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312be567a0
bionic/libc/unistd/sysconf.c
Mikael Ohlson b44fcd6e8f Fix for incorrect reply from sysconf(_SC_NPROCESSORS_ONLN) 
When calling sysconf with _SC_NPROCESSORS_ONLN, the value one (1) was
returned on systems with two or more cores, since '/proc/stat' was
incorrectly parsed.

The function line_parser_getc (LineParser* p) read 128 characters of
input for each invocation.

The proper and probably aimed for behavior is to read 128 characters
at the first call, then for each subsequent call only return the next
buffered character until a new read is needed and only then read
another 128 characters.

Due to a flipped comparison between the two variables in_len and
in_pos that track the number of bytes of data read into the input
buffer and how much of it has been parsed, a new group of 128
characters were read at almost every call to line_parser_getc,
overwriting the still unhandled bytes from the previous call to
read. This caused the lines to be read to be sampled more than parsed.

Change-Id: I93eec3c8c9b9f19ef798748579d0977111b5c0bb

Signed-off-by: Christian Bejram <christian.bejram@stericsson.com>
2010-06-16 22:02:20 +00:00

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/*
* Copyright (C) 2008 The Android Open Source Project
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <unistd.h>
#include <sys/sysconf.h>
#include <limits.h>
#include <bionic_tls.h>
#include <asm/page.h>
#include <stdio.h> /* for FOPEN_MAX */
#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <ctype.h>
/* seems to be the default on Linux, per the GLibc sources and my own digging */
#define SYSTEM_CLK_TCK 100
#define SYSTEM_IOV_MAX 1024
#define SYSTEM_DELAYTIMER_MAX 2147483647
#define SYSTEM_MQ_OPEN_MAX 8
#define SYSTEM_MQ_PRIO_MAX 32768
#define SYSTEM_SEM_NSEMS_MAX 256
#define SYSTEM_SEM_VALUE_MAX (2147483647)
#define SYSTEM_SIGQUEUE_MAX 32
#define SYSTEM_TIMER_MAX 32
#define SYSTEM_LOGIN_NAME_MAX 256
#define SYSTEM_TTY_NAME_MAX 32
/* the following depends on our implementation */
#define SYSTEM_ATEXIT_MAX 65536 /* our implementation is unlimited */
#define SYSTEM_THREAD_KEYS_MAX BIONIC_TLS_SLOTS
#define SYSTEM_THREAD_STACK_MIN 32768 /* lower values may be possible, but be conservative */
#define SYSTEM_THREAD_THREADS_MAX 2048 /* really unlimited */
#define SYSTEM_2_C_BIND _POSIX_VERSION /* Posix C binding version */
#define SYSTEM_2_C_VER _POSIX2_C_VERSION
#define SYSTEM_2_C_DEV -1 /* Posix C development tools unsupported on the device */
#define SYSTEM_2_FORT_DEV -1 /* Fortran development unsupported */
#define SYSTEM_2_FORT_RUN -1 /* Fortran runtime unsupported */
#define SYSTEM_2_SW_DEV -1 /* posix software dev utilities unsupported */
#define SYSTEM_2_LOCALEDEF -1 /* localdef() unimplemented */
#define SYSTEM_2_UPE -1 /* No UPE for you ! (User Portability Utilities) */
