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Diffstat (limited to 'drivers/mtd/ubi/io.c')
-rw-r--r--drivers/mtd/ubi/io.c145
1 files changed, 104 insertions, 41 deletions
diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c
index 811775aa8ee8..aaa6e1e83b29 100644
--- a/drivers/mtd/ubi/io.c
+++ b/drivers/mtd/ubi/io.c
@@ -91,7 +91,7 @@
#include <linux/slab.h>
#include "ubi.h"
-#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
+#ifdef CONFIG_MTD_UBI_DEBUG
static int paranoid_check_not_bad(const struct ubi_device *ubi, int pnum);
static int paranoid_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum);
static int paranoid_check_ec_hdr(const struct ubi_device *ubi, int pnum,
@@ -146,6 +146,28 @@ int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
if (err)
return err;
+ /*
+ * Deliberately corrupt the buffer to improve robustness. Indeed, if we
+ * do not do this, the following may happen:
+ * 1. The buffer contains data from previous operation, e.g., read from
+ * another PEB previously. The data looks like expected, e.g., if we
+ * just do not read anything and return - the caller would not
+ * notice this. E.g., if we are reading a VID header, the buffer may
+ * contain a valid VID header from another PEB.
+ * 2. The driver is buggy and returns us success or -EBADMSG or
+ * -EUCLEAN, but it does not actually put any data to the buffer.
+ *
+ * This may confuse UBI or upper layers - they may think the buffer
+ * contains valid data while in fact it is just old data. This is
+ * especially possible because UBI (and UBIFS) relies on CRC, and
+ * treats data as correct even in case of ECC errors if the CRC is
+ * correct.
+ *
+ * Try to prevent this situation by changing the first byte of the
+ * buffer.
+ */
+ *((uint8_t *)buf) ^= 0xFF;
+
addr = (loff_t)pnum * ubi->peb_size + offset;
retry:
err = ubi->mtd->read(ubi->mtd, addr, len, &read, buf);
@@ -166,7 +188,7 @@ retry:
return UBI_IO_BITFLIPS;
}
- if (read != len && retries++ < UBI_IO_RETRIES) {
+ if (retries++ < UBI_IO_RETRIES) {
dbg_io("error %d%s while reading %d bytes from PEB %d:%d,"
" read only %zd bytes, retry",
err, errstr, len, pnum, offset, read);
@@ -480,6 +502,13 @@ static int nor_erase_prepare(struct ubi_device *ubi, int pnum)
size_t written;
loff_t addr;
uint32_t data = 0;
+ /*
+ * Note, we cannot generally define VID header buffers on stack,
+ * because of the way we deal with these buffers (see the header
+ * comment in this file). But we know this is a NOR-specific piece of
+ * code, so we can do this. But yes, this is error-prone and we should
+ * (pre-)allocate VID header buffer instead.
+ */
struct ubi_vid_hdr vid_hdr;
/*
@@ -507,11 +536,13 @@ static int nor_erase_prepare(struct ubi_device *ubi, int pnum)
* PEB.
*/
err1 = ubi_io_read_vid_hdr(ubi, pnum, &vid_hdr, 0);
- if (err1 == UBI_IO_BAD_HDR_EBADMSG || err1 == UBI_IO_BAD_HDR) {
+ if (err1 == UBI_IO_BAD_HDR_EBADMSG || err1 == UBI_IO_BAD_HDR ||
+ err1 == UBI_IO_FF) {
struct ubi_ec_hdr ec_hdr;
err1 = ubi_io_read_ec_hdr(ubi, pnum, &ec_hdr, 0);
- if (err1 == UBI_IO_BAD_HDR_EBADMSG || err1 == UBI_IO_BAD_HDR)
+ if (err1 == UBI_IO_BAD_HDR_EBADMSG || err1 == UBI_IO_BAD_HDR ||
+ err1 == UBI_IO_FF)
/*
* Both VID and EC headers are corrupted, so we can
* safely erase this PEB and not afraid that it will be
@@ -752,9 +783,8 @@ int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
if (verbose)
ubi_warn("no EC header found at PEB %d, "
"only 0xFF bytes", pnum);
- else if (UBI_IO_DEBUG)
- dbg_msg("no EC header found at PEB %d, "
- "only 0xFF bytes", pnum);
+ dbg_bld("no EC header found at PEB %d, "
+ "only 0xFF bytes", pnum);
if (!read_err)
return UBI_IO_FF;
else
@@ -769,9 +799,9 @@ int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
ubi_warn("bad magic number at PEB %d: %08x instead of "
"%08x", pnum, magic, UBI_EC_HDR_MAGIC);
ubi_dbg_dump_ec_hdr(ec_hdr);
- } else if (UBI_IO_DEBUG)
- dbg_msg("bad magic number at PEB %d: %08x instead of "
- "%08x", pnum, magic, UBI_EC_HDR_MAGIC);
+ }
+ dbg_bld("bad magic number at PEB %d: %08x instead of "
+ "%08x", pnum, magic, UBI_EC_HDR_MAGIC);
return UBI_IO_BAD_HDR;
}
@@ -783,9 +813,9 @@ int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
ubi_warn("bad EC header CRC at PEB %d, calculated "
"%#08x, read %#08x", pnum, crc, hdr_crc);
ubi_dbg_dump_ec_hdr(ec_hdr);
- } else if (UBI_IO_DEBUG)
- dbg_msg("bad EC header CRC at PEB %d, calculated "
- "%#08x, read %#08x", pnum, crc, hdr_crc);
+ }
+ dbg_bld("bad EC header CRC at PEB %d, calculated "
+ "%#08x, read %#08x", pnum, crc, hdr_crc);
if (!read_err)
return UBI_IO_BAD_HDR;
@@ -1008,9 +1038,8 @@ int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
if (verbose)
ubi_warn("no VID header found at PEB %d, "
"only 0xFF bytes", pnum);
- else if (UBI_IO_DEBUG)
- dbg_msg("no VID header found at PEB %d, "
- "only 0xFF bytes", pnum);
+ dbg_bld("no VID header found at PEB %d, "
+ "only 0xFF bytes", pnum);
if (!read_err)
return UBI_IO_FF;
else
@@ -1021,9 +1050,9 @@ int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
ubi_warn("bad magic number at PEB %d: %08x instead of "
"%08x", pnum, magic, UBI_VID_HDR_MAGIC);
ubi_dbg_dump_vid_hdr(vid_hdr);
- } else if (UBI_IO_DEBUG)
- dbg_msg("bad magic number at PEB %d: %08x instead of "
- "%08x", pnum, magic, UBI_VID_HDR_MAGIC);
+ }
+ dbg_bld("bad magic number at PEB %d: %08x instead of "
+ "%08x", pnum, magic, UBI_VID_HDR_MAGIC);
return UBI_IO_BAD_HDR;
}
@@ -1035,9 +1064,9 @@ int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
ubi_warn("bad CRC at PEB %d, calculated %#08x, "
"read %#08x", pnum, crc, hdr_crc);
ubi_dbg_dump_vid_hdr(vid_hdr);
- } else if (UBI_IO_DEBUG)
- dbg_msg("bad CRC at PEB %d, calculated %#08x, "
- "read %#08x", pnum, crc, hdr_crc);
+ }
+ dbg_bld("bad CRC at PEB %d, calculated %#08x, "
+ "read %#08x", pnum, crc, hdr_crc);
if (!read_err)
return UBI_IO_BAD_HDR;
else
@@ -1097,7 +1126,7 @@ int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
return err;
}
-#ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
+#ifdef CONFIG_MTD_UBI_DEBUG
/**
* paranoid_check_not_bad - ensure that a physical eraseblock is not bad.
@@ -1111,6 +1140,9 @@ static int paranoid_check_not_bad(const struct ubi_device *ubi, int pnum)
{
int err;
+ if (!(ubi_chk_flags & UBI_CHK_IO))
+ return 0;
+
err = ubi_io_is_bad(ubi, pnum);
if (!err)
return err;
@@ -1135,6 +1167,9 @@ static int paranoid_check_ec_hdr(const struct ubi_device *ubi, int pnum,
int err;
uint32_t magic;
+ if (!(ubi_chk_flags & UBI_CHK_IO))
+ return 0;
+
magic = be32_to_cpu(ec_hdr->magic);
if (magic != UBI_EC_HDR_MAGIC) {
ubi_err("bad magic %#08x, must be %#08x",
@@ -1170,6 +1205,9 @@ static int paranoid_check_peb_ec_hdr(const struct ubi_device *ubi, int pnum)
uint32_t crc, hdr_crc;
struct ubi_ec_hdr *ec_hdr;
+ if (!(ubi_chk_flags & UBI_CHK_IO))
+ return 0;
+
ec_hdr = kzalloc(ubi->ec_hdr_alsize, GFP_NOFS);
if (!ec_hdr)
return -ENOMEM;
