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-rw-r--r--lib/string_helpers.c271
1 files changed, 131 insertions, 140 deletions
diff --git a/lib/string_helpers.c b/lib/string_helpers.c
index 58b78ba57439..c98ae818eb4e 100644
--- a/lib/string_helpers.c
+++ b/lib/string_helpers.c
@@ -4,6 +4,7 @@
* Copyright 31 August 2008 James Bottomley
* Copyright (C) 2013, Intel Corporation
*/
+#include <linux/bug.h>
#include <linux/kernel.h>
#include <linux/math64.h>
#include <linux/export.h>
@@ -14,25 +15,25 @@
/**
* string_get_size - get the size in the specified units
- * @size: The size to be converted
+ * @size: The size to be converted in blocks
+ * @blk_size: Size of the block (use 1 for size in bytes)
* @units: units to use (powers of 1000 or 1024)
* @buf: buffer to format to
* @len: length of buffer
*
* This function returns a string formatted to 3 significant figures
- * giving the size in the required units. Returns 0 on success or
- * error on failure. @buf is always zero terminated.
+ * giving the size in the required units. @buf should have room for
+ * at least 9 bytes and will always be zero terminated.
*
*/
-int string_get_size(u64 size, const enum string_size_units units,
- char *buf, int len)
+void string_get_size(u64 size, u64 blk_size, const enum string_size_units units,
+ char *buf, int len)
{
static const char *const units_10[] = {
- "B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB", NULL
+ "B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"
};
static const char *const units_2[] = {
- "B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB",
- NULL
+ "B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB"
};
static const char *const *const units_str[] = {
[STRING_UNITS_10] = units_10,
@@ -43,34 +44,57 @@ int string_get_size(u64 size, const enum string_size_units units,
[STRING_UNITS_2] = 1024,
};
int i, j;
- u64 remainder = 0, sf_cap;
+ u32 remainder = 0, sf_cap, exp;
char tmp[8];
+ const char *unit;
tmp[0] = '\0';
i = 0;
- if (size >= divisor[units]) {
- while (size >= divisor[units] && units_str[units][i]) {
- remainder = do_div(size, divisor[units]);
- i++;
- }
+ if (!size)
+ goto out;
- sf_cap = size;
- for (j = 0; sf_cap*10 < 1000; j++)
- sf_cap *= 10;
+ while (blk_size >= divisor[units]) {
+ remainder = do_div(blk_size, divisor[units]);
+ i++;
+ }
- if (j) {
- remainder *= 1000;
- do_div(remainder, divisor[units]);
- snprintf(tmp, sizeof(tmp), ".%03lld",
- (unsigned long long)remainder);
- tmp[j+1] = '\0';
- }
+ exp = divisor[units] / (u32)blk_size;
+ if (size >= exp) {
+ remainder = do_div(size, divisor[units]);
+ remainder *= blk_size;
+ i++;
+ } else {
+ remainder *= size;
+ }
+
+ size *= blk_size;
+ size += remainder / divisor[units];
+ remainder %= divisor[units];
+
+ while (size >= divisor[units]) {
+ remainder = do_div(size, divisor[units]);
+ i++;
}
- snprintf(buf, len, "%lld%s %s", (unsigned long long)size,
- tmp, units_str[units][i]);
+ sf_cap = size;
+ for (j = 0; sf_cap*10 < 1000; j++)
+ sf_cap *= 10;
- return 0;
+ if (j) {
+ remainder *= 1000;
+ remainder /= divisor[units];
+ snprintf(tmp, sizeof(tmp), ".%03u", remainder);
+ tmp[j+1] = '\0';
+ }
+
+ out:
+ if (i >= ARRAY_SIZE(units_2))
+ unit = "UNK";
+ else
+ unit = units_str[units][i];
+
+ snprintf(buf, len, "%u%s %s", (u32)size,
+ tmp, unit);
}
EXPORT_SYMBOL(string_get_size);
@@ -243,29 +267,21 @@ int string_unescape(char *src, char *dst, size_t size, unsigned int flags)
}
EXPORT_SYMBOL(string_unescape);
-static int escape_passthrough(unsigned char c, char **dst, size_t *osz)
+static bool escape_passthrough(unsigned char c, char **dst, char *end)
{
char *out = *dst;
- if (*osz < 1)
- return -ENOMEM;
-
- *out++ = c;
-
- *dst = out;
- *osz -= 1;
-
- return 1;
+ if (out < end)
+ *out = c;
+ *dst = out + 1;
+ return true;
}
-static int escape_space(unsigned char c, char **dst, size_t *osz)
+static bool escape_space(unsigned char c, char **dst, char *end)
{
char *out = *dst;
unsigned char to;
- if (*osz < 2)
- return -ENOMEM;
-
switch (c) {
case '\n':
to = 'n';
@@ -283,26 +299,25 @@ static int escape_space(unsigned char c, char **dst, size_t *osz)
to = 'f';
break;
default:
- return 0;
+ return false;
}
- *out++ = '\\';
- *out++ = to;
+ if (out < end)
+ *out = '\\';
+ ++out;
+ if (out < end)
+ *out = to;
+ ++out;
*dst = out;
- *osz -= 2;
-
- return 1;
+ return true;
}
-static int escape_special(unsigned char c, char **dst, size_t *osz)