#define SYSTEM_2_VERSION -1 /* No posix command-line tools */
static int __get_nproc_conf(void);
static int __get_nproc_onln(void);
static int __get_phys_pages(void);
static int __get_avphys_pages(void);
int
sysconf( int name )
{
switch (name) {
#ifdef _POSIX_ARG_MAX
case _SC_ARG_MAX: return _POSIX_ARG_MAX;
#endif
#ifdef _POSIX2_BC_BASE_MAX
case _SC_BC_BASE_MAX: return _POSIX2_BC_BASE_MAX;
#endif
#ifdef _POSIX2_BC_DIM_MAX
case _SC_BC_DIM_MAX: return _POSIX2_BC_DIM_MAX;
#endif
#ifdef _POSIX2_BC_SCALE_MAX
case _SC_BC_SCALE_MAX: return _POSIX2_BC_SCALE_MAX;
#endif
#ifdef _POSIX2_BC_STRING_MAX
case _SC_BC_STRING_MAX: return _POSIX2_BC_STRING_MAX;
#endif
case _SC_CHILD_MAX: return CHILD_MAX;
case _SC_CLK_TCK: return SYSTEM_CLK_TCK;
#ifdef _POSIX2_COLL_WEIGHTS_MASK
case _SC_COLL_WEIGHTS_MAX: return _POSIX2_COLL_WEIGHTS_MASK;
#endif
#ifdef _POSIX2_EXPR_NEST_MAX
case _SC_EXPR_NEXT_MASK: return _POSIX2_EXPR_NEST_MAX;
#endif
#ifdef _POSIX2_LINE_MAX
case _SC_LINE_MAX: return _POSIX2_LINE_MAX;
#endif
case _SC_NGROUPS_MAX: return NGROUPS_MAX;
case _SC_OPEN_MAX: return OPEN_MAX;
//case _SC_PASS_MAX: return PASS_MAX;
case _SC_2_C_BIND: return SYSTEM_2_C_BIND;
case _SC_2_C_DEV: return SYSTEM_2_C_DEV;
case _SC_2_C_VERSION: return SYSTEM_2_C_VER;
//case _SC_2_CHAR_TERM: return ;
case _SC_2_FORT_DEV: return SYSTEM_2_FORT_DEV;
case _SC_2_FORT_RUN: return SYSTEM_2_FORT_RUN;
case _SC_2_LOCALEDEF: return SYSTEM_2_LOCALEDEF;
case _SC_2_SW_DEV: return SYSTEM_2_SW_DEV;
case _SC_2_UPE: return SYSTEM_2_UPE;
case _SC_2_VERSION: return SYSTEM_2_VERSION;
#ifdef _POSIX_JOB_CONTROL
case _SC_JOB_CONTROL: return _POSIX_JOB_CONTROL;
#endif
#ifdef _POSIX_SAVED_IDS
case _SC_SAVED_IDS: return _POSIX_SAVED_IDS;
#endif
#ifdef _POSIX_VERSION
case _SC_VERSION: return _POSIX_VERSION;
#endif
//case _SC_RE_DUP_<AX: return ;
case _SC_STREAM_MAX: return FOPEN_MAX;
//case _SC_TZNAME_MAX: return ;
#if _XOPEN_CRYPT
case _SC_XOPEN_CRYPT: return _XOPEN_CRYPT;
#endif
#ifdef _XOPEN_ENH_I18N
case _SC_XOPEN_ENH_I18N: return _XOPEN_ENH_I18N;
#endif
#ifdef _XOPEN_SHM
case _SC_XOPEN_SHM: return _XOPEN_SHM;
#endif
#ifdef _XOPEN_VERSION
case _SC_XOPEN_VERSION: return _XOPEN_VERSION;
#endif
#ifdef _XOPEN_XCU_VERSION
case _SC_XOPEN_XCU_VERSION: return _XOPEN_XCU_VERSION;
#endif
#ifdef _XOPEN_REALTIME
case _SC_XOPEN_REALTIME: return _XOPEN_REALTIME;
#endif
#ifdef _XOPEN_REALTIME_THREADS
case _SC_XOPEN_REALTIME_THREADS: return _XOPEN_REALTIME_THREADS;
#endif
#ifdef _XOPEN_LEGACY
case _SC_XOPEN_LEGACY: return _XOPEN_LEGACY;
#endif
case _SC_ATEXIT_MAX: return SYSTEM_ATEXIT_MAX;
case _SC_IOV_MAX: return SYSTEM_IOV_MAX;
case _SC_PAGESIZE: return PAGE_SIZE;
case _SC_PAGE_SIZE: return PAGE_SIZE;
#ifdef _XOPEN_UNIX
case _SC_XOPEN_UNIX: return _XOPEN_UNIX;
#endif
// XXX: TODO: XBS5 nonsense
#ifdef AIO_LISTIO_MAX
case _SC_AIO_LISTIO_MAX: return AIO_LISTIO_MAX;
#endif
#ifdef AIO_MAX
case _SC_AIO_MAX: return AIO_MAX;
