[PATCH -next 3/5] ubi: Add six fault injection type for testing

From: ZhaoLong Wang
Date: Fri Mar 17 2023 - 21:57:34 EST


This commit adds six fault injection type for testing to cover the
abnormal path of the UBI driver.

Inject the following faults when the UBI reads the LEB:
+----------------------------+-----------------------------------+
| Interface name | emulate behavior |
+----------------------------+-----------------------------------+
| emulate_eccerr | ECC error |
+----------------------------+-----------------------------------+
| emulate_read_failure | read failure |
|----------------------------+-----------------------------------+
| emulate_io_ff | read content as all FF |
|----------------------------+-----------------------------------+
| emulate_io_ff_bitflips | content FF with MTD err reported |
+----------------------------+-----------------------------------+
| emulate_bad_hdr | bad leb header |
|----------------------------+-----------------------------------+
| emulate_bad_hdr_ebadmsg | bad header with ECC err |
+----------------------------+-----------------------------------+

Signed-off-by: ZhaoLong Wang <wangzhaolong1@xxxxxxxxxx>
---
drivers/mtd/ubi/debug.c | 30 ++++++++++
drivers/mtd/ubi/debug.h | 123 +++++++++++++++++++++++++++++++++++-----
drivers/mtd/ubi/io.c | 91 +++++++++++++++++++++++++----
drivers/mtd/ubi/ubi.h | 31 ++++++----
4 files changed, 240 insertions(+), 35 deletions(-)

diff --git a/drivers/mtd/ubi/debug.c b/drivers/mtd/ubi/debug.c
index 9c92bd59b639..0c58cbabe9fc 100644
--- a/drivers/mtd/ubi/debug.c
+++ b/drivers/mtd/ubi/debug.c
@@ -13,10 +13,16 @@
#include <linux/fault-inject.h>

#ifdef CONFIG_MTD_UBI_FAULT_INJECTION
+static DECLARE_FAULT_ATTR(fault_eccerr_attr);
static DECLARE_FAULT_ATTR(fault_bitflips_attr);
+static DECLARE_FAULT_ATTR(fault_read_failure_attr);
static DECLARE_FAULT_ATTR(fault_write_failure_attr);
static DECLARE_FAULT_ATTR(fault_erase_failure_attr);
static DECLARE_FAULT_ATTR(fault_power_cut_attr);
+static DECLARE_FAULT_ATTR(fault_io_ff_attr);
+static DECLARE_FAULT_ATTR(fault_io_ff_bitflips_attr);
+static DECLARE_FAULT_ATTR(fault_bad_hdr_attr);
+static DECLARE_FAULT_ATTR(fault_bad_hdr_ebadmsg_attr);

#define FAIL_ACTION(name, fault_attr) \
bool should_fail_##name(void) \
@@ -24,10 +30,16 @@ bool should_fail_##name(void) \
return should_fail(&fault_attr, 1); \
}

+FAIL_ACTION(eccerr, fault_eccerr_attr)
FAIL_ACTION(bitflips, fault_bitflips_attr)
+FAIL_ACTION(read_failure, fault_read_failure_attr)
FAIL_ACTION(write_failure, fault_write_failure_attr)
FAIL_ACTION(erase_failure, fault_erase_failure_attr)
FAIL_ACTION(power_cut, fault_power_cut_attr)
+FAIL_ACTION(io_ff, fault_io_ff_attr)
+FAIL_ACTION(io_ff_bitflips, fault_io_ff_bitflips_attr)
+FAIL_ACTION(bad_hdr, fault_bad_hdr_attr)
+FAIL_ACTION(bad_hdr_ebadmsg, fault_bad_hdr_ebadmsg_attr)
#endif


@@ -245,9 +257,15 @@ static void dfs_create_fault_entry(struct dentry *parent)
return;
}

+ fault_create_debugfs_attr("emulate_eccerr", dir,
+ &fault_eccerr_attr);
+
fault_create_debugfs_attr("emulate_bitflips", dir,
&fault_bitflips_attr);

+ fault_create_debugfs_attr("emulate_read_failure", dir,
+ &fault_read_failure_attr);
+
fault_create_debugfs_attr("emulate_write_failure", dir,
&fault_write_failure_attr);

@@ -256,6 +274,18 @@ static void dfs_create_fault_entry(struct dentry *parent)

fault_create_debugfs_attr("emulate_power_cut", dir,
&fault_power_cut_attr);
+
+ fault_create_debugfs_attr("emulate_io_ff", dir,
+ &fault_io_ff_attr);
+
+ fault_create_debugfs_attr("emulate_io_ff_bitflips", dir,
+ &fault_io_ff_bitflips_attr);
+
+ fault_create_debugfs_attr("emulate_bad_hdr", dir,
+ &fault_bad_hdr_attr);
+
+ fault_create_debugfs_attr("emulate_bad_hdr_ebadmsg", dir,
+ &fault_bad_hdr_ebadmsg_attr);
}
#endif

diff --git a/drivers/mtd/ubi/debug.h b/drivers/mtd/ubi/debug.h
index 2486fcab4205..8272c2b93dd4 100644
--- a/drivers/mtd/ubi/debug.h
+++ b/drivers/mtd/ubi/debug.h
@@ -13,13 +13,34 @@
* precisely control the type and process of fault injection.
*/
/* Emulate bit-flips */
-#define MASK_BITFLIPS (1 << 0)
-/* Emulates -EIO during write/erase */
-#define MASK_WRITE_FAILURE (1 << 1)
-#define MASK_ERASE_FAILURE (1 << 2)
+#define MASK_BITFLIPS (1 << 0)
+/* Emulate ecc error */
+#define MASK_ECCERR (1 << 1)
+/* Emulates -EIO during data read */
+#define MASK_READ_FAILURE (1 << 2)
+#define MASK_READ_FAILURE_EC (1 << 3)
+#define MASK_READ_FAILURE_VID (1 << 4)
+/* Emulates -EIO during data write */
+#define MASK_WRITE_FAILURE (1 << 5)
+/* Emulates -EIO during erase a PEB*/
+#define MASK_ERASE_FAILURE (1 << 6)
/* Emulate a power cut when writing EC/VID header */
-#define MASK_POWER_CUT_EC (1 << 3)
-#define MASK_POWER_CUT_VID (1 << 4)
+#define MASK_POWER_CUT_EC (1 << 7)
+#define MASK_POWER_CUT_VID (1 << 8)
+/* Emulate a power cut when writing data*/
+#define MASK_POWER_CUT_DATA (1 << 9)
+/* Return UBI_IO_FF when reading EC/VID header */
+#define MASK_IO_FF_EC (1 << 10)
+#define MASK_IO_FF_VID (1 << 11)
+/* Return UBI_IO_FF_BITFLIPS when reading EC/VID header */
+#define MASK_IO_FF_BITFLIPS_EC (1 << 12)
+#define MASK_IO_FF_BITFLIPS_VID (1 << 13)
+/* Return UBI_IO_BAD_HDR when reading EC/VID header */
+#define MASK_BAD_HDR_EC (1 << 14)
+#define MASK_BAD_HDR_VID (1 << 15)
+/* Return UBI_IO_BAD_HDR_EBADMSG when reading EC/VID header */
+#define MASK_BAD_HDR_EBADMSG_EC (1 << 16)
+#define MASK_BAD_HDR_EBADMSG_VID (1 << 17)

void ubi_dump_flash(struct ubi_device *ubi, int pnum, int offset, int len);
void ubi_dump_ec_hdr(const struct ubi_ec_hdr *ec_hdr);
@@ -79,10 +100,16 @@ static inline int ubi_dbg_is_bgt_disabled(const struct ubi_device *ubi)

#ifdef CONFIG_MTD_UBI_FAULT_INJECTION

+extern bool should_fail_eccerr(void);
extern bool should_fail_bitflips(void);
+extern bool should_fail_read_failure(void);
extern bool should_fail_write_failure(void);
extern bool should_fail_erase_failure(void);
extern bool should_fail_power_cut(void);
+extern bool should_fail_io_ff(void);
+extern bool should_fail_io_ff_bitflips(void);
+extern bool should_fail_bad_hdr(void);
+extern bool should_fail_bad_hdr_ebadmsg(void);

/**
* ubi_dbg_is_bitflip - if it is time to emulate a bit-flip.
@@ -97,6 +124,34 @@ static inline bool ubi_dbg_is_bitflip(const struct ubi_device *ubi)
return false;
}