+static bool escape_special(unsigned char c, char **dst, char *end)
{
char *out = *dst;
unsigned char to;
- if (*osz < 2)
- return -ENOMEM;
-
switch (c) {
case '\\':
to = '\\';
@@ -314,71 +329,78 @@ static int escape_special(unsigned char c, char **dst, size_t *osz)
to = 'e';
break;
default:
- return 0;
+ return false;
}
- *out++ = '\\';
- *out++ = to;
+ if (out < end)
+ *out = '\\';
+ ++out;
+ if (out < end)
+ *out = to;
+ ++out;
*dst = out;
- *osz -= 2;
-
- return 1;
+ return true;
}
-static int escape_null(unsigned char c, char **dst, size_t *osz)
+static bool escape_null(unsigned char c, char **dst, char *end)
{
char *out = *dst;
- if (*osz < 2)
- return -ENOMEM;
-
if (c)
- return 0;
+ return false;
- *out++ = '\\';
- *out++ = '0';
+ if (out < end)
+ *out = '\\';
+ ++out;
+ if (out < end)
+ *out = '0';
+ ++out;
*dst = out;
- *osz -= 2;
-
- return 1;
+ return true;
}
-static int escape_octal(unsigned char c, char **dst, size_t *osz)
+static bool escape_octal(unsigned char c, char **dst, char *end)
{
char *out = *dst;
- if (*osz < 4)
- return -ENOMEM;
-
- *out++ = '\\';
- *out++ = ((c >> 6) & 0x07) + '0';
- *out++ = ((c >> 3) & 0x07) + '0';
- *out++ = ((c >> 0) & 0x07) + '0';
+ if (out < end)
+ *out = '\\';
+ ++out;
+ if (out < end)
+ *out = ((c >> 6) & 0x07) + '0';
+ ++out;
+ if (out < end)
+ *out = ((c >> 3) & 0x07) + '0';
+ ++out;
+ if (out < end)
+ *out = ((c >> 0) & 0x07) + '0';
+ ++out;
*dst = out;
- *osz -= 4;
-
- return 1;
+ return true;
}
-static int escape_hex(unsigned char c, char **dst, size_t *osz)
+static bool escape_hex(unsigned char c, char **dst, char *end)
{
char *out = *dst;
- if (*osz < 4)
- return -ENOMEM;
-
- *out++ = '\\';
- *out++ = 'x';
- *out++ = hex_asc_hi(c);
- *out++ = hex_asc_lo(c);
+ if (out < end)
+ *out = '\\';
+ ++out;
+ if (out < end)
+ *out = 'x';
+ ++out;
+ if (out < end)
+ *out = hex_asc_hi(c);
+ ++out;
+ if (out < end)
+ *out = hex_asc_lo(c);
+ ++out;
*dst = out;
- *osz -= 4;
-
- return 1;
+ return true;
}
/**
@@ -430,19 +452,17 @@ static int escape_hex(unsigned char c, char **dst, size_t *osz)
* it if needs.
*
* Return:
- * The amount of the characters processed to the destination buffer, or
- * %-ENOMEM if the size of buffer is not enough to put an escaped character is
- * returned.
- *
- * Even in the case of error @dst pointer will be updated to point to the byte
- * after the last processed character.
+ * The total size of the escaped output that would be generated for
+ * the given input and flags. To check whether the output was
+ * truncated, compare the return value to osz. There is room left in
+ * dst for a '\0' terminator if and only if ret < osz.
*/
-int string_escape_mem(const char *src, size_t isz, char **dst, size_t osz,
+int string_escape_mem(const char *src, size_t isz, char *dst, size_t osz,
unsigned int flags, const char *esc)
{
- char *out = *dst, *p = out;
+ char *p = dst;
+ char *end = p + osz;
bool is_dict = esc && *esc;
- int ret = 0;
while (isz--) {
unsigned char c = *src++;
@@ -462,55 +482,26 @@ int string_escape_mem(const char *src, size_t isz, char **dst, size_t osz,
(is_dict && !strchr(esc, c))) {
/* do nothing */
} else {
- if (flags & ESCAPE_SPACE) {
- ret = escape_space(c, &p, &osz);
- if (ret < 0)
- break;
- if (ret > 0)
- continue;
- }
-
- if (flags & ESCAPE_SPECIAL) {
- ret = escape_special(c, &p, &osz);
- if (ret < 0)
- break;
- if (ret > 0)
- continue;
- }
-
- if (flags & ESCAPE_NULL) {
- ret = escape_null(c, &p, &osz);
- if (ret < 0)
- break;
- if (ret > 0)
- continue;
- }
+ if (flags & ESCAPE_SPACE && escape_space(c, &p, end))
+ continue;
+
+ if (flags & ESCAPE_SPECIAL && escape_special(c, &p, end))
+ continue;
+
+ if (flags & ESCAPE_NULL && escape_null(c, &p, end))
+ continue;
/* ESCAPE_OCTAL and ESCAPE_HEX always go last */
- if (flags & ESCAPE_OCTAL) {
- ret = escape_octal(c, &p, &osz);
- if (ret < 0)
- break;
+ if (flags & ESCAPE_OCTAL && escape_octal(c, &p, end))
continue;
- }
- if (flags & ESCAPE_HEX) {
- ret = escape_hex(c, &p, &osz);
- if (ret < 0)
- break;
+
+ if (flags & ESCAPE_HEX && escape_hex(c, &p, end))
continue;
- }
}
- ret = escape_passthrough(c, &p, &osz);
- if (ret < 0)
- break;
+ escape_passthrough(c, &p, end);
}
- *dst = p;
-
- if (ret < 0)
- return ret;
-
- return p - out;
+ return p - dst;
}
EXPORT_SYMBOL(string_escape_mem);
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