[flashrom] [PATCH] layout: Verify layout entries before building a new image using them.

[Stefan Tauner]

This fixes a SEGFAULT if a layout entry is included that addresses memory
outside the current chip's address range.

Also, abort for non-write operations if a layout file is given.

Signed-off-by: Stefan Tauner <stefan.tauner at student.tuwien.ac.at>
---
 cli_classic.c |  6 ++++++
 flash.h       | 11 ++++++++++-
 flashrom.c    | 11 ++++++++---
 layout.c      | 33 +++++++++++++++++++++++++++++----
 4 files changed, 53 insertions(+), 8 deletions(-)

diff --git a/cli_classic.c b/cli_classic.c
index 70bccb5..a0c2d64 100644
--- a/cli_classic.c
+++ b/cli_classic.c
@@ -370,6 +370,12 @@ int main(int argc, char *argv[])
 		ret = 1;
 		goto out;
 	}
+	if (layoutfile != NULL && !write_it) {
+		msg_gerr("Layout files are currently supported for write operations only.\n");
+		ret = 1;
+		goto out;
+	}
+
 	if (process_include_args()) {
 		ret = 1;
 		goto out;
diff --git a/flash.h b/flash.h
index 7b88477..e320ced 100644
--- a/flash.h
+++ b/flash.h
@@ -45,6 +45,14 @@
 typedef uintptr_t chipaddr;
 #define PRIxPTR_WIDTH ((int)(sizeof(uintptr_t)*2))
 
+/* Types and macros regarding the maximum flash space size supported by generic code. */
+typedef uint32_t chipoff_t; /* Able to store any addressable offset within a supported flash memory. */
+typedef uint32_t chipsize_t; /* Able to store the number of bytes of any supported flash memory. */
+#define FL_MAX_CHIPADDR_BITS (24)
+#define FL_MAX_CHIPADDR ((chipoff_t)(1ULL<<FL_MAX_CHIPADDR_BITS)-1)
+#define PRIxCHIPADDR "06"PRIx32
+#define PRIuCHIPSIZE PRIu32
+
 int register_shutdown(int (*function) (void *data), void *data);
 void *programmer_map_flash_region(const char *descr, uintptr_t phys_addr, size_t len);
 void programmer_unmap_flash_region(void *virt_addr, size_t len);
@@ -319,7 +327,8 @@ __attribute__((format(printf, 2, 3)));
 int register_include_arg(char *name);
 int process_include_args(void);
 int read_romlayout(char *name);
-int handle_romentries(const struct flashctx *flash, uint8_t *oldcontents, uint8_t *newcontents);
+int normalize_romentries(const struct flashctx *flash);
+int build_new_image(const struct flashctx *flash, uint8_t *oldcontents, uint8_t *newcontents);
 void layout_cleanup(void);
 
 /* spi.c */
diff --git a/flashrom.c b/flashrom.c
index 9169620..afab57c 100644
--- a/flashrom.c
+++ b/flashrom.c
@@ -1916,6 +1916,12 @@ int doit(struct flashctx *flash, int force, const char *filename, int read_it,
 		goto out_nofree;
 	}
 
+	if (normalize_romentries(flash)) {
+		msg_cerr("Requested regions can not be handled. Aborting.\n");
+		ret = 1;
+		goto out_nofree;
+	}
+
 	/* Given the existence of read locks, we want to unlock for read,
 	 * erase and write.
 	 */
@@ -1995,9 +2001,8 @@ int doit(struct flashctx *flash, int force, const char *filename, int read_it,
 	}
 	msg_cinfo("done.\n");
 
-	// This should be moved into each flash part's code to do it 
-	// cleanly. This does the job.
-	handle_romentries(flash, oldcontents, newcontents);
+	/* Build a new image taking the given layout into account. */
+	build_new_image(flash, oldcontents, newcontents);
 
 	// ////////////////////////////////////////////////////////////
 
diff --git a/layout.c b/layout.c
index 86351b8..5254115 100644
--- a/layout.c
+++ b/layout.c
@@ -29,15 +29,15 @@
 #define MAX_ROMLAYOUT	32
 
 typedef struct {
-	unsigned int start;
-	unsigned int end;
+	chipoff_t start;
+	chipoff_t end;
 	unsigned int included;
 	char name[256];
 } romentry_t;
 
 /* rom_entries store the entries specified in a layout file and associated run-time data */
 static romentry_t rom_entries[MAX_ROMLAYOUT];
-static int num_rom_entries = 0; /* the number of valid rom_entries */
+static int num_rom_entries = 0; /* the number of successfully parsed rom_entries */
 
 /* include_args holds the arguments specified at the command line with -i. They must be processed at some point
  * so that desired regions are marked as "included" in the rom_entries list. */
@@ -232,7 +232,32 @@ romentry_t *get_next_included_romentry(unsigned int start)
 	return best_entry;
 }
 
-int handle_romentries(const struct flashctx *flash, uint8_t *oldcontents, uint8_t *newcontents)
+/* Validate and - if needed - normalize layout entries. */
+int normalize_romentries(const struct flashctx *flash)
+{
+	chipsize_t total_size = flash->chip->total_size * 1024;
+	int ret = 0;
+
+	int i;
+	for (i = 0; i < num_rom_entries; i++) {
+		if (rom_entries[i].start >= total_size || rom_entries[i].end >= total_size) {
+			msg_gwarn("Warning: Address range of region \"%s\" exceeds the current chip's "
+				  "address space.\n", rom_entries[i].name);
+			if (rom_entries[i].included)
+				ret = 1;
+		}
+		if (rom_entries[i].start > rom_entries[i].end) {
+			msg_gwarn("Warning: Size of the address range of region \"%s\" is not positive.\n",
+				  rom_entries[i].name);
+			if (rom_entries[i].included)
+				ret = 1;
+		}
+	}
+
+	return ret;
+}
+
+int build_new_image(const struct flashctx *flash, uint8_t *oldcontents, uint8_t *newcontents)
 {
 	unsigned int start = 0;
 	romentry_t *entry;
-- 
Kind regards, Stefan Tauner