+/**
+ * ubi_dbg_is_eccerr - if it is time to emulate ECC error.
+ * @ubi: UBI device description object
+ *
+ * Returns true if a ECC error should be emulated, otherwise returns false.
+ */
+static inline bool ubi_dbg_is_eccerr(const struct ubi_device *ubi)
+{
+ if (ubi->dbg.emulate_failures & MASK_ECCERR)
+ return should_fail_eccerr();
+ return false;
+}
+
+/**
+ * ubi_dbg_is_read_failure - if it is time to emulate a read failure.
+ * @ubi: UBI device description object
+ *
+ * Returns true if a read failure should be emulated, otherwise returns
+ * false.
+ */
+static inline bool ubi_dbg_is_read_failure(const struct ubi_device *ubi,
+ unsigned int caller)
+{
+ if (ubi->dbg.emulate_failures & caller)
+ return should_fail_read_failure();
+ return false;
+}
+
/**
* ubi_dbg_is_write_failure - if it is time to emulate a write failure.
* @ubi: UBI device description object
@@ -139,28 +194,70 @@ static inline bool ubi_dbg_power_cut(const struct ubi_device *ubi,
return false;
}

-#else /* CONFIG_MTD_UBI_FAULT_INJECTION */
-
-static inline bool ubi_dbg_is_bitflip(const struct ubi_device *ubi)
+/**
+ * ubi_dbg_is_ff - if it is time to emulate that read region is only 0xFF.
+ * @ubi: UBI device description object
+ *
+ * Returns true if read region should be emulated 0xFF, otherwise
+ * returns false.
+ */
+static inline bool ubi_dbg_is_ff(const struct ubi_device *ubi,
+ unsigned int caller)
{
+ if (ubi->dbg.emulate_failures & caller)
+ return should_fail_io_ff();
return false;
}

-static inline bool ubi_dbg_is_write_failure(const struct ubi_device *ubi)
+/**
+ * ubi_dbg_is_ff_bitflips - if it is time to emulate that read region is only 0xFF
+ * with error reported by the MTD driver
+ *
+ * @ubi: UBI device description object
+ *
+ * Returns true if read region should be emulated 0xFF and error
+ * reported by the MTD driver, otherwise returns false.
+ */
+static inline bool ubi_dbg_is_ff_bitflips(const struct ubi_device *ubi,
+ unsigned int caller)
{
+ if (ubi->dbg.emulate_failures & caller)
+ return should_fail_io_ff_bitflips();
return false;
}

-static inline bool ubi_dbg_is_erase_failure(const struct ubi_device *ubi)
+/**
+ * ubi_dbg_is_bad_hdr - if it is time to emulate a bad header
+ * @ubi: UBI device description object
+ *
+ * Returns true if a bad header error should be emulated, otherwise
+ * returns false.
+ */
+static inline bool ubi_dbg_is_bad_hdr(const struct ubi_device *ubi,
+ unsigned int caller)
{
+ if (ubi->dbg.emulate_failures & caller)
+ return should_fail_bad_hdr();
return false;
}

-static inline bool ubi_dbg_power_cut(const struct ubi_device *ubi,
- unsigned int caller)
+/**
+ * ubi_dbg_is_bad_hdr_ebadmsg - if it is time to emulate a bad header with
+ * ECC error.
+ *
+ * @ubi: UBI device description object
+ *
+ * Returns true if a bad header with ECC error should be emulated, otherwise
+ * returns false.
+ */
+static inline bool ubi_dbg_is_bad_hdr_ebadmsg(const struct ubi_device *ubi,
+ unsigned int caller)
{
+ if (ubi->dbg.emulate_failures & caller)
+ return should_fail_bad_hdr_ebadmsg();
return false;
}
+
#endif

static inline int ubi_dbg_chk_io(const struct ubi_device *ubi)
diff --git a/drivers/mtd/ubi/io.c b/drivers/mtd/ubi/io.c
index 906ad0811d52..e64914c3cc8d 100644
--- a/drivers/mtd/ubi/io.c
+++ b/drivers/mtd/ubi/io.c
@@ -192,11 +192,24 @@ int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
}
} else {
ubi_assert(len == read);
+#ifdef CONFIG_MTD_UBI_FAULT_INJECTION
+ if (ubi_dbg_is_read_failure(ubi, MASK_READ_FAILURE)) {
+ ubi_warn(ubi, "cannot read %d bytes from PEB %d:%d (emulated)",
+ len, pnum, offset);
+ return -EIO;
+ }
+
+ if (ubi_dbg_is_eccerr(ubi)) {
+ ubi_warn(ubi, "ECC error (emulated) while reading %d bytes from PEB %d:%d, read %zd bytes",
+ len, pnum, offset, read);
+ return -EBADMSG;
+ }

