| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Fri, 4 Jan 2013 13:02:28 +1300
From: Austin Boyle <Austin.Boyle@...atnet.com>
To: David Woodhouse <dwmw2@...radead.org>,
<linux-mtd@...ts.infradead.org>
CC: <linux-kernel@...r.kernel.org>,
Artem Bityutskiy <artem.bityutskiy@...ux.intel.com>
Subject: [PATCH] mtd: m25p80: Flash protection support for STmicro chips
This patch adds generic support for flash protection on STmicro chips.
On chips with less than 3 protection bits, the unused bits are don't cares
and so can be written anyway. The lock function will only change the
protection bits if it would not unlock other areas. Similarly, the unlock
function will not lock currently unlocked areas. Tested on the m25p64.
From: Austin Boyle <Austin.Boyle@...atnet.com>
Signed-off-by: Austin Boyle <Austin.Boyle@...atnet.com>
---
diff --git a/drivers/mtd/devices/m25p80.c b/drivers/mtd/devices/m25p80.c
index 4eeeb2d..069e34f 100644
--- a/drivers/mtd/devices/m25p80.c
+++ b/drivers/mtd/devices/m25p80.c
@@ -565,6 +565,96 @@ time_out:
return ret;
}
+static int m25p80_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
+{
+ struct m25p *flash = mtd_to_m25p(mtd);
+ uint32_t offset = ofs;
+ uint8_t status_old, status_new;
+ int res = 0;
+
+ mutex_lock(&flash->lock);
+ /* Wait until finished previous command */
+ if (wait_till_ready(flash)) {
+ res = 1;
+ goto err;
+ }
+
+ status_old = read_sr(flash);
+
+ if (offset < flash->mtd.size-(flash->mtd.size/2))
+ status_new = status_old | SR_BP2 | SR_BP1 | SR_BP0;
+ else if (offset < flash->mtd.size-(flash->mtd.size/4))
+ status_new = (status_old & ~SR_BP0) | SR_BP2 | SR_BP1;
+ else if (offset < flash->mtd.size-(flash->mtd.size/8))
+ status_new = (status_old & ~SR_BP1) | SR_BP2 | SR_BP0;
+ else if (offset < flash->mtd.size-(flash->mtd.size/16))
+ status_new = (status_old & ~(SR_BP0|SR_BP1)) | SR_BP2;
+ else if (offset < flash->mtd.size-(flash->mtd.size/32))
+ status_new = (status_old & ~SR_BP2) | SR_BP1 | SR_BP0;
+ else if (offset < flash->mtd.size-(flash->mtd.size/64))
+ status_new = (status_old & ~(SR_BP2|SR_BP0)) | SR_BP1;
+ else
+ status_new = (status_old & ~(SR_BP2|SR_BP1)) | SR_BP0;
+
+ /* Only modify protection if it will not unlock other areas */
+ if ((status_new&(SR_BP2|SR_BP1|SR_BP0)) >
+ (status_old&(SR_BP2|SR_BP1|SR_BP0))) {
+ write_enable(flash);
+ if (write_sr(flash, status_new) < 0) {
+ res = 1;
+ goto err;
+ }
+ }
+
+err: mutex_unlock(&flash->lock);
+ return res;
+}
+
+static int m25p80_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
+{
+ struct m25p *flash = mtd_to_m25p(mtd);
+ uint32_t offset = ofs;
+ uint8_t status_old, status_new;
+ int res = 0;
+
+ mutex_lock(&flash->lock);
+ /* Wait until finished previous command */
+ if (wait_till_ready(flash)) {
+ res = 1;
+ goto err;
+ }
+
+ status_old = read_sr(flash);
+
+ if (offset+len > flash->mtd.size-(flash->mtd.size/64))
+ status_new = status_old & ~(SR_BP2|SR_BP1|SR_BP0);
+ else if (offset+len > flash->mtd.size-(flash->mtd.size/32))
+ status_new = (status_old & ~(SR_BP2|SR_BP1)) | SR_BP0;
+ else if (offset+len > flash->mtd.size-(flash->mtd.size/16))
+ status_new = (status_old & ~(SR_BP2|SR_BP0)) | SR_BP1;
+ else if (offset+len > flash->mtd.size-(flash->mtd.size/8))
+ status_new = (status_old & ~SR_BP2) | SR_BP1 | SR_BP0;
+ else if (offset+len > flash->mtd.size-(flash->mtd.size/4))
+ status_new = (status_old & ~(SR_BP0|SR_BP1)) | SR_BP2;
+ else if (offset+len > flash->mtd.size-(flash->mtd.size/2))
+ status_new = (status_old & ~SR_BP1) | SR_BP2 | SR_BP0;
+ else
+ status_new = (status_old & ~SR_BP0) | SR_BP2 | SR_BP1;
+
+ /* Only modify protection if it will not lock other areas */
+ if ((status_new&(SR_BP2|SR_BP1|SR_BP0)) <
+ (status_old&(SR_BP2|SR_BP1|SR_BP0))) {
+ write_enable(flash);
+ if (write_sr(flash, status_new) < 0) {
+ res = 1;
+ goto err;
+ }
+ }
+
+err: mutex_unlock(&flash->lock);
+ return res;
+}
+
/****************************************************************************/
/*
@@ -899,6 +989,12 @@ static int m25p_probe(struct spi_device *spi)
flash->mtd._erase = m25p80_erase;
flash->mtd._read = m25p80_read;
+ /* flash protection support for STmicro chips */
+ if (JEDEC_MFR(info->jedec_id) == CFI_MFR_ST) {
+ flash->mtd._lock = m25p80_lock;
+ flash->mtd._unlock = m25p80_unlock;
+ }
+
/* sst flash chips use AAI word program */
if (JEDEC_MFR(info->jedec_id) == CFI_MFR_SST)
flash->mtd._write = sst_write;
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists