(stage))
+		return CB_CBFS_IO;
+
+	fsize = region_device_sz(&rdev);
 	fsize -= sizeof(stage);
 	foffset = 0;
 	foffset += sizeof(stage);
@@ -416,16 +426,16 @@ int cbfs_prog_stage_load(struct prog *pstage)
 	 * that would hit this path initialize themselves. */
 	if ((ENV_BOOTBLOCK || ENV_SEPARATE_VERSTAGE) &&
 	    !CONFIG(NO_XIP_EARLY_STAGES) && CONFIG(BOOT_DEVICE_MEMORY_MAPPED)) {
-		void *mapping = rdev_mmap(fh, foffset, fsize);
-		rdev_munmap(fh, mapping);
+		void *mapping = rdev_mmap(&rdev, foffset, fsize);
+		rdev_munmap(&rdev, mapping);
 		if (mapping == load)
 			goto out;
 	}
 
-	fsize = cbfs_stage_load_and_decompress(fh, foffset, fsize, load,
-					stage.memlen, stage.compression);
+	fsize = cbfs_stage_load_and_decompress(&rdev, foffset, fsize, load,
+					       stage.memlen, stage.compression);
 	if (!fsize)
-		return -1;
+		return CB_ERR;
 
 	/* Clear area not covered by file. */
 	memset(&load[fsize], 0, stage.memlen - fsize);
@@ -436,7 +446,7 @@ out:
 	prog_set_area(pstage, load, stage.memlen);
 	prog_set_entry(pstage, entry, NULL);
 
-	return 0;
+	return CB_SUCCESS;
 }
 
 void cbfs_boot_device_find_mcache(struct cbfs_boot_device *cbd, uint32_t id)

src/lib/prog_loaders.c

@@ -45,18 +45,15 @@ void run_romstage(void)
 
 	vboot_run_logic();
 
-	if (ENV_X86 && CONFIG(BOOTBLOCK_NORMAL)) {
-		if (legacy_romstage_selector(&romstage))
-			goto fail;
-	} else {
-		if (prog_locate(&romstage))
-			goto fail;
-	}
-
 	timestamp_add_now(TS_START_COPYROM);
 
-	if (cbfs_prog_stage_load(&romstage))
-		goto fail;
+	if (ENV_X86 && CONFIG(BOOTBLOCK_NORMAL)) {
+		if (legacy_romstage_select_and_load(&romstage))
+			goto fail;
+	} else {
+		if (cbfs_prog_stage_load(&romstage))
+			goto fail;
+	}
 
 	timestamp_add_now(TS_END_COPYROM);
 
@@ -78,6 +75,7 @@ static void run_ramstage_from_resume(struct prog *ramstage)
 	/* Load the cached ramstage to runtime location. */
 	stage_cache_load_stage(STAGE_RAMSTAGE, ramstage);
 
+	ramstage->cbfs_type = CBFS_TYPE_STAGE;
 	prog_set_arg(ramstage, cbmem_top());
 
 	if (prog_entry(ramstage) != NULL) {
@@ -120,9 +118,6 @@ void run_ramstage(void)
 
 	vboot_run_logic();
 
-	if (prog_locate(&ramstage))
-		goto fail;
-
 	timestamp_add_now(TS_START_COPYRAM);
 
 	if (ENV_X86) {

src/lib/rmodule.c

@@ -2,6 +2,7 @@
 #include <assert.h>
 #include <cbmem.h>
 #include <cbfs.h>
+#include <cbfs_private.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>
@@ -244,14 +245,22 @@ int rmodule_stage_load(struct rmod_stage_load *rsl)
 	int load_offset;
 	struct cbfs_stage stage;
 	void *rmod_loc;
-	struct region_device *fh;
+	struct region_device rdev;
+	union cbfs_mdata mdata;
 
 	if (rsl->prog == NULL || prog_name(rsl->prog) == NULL)
 		return -1;
 
-	fh = prog_rdev(rsl->prog);
+	if (prog_locate_hook(rsl->prog))
+		return -1;
 
-	if (rdev_readat(fh, &stage, 0, sizeof(stage)) != sizeof(stage))
+	if (cbfs_boot_lookup(prog_name(rsl->prog), false, &mdata, &rdev) != CB_SUCCESS)
+		return -1;
+
+	assert(be32toh(mdata.h.type) == CBFS_TYPE_STAGE);
+	rsl->prog->cbfs_type = CBFS_TYPE_STAGE;
+
+	if (rdev_readat(&rdev, &stage, 0, sizeof(stage)) != sizeof(stage))
 		return -1;
 
 	rmodule_offset =
@@ -268,7 +277,7 @@ int rmodule_stage_load(struct rmod_stage_load *rsl)
 	printk(BIOS_INFO, "Decompressing stage %s @ %p (%d bytes)\n",
 	       prog_name(rsl->prog), rmod_loc, stage.memlen);
 
