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Rework cpu affinity parsing

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The CPU_SET_S api is pretty bad. In particular, it has a parameter for the size
of the array, but operations which take two (CPU_EQUAL_S) or even three arrays
(CPU_{AND,OR,XOR}_S) still take just one size. This means that all arrays must
be of the same size, or buffer overruns will occur. This is exactly what our
code would do, if it received an array of unexpected size over the network.
("Unexpected" here means anything different from what cpu_set_malloc() detects
as the "right" size.)

Let's rework this, and store the size in bytes of the allocated storage area.

The code will now parse any number up to 8191, independently of what the current
kernel supports. This matches the kernel maximum setting for any architecture,
to make things more portable.

Fixes #12605.
This commit is contained in:
Zbigniew Jędrzejewski-Szmek
2019-05-29 10:20:42 +02:00
parent b12ef71416
commit 0985c7c4e2
14 changed files with 293 additions and 254 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/shared/bus-unit-util.c
+2 -2
View File
@@ -992,13 +992,13 @@ static int bus_append_execute_property(sd_bus_message *m, const char *field, con
}
if (streq(field, "CPUAffinity")) {
_cleanup_cpu_free_ cpu_set_t *cpuset = NULL;
_cleanup_(cpu_set_reset) CPUSet cpuset = {};
r = parse_cpu_set(eq, &cpuset);
if (r < 0)
return log_error_errno(r, "Failed to parse %s value: %s", field, eq);
return bus_append_byte_array(m, field, cpuset, CPU_ALLOC_SIZE(r));
return bus_append_byte_array(m, field, cpuset.set, cpuset.allocated);
}
if (STR_IN_SET(field, "RestrictAddressFamilies", "SystemCallFilter")) {
src/shared/cpu-set-util.c
+108 -25
View File
@@ -10,16 +10,17 @@
#include "extract-word.h"
#include "log.h"
#include "macro.h"
#include "memory-util.h"
#include "parse-util.h"
#include "string-util.h"
char* cpu_set_to_string(const cpu_set_t *set, size_t setsize) {
char* cpu_set_to_string(const CPUSet *a) {
_cleanup_free_ char *str = NULL;
size_t allocated = 0, len = 0;
int i, r;
for (i = 0; (size_t) i < setsize * 8; i++) {
if (!CPU_ISSET_S(i, setsize, set))
for (i = 0; (size_t) i < a->allocated * 8; i++) {
if (!CPU_ISSET_S(i, a->allocated, a->set))
continue;
if (!GREEDY_REALLOC(str, allocated, len + 1 + DECIMAL_STR_MAX(int)))
@@ -62,24 +63,74 @@ cpu_set_t* cpu_set_malloc(unsigned *ncpus) {
}
}
int parse_cpu_set_internal(
static int cpu_set_realloc(CPUSet *cpu_set, unsigned ncpus) {
size_t need;
assert(cpu_set);
need = CPU_ALLOC_SIZE(ncpus);
if (need > cpu_set->allocated) {
cpu_set_t *t;
t = realloc(cpu_set->set, need);
if (!t)
return -ENOMEM;
memzero((uint8_t*) t + cpu_set->allocated, need - cpu_set->allocated);
cpu_set->set = t;
cpu_set->allocated = need;
}
return 0;
}
static int cpu_set_add(CPUSet *cpu_set, unsigned cpu) {
int r;
if (cpu >= 8192)
/* As of kernel 5.1, CONFIG_NR_CPUS can be set to 8192 on PowerPC */
return -ERANGE;
r = cpu_set_realloc(cpu_set, cpu + 1);
if (r < 0)
return r;
CPU_SET_S(cpu, cpu_set->allocated, cpu_set->set);
return 0;
}
int cpu_set_add_all(CPUSet *a, const CPUSet *b) {
int r;
/* Do this backwards, so if we fail, we fail before changing anything. */
for (unsigned cpu_p1 = b->allocated * 8; cpu_p1 > 0; cpu_p1--)
if (CPU_ISSET_S(cpu_p1 - 1, b->allocated, b->set)) {
r = cpu_set_add(a, cpu_p1 - 1);
if (r < 0)
return r;
}
return 0;
}
int parse_cpu_set_full(
const char *rvalue,
cpu_set_t **cpu_set,
CPUSet *cpu_set,
bool warn,
const char *unit,
const char *filename,
unsigned line,
const char *lvalue) {
_cleanup_cpu_free_ cpu_set_t *c = NULL;
_cleanup_(cpu_set_reset) CPUSet c = {};
const char *p = rvalue;
unsigned ncpus = 0;
assert(rvalue);
assert(p);
for (;;) {
_cleanup_free_ char *word = NULL;
unsigned cpu, cpu_lower, cpu_upper;
