Revision 9c29bcd189f4ab1644b7125713602532d0aefdb7 authored by Eric Dumazet on 21 September 2018, 22:27:48 UTC, committed by David S. Miller on 24 September 2018, 04:55:25 UTC
As diagnosed by Song Liu, ndo_poll_controller() can be very dangerous on loaded hosts, since the cpu calling ndo_poll_controller() might steal all NAPI contexts (for all RX/TX queues of the NIC). This capture can last for unlimited amount of time, since one cpu is generally not able to drain all the queues under load. mlx5 uses NAPI for TX completions, so we better let core networking stack call the napi->poll() to avoid the capture. Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Saeed Mahameed <saeedm@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent a24b66c
string.c
// SPDX-License-Identifier: GPL-2.0
#include "string2.h"
#include <linux/kernel.h>
#include <linux/string.h>
#include <stdlib.h>
#include "sane_ctype.h"
#define K 1024LL
/*
* perf_atoll()
* Parse (\d+)(b|B|kb|KB|mb|MB|gb|GB|tb|TB) (e.g. "256MB")
* and return its numeric value
*/
s64 perf_atoll(const char *str)
{
s64 length;
char *p;
char c;
if (!isdigit(str[0]))
goto out_err;
length = strtoll(str, &p, 10);
switch (c = *p++) {
case 'b': case 'B':
if (*p)
goto out_err;
__fallthrough;
case '\0':
return length;
default:
goto out_err;
/* two-letter suffices */
case 'k': case 'K':
length <<= 10;
break;
case 'm': case 'M':
length <<= 20;
break;
case 'g': case 'G':
length <<= 30;
break;
case 't': case 'T':
length <<= 40;
break;
}
/* we want the cases to match */
if (islower(c)) {
if (strcmp(p, "b") != 0)
goto out_err;
} else {
if (strcmp(p, "B") != 0)
goto out_err;
}
return length;
out_err:
return -1;
}
/*
* Helper function for splitting a string into an argv-like array.
* originally copied from lib/argv_split.c
*/
static const char *skip_sep(const char *cp)
{
while (*cp && isspace(*cp))
cp++;
return cp;
}
static const char *skip_arg(const char *cp)
{
while (*cp && !isspace(*cp))
cp++;
return cp;
}
static int count_argc(const char *str)
{
int count = 0;
while (*str) {
str = skip_sep(str);
if (*str) {
count++;
str = skip_arg(str);
}
}
return count;
}
/**
* argv_free - free an argv
* @argv - the argument vector to be freed
*
* Frees an argv and the strings it points to.
*/
void argv_free(char **argv)
{
char **p;
for (p = argv; *p; p++) {
free(*p);
*p = NULL;
}
free(argv);
}
/**
* argv_split - split a string at whitespace, returning an argv
* @str: the string to be split
* @argcp: returned argument count
*
* Returns an array of pointers to strings which are split out from
* @str. This is performed by strictly splitting on white-space; no
* quote processing is performed. Multiple whitespace characters are
* considered to be a single argument separator. The returned array
* is always NULL-terminated. Returns NULL on memory allocation
* failure.
*/
char **argv_split(const char *str, int *argcp)
{
int argc = count_argc(str);
char **argv = calloc(argc + 1, sizeof(*argv));
char **argvp;
if (argv == NULL)
goto out;
if (argcp)
*argcp = argc;
argvp = argv;
while (*str) {
str = skip_sep(str);
if (*str) {
const char *p = str;
char *t;
str = skip_arg(str);
t = strndup(p, str-p);
if (t == NULL)
goto fail;
*argvp++ = t;
}
}
*argvp = NULL;
out:
return argv;
fail:
argv_free(argv);
return NULL;
}
/* Character class matching */
static bool __match_charclass(const char *pat, char c, const char **npat)
{
bool complement = false, ret = true;
if (*pat == '!') {
complement = true;
pat++;
}
if (*pat++ == c) /* First character is special */
goto end;
while (*pat && *pat != ']') { /* Matching */
if (*pat == '-' && *(pat + 1) != ']') { /* Range */
if (*(pat - 1) <= c && c <= *(pat + 1))
goto end;
if (*(pat - 1) > *(pat + 1))
goto error;
pat += 2;
} else if (*pat++ == c)
goto end;
}
if (!*pat)
goto error;
ret = false;
end:
while (*pat && *pat != ']') /* Searching closing */
pat++;
if (!*pat)
goto error;
*npat = pat + 1;
return complement ? !ret : ret;
error:
return false;
}
/* Glob/lazy pattern matching */
static bool __match_glob(const char *str, const char *pat, bool ignore_space,
bool case_ins)
{
while (*str && *pat && *pat != '*') {
if (ignore_space) {
/* Ignore spaces for lazy matching */
if (isspace(*str)) {
str++;
continue;
}
if (isspace(*pat)) {
pat++;
continue;
}
}
if (*pat == '?') { /* Matches any single character */
str++;
pat++;
continue;
} else if (*pat == '[') /* Character classes/Ranges */
if (__match_charclass(pat + 1, *str, &pat)) {
str++;
continue;
} else
return false;
else if (*pat == '\\') /* Escaped char match as normal char */
pat++;
if (case_ins) {
if (tolower(*str) != tolower(*pat))
return false;
} else if (*str != *pat)
return false;
str++;
pat++;
}
/* Check wild card */
if (*pat == '*') {
while (*pat == '*')
pat++;
if (!*pat) /* Tail wild card matches all */
return true;
while (*str)
if (__match_glob(str++, pat, ignore_space, case_ins))
return true;
}
return !*str && !*pat;
}
/**
* strglobmatch - glob expression pattern matching
* @str: the target string to match
* @pat: the pattern string to match
*
* This returns true if the @str matches @pat. @pat can includes wildcards
* ('*','?') and character classes ([CHARS], complementation and ranges are
* also supported). Also, this supports escape character ('\') to use special
* characters as normal character.