if (ubi_dbg_is_bitflip(ubi)) {
dbg_gen("bit-flip (emulated)");
err = UBI_IO_BITFLIPS;
}
+#endif
}

return err;
@@ -259,14 +272,14 @@ int ubi_io_write(struct ubi_device *ubi, const void *buf, int pnum, int offset,
if (err)
return err;
}
-
+#ifdef CONFIG_MTD_UBI_FAULT_INJECTION
if (ubi_dbg_is_write_failure(ubi)) {
ubi_err(ubi, "cannot write %d bytes to PEB %d:%d (emulated)",
len, pnum, offset);
dump_stack();
return -EIO;
}
-
+#endif
addr = (loff_t)pnum * ubi->peb_size + offset;
err = mtd_write(ubi->mtd, addr, len, &written, buf);
if (err) {
@@ -339,12 +352,12 @@ static int do_sync_erase(struct ubi_device *ubi, int pnum)
err = ubi_self_check_all_ff(ubi, pnum, 0, ubi->peb_size);
if (err)
return err;
-
+#ifdef CONFIG_MTD_UBI_FAULT_INJECTION
if (ubi_dbg_is_erase_failure(ubi)) {
ubi_err(ubi, "cannot erase PEB %d (emulated)", pnum);
return -EIO;
}
-
+#endif
return 0;
}

@@ -782,7 +795,36 @@ int ubi_io_read_ec_hdr(struct ubi_device *ubi, int pnum,
* If there was %-EBADMSG, but the header CRC is still OK, report about
* a bit-flip to force scrubbing on this PEB.
*/
- return read_err ? UBI_IO_BITFLIPS : 0;
+ if (read_err)
+ return UBI_IO_BITFLIPS;
+#ifdef CONFIG_MTD_UBI_FAULT_INJECTION
+ if (ubi_dbg_is_read_failure(ubi, MASK_READ_FAILURE_EC)) {
+ ubi_warn(ubi, "cannot read EC header from PEB %d(emulated)",
+ pnum);
+ return -EIO;
+ }
+
+ if (ubi_dbg_is_ff(ubi, MASK_IO_FF_EC)) {
+ ubi_warn(ubi, "bit-all-ff (emulated)");
+ return UBI_IO_FF;
+ }
+
+ if (ubi_dbg_is_ff_bitflips(ubi, MASK_IO_FF_BITFLIPS_EC)) {
+ ubi_warn(ubi, "bit-all-ff with error reported by MTD driver (emulated)");
+ return UBI_IO_FF_BITFLIPS;
+ }
+
+ if (ubi_dbg_is_bad_hdr(ubi, MASK_BAD_HDR_EC)) {
+ ubi_warn(ubi, "bad_hdr (emulated)");
+ return UBI_IO_BAD_HDR;
+ }
+
+ if (ubi_dbg_is_bad_hdr_ebadmsg(ubi, MASK_BAD_HDR_EBADMSG_EC)) {
+ ubi_warn(ubi, "bad_hdr with ECC error (emulated)");
+ return UBI_IO_BAD_HDR_EBADMSG;
+ }
+#endif
+ return 0;
}

/**
@@ -820,13 +862,13 @@ int ubi_io_write_ec_hdr(struct ubi_device *ubi, int pnum,
err = self_check_ec_hdr(ubi, pnum, ec_hdr);
if (err)
return err;
-
+#ifdef CONFIG_MTD_UBI_FAULT_INJECTION
if (ubi_dbg_power_cut(ubi, MASK_POWER_CUT_EC)) {
ubi_warn(ubi, "XXXXX emulating a power cut when writing EC header XXXXX");
ubi_ro_mode(ubi);
return -EROFS;
}
-
+#endif
err = ubi_io_write(ubi, ec_hdr, pnum, 0, ubi->ec_hdr_alsize);
return err;
}
@@ -1032,7 +1074,36 @@ int ubi_io_read_vid_hdr(struct ubi_device *ubi, int pnum,
return -EINVAL;
}