unsigned cpu_lower, cpu_upper;
int r;
r = extract_first_word(&p, &word, WHITESPACE ",", EXTRACT_QUOTES);
@@ -90,31 +141,63 @@ int parse_cpu_set_internal(
if (r == 0)
break;
if (!c) {
c = cpu_set_malloc(&ncpus);
if (!c)
return warn ? log_oom() : -ENOMEM;
}
r = parse_range(word, &cpu_lower, &cpu_upper);
if (r < 0)
return warn ? log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse CPU affinity '%s'", word) : r;
if (cpu_lower >= ncpus || cpu_upper >= ncpus)
return warn ? log_syntax(unit, LOG_ERR, filename, line, EINVAL, "CPU out of range '%s' ncpus is %u", word, ncpus) : -EINVAL;
if (cpu_lower > cpu_upper) {
if (warn)
log_syntax(unit, LOG_WARNING, filename, line, 0, "Range '%s' is invalid, %u > %u, ignoring", word, cpu_lower, cpu_upper);
continue;
log_syntax(unit, LOG_WARNING, filename, line, 0, "Range '%s' is invalid, %u > %u, ignoring.",
word, cpu_lower, cpu_upper);
/* Make sure something is allocated, to distinguish this from the empty case */
r = cpu_set_realloc(&c, 1);
if (r < 0)
return r;
}
for (cpu = cpu_lower; cpu <= cpu_upper; cpu++)
CPU_SET_S(cpu, CPU_ALLOC_SIZE(ncpus), c);
for (unsigned cpu_p1 = MIN(cpu_upper, UINT_MAX-1) + 1; cpu_p1 > cpu_lower; cpu_p1--) {
r = cpu_set_add(&c, cpu_p1 - 1);
if (r < 0)
return warn ? log_syntax(unit, LOG_ERR, filename, line, r,
"Cannot add CPU %u to set: %m", cpu_p1 - 1) : r;
}
}
/* On success, sets *cpu_set and returns ncpus for the system. */
if (c)
*cpu_set = TAKE_PTR(c);
/* On success, transfer ownership to the output variable */
*cpu_set = c;
c = (CPUSet) {};
return (int) ncpus;
return 0;
}
int parse_cpu_set_extend(
const char *rvalue,
CPUSet *old,
bool warn,
const char *unit,
const char *filename,
unsigned line,
const char *lvalue) {
_cleanup_(cpu_set_reset) CPUSet cpuset = {};
int r;
r = parse_cpu_set_full(rvalue, &cpuset, true, unit, filename, line, lvalue);
if (r < 0)
return r;
if (!cpuset.set) {
/* An empty assignment resets the CPU list */
cpu_set_reset(old);
return 0;
}
if (!old->set) {
*old = cpuset;
cpuset = (CPUSet) {};
return 0;
}
return cpu_set_add_all(old, &cpuset);
}
src/shared/cpu-set-util.h
+31 -14
View File
@@ -8,23 +8,40 @@
DEFINE_TRIVIAL_CLEANUP_FUNC(cpu_set_t*, CPU_FREE);
#define _cleanup_cpu_free_ _cleanup_(CPU_FREEp)
static inline cpu_set_t* cpu_set_mfree(cpu_set_t *p) {
if (p)
CPU_FREE(p);
return NULL;
}
cpu_set_t* cpu_set_malloc(unsigned *ncpus);
char* cpu_set_to_string(const cpu_set_t *set, size_t setsize);
int parse_cpu_set_internal(const char *rvalue, cpu_set_t **cpu_set, bool warn, const char *unit, const char *filename, unsigned line, const char *lvalue);
/* This wraps the libc interface with a variable to keep the allocated size. */
typedef struct CPUSet {
cpu_set_t *set;
size_t allocated; /* in bytes */
} CPUSet;
static inline int parse_cpu_set_and_warn(const char *rvalue, cpu_set_t **cpu_set, const char *unit, const char *filename, unsigned line, const char *lvalue) {
assert(lvalue);
return parse_cpu_set_internal(rvalue, cpu_set, true, unit, filename, line, lvalue);
static inline void cpu_set_reset(CPUSet *a) {
assert((a->allocated > 0) == !!a->set);
if (a->set)
CPU_FREE(a->set);
*a = (CPUSet) {};
}
static inline int parse_cpu_set(const char *rvalue, cpu_set_t **cpu_set){
return parse_cpu_set_internal(rvalue, cpu_set, false, NULL, NULL, 0, NULL);
int cpu_set_add_all(CPUSet *a, const CPUSet *b);
char* cpu_set_to_string(const CPUSet *a);
int parse_cpu_set_full(
const char *rvalue,
CPUSet *cpu_set,
bool warn,
const char *unit,
const char *filename, unsigned line,
const char *lvalue);
int parse_cpu_set_extend(
const char *rvalue,
CPUSet *old,
bool warn,
const char *unit,
const char *filename,
unsigned line,
const char *lvalue);
static inline int parse_cpu_set(const char *rvalue, CPUSet *cpu_set){
return parse_cpu_set_full(rvalue, cpu_set, false, NULL, NULL, 0, NULL);
}