Change in flashrom[master]: linux_mtd: fix wp range detection in mtd_wp_status

[David Hendricks (Code Review)]

Hello Nicolas Boichat,

I'd like you to do a code review. Please visit

https://review.coreboot.org/22506

to review the following change.

Change subject: linux_mtd: fix wp range detection in mtd_wp_status
......................................................................

linux_mtd: fix wp range detection in mtd_wp_status

The logic in wp range detection in mtd_wp_status is wrong. The first
block (start == 0) may possible be write-protected, thus we can't use
'if (!start)' for detecting start of write-protection. Since start and
end are both uint32_t, we add two new int variables to flag the status.

Signed-off-by: Wei-Ning Huang

BUG=chrome-os-partner:40208
TEST=`flashrom --wp-enable --wp-range 0x0 0x200000` then `flashrom --wp-status`
     should display: 'WP: write protect range: start=0x00000000, len=0x00200000'

Change-Id: Id8934c2ba997ff8558a9be3a5aa05b56272c9e85
Reviewed-on: https://chromium-review.googlesource.com/330225
Commit-Ready: Wei-Ning Huang 
Tested-by: Wei-Ning Huang 
Reviewed-by: David Hendricks 
Reviewed-by: Nicolas Boichat 
---
M linux_mtd.c
1 file changed, 9 insertions(+), 4 deletions(-)

git pull ssh://review.coreboot.org:29418/flashrom refs/changes/06/22506/1

diff --git a/linux_mtd.c b/linux_mtd.c
index c707167..6055aef 100644
--- a/linux_mtd.c
+++ b/linux_mtd.c
@@ -476,6 +476,7 @@
 static int mtd_wp_status(const struct flashchip *flash)
 {
    uint32_t start = 0, end = 0;
+	int start_found = 0, end_found = 0;
    unsigned int u;

/* For now, assume only one contiguous region can be locked (NOR) */
@@ -492,14 +493,18 @@
    		msg_perr("%s: ioctl: %s\n", __func__, strerror(errno));
    		return 1;
    	} else if (rc == 1) {
-			if (!start)
+			if (!start_found) {
    			start = erase_info.start;
+				start_found = 1;
+			}
    	} else if (rc == 0) {
-			if (start)
-				end = erase_info.start - 1;
+			if (start_found) {
+				end = erase_info.start;
+				end_found = 1;
+			}
    	}

-		if (start && end) {
+		if (start_found && end_found) {
    		msg_pinfo("WP: write protect range: start=0x%08x, "
    			"len=0x%08x\n", start, end - start);
    		/* TODO: Replace this break with "start = end = 0" if