From 976e741c59b64d51fec0b8c4f5c1c8d3cf8ed3be Mon Sep 17 00:00:00 2001

From: Rik van Riel <riel@redhat.com>

Date: Thu, 12 Mar 2015 17:47:00 -0400

Subject: [PATCH 1/3] import __bitmap_parselist from Linux kernel

Import __bitmap_parselist from the Linux kernel, in order to parse

CPU ranges as used in eg. the kernel isolcpus= commandline argument.

This code appears to have been in the Linux kernel since the initial

git import in 2005, so I do not have attribution of which changeset(s)

introduced it into the kernel.

Signed-off-by: Rik van Riel <riel@redhat.com>

---

 bitmap.c | 84 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

 bitmap.h | 10 ++++++--

 2 files changed, 92 insertions(+), 2 deletions(-)

diff --git a/bitmap.c b/bitmap.c

index 2f44660..6a7421a 100644

--- a/bitmap.c

+++ b/bitmap.c

@@ -377,3 +377,87 @@ int __bitmap_parse(const char *buf, unsigned int buflen,

 	return 0;

 }

+

+/**

+ * __bitmap_parselist - convert list format ASCII string to bitmap

+ * @buf: read nul-terminated user string from this buffer

+ * @buflen: buffer size in bytes.  If string is smaller than this

+ *    then it must be terminated with a \0.

+ * @is_user: location of buffer, 0 indicates kernel space

+ * @maskp: write resulting mask here

+ * @nmaskbits: number of bits in mask to be written

+ *

+ * Input format is a comma-separated list of decimal numbers and

+ * ranges.  Consecutively set bits are shown as two hyphen-separated

+ * decimal numbers, the smallest and largest bit numbers set in

+ * the range.

+ *

+ * Returns 0 on success, -errno on invalid input strings.

+ * Error values:

+ *    %-EINVAL: second number in range smaller than first

+ *    %-EINVAL: invalid character in string

+ *    %-ERANGE: bit number specified too large for mask

+ */

+int __bitmap_parselist(const char *buf, unsigned int buflen,

+		int is_user __attribute((unused)), unsigned long *maskp,

+		int nmaskbits)

+{

+	int a, b, c, old_c, totaldigits;

+	int exp_digit, in_range;

+

+	totaldigits = c = 0;

+	bitmap_zero(maskp, nmaskbits);

+	do {

+		exp_digit = 1;

+		in_range = 0;

+		a = b = 0;

+

+		/* Get the next cpu# or a range of cpu#'s */

+		while (buflen) {

+			old_c = c;

+			c = *buf++;

+			buflen--;

+			if (isspace(c))

+				continue;

+

+			/*

+			 * If the last character was a space and the current

+			 * character isn't '\0', we've got embedded whitespace.

+			 * This is a no-no, so throw an error.

+			 */

+			if (totaldigits && c && isspace(old_c))

+				return -EINVAL;

+

+			/* A '\0' or a ',' signal the end of a cpu# or range */

+			if (c == '\0' || c == ',')

+				break;

+

+			if (c == '-') {

+				if (exp_digit || in_range)

+					return -EINVAL;

+				b = 0;

+				in_range = 1;

+				exp_digit = 1;

+				continue;

+			}

+

+			if (!isdigit(c))

+				return -EINVAL;

+

+			b = b * 10 + (c - '0');

+			if (!in_range)

+				a = b;

+			exp_digit = 0;

+			totaldigits++;

+		}

+		if (!(a <= b))

+			return -EINVAL;

+		if (b >= nmaskbits)

+			return -ERANGE;

+		while (a <= b) {

+			set_bit(a, maskp);

+			a++;

+		}

+	} while (buflen && c == ',');

+	return 0;

+}

diff --git a/bitmap.h b/bitmap.h

index 91ed499..7afce59 100644

--- a/bitmap.h

+++ b/bitmap.h

@@ -185,8 +185,8 @@ extern int __bitmap_parse(const char *buf, unsigned int buflen, int is_user,

 			unsigned long *dst, int nbits);

 extern int bitmap_scnlistprintf(char *buf, unsigned int len,

 			const unsigned long *src, int nbits);

-extern int bitmap_parselist(const char *buf, unsigned long *maskp,

-			int nmaskbits);

+extern int __bitmap_parselist(const char *buf, unsigned int buflen, int is_user,

+			unsigned long *dst, int nbits);

 extern void bitmap_remap(unsigned long *dst, const unsigned long *src,

 		const unsigned long *old, const unsigned long *new, int bits);

 extern int bitmap_bitremap(int oldbit,

@@ -351,6 +351,12 @@ static inline int bitmap_parse(const char *buf, unsigned int buflen,

 	return __bitmap_parse(buf, buflen, 0, maskp, nmaskbits);

 }

+static inline int bitmap_parselist(const char *buf, unsigned int buflen,

+			unsigned long *maskp, int nmaskbits)

+{

+	return __bitmap_parselist(buf, buflen, 0, maskp, nmaskbits);

+}

+

 #endif /* __ASSEMBLY__ */

 #endif /* __LINUX_BITMAP_H */

-- 

2.1.0