selfload: check target memory type in selfload_check

Currently, selflock_check() verifies that the binary is loaded in an
usable RAM area.

Extend its functionality so we can also check that BL31 is loaded in
a manually reserved area, and fail early if the range is not protected.

Change-Id: Iecdeedd9e8da67f73ac47d2a82e85b306469a626
Signed-off-by: Ting Shen <phoenixshen@google.com>
Reviewed-on: https://review.coreboot.org/c/31122
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>

3 files changed, 19 insertions, 24 deletions

diff --git a/src/lib/bootmem.c b/src/lib/bootmem.c
index 2f9b5dc0b1..c804df5973 100644
--- a/src/lib/bootmem.c
+++ b/src/lib/bootmem.c
@@ -201,33 +201,25 @@ bool bootmem_walk(range_action_t action, void *arg)
 	return false;
 }
 
-static int bootmem_region_targets_ram(uint64_t start, uint64_t end,
-				struct memranges *bm)
+int bootmem_region_targets_type(uint64_t start, uint64_t size,
+				enum bootmem_type dest_type)
 {
 	const struct range_entry *r;
+	uint64_t end = start + size;
 
-	memranges_each_entry(r, bm) {
+	memranges_each_entry(r, &bootmem) {
 		/* All further bootmem entries are beyond this range. */
 		if (end <= range_entry_base(r))
 			break;
 
 		if (start >= range_entry_base(r) && end <= range_entry_end(r)) {
-			if (range_entry_tag(r) == BM_MEM_RAM)
+			if (range_entry_tag(r) == dest_type)
 				return 1;
 		}
 	}
 	return 0;
 }
 
-/* Common testcase for loading any segments to bootmem.
- * Returns 1 if the requested memory range is all tagged as type BM_MEM_RAM.
- * Otherwise returns 0.
- */
-int bootmem_region_targets_usable_ram(uint64_t start, uint64_t size)
-{
-	return bootmem_region_targets_ram(start, start + size, &bootmem);
-}
-
 void *bootmem_allocate_buffer(size_t size)
 {
 	const struct range_entry *r;
diff --git a/src/lib/prog_loaders.c b/src/lib/prog_loaders.c
index ac80a62c9d..70ea7efe66 100644
--- a/src/lib/prog_loaders.c
+++ b/src/lib/prog_loaders.c
@@ -182,7 +182,7 @@ void payload_load(void)
 
 	switch (prog_cbfs_type(payload)) {
 	case CBFS_TYPE_SELF: /* Simple ELF */
-		selfload_check(payload);
+		selfload_check(payload, BM_MEM_RAM);
 		break;
 	case CBFS_TYPE_FIT: /* Flattened image tree */
 		if (IS_ENABLED(CONFIG_PAYLOAD_FIT_SUPPORT)) {
diff --git a/src/lib/selfboot.c b/src/lib/selfboot.c
index 9c52cd6bef..9aa47413c5 100644
--- a/src/lib/selfboot.c
+++ b/src/lib/selfboot.c
@@ -30,7 +30,7 @@
 #include <cbmem.h>
 
 /* The type syntax for C is essentially unparsable. -- Rob Pike */
-typedef int (*checker_t)(struct cbfs_payload_segment *cbfssegs);
+typedef int (*checker_t)(struct cbfs_payload_segment *cbfssegs, void *args);
 
 /* Decode a serialized cbfs payload segment
  * from memory into native endianness.
@@ -46,10 +46,11 @@ static void cbfs_decode_payload_segment(struct cbfs_payload_segment *segment,
 	segment->mem_len     = read_be32(&src->mem_len);
 }
 
-static int segment_targets_usable_ram(void *dest, unsigned long memsz)
+static int segment_targets_type(void *dest, unsigned long memsz,
+		enum bootmem_type dest_type)
 {
 	uintptr_t d = (uintptr_t) dest;
-	if (bootmem_region_targets_usable_ram(d, memsz))
+	if (bootmem_region_targets_type(d, memsz, dest_type))
 		return 1;
 
 	if (payload_arch_usable_ram_quirk(d, memsz))
@@ -140,11 +141,13 @@ static int last_loadable_segment(struct cbfs_payload_segment *seg)
 	return read_be32(&(seg + 1)->type) == PAYLOAD_SEGMENT_ENTRY;
 }
 
-static int check_payload_segments(struct cbfs_payload_segment *cbfssegs)
+static int check_payload_segments(struct cbfs_payload_segment *cbfssegs,
+		void *args)
 {
 	uint8_t *dest;
 	size_t memsz;
 	struct cbfs_payload_segment *first_segment, *seg, segment;
+	enum bootmem_type dest_type = *(enum bootmem_type *)args;
 
 	for (first_segment = seg = cbfssegs;; ++seg) {
 		printk(BIOS_DEBUG, "Checking segment from ROM address 0x%p\n", seg);
@@ -153,7 +156,7 @@ static int check_payload_segments(struct cbfs_payload_segment *cbfssegs)
 		memsz = segment.mem_len;
 		if (segment.type == PAYLOAD_SEGMENT_ENTRY)
 			break;
-		if (!segment_targets_usable_ram(dest, memsz))
+		if (!segment_targets_type(dest, memsz, dest_type))
 			return -1;
 	}
 	return 0;
@@ -244,7 +247,7 @@ static void *selfprepare(struct prog *payload)
 	return data;
 }
 
-static bool _selfload(struct prog *payload, checker_t f)
+static bool _selfload(struct prog *payload, checker_t f, void *args)
 {
 	uintptr_t entry = 0;
 	struct cbfs_payload_segment *cbfssegs;
@@ -256,7 +259,7 @@ static bool _selfload(struct prog *payload, checker_t f)
 
 	cbfssegs = &((struct cbfs_payload *)data)->segments;
 
-	if (f && f(cbfssegs))
+	if (f && f(cbfssegs, args))
 		goto out;
 
 	if (load_payload_segments(cbfssegs, &entry))
@@ -275,12 +278,12 @@ out:
 	return false;
 }
 
-bool selfload_check(struct prog *payload)
+bool selfload_check(struct prog *payload, enum bootmem_type dest_type)
 {
-	return _selfload(payload, check_payload_segments);
+	return _selfload(payload, check_payload_segments, &dest_type);
 }
 
 bool selfload(struct prog *payload)
 {
-	return _selfload(payload, NULL);
+	return _selfload(payload, NULL, 0);
 }