[PATCH v2 net] ptp: clockmatrix: bug fix for idtcm_strverscmp

[PATCH v2 net] ptp: clockmatrix: bug fix for idtcm_strverscmp

[min.li.xe]

From: Min Li <min.li.xe@renesas.com>

Feed kstrtou8 with NULL terminated string.

Changes since v1:
-Use strscpy instead of strncpy for safety.

Signed-off-by: Min Li <min.li.xe@renesas.com>
---
 drivers/ptp/ptp_clockmatrix.c | 60 ++++++++++++++++++++++++++++++-------------
 tools/bpf/example             | 12 +++++++++
 tools/bpf/novlan              |  7 +++++
 3 files changed, 61 insertions(+), 18 deletions(-)
 create mode 100644 tools/bpf/example
 create mode 100644 tools/bpf/novlan

diff --git a/drivers/ptp/ptp_clockmatrix.c b/drivers/ptp/ptp_clockmatrix.c
index e020faf..d4e434b 100644
--- a/drivers/ptp/ptp_clockmatrix.c
+++ b/drivers/ptp/ptp_clockmatrix.c
@@ -103,42 +103,66 @@ static int timespec_to_char_array(struct timespec64 const *ts,
 	return 0;
 }
 
-static int idtcm_strverscmp(const char *ver1, const char *ver2)
+static int idtcm_strverscmp(const char *version1, const char *version2)
 {
 	u8 num1;
 	u8 num2;
 	int result = 0;
+	char ver1[16];
+	char ver2[16];
+	char *cur1;
+	char *cur2;
+	char *next1;
+	char *next2;
+
+	if (strscpy(ver1, version1, 16) < 0 ||
+	    strscpy(ver2, version2, 16) < 0)
+		return -1;
+	cur1 = ver1;
+	cur2 = ver2;
 
 	/* loop through each level of the version string */
 	while (result == 0) {
+		next1 = strchr(cur1, '.');
+		next2 = strchr(cur2, '.');
+
+		/* kstrtou8 could fail for dot */
+		if (next1) {
+			*next1 = '\0';
+			next1++;
+		}
+
+		if (next2) {
+			*next2 = '\0';
+			next2++;
+		}
+
 		/* extract leading version numbers */
-		if (kstrtou8(ver1, 10, &num1) < 0)
+		if (kstrtou8(cur1, 10, &num1) < 0)
 			return -1;
 
-		if (kstrtou8(ver2, 10, &num2) < 0)
+		if (kstrtou8(cur2, 10, &num2) < 0)
 			return -1;
 
 		/* if numbers differ, then set the result */
 		if (num1 < num2)
+			return -1;
+		if (num1 > num2)
+			return 1;
+
+		/* if numbers are the same, go to next level */
+		if (!next1 && !next2)
+			break;
+		else if (!next1) {
 			result = -1;
-		else if (num1 > num2)
+		} else if (!next2) {
 			result = 1;
-		else {
-			/* if numbers are the same, go to next level */
-			ver1 = strchr(ver1, '.');
-			ver2 = strchr(ver2, '.');
-			if (!ver1 && !ver2)
-				break;
-			else if (!ver1)
-				result = -1;
-			else if (!ver2)
-				result = 1;
-			else {
-				ver1++;
-				ver2++;
-			}
+		} else {
+			cur1 = next1;
+			cur2 = next2;
 		}
 	}
+
 	return result;
 }
 
diff --git a/tools/bpf/example b/tools/bpf/example
new file mode 100644
index 0000000..a0ac81f
--- /dev/null
+++ b/tools/bpf/example
@@ -0,0 +1,12 @@
+  ldh [12]
+  jne #0x8100, nonvlan
+  ldh [16]
+  jne #0x88f7, bad
+  ldb [18]
+  ja test
+  nonvlan: jne #0x88f7, bad
+  ldb [14]
+  test: and #0x8
+  jeq #0, bad
+  good: ret #1500
+  bad: ret #0
diff --git a/tools/bpf/novlan b/tools/bpf/novlan
new file mode 100644
index 0000000..fe35288
--- /dev/null
+++ b/tools/bpf/novlan
@@ -0,0 +1,7 @@
+  ldh [12]
+  jne #0x88f7, bad
+  ldb [14]
+  and #0x8
+  jeq #0, bad
+  good: ret #1500
+  bad: ret #0
-- 
2.7.4

Re: [PATCH v2 net] ptp: clockmatrix: bug fix for idtcm_strverscmp

[Richard Cochran]