*
* Note: if @pat syntax is broken, this always returns false.
*/
bool strglobmatch(const char *str, const char *pat)
{
return __match_glob(str, pat, false, false);
}
bool strglobmatch_nocase(const char *str, const char *pat)
{
return __match_glob(str, pat, false, true);
}
/**
* strlazymatch - matching pattern strings lazily with glob pattern
* @str: the target string to match
* @pat: the pattern string to match
*
* This is similar to strglobmatch, except this ignores spaces in
* the target string.
*/
bool strlazymatch(const char *str, const char *pat)
{
return __match_glob(str, pat, true, false);
}
/**
* strtailcmp - Compare the tail of two strings
* @s1: 1st string to be compared
* @s2: 2nd string to be compared
*
* Return 0 if whole of either string is same as another's tail part.
*/
int strtailcmp(const char *s1, const char *s2)
{
int i1 = strlen(s1);
int i2 = strlen(s2);
while (--i1 >= 0 && --i2 >= 0) {
if (s1[i1] != s2[i2])
return s1[i1] - s2[i2];
}
return 0;
}
/**
* strxfrchar - Locate and replace character in @s
* @s: The string to be searched/changed.
* @from: Source character to be replaced.
* @to: Destination character.
*
* Return pointer to the changed string.
*/
char *strxfrchar(char *s, char from, char to)
{
char *p = s;
while ((p = strchr(p, from)) != NULL)
*p++ = to;
return s;
}
/**
* ltrim - Removes leading whitespace from @s.
* @s: The string to be stripped.
*
* Return pointer to the first non-whitespace character in @s.
*/
char *ltrim(char *s)
{
while (isspace(*s))
s++;
return s;
}
/**
* rtrim - Removes trailing whitespace from @s.
* @s: The string to be stripped.
*
* Note that the first trailing whitespace is replaced with a %NUL-terminator
* in the given string @s. Returns @s.
*/
char *rtrim(char *s)
{
size_t size = strlen(s);
char *end;
if (!size)
return s;
end = s + size - 1;
while (end >= s && isspace(*end))
end--;
*(end + 1) = '\0';
return s;
}
char *asprintf_expr_inout_ints(const char *var, bool in, size_t nints, int *ints)
{
/*
* FIXME: replace this with an expression using log10() when we
* find a suitable implementation, maybe the one in the dvb drivers...
*
* "%s == %d || " = log10(MAXINT) * 2 + 8 chars for the operators
*/
size_t size = nints * 28 + 1; /* \0 */
size_t i, printed = 0;
char *expr = malloc(size);
if (expr) {
const char *or_and = "||", *eq_neq = "==";
char *e = expr;
if (!in) {
or_and = "&&";
eq_neq = "!=";
}
for (i = 0; i < nints; ++i) {
if (printed == size)
goto out_err_overflow;
if (i > 0)
printed += scnprintf(e + printed, size - printed, " %s ", or_and);
printed += scnprintf(e + printed, size - printed,
"%s %s %d", var, eq_neq, ints[i]);
}
}
return expr;
out_err_overflow:
free(expr);
return NULL;
}
/* Like strpbrk(), but not break if it is right after a backslash (escaped) */
char *strpbrk_esc(char *str, const char *stopset)
{
char *ptr;
do {
ptr = strpbrk(str, stopset);
if (ptr == str ||
(ptr == str + 1 && *(ptr - 1) != '\\'))
break;
str = ptr + 1;
} while (ptr && *(ptr - 1) == '\\' && *(ptr - 2) != '\\');
return ptr;
}
/* Like strdup, but do not copy a single backslash */
char *strdup_esc(const char *str)
{
char *s, *d, *p, *ret = strdup(str);
if (!ret)
return NULL;
d = strchr(ret, '\\');
if (!d)
return ret;
s = d + 1;
do {
if (*s == '\0') {
*d = '\0';
break;
}
p = strchr(s + 1, '\\');
if (p) {
memmove(d, s, p - s);
d += p - s;
s = p + 1;
} else
memmove(d, s, strlen(s) + 1);
} while (p);
return ret;
}
![swh spinner](/static/img/swh-spinner.gif)
Computing file changes ...