-	if (!cbfs_load_and_decompress(fh, sizeof(stage), stage.len, rmod_loc,
+	if (!cbfs_load_and_decompress(&rdev, sizeof(stage), stage.len, rmod_loc,
 				      stage.memlen, stage.compression))
 		return -1;
 

src/security/vboot/vboot_loader.c

@@ -45,19 +45,12 @@ void vboot_run_logic(void)
 		verstage_main();
 		after_verstage();
 	} else if (verstage_should_load()) {
-		struct cbfsf file;
 		struct prog verstage =
 			PROG_INIT(PROG_VERSTAGE,
 				CONFIG_CBFS_PREFIX "/verstage");
 
 		printk(BIOS_DEBUG, "VBOOT: Loading verstage.\n");
 
-		/* load verstage from RO */
-		if (cbfs_boot_locate(&file, prog_name(&verstage), NULL))
-			die("failed to load verstage");
-
-		cbfs_file_data(prog_rdev(&verstage), &file);
-
 		if (cbfs_prog_stage_load(&verstage))
 			die("failed to load verstage");
 

src/soc/amd/common/block/pi/refcode_loader.c

@@ -51,9 +51,6 @@ static int agesa_locate_stage_file_ramstage(const char *name,
 	if (resume_from_stage_cache()) {
 		stage_cache_load_stage(STAGE_REFCODE, &prog);
 	} else {
-		if (prog_locate(&prog))
-			return -1;
-
 		if (rmodule_stage_load(&rmod_agesa) < 0)
 			return -1;
 

src/soc/intel/baytrail/refcode.c

@@ -32,11 +32,6 @@ static efi_wrapper_entry_t load_reference_code(void)
 		.prog = &prog,
 	};
 
-	if (prog_locate(&prog)) {
-		printk(BIOS_DEBUG, "Couldn't locate reference code.\n");
-		return NULL;
-	}
-
 	if (rmodule_stage_load(&refcode)) {
 		printk(BIOS_DEBUG, "Error loading reference code.\n");
 		return NULL;

src/soc/intel/broadwell/refcode.c

@@ -28,11 +28,6 @@ static pei_wrapper_entry_t load_reference_code(void)
 		.prog = &prog,
 	};
 
-	if (prog_locate(&prog)) {
-		printk(BIOS_DEBUG, "Couldn't locate reference code.\n");
-		return NULL;
-	}
-
 	if (rmodule_stage_load(&refcode)) {
 		printk(BIOS_DEBUG, "Error loading reference code.\n");
 		return NULL;

src/soc/mediatek/common/memory.c

@@ -132,11 +132,6 @@ static int dram_run_full_calibration(struct dramc_param *dparam)
 
 	initialize_dramc_param(dparam);
 
-	if (prog_locate(&dram)) {
-		printk(BIOS_ERR, "DRAM-K: Locate program failed\n");
-		return -1;
-	}
-
 	if (cbfs_prog_stage_load(&dram)) {
 		printk(BIOS_ERR, "DRAM-K: CBFS load program failed\n");
 		return -2;

src/soc/mediatek/mt8183/memory.c

@@ -105,9 +105,6 @@ static int dram_run_full_calibration(struct dramc_param *dparam,
 	/* Load and run the provided blob for full-calibration if available */
 	struct prog dram = PROG_INIT(PROG_REFCODE, CONFIG_CBFS_PREFIX "/dram");
 
-	if (prog_locate(&dram))
-		return -1;
-
 	if (cbfs_prog_stage_load(&dram))
 		return -2;
 

src/soc/qualcomm/common/qclib.c

@@ -157,9 +157,6 @@ void qclib_load_and_run(void)
 				CONFIG_CBFS_PREFIX "/qcsdi");
 
 		/* Attempt to load QCSDI elf */
-		if (prog_locate(&qcsdi))
-			goto fail;
-
 		if (cbfs_prog_stage_load(&qcsdi))
 			goto fail;
 
@@ -174,9 +171,6 @@ void qclib_load_and_run(void)
 	struct prog qclib =
 		PROG_INIT(PROG_REFCODE, CONFIG_CBFS_PREFIX "/qclib");
 
-	if (prog_locate(&qclib))
-		goto fail;
-
 	if (cbfs_prog_stage_load(&qclib))
 		goto fail;