On Mon, Nov 23, 2020 at 03:20:06PM -0500, min.li.xe@renesas.com wrote:
> From: Min Li <min.li.xe@renesas.com>
> 
> Feed kstrtou8 with NULL terminated string.
> 
> Changes since v1:
> -Use strscpy instead of strncpy for safety.
> 
> Signed-off-by: Min Li <min.li.xe@renesas.com>
> ---
>  drivers/ptp/ptp_clockmatrix.c | 60 ++++++++++++++++++++++++++++++-------------
>  tools/bpf/example             | 12 +++++++++
>  tools/bpf/novlan              |  7 +++++
>  3 files changed, 61 insertions(+), 18 deletions(-)
>  create mode 100644 tools/bpf/example
>  create mode 100644 tools/bpf/novlan
> 
> diff --git a/drivers/ptp/ptp_clockmatrix.c b/drivers/ptp/ptp_clockmatrix.c
> index e020faf..d4e434b 100644
> --- a/drivers/ptp/ptp_clockmatrix.c
> +++ b/drivers/ptp/ptp_clockmatrix.c
> @@ -103,42 +103,66 @@ static int timespec_to_char_array(struct timespec64 const *ts,
>  	return 0;
>  }
>  
> -static int idtcm_strverscmp(const char *ver1, const char *ver2)
> +static int idtcm_strverscmp(const char *version1, const char *version2)
>  {
>  	u8 num1;
>  	u8 num2;
>  	int result = 0;
> +	char ver1[16];
> +	char ver2[16];
> +	char *cur1;
> +	char *cur2;
> +	char *next1;
> +	char *next2;
> +
> +	if (strscpy(ver1, version1, 16) < 0 ||
> +	    strscpy(ver2, version2, 16) < 0)
> +		return -1;
> +	cur1 = ver1;
> +	cur2 = ver2;
>  
>  	/* loop through each level of the version string */
>  	while (result == 0) {
> +		next1 = strchr(cur1, '.');
> +		next2 = strchr(cur2, '.');
> +
> +		/* kstrtou8 could fail for dot */
> +		if (next1) {
> +			*next1 = '\0';
> +			next1++;
> +		}
> +
> +		if (next2) {
> +			*next2 = '\0';
> +			next2++;
> +		}
> +

All of this looping and ad-hoc string parsing can be make MUCH
simpler by using sscanf() and then comparing the binary values
directly.

>  		/* extract leading version numbers */
> -		if (kstrtou8(ver1, 10, &num1) < 0)
> +		if (kstrtou8(cur1, 10, &num1) < 0)
>  			return -1;
>  
> -		if (kstrtou8(ver2, 10, &num2) < 0)
> +		if (kstrtou8(cur2, 10, &num2) < 0)
>  			return -1;
>  
>  		/* if numbers differ, then set the result */
>  		if (num1 < num2)
> +			return -1;
> +		if (num1 > num2)
> +			return 1;
> +
> +		/* if numbers are the same, go to next level */
> +		if (!next1 && !next2)
> +			break;
> +		else if (!next1) {
>  			result = -1;
> -		else if (num1 > num2)
> +		} else if (!next2) {
>  			result = 1;
> -		else {
> -			/* if numbers are the same, go to next level */
> -			ver1 = strchr(ver1, '.');
> -			ver2 = strchr(ver2, '.');
> -			if (!ver1 && !ver2)
> -				break;
> -			else if (!ver1)
> -				result = -1;
> -			else if (!ver2)
> -				result = 1;
> -			else {
> -				ver1++;
> -				ver2++;
> -			}
> +		} else {
> +			cur1 = next1;
> +			cur2 = next2;
>  		}
>  	}
> +
>  	return result;
>  }
>  

> diff --git a/tools/bpf/example b/tools/bpf/example
> new file mode 100644
> index 0000000..a0ac81f
> --- /dev/null
> +++ b/tools/bpf/example
> @@ -0,0 +1,12 @@
> +  ldh [12]
> +  jne #0x8100, nonvlan
> +  ldh [16]
> +  jne #0x88f7, bad
> +  ldb [18]
> +  ja test
> +  nonvlan: jne #0x88f7, bad
> +  ldb [14]
> +  test: and #0x8
> +  jeq #0, bad
> +  good: ret #1500
> +  bad: ret #0

Looks like this hunk and the next got included by mistake.

Thanks,
Richard

> diff --git a/tools/bpf/novlan b/tools/bpf/novlan
> new file mode 100644
> index 0000000..fe35288
> --- /dev/null
> +++ b/tools/bpf/novlan
> @@ -0,0 +1,7 @@
> +  ldh [12]
> +  jne #0x88f7, bad
> +  ldb [14]
> +  and #0x8
> +  jeq #0, bad
> +  good: ret #1500
> +  bad: ret #0
> -- 
> 2.7.4
> 

Re: [PATCH v2 net] ptp: clockmatrix: bug fix for idtcm_strverscmp

[Richard Cochran]

On Tue, Nov 24, 2020 at 11:01:26AM -0500, min.li.xe@renesas.com wrote:
> From: Min Li <min.li.xe@renesas.com>
> 
> Feed kstrtou8 with NULL terminated string.
> 
> Changes since v1:
> -Use sscanf to get rid of adhoc string parse.