- return read_err ? UBI_IO_BITFLIPS : 0;
+ if (read_err)
+ return UBI_IO_BITFLIPS;
+#ifdef CONFIG_MTD_UBI_FAULT_INJECTION
+ if (ubi_dbg_is_read_failure(ubi, MASK_READ_FAILURE_VID)) {
+ ubi_warn(ubi, "cannot read VID header from PEB %d(emulated)",
+ pnum);
+ return -EIO;
+ }
+
+ if (ubi_dbg_is_ff(ubi, MASK_IO_FF_VID)) {
+ ubi_warn(ubi, "bit-all-ff (emulated)\n");
+ return UBI_IO_FF;
+ }
+
+ if (ubi_dbg_is_ff_bitflips(ubi, MASK_IO_FF_BITFLIPS_VID)) {
+ ubi_warn(ubi, "bit-all-ff with error reported by MTD driver (emulated)\n");
+ return UBI_IO_FF_BITFLIPS;
+ }
+
+ if (ubi_dbg_is_bad_hdr(ubi, MASK_BAD_HDR_VID)) {
+ ubi_warn(ubi, "bad_hdr (emulated)\n");
+ return UBI_IO_BAD_HDR;
+ }
+
+ if (ubi_dbg_is_bad_hdr_ebadmsg(ubi, MASK_BAD_HDR_EBADMSG_VID)) {
+ ubi_warn(ubi, "bad_hdr with ECC error (emulated)\n");
+ return UBI_IO_BAD_HDR_EBADMSG;
+ }
+#endif
+ return 0;
}

/**
@@ -1073,13 +1144,13 @@ int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
err = self_check_vid_hdr(ubi, pnum, vid_hdr);
if (err)
return err;
-
+#ifdef CONFIG_MTD_UBI_FAULT_INJECTION
if (ubi_dbg_power_cut(ubi, MASK_POWER_CUT_VID)) {
ubi_warn(ubi, "XXXXX emulating a power cut when writing VID header XXXXX");
ubi_ro_mode(ubi);
return -EROFS;
}
-
+#endif
err = ubi_io_write(ubi, p, pnum, ubi->vid_hdr_aloffset,
ubi->vid_hdr_alsize);
return err;
diff --git a/drivers/mtd/ubi/ubi.h b/drivers/mtd/ubi/ubi.h
index e20e9a6f9c05..7ff55a74b313 100644
--- a/drivers/mtd/ubi/ubi.h
+++ b/drivers/mtd/ubi/ubi.h
@@ -1107,18 +1107,6 @@ static inline int ubi_io_read_data(const struct ubi_device *ubi, void *buf,
return ubi_io_read(ubi, buf, pnum, offset + ubi->leb_start, len);
}

-/*
- * This function is equivalent to 'ubi_io_write()', but @offset is relative to
- * the beginning of the logical eraseblock, not to the beginning of the
- * physical eraseblock.
- */
-static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
- int pnum, int offset, int len)
-{
- ubi_assert(offset >= 0);
- return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
-}
-
/**
* ubi_ro_mode - switch to read-only mode.
* @ubi: UBI device description object
@@ -1132,6 +1120,25 @@ static inline void ubi_ro_mode(struct ubi_device *ubi)
}
}

+/*
+ * This function is equivalent to 'ubi_io_write()', but @offset is relative to
+ * the beginning of the logical eraseblock, not to the beginning of the
+ * physical eraseblock.
+ */
+static inline int ubi_io_write_data(struct ubi_device *ubi, const void *buf,
+ int pnum, int offset, int len)
+{
+ ubi_assert(offset >= 0);
+#ifdef CONFIG_MTD_UBI_FAULT_INJECTION
+ if (ubi_dbg_power_cut(ubi, MASK_POWER_CUT_DATA)) {
+ ubi_warn(ubi, "XXXXX emulating a power cut when writing data XXXXX");
+ ubi_ro_mode(ubi);
+ return -EROFS;
+ }
+#endif
+ return ubi_io_write(ubi, buf, pnum, offset + ubi->leb_start, len);
+}
+
/**
* vol_id2idx - get table index by volume ID.
* @ubi: UBI device description object
--
2.31.1