@@ -1211,6 +1249,9 @@ static int paranoid_check_vid_hdr(const struct ubi_device *ubi, int pnum,
int err;
uint32_t magic;
+ if (!(ubi_chk_flags & UBI_CHK_IO))
+ return 0;
+
magic = be32_to_cpu(vid_hdr->magic);
if (magic != UBI_VID_HDR_MAGIC) {
ubi_err("bad VID header magic %#08x at PEB %d, must be %#08x",
@@ -1249,6 +1290,9 @@ static int paranoid_check_peb_vid_hdr(const struct ubi_device *ubi, int pnum)
struct ubi_vid_hdr *vid_hdr;
void *p;
+ if (!(ubi_chk_flags & UBI_CHK_IO))
+ return 0;
+
vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
if (!vid_hdr)
return -ENOMEM;
@@ -1294,15 +1338,26 @@ int ubi_dbg_check_write(struct ubi_device *ubi, const void *buf, int pnum,
int offset, int len)
{
int err, i;
+ size_t read;
+ void *buf1;
+ loff_t addr = (loff_t)pnum * ubi->peb_size + offset;
- mutex_lock(&ubi->dbg_buf_mutex);
- err = ubi_io_read(ubi, ubi->dbg_peb_buf, pnum, offset, len);
- if (err)
- goto out_unlock;
+ if (!(ubi_chk_flags & UBI_CHK_IO))
+ return 0;
+
+ buf1 = __vmalloc(len, GFP_KERNEL | GFP_NOFS, PAGE_KERNEL);
+ if (!buf1) {
+ ubi_err("cannot allocate memory to check writes");
+ return 0;
+ }
+
+ err = ubi->mtd->read(ubi->mtd, addr, len, &read, buf1);
+ if (err && err != -EUCLEAN)
+ goto out_free;
for (i = 0; i < len; i++) {
uint8_t c = ((uint8_t *)buf)[i];
- uint8_t c1 = ((uint8_t *)ubi->dbg_peb_buf)[i];
+ uint8_t c1 = ((uint8_t *)buf1)[i];
int dump_len;
if (c == c1)
@@ -1319,17 +1374,17 @@ int ubi_dbg_check_write(struct ubi_device *ubi, const void *buf, int pnum,
ubi_msg("hex dump of the read buffer from %d to %d",
i, i + dump_len);
print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
- ubi->dbg_peb_buf + i, dump_len, 1);
+ buf1 + i, dump_len, 1);
ubi_dbg_dump_stack();
err = -EINVAL;
- goto out_unlock;
+ goto out_free;
}
- mutex_unlock(&ubi->dbg_buf_mutex);
+ vfree(buf1);
return 0;
-out_unlock:
- mutex_unlock(&ubi->dbg_buf_mutex);
+out_free:
+ vfree(buf1);
return err;
}
@@ -1348,36 +1403,44 @@ int ubi_dbg_check_all_ff(struct ubi_device *ubi, int pnum, int offset, int len)
{
size_t read;
int err;
+ void *buf;
loff_t addr = (loff_t)pnum * ubi->peb_size + offset;
- mutex_lock(&ubi->dbg_buf_mutex);
- err = ubi->mtd->read(ubi->mtd, addr, len, &read, ubi->dbg_peb_buf);
+ if (!(ubi_chk_flags & UBI_CHK_IO))
+ return 0;
+
+ buf = __vmalloc(len, GFP_KERNEL | GFP_NOFS, PAGE_KERNEL);
+ if (!buf) {
+ ubi_err("cannot allocate memory to check for 0xFFs");
+ return 0;
+ }
+
+ err = ubi->mtd->read(ubi->mtd, addr, len, &read, buf);
if (err && err != -EUCLEAN) {
ubi_err("error %d while reading %d bytes from PEB %d:%d, "
"read %zd bytes", err, len, pnum, offset, read);
goto error;
}
- err = ubi_check_pattern(ubi->dbg_peb_buf, 0xFF, len);
+ err = ubi_check_pattern(buf, 0xFF, len);
if (err == 0) {
ubi_err("flash region at PEB %d:%d, length %d does not "
"contain all 0xFF bytes", pnum, offset, len);
goto fail;
}
- mutex_unlock(&ubi->dbg_buf_mutex);
+ vfree(buf);
return 0;
fail:
ubi_err("paranoid check failed for PEB %d", pnum);
ubi_msg("hex dump of the %d-%d region", offset, offset + len);
- print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
- ubi->dbg_peb_buf, len, 1);
+ print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1, buf, len, 1);
err = -EINVAL;
error:
ubi_dbg_dump_stack();
- mutex_unlock(&ubi->dbg_buf_mutex);
+ vfree(buf);
return err;
}
-#endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */
+#endif /* CONFIG_MTD_UBI_DEBUG */
generated by cgit v1.2.3 (git 2.39.0) at 2024-12-02 12:54:59 +0300