This is much nicer.  Small issue remains...

> +	u8 ver1[3], ver2[3];
> +	int i;
> +
> +	if (sscanf(version1, "%hhu.%hhu.%hhu",
> +		   &ver1[0], &ver1[1], &ver1[2]) < 0)
> +		return -1;

The sscanf function returns the number of scanned items, and so you
should check that it returns 3 (three).

> +	if (sscanf(version2, "%hhu.%hhu.%hhu",
> +		   &ver2[0], &ver2[1], &ver2[2]) < 0)
> +		return -1;

Same here.

Thanks,
Richard

[PATCH v2 net] ptp: clockmatrix: bug fix for idtcm_strverscmp

[min.li.xe]

From: Min Li <min.li.xe@renesas.com>

Feed kstrtou8 with NULL terminated string.

Changes since v1:
-Use sscanf to get rid of adhoc string parse.

Signed-off-by: Min Li <min.li.xe@renesas.com>
---
 drivers/ptp/ptp_clockmatrix.c | 53 +++++++++++++++----------------------------
 1 file changed, 18 insertions(+), 35 deletions(-)

diff --git a/drivers/ptp/ptp_clockmatrix.c b/drivers/ptp/ptp_clockmatrix.c
index e020faf..12d939f 100644
--- a/drivers/ptp/ptp_clockmatrix.c
+++ b/drivers/ptp/ptp_clockmatrix.c
@@ -103,43 +103,26 @@ static int timespec_to_char_array(struct timespec64 const *ts,
 	return 0;
 }
 
-static int idtcm_strverscmp(const char *ver1, const char *ver2)
+static int idtcm_strverscmp(const char *version1, const char *version2)
 {
-	u8 num1;
-	u8 num2;
-	int result = 0;
-
-	/* loop through each level of the version string */
-	while (result == 0) {
-		/* extract leading version numbers */
-		if (kstrtou8(ver1, 10, &num1) < 0)
-			return -1;
-
-		if (kstrtou8(ver2, 10, &num2) < 0)
-			return -1;
-
-		/* if numbers differ, then set the result */
-		if (num1 < num2)
-			result = -1;
-		else if (num1 > num2)
-			result = 1;
-		else {
-			/* if numbers are the same, go to next level */
-			ver1 = strchr(ver1, '.');
-			ver2 = strchr(ver2, '.');
-			if (!ver1 && !ver2)
-				break;
-			else if (!ver1)
-				result = -1;
-			else if (!ver2)
-				result = 1;
-			else {
-				ver1++;
-				ver2++;
-			}
-		}
+	u8 ver1[3], ver2[3];
+	int i;
+
+	if (sscanf(version1, "%hhu.%hhu.%hhu",
+		   &ver1[0], &ver1[1], &ver1[2]) < 0)
+		return -1;
+	if (sscanf(version2, "%hhu.%hhu.%hhu",
+		   &ver2[0], &ver2[1], &ver2[2]) < 0)
+		return -1;
+
+	for (i = 0; i < 3; i++) {
+		if (ver1[i] > ver2[i])
+			return 1;
+		if (ver1[i] < ver2[i])
+			return -1;		
 	}
-	return result;
+
+	return 0;		
 }
 
 static int idtcm_xfer_read(struct idtcm *idtcm,
-- 
2.7.4

Re: [PATCH v2 net] ptp: clockmatrix: bug fix for idtcm_strverscmp

[Jakub Kicinski]

On Wed, 18 Nov 2020 22:50:24 -0500 min.li.xe@renesas.com wrote:
> From: Min Li <min.li.xe@renesas.com>
> 
> Feed kstrtou8 with NULL terminated string.
> 
> Changes since v1:
> -Only strcpy 15 characters to leave 1 space for '\0'
> 
> Signed-off-by: Min Li <min.li.xe@renesas.com>

> -static int idtcm_strverscmp(const char *ver1, const char *ver2)
> +static int idtcm_strverscmp(const char *version1, const char *version2)
>  {
>  	u8 num1;
>  	u8 num2;
>  	int result = 0;
> +	char ver1[16];
> +	char ver2[16];
> +	char *cur1;
> +	char *cur2;
> +	char *next1;
> +	char *next2;
> +
> +	strncpy(ver1, version1, 15);
> +	strncpy(ver2, version2, 15);
> +	cur1 = ver1;
> +	cur2 = ver2;

Now there is no guarantee that the buffer is null terminated.

You need to use strscpy(ver... 16) or add ver[15] = '\0';

>  	/* loop through each level of the version string */
>  	while (result == 0) {
> +		next1 = strchr(cur1, '.');
> +		next2 = strchr(cur2, '.');
> +
> +		/* kstrtou8 could fail for dot */
> +		if (next1) {
> +			*next1 = '\0';
> +			next1++;
> +		}
> +
> +		if (next2) {
> +			*next2 = '\0';
> +			next2++;
> +		}
> +
>  		/* extract leading version numbers */
> -		if (kstrtou8(ver1, 10, &num1) < 0)
> +		if (kstrtou8(cur1, 10, &num1) < 0)
>  			return -1;
>  
> -		if (kstrtou8(ver2, 10, &num2) < 0)
> +		if (kstrtou8(cur2, 10, &num2) < 0)
>  			return -1;
>  
>  		/* if numbers differ, then set the result */
> -		if (num1 < num2)
> +		if (num1 < num2) {
>  			result = -1;

Why do you set the result to something instead of just returning that
value? The kstrtou8() checks above just return value directly...

If you use a return you can save yourself all the else branches.

> -		else if (num1 > num2)
> +		} else if (num1 > num2) {
>  			result = 1;
> -		else {
> +		} else {
>  			/* if numbers are the same, go to next level */
> -			ver1 = strchr(ver1, '.');
> -			ver2 = strchr(ver2, '.');
> -			if (!ver1 && !ver2)
> +			if (!next1 && !next2)
>  				break;
> -			else if (!ver1)
> +			else if (!next1) {
>  				result = -1;
> -			else if (!ver2)
> +			} else if (!next2) {
>  				result = 1;
> -			else {
> -				ver1++;
> -				ver2++;
> +			} else {
> +				cur1 = next1;
> +				cur2 = next2;
>  			}
>  		}
>  	}
> +
>  	return result;
>  }
>  

[PATCH v2 net] ptp: clockmatrix: bug fix for idtcm_strverscmp

[min.li.xe]

From: Min Li <min.li.xe@renesas.com>

Feed kstrtou8 with NULL terminated string.

Changes since v1:
-Only strcpy 15 characters to leave 1 space for '\0'

Signed-off-by: Min Li <min.li.xe@renesas.com>
---
 drivers/ptp/ptp_clockmatrix.c | 52 +++++++++++++++++++++++++++++++------------
 1 file changed, 38 insertions(+), 14 deletions(-)

diff --git a/drivers/ptp/ptp_clockmatrix.c b/drivers/ptp/ptp_clockmatrix.c
index e020faf..efe5639 100644
--- a/drivers/ptp/ptp_clockmatrix.c
+++ b/drivers/ptp/ptp_clockmatrix.c
@@ -103,42 +103,66 @@ static int timespec_to_char_array(struct timespec64 const *ts,
 	return 0;
 }
 
-static int idtcm_strverscmp(const char *ver1, const char *ver2)
+static int idtcm_strverscmp(const char *version1, const char *version2)
 {
 	u8 num1;
 	u8 num2;
 	int result = 0;
+	char ver1[16];
+	char ver2[16];
+	char *cur1;
+	char *cur2;
+	char *next1;
+	char *next2;
+
+	strncpy(ver1, version1, 15);
+	strncpy(ver2, version2, 15);
+	cur1 = ver1;
+	cur2 = ver2;
 
 	/* loop through each level of the version string */
 	while (result == 0) {
+		next1 = strchr(cur1, '.');
+		next2 = strchr(cur2, '.');
+
+		/* kstrtou8 could fail for dot */
+		if (next1) {
+			*next1 = '\0';
+			next1++;
+		}
+
+		if (next2) {
+			*next2 = '\0';
+			next2++;
+		}
+
 		/* extract leading version numbers */
-		if (kstrtou8(ver1, 10, &num1) < 0)
+		if (kstrtou8(cur1, 10, &num1) < 0)
 			return -1;
 
-		if (kstrtou8(ver2, 10, &num2) < 0)
+		if (kstrtou8(cur2, 10, &num2) < 0)
 			return -1;
 
 		/* if numbers differ, then set the result */
-		if (num1 < num2)
+		if (num1 < num2) {
 			result = -1;
-		else if (num1 > num2)
+		} else if (num1 > num2) {
 			result = 1;
-		else {
+		} else {
 			/* if numbers are the same, go to next level */
-			ver1 = strchr(ver1, '.');
-			ver2 = strchr(ver2, '.');
-			if (!ver1 && !ver2)
+			if (!next1 && !next2)
 				break;
-			else if (!ver1)
+			else if (!next1) {
 				result = -1;
-			else if (!ver2)
+			} else if (!next2) {
 				result = 1;
-			else {
-				ver1++;
-				ver2++;
+			} else {
+				cur1 = next1;
+				cur2 = next2;
 			}
 		}
 	}
+
 	return result;
 }
 
-- 
2.7.4