#endif
#ifdef AIO_PRIO_DELTA_MAX
case _SC_AIO_PRIO_DELTA_MAX: return AIO_PRIO_DELTA_MAX;
#endif
case _SC_DELAYTIMER_MAX: return SYSTEM_DELAYTIMER_MAX;
case _SC_MQ_OPEN_MAX: return SYSTEM_MQ_OPEN_MAX;
case _SC_MQ_PRIO_MAX: return SYSTEM_MQ_PRIO_MAX;
case _SC_RTSIG_MAX: return RTSIG_MAX;
case _SC_SEM_NSEMS_MAX: return SYSTEM_SEM_NSEMS_MAX;
case _SC_SEM_VALUE_MAX: return SYSTEM_SEM_VALUE_MAX;
case _SC_SIGQUEUE_MAX: return SYSTEM_SIGQUEUE_MAX;
case _SC_TIMER_MAX: return SYSTEM_TIMER_MAX;
#ifdef _POSIX_ASYNCHRONOUS_IO
case _SC_ASYNCHRONOUS_IO: return _POSIX_ASYNCHRONOUS_IO;
#endif
#ifdef _POSIX_FSYNC
case _SC_FSYNC: return _POSIX_FSYNC;
#endif
#ifdef _POSIX_MAPPED_FILES
case _SC_MAPPED_FILES: return _POSIX_MAPPED_FILES;
#endif
#ifdef _POSIX_MEMLOCK
case _SC_MEMLOCK: return _POSIX_MEMLOCK;
#endif
#ifdef _POSIX_MEMLOCK_RANGE
case _SC_MEMLOCK_RANGE: return _POSIX_MEMLOCK_RANGE
#endif
#ifdef _POSIX_MEMORY_PROTECTION
case _SC_MEMORY_PROTECTION: return _POSIX_MEMORY_PROTECTION;
#endif
#ifdef _POSIX_MESSAGE_PASSING
case _SC_MESSAGE_PASSING: return _POSIX_MESSAGE_PASSING;
#endif
#ifdef _POSIX_PRIORITIZED_IO
case _SC_PRIORITIZED_IO: return _POSIX_PRIORITIZED_IO;
#endif
#ifdef _POSIX_PRIORITY_SCHEDULING
case _SC_PRIORITY_SCHEDULING: return _POSIX_PRIORITY_SCHEDULING;
#endif
#ifdef _POSIX_REALTIME_SIGNALS
case _SC_REALTIME_SIGNALS: return _POSIX_REALTIME_SIGNALS;
#endif
#ifdef _POSIX_SEMAPHORES
case _SC_SEMAPHORES: return _POSIX_SEMAPHORES;
#endif
#ifdef _POSIX_SHARED_MEMORY_OBJECTS
case _SC_SHARED_MEMORY_OBJECTS: return _POSIX_SHARED_MEMORY_OBJECTS;
#endif
#ifdef _POSIX_SYNCHRONIZED_IO
case _SC_SYNCHRONIZED_IO: return _POSIX_SYNCHRONIZED_IO;
#endif
#ifdef _POSIX_TIMERS
case _SC_TIMERS: return _POSIX_TIMERS;
#endif
// GETGR_R_SIZE_MAX ?
// GETPW_R_SIZE_MAX ?
case _SC_LOGIN_NAME_MAX: return SYSTEM_LOGIN_NAME_MAX;
#ifdef _POSIX_THREAD_DESTRUCTOR_ITERATIONS
case _SC_THREAD_DESTRUCTOR_ITERATIONS: return _POSIX_THREAD_DESTRUCTOR_ITERATIONS;
#endif
case _SC_THREAD_KEYS_MAX: return SYSTEM_THREAD_KEYS_MAX;
case _SC_THREAD_STACK_MIN: return SYSTEM_THREAD_STACK_MIN;
case _SC_THREAD_THREADS_MAX: return SYSTEM_THREAD_THREADS_MAX;
case _SC_TTY_NAME_MAX: return SYSTEM_TTY_NAME_MAX;
#ifdef _POSIX_THREADS
case _SC_THREADS: return _POSIX_THREADS;
#endif
#ifdef _POSIX_THREAD_ATTR_STACKADDR
case _SC_THREAD_ATTR_STACKADDR: return _POSIX_THREAD_ATTR_STACKADDR;
#endif
#ifdef _POSIX_THREAD_ATTR_STACKSIZE
case _SC_THREAD_ATTR_STACKSIZE: return _POSIX_THREAD_ATTR_STACKSIZE;
#endif
#ifdef _POSIX_THREAD_PRIORITY_SCHEDULING
case _SC_THREAD_PRIORITY_SCHEDULING: return _POSIX_THREAD_PRIORITY_SCHEDULING;
#endif
#ifdef _POSIX_THREAD_PRIO_INHERIT
case _SC_THREAD_PRIO_INHERIT: return _POSIX_THREAD_PRIO_INHERIT;
#endif
#ifdef _POSIX_THREAD_PRIO_PROTECT
case _SC_THREAD_PRIO_PROTECT: return _POSIX_THREAD_PRIO_PROTECT;
#endif
#ifdef _POSIX_THREAD_SAFE_FUNCTIONS
case _SC_THREAD_SAFE_FUNCTIONS: return _POSIX_THREAD_SAFE_FUNCTIONS
#endif
case _SC_NPROCESSORS_CONF: return __get_nproc_conf();
case _SC_NPROCESSORS_ONLN: return __get_nproc_onln();
case _SC_PHYS_PAGES: return __get_phys_pages();
case _SC_AVPHYS_PAGES: return __get_avphys_pages();
default:
/* Posix says EINVAL is the only error that shall be returned,
* but GLibc uses ENOSYS */
errno = ENOSYS;
return -1;
}
}
typedef struct {
int rpos;
int len;
int overflow;
int fd;
int in_len;
int in_pos;
char buff[128];
char input[128];
} LineParser;
static int
line_parser_init( LineParser* p, const char* path )
{
p->rpos = 0;
p->len = (int)sizeof(p->buff);
p->overflow = 0;
p->in_len = 0;
p->in_pos = 0;
p->fd = open( path, O_RDONLY );
return p->fd;
}
static int
line_parser_addc( LineParser* p, int c )
{
if (p->overflow) {
p->overflow = (c == '\n');
return 0;
}
if (p->rpos >= p->len) {
p->overflow = 1;
return 0;
}
if (c == '\n') {
p->buff[p->rpos] = 0;
p->rpos = 0;
return 1;
}
p->buff[p->rpos++] = (char) c;
return 0;
}
static int
line_parser_getc( LineParser* p )
{
if (p->in_pos >= p->in_len) {
int ret;
p->in_len = p->in_pos = 0;
do {
ret = read(p->fd, p->input, sizeof(p->input));
} while (ret < 0 && errno == EINTR);
if (ret <= 0)
return -1;
p->in_len = ret;
}
return p->input[ p->in_pos++ ];
}
static const char*
line_parser_gets( LineParser* p )
{
for (;;) {
for (;;) {
int c = line_parser_getc(p);
if (c < 0) {
close(p->fd);
p->fd = -1;
return NULL;
}
if (line_parser_addc(p, c))
return p->buff;
}
}
}
static void
line_parser_done( LineParser* p )
{
if (p->fd >= 0) {
close(p->fd);
p->fd = -1;
}
}
static int
__get_nproc_conf(void)
{
LineParser parser[1];
const char* p;
int count = 0;
if (line_parser_init(parser, "/proc/cpuinfo") < 0)
return 1;
while ((p = line_parser_gets(parser))) {
if ( !memcmp(p, "processor", 9) )
count += 1;
}
return (count < 1) ? 1 : count;
}
static int
__get_nproc_onln(void)
{
LineParser parser[1];
const char* p;
int count = 0;
if (line_parser_init(parser, "/proc/stat") < 0)
return 1;
while ((p = line_parser_gets(parser))) {
if ( !memcmp(p, "cpu", 3) && isdigit(p[3]) )
count += 1;
}
return (count < 1) ? 1 : count;
}
static int
__get_phys_pages(void)
{
LineParser parser[1];
const char* p;
if (line_parser_init(parser, "/proc/meminfo") < 0)
return -2; /* what ? */
while ((p = line_parser_gets(parser))) {
long total;
if ( sscanf(p, "MemTotal: %ld kB", &total) == 1 ) {
line_parser_done(parser);
return (int) (total / (PAGE_SIZE/1024));
}
}
return -3;
}
static int
__get_avphys_pages(void)
{
LineParser parser[1];
const char* p;
if (line_parser_init(parser, "/proc/meminfo") < 0)
return -1; /* what ? */
while ((p = line_parser_gets(parser))) {
long total;
if ( sscanf(p, "MemFree: %ld kB", &total) == 1 ) {
line_parser_done(parser);
return (int) (total / (PAGE_SIZE/1024));
}
}
return -1;
}
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