qemu-e2k/include/qemu/osdep.h
Eric Blake 6b39b06339 build: Work around SIZE_MAX bug in OSX headers
C99 requires SIZE_MAX to be declared with the same type as the
integral promotion of size_t, but OSX mistakenly defines it as
an 'unsigned long long' expression even though size_t is only
'unsigned long'.  Rather than futzing around with whether size_t
is 32- or 64-bits wide (which would be needed if we cared about
using SIZE_T in a #if expression), just hard-code it with a cast.
This is not a strict C99-compliant definition, because it doesn't
work in the preprocessor, but if we later need that, the build
will break on Mac to inform us to improve our replacement at that
time.

See also https://patchwork.ozlabs.org/patch/542327/ for an
instance where the wrong type trips us up if we don't fix it
for good in osdep.h.

Some versions of glibc make a similar mistake with SSIZE_MAX; the
goal is that the approach of this patch could be copied to work
around that problem if it ever becomes important to us.

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-id: 1476200784-17210-1-git-send-email-eblake@redhat.com
Reviewed-by: John Arbuckle <programmingkidx@gmail.com>
Tested-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2016-10-11 19:22:20 +01:00

423 lines
11 KiB
C

/*
* OS includes and handling of OS dependencies
*
* This header exists to pull in some common system headers that
* most code in QEMU will want, and to fix up some possible issues with
* it (missing defines, Windows weirdness, and so on).
*
* To avoid getting into possible circular include dependencies, this
* file should not include any other QEMU headers, with the exceptions
* of config-host.h, config-target.h, qemu/compiler.h,
* sysemu/os-posix.h, sysemu/os-win32.h, glib-compat.h and
* qemu/typedefs.h, all of which are doing a similar job to this file
* and are under similar constraints.
*
* This header also contains prototypes for functions defined in
* os-*.c and util/oslib-*.c; those would probably be better split
* out into separate header files.
*
* In an ideal world this header would contain only:
* (1) things which everybody needs
* (2) things without which code would work on most platforms but
* fail to compile or misbehave on a minority of host OSes
*
* This work is licensed under the terms of the GNU GPL, version 2 or later.
* See the COPYING file in the top-level directory.
*/
#ifndef QEMU_OSDEP_H
#define QEMU_OSDEP_H
#include "config-host.h"
#ifdef NEED_CPU_H
#include "config-target.h"
#else
#include "exec/poison.h"
#endif
#include "qemu/compiler.h"
/* Older versions of C++ don't get definitions of various macros from
* stdlib.h unless we define these macros before first inclusion of
* that system header.
*/
#ifndef __STDC_CONSTANT_MACROS
#define __STDC_CONSTANT_MACROS
#endif
#ifndef __STDC_LIMIT_MACROS
#define __STDC_LIMIT_MACROS
#endif
#ifndef __STDC_FORMAT_MACROS
#define __STDC_FORMAT_MACROS
#endif
/* The following block of code temporarily renames the daemon() function so the
* compiler does not see the warning associated with it in stdlib.h on OSX
*/
#ifdef __APPLE__
#define daemon qemu_fake_daemon_function
#include <stdlib.h>
#undef daemon
extern int daemon(int, int);
#endif
#include <stdarg.h>
#include <stddef.h>
#include <stdbool.h>
#include <stdint.h>
#include <sys/types.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <strings.h>
#include <inttypes.h>
#include <limits.h>
/* Put unistd.h before time.h as that triggers localtime_r/gmtime_r
* function availability on recentish Mingw-w64 platforms. */
#include <unistd.h>
#include <time.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <assert.h>
/* setjmp must be declared before sysemu/os-win32.h
* because it is redefined there. */
#include <setjmp.h>
#include <signal.h>
#ifdef __OpenBSD__
#include <sys/signal.h>
#endif
#ifndef _WIN32
#include <sys/wait.h>
#else
#define WIFEXITED(x) 1
#define WEXITSTATUS(x) (x)
#endif
#ifdef _WIN32
#include "sysemu/os-win32.h"
#endif
#ifdef CONFIG_POSIX
#include "sysemu/os-posix.h"
#endif
#include "glib-compat.h"
#include "qemu/typedefs.h"
#ifndef O_LARGEFILE
#define O_LARGEFILE 0
#endif
#ifndef O_BINARY
#define O_BINARY 0
#endif
#ifndef MAP_ANONYMOUS
#define MAP_ANONYMOUS MAP_ANON
#endif
