flashrom.c: Fail immediately when trying to write/erase wp regions

.gitignore

@@ -20,3 +20,6 @@
 /util/ich_descriptors_tool/.obj
 
 target/
+
+subprojects/cmocka-*/
+subprojects/packagecache/

flashrom.c

@@ -383,6 +383,13 @@ void get_flash_region(const struct flashctx *flash, int addr, struct flash_regio
 	}
 }
 
+struct protected_ranges get_protected_ranges(const struct flashctx *flash) {
+	struct protected_ranges ranges = { 0 };
+	if ((flash->mst->buses_supported & BUS_PROG) && flash->mst->opaque.get_protected_ranges)
+		ranges = flash->mst->opaque.get_protected_ranges();
+	return ranges;
+}
+
 int check_for_unwritable_regions(const struct flashctx *flash, unsigned int start, unsigned int len)
 {
 	struct flash_region region;
@@ -1738,6 +1745,43 @@ static int unlock_flash_wp(struct flashctx *const flash,
 	return ret;
 }
 
+static int write_protect_check(struct flashctx *flash) {
+	bool check_wp = false;
+	size_t wp_start, wp_len;
+	enum flashrom_wp_mode mode;
+	struct flashrom_wp_cfg *cfg = NULL;
+	const struct romentry *entry = NULL;
+	const struct flashrom_layout *const layout = get_layout(flash);
+	struct protected_ranges ranges = get_protected_ranges(flash);
+
+	if (flashrom_wp_cfg_new(&cfg) == FLASHROM_WP_OK &&
+		flashrom_wp_read_cfg(cfg, flash) == FLASHROM_WP_OK )
+	{
+		flashrom_wp_get_range(&wp_start, &wp_len, cfg);
+		mode = flashrom_wp_get_mode(cfg);
+		if (mode != FLASHROM_WP_MODE_DISABLED && wp_len != 0)
+			check_wp = true;
+	}
+	flashrom_wp_cfg_release(cfg);
+
+	while ((entry = layout_next_included(layout, entry))) {
+		if (!flash->flags.skip_unwritable_regions &&
+			check_for_unwritable_regions(flash, entry->region.start, entry->region.end - entry->region.start))
+		{
+			return -1;
+		}
+		if (check_wp && entry->region.start < wp_start + wp_len && wp_start <= entry->region.end)
+			return -1;
+		for (int i = 0; i < ranges.count; ++i) {
+			struct protected_range prot = ranges.ranges[i];
+			if (prot.write_prot && entry->region.start < prot.base + prot.limit && prot.base <= entry->region.end)
+				return -1;
+		}
+	}
+
+	return 0;
+}
+
 int prepare_flash_access(struct flashctx *const flash,
 			 const bool read_it, const bool write_it,
 			 const bool erase_it, const bool verify_it)
@@ -1752,6 +1796,13 @@ int prepare_flash_access(struct flashctx *const flash,
 		return 1;
 	}
 
+	if ((write_it || erase_it) && !flash->flags.force) {
+		if (write_protect_check(flash)) {
+			msg_cerr("Requested regions are write protected. Aborting.\n");
+			return 1;
+		}
+	}
+
 	if (map_flash(flash) != 0)
 		return 1;
 

ichspi.c

@@ -1289,6 +1289,13 @@ struct hwseq_data {
 	struct fd_region fd_regions[MAX_FD_REGIONS];
 };
 
+#define MAX_PR_REGISTERS 6
+struct protected_range _ranges[MAX_PR_REGISTERS];
+struct protected_ranges ranges = {
+	.count = 0,
+	.ranges = _ranges,
+};
+
 static struct hwseq_data *get_hwseq_data_from_context(const struct flashctx *flash)
 {
 	return flash->mst->opaque.data;
@@ -1471,6 +1478,10 @@ static void ich_get_region(const struct flashctx *flash, unsigned int addr, stru
 	region->name = strdup(name);
 }
 
+static struct protected_ranges ich_get_protected_ranges() {
+	return ranges;
+}
+
 /* Given RDID info, return pointer to entry in flashchips[] */
 static const struct flashchip *flash_id_to_entry(uint32_t mfg_id, uint32_t model_id)
 {
@@ -1950,13 +1961,18 @@ static enum ich_access_protection ich9_handle_region_access(struct fd_region *fd
 #define ICH_PR_PERMS(pr)	(((~((pr) >> PR_RP_OFF) & 1) << 0) | \
 				 ((~((pr) >> PR_WP_OFF) & 1) << 1))
 
-static enum ich_access_protection ich9_handle_pr(const size_t reg_pr0, unsigned int i)
+static enum ich_access_protection ich9_handle_pr(const size_t reg_pr0, unsigned int i, struct protected_range* prot)
 {
 	uint8_t off = reg_pr0 + (i * 4);
 	uint32_t pr = mmio_readl(ich_spibar + off);
 	unsigned int rwperms_idx = ICH_PR_PERMS(pr);
 	enum ich_access_protection rwperms = access_perms_to_protection[rwperms_idx];
 
+	prot->base = ICH_FREG_BASE(pr);
+	prot->limit = ICH_FREG_LIMIT(pr);
+	prot->write_prot = rwperms == WRITE_PROT;
+	prot->read_prot = (rwperms == READ_PROT) || (rwperms == LOCKED);
+
 	/* From 5 on we have GPR registers and start from 0 again. */
 	const char *const prefix = i >= 5 ? "G" : "";
 	if (i >= 5)
@@ -2019,6 +2035,7 @@ static const struct opaque_master opaque_master_ich_hwseq = {
 	.read_register	= ich_hwseq_read_status,
 	.write_register	= ich_hwseq_write_status,
 	.get_region	= ich_get_region,
+	.get_protected_ranges = ich_get_protected_ranges,
 	.shutdown	= ich_hwseq_shutdown,
 };
 
@@ -2239,11 +2256,12 @@ static int init_ich_default(const struct programmer_cfg *cfg, void *spibar, enum
 	}
 
 	/* Handle PR registers */
+	ranges.count = num_pr;
 	for (i = 0; i < num_pr; i++) {
 		/* if not locked down try to disable PR locks first */
 		if (!ichspi_lock)
 			ich9_set_pr(reg_pr0, i, 0, 0);
-		ich_spi_rw_restricted |= ich9_handle_pr(reg_pr0, i);
+		ich_spi_rw_restricted |= ich9_handle_pr(reg_pr0, i, &_ranges[i]);
 	}
 
 	switch (ich_spi_rw_restricted) {

include/layout.h

@@ -57,6 +57,18 @@ struct romentry {
 	struct flash_region region;
 };
 
+struct protected_range {
+	uint32_t base;
+	uint32_t limit;
+	bool read_prot;
+	bool write_prot;
+};
+
+struct protected_ranges {
+	int count;
+	const struct protected_range *ranges;
+};
+
 struct flashrom_layout;
 
 struct layout_include_args;
@@ -79,5 +91,6 @@ void prepare_layout_for_extraction(struct flashrom_flashctx *);
 int layout_sanity_checks(const struct flashrom_flashctx *);
 int check_for_unwritable_regions(const struct flashrom_flashctx *flash, unsigned int start, unsigned int len);
 void get_flash_region(const struct flashrom_flashctx *flash, int addr, struct flash_region *region);
+struct protected_ranges get_protected_ranges(const struct flashrom_flashctx *flash);
 
 #endif /* !__LAYOUT_H__ */

include/programmer.h

@@ -450,6 +450,7 @@ struct opaque_master {
 	enum flashrom_wp_result (*wp_read_cfg)(struct flashrom_wp_cfg *, struct flashctx *);
 	enum flashrom_wp_result (*wp_get_ranges)(struct flashrom_wp_ranges **, struct flashctx *);
 	void (*get_region)(const struct flashctx *flash, unsigned int addr, struct flash_region *region);
+	struct protected_ranges (*get_protected_ranges)();
 	int (*shutdown)(void *data);
 	void (*delay) (const struct flashctx *flash, unsigned int usecs);
 	void *data;