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lib/string_helpers: Add flags param to string_get_size() 

The new flags parameter allows controlling
 - Whether or not the units suffix is separated by a space, for
   compatibility with sort -h
 - Whether or not to append a B suffix - we're not always printing
   bytes.

Co-developed-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Kent Overstreet <kent.overstreet@linux.dev>
Link: https://lore.kernel.org/r/20240229205345.93902-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Kees Cook <keescook@chromium.org>
This commit is contained in:
Andy Shevchenko 2024-02-29 22:52:30 +02:00 committed by Kees Cook
parent aaa8736370
commit f0b7f8ade9
3 changed files with 78 additions and 26 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
include/linux/string_helpers.h
View File

@ -17,14 +17,18 @@ static inline bool string_is_terminated(const char *s, int len)
return memchr(s, '\0', len) ? true : false;
}
/* Descriptions of the types of units to
* print in */
/* Descriptions of the types of units to print in */
enum string_size_units {
STRING_UNITS_10, /* use powers of 10^3 (standard SI) */
STRING_UNITS_2, /* use binary powers of 2^10 */
STRING_UNITS_MASK = BIT(0),
/* Modifiers */
STRING_UNITS_NO_SPACE = BIT(30),
STRING_UNITS_NO_BYTES = BIT(31),
};
int string_get_size(u64 size, u64 blk_size, enum string_size_units units,
int string_get_size(u64 size, u64 blk_size, const enum string_size_units units,
char *buf, int len);
int parse_int_array_user(const char __user *from, size_t count, int **array);

29
lib/string_helpers.c
View File

@ -25,7 +25,7 @@
* string_get_size - get the size in the specified units
* @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)
* @units: Units to use (powers of 1000 or 1024), whether to include space separator
* @buf: buffer to format to
* @len: length of buffer
*
@ -39,11 +39,12 @@
int string_get_size(u64 size, u64 blk_size, const enum string_size_units units,
char *buf, int len)
{
enum string_size_units units_base = units & STRING_UNITS_MASK;
static const char *const units_10[] = {
"B", "kB", "MB", "GB", "TB", "PB", "EB", "ZB", "YB"
"", "k", "M", "G", "T", "P", "E", "Z", "Y",
};
static const char *const units_2[] = {
"B", "KiB", "MiB", "GiB", "TiB", "PiB", "EiB", "ZiB", "YiB"
"", "Ki", "Mi", "Gi", "Ti", "Pi", "Ei", "Zi", "Yi",
};
static const char *const *const units_str[] = {
[STRING_UNITS_10] = units_10,
@ -68,7 +69,7 @@ int string_get_size(u64 size, u64 blk_size, const enum string_size_units units,
/* This is Napier's algorithm. Reduce the original block size to
*
* coefficient * divisor[units]^i
* coefficient * divisor[units_base]^i
*
* we do the reduction so both coefficients are just under 32 bits so
* that multiplying them together won't overflow 64 bits and we keep
@ -78,12 +79,12 @@ int string_get_size(u64 size, u64 blk_size, const enum string_size_units units,
* precision is in the coefficients.
*/
while (blk_size >> 32) {
do_div(blk_size, divisor[units]);
do_div(blk_size, divisor[units_base]);
i++;
}
while (size >> 32) {
do_div(size, divisor[units]);
do_div(size, divisor[units_base]);
i++;
}
@ -92,8 +93,8 @@ int string_get_size(u64 size, u64 blk_size, const enum string_size_units units,
size *= blk_size;
/* and logarithmically reduce it until it's just under the divisor */
while (size >= divisor[units]) {
remainder = do_div(size, divisor[units]);
while (size >= divisor[units_base]) {
remainder = do_div(size, divisor[units_base]);
i++;
}
@ -103,10 +104,10 @@ int string_get_size(u64 size, u64 blk_size, const enum string_size_units units,
for (j = 0; sf_cap*10 < 1000; j++)
sf_cap *= 10;
if (units == STRING_UNITS_2) {
if (units_base == STRING_UNITS_2) {
/* express the remainder as a decimal. It's currently the
* numerator of a fraction whose denominator is
* divisor[units], which is 1 << 10 for STRING_UNITS_2 */
* divisor[units_base], which is 1 << 10 for STRING_UNITS_2 */
remainder *= 1000;
remainder >>= 10;
}
@ -128,10 +129,12 @@ int string_get_size(u64 size, u64 blk_size, const enum string_size_units units,
if (i >= ARRAY_SIZE(units_2))
unit = "UNK";
else
unit = units_str[units][i];
unit = units_str[units_base][i];
return snprintf(buf, len, "%u%s %s", (u32)size,
tmp, unit);
return snprintf(buf, len, "%u%s%s%s%s", (u32)size, tmp,
(units & STRING_UNITS_NO_SPACE) ? "" : " ",
unit,
(units & STRING_UNITS_NO_BYTES) ? "" : "B");
}
EXPORT_SYMBOL(string_get_size);

65
lib/test-string_helpers.c
View File

@ -3,6 +3,7 @@
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/array_size.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/slab.h>
@ -500,21 +501,65 @@ static __init void test_string_get_size_check(const char *units,
pr_warn("expected: '%s', got '%s'\n", exp, res);
}
static __init void __strchrcut(char *dst, const char *src, const char *cut)
{
const char *from = src;
size_t len;
do {
len = strcspn(from, cut);
memcpy(dst, from, len);
dst += len;
from += len;
} while (*from++);
*dst = '\0';
}
static __init void __test_string_get_size_one(const u64 size, const u64 blk_size,
const char *exp_result10,
const char *exp_result2,
enum string_size_units units,
const char *cut)
{
char buf10[string_get_size_maxbuf];
char buf2[string_get_size_maxbuf];
char exp10[string_get_size_maxbuf];
char exp2[string_get_size_maxbuf];
char prefix10[64];
char prefix2[64];
sprintf(prefix10, "STRING_UNITS_10 [%s]", cut);
sprintf(prefix2, "STRING_UNITS_2 [%s]", cut);
__strchrcut(exp10, exp_result10, cut);
__strchrcut(exp2, exp_result2, cut);
string_get_size(size, blk_size, STRING_UNITS_10 | units, buf10, sizeof(buf10));
string_get_size(size, blk_size, STRING_UNITS_2 | units, buf2, sizeof(buf2));
test_string_get_size_check(prefix10, exp10, buf10, size, blk_size);
test_string_get_size_check(prefix2, exp2, buf2, size, blk_size);
}
static __init void __test_string_get_size(const u64 size, const u64 blk_size,
const char *exp_result10,
const char *exp_result2)
{
char buf10[string_get_size_maxbuf];
char buf2[string_get_size_maxbuf];
struct {
enum string_size_units units;
const char *cut;
} get_size_test_cases[] = {
{ 0, "" },
{ STRING_UNITS_NO_SPACE, " " },
{ STRING_UNITS_NO_SPACE | STRING_UNITS_NO_BYTES, " B" },
{ STRING_UNITS_NO_BYTES, "B" },
};
int i;
string_get_size(size, blk_size, STRING_UNITS_10, buf10, sizeof(buf10));
string_get_size(size, blk_size, STRING_UNITS_2, buf2, sizeof(buf2));
test_string_get_size_check("STRING_UNITS_10", exp_result10, buf10,
size, blk_size);
test_string_get_size_check("STRING_UNITS_2", exp_result2, buf2,
size, blk_size);
for (i = 0; i < ARRAY_SIZE(get_size_test_cases); i++)
__test_string_get_size_one(size, blk_size, exp_result10, exp_result2,
get_size_test_cases[i].units,
get_size_test_cases[i].cut);
}
static __init void test_string_get_size(void)