#ifndef ENOMEDIUM
#define ENOMEDIUM ENODEV
#endif
#if !defined(ENOTSUP)
#define ENOTSUP 4096
#endif
#if !defined(ECANCELED)
#define ECANCELED 4097
#endif
#if !defined(EMEDIUMTYPE)
#define EMEDIUMTYPE 4098
#endif
#ifndef TIME_MAX
#define TIME_MAX LONG_MAX
#endif
/* HOST_LONG_BITS is the size of a native pointer in bits. */
#if UINTPTR_MAX == UINT32_MAX
# define HOST_LONG_BITS 32
#elif UINTPTR_MAX == UINT64_MAX
# define HOST_LONG_BITS 64
#else
# error Unknown pointer size
#endif
/* Mac OSX has a <stdint.h> bug that incorrectly defines SIZE_MAX with
* the wrong type. Our replacement isn't usable in preprocessor
* expressions, but it is sufficient for our needs. */
#if defined(HAVE_BROKEN_SIZE_MAX) && HAVE_BROKEN_SIZE_MAX
#undef SIZE_MAX
#define SIZE_MAX ((size_t)-1)
#endif
#ifndef MIN
#define MIN(a, b) (((a) < (b)) ? (a) : (b))
#endif
#ifndef MAX
#define MAX(a, b) (((a) > (b)) ? (a) : (b))
#endif
/* Minimum function that returns zero only iff both values are zero.
* Intended for use with unsigned values only. */
#ifndef MIN_NON_ZERO
#define MIN_NON_ZERO(a, b) ((a) == 0 ? (b) : \
((b) == 0 ? (a) : (MIN(a, b))))
#endif
/* Round number down to multiple */
#define QEMU_ALIGN_DOWN(n, m) ((n) / (m) * (m))
/* Round number up to multiple. Safe when m is not a power of 2 (see
* ROUND_UP for a faster version when a power of 2 is guaranteed) */
#define QEMU_ALIGN_UP(n, m) QEMU_ALIGN_DOWN((n) + (m) - 1, (m))
/* Check if n is a multiple of m */
#define QEMU_IS_ALIGNED(n, m) (((n) % (m)) == 0)
/* n-byte align pointer down */
#define QEMU_ALIGN_PTR_DOWN(p, n) \
((typeof(p))QEMU_ALIGN_DOWN((uintptr_t)(p), (n)))
/* n-byte align pointer up */
#define QEMU_ALIGN_PTR_UP(p, n) \
((typeof(p))QEMU_ALIGN_UP((uintptr_t)(p), (n)))
/* Check if pointer p is n-bytes aligned */
#define QEMU_PTR_IS_ALIGNED(p, n) QEMU_IS_ALIGNED((uintptr_t)(p), (n))
/* Round number up to multiple. Requires that d be a power of 2 (see
* QEMU_ALIGN_UP for a safer but slower version on arbitrary
* numbers) */
#ifndef ROUND_UP
#define ROUND_UP(n,d) (((n) + (d) - 1) & -(d))
#endif
#ifndef DIV_ROUND_UP
#define DIV_ROUND_UP(n,d) (((n) + (d) - 1) / (d))
#endif
#ifndef ARRAY_SIZE
#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
#endif
int qemu_daemon(int nochdir, int noclose);
void *qemu_try_memalign(size_t alignment, size_t size);
void *qemu_memalign(size_t alignment, size_t size);
void *qemu_anon_ram_alloc(size_t size, uint64_t *align);
void qemu_vfree(void *ptr);
void qemu_anon_ram_free(void *ptr, size_t size);
#define QEMU_MADV_INVALID -1
#if defined(CONFIG_MADVISE)
#define QEMU_MADV_WILLNEED MADV_WILLNEED
#define QEMU_MADV_DONTNEED MADV_DONTNEED
#ifdef MADV_DONTFORK
#define QEMU_MADV_DONTFORK MADV_DONTFORK
#else
#define QEMU_MADV_DONTFORK QEMU_MADV_INVALID
#endif
#ifdef MADV_MERGEABLE
#define QEMU_MADV_MERGEABLE MADV_MERGEABLE
#else
#define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
#endif
#ifdef MADV_UNMERGEABLE
#define QEMU_MADV_UNMERGEABLE MADV_UNMERGEABLE
#else
#define QEMU_MADV_UNMERGEABLE QEMU_MADV_INVALID
#endif
#ifdef MADV_DODUMP
#define QEMU_MADV_DODUMP MADV_DODUMP
#else
#define QEMU_MADV_DODUMP QEMU_MADV_INVALID
#endif
#ifdef MADV_DONTDUMP
#define QEMU_MADV_DONTDUMP MADV_DONTDUMP
#else
#define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
#endif
#ifdef MADV_HUGEPAGE
#define QEMU_MADV_HUGEPAGE MADV_HUGEPAGE
#else
#define QEMU_MADV_HUGEPAGE QEMU_MADV_INVALID
#endif
#ifdef MADV_NOHUGEPAGE
#define QEMU_MADV_NOHUGEPAGE MADV_NOHUGEPAGE
#else
#define QEMU_MADV_NOHUGEPAGE QEMU_MADV_INVALID
#endif
#elif defined(CONFIG_POSIX_MADVISE)
#define QEMU_MADV_WILLNEED POSIX_MADV_WILLNEED
#define QEMU_MADV_DONTNEED POSIX_MADV_DONTNEED
#define QEMU_MADV_DONTFORK QEMU_MADV_INVALID
#define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
#define QEMU_MADV_UNMERGEABLE QEMU_MADV_INVALID
#define QEMU_MADV_DODUMP QEMU_MADV_INVALID
#define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
#define QEMU_MADV_HUGEPAGE QEMU_MADV_INVALID
#define QEMU_MADV_NOHUGEPAGE QEMU_MADV_INVALID
#else /* no-op */
#define QEMU_MADV_WILLNEED QEMU_MADV_INVALID
#define QEMU_MADV_DONTNEED QEMU_MADV_INVALID
#define QEMU_MADV_DONTFORK QEMU_MADV_INVALID
#define QEMU_MADV_MERGEABLE QEMU_MADV_INVALID
#define QEMU_MADV_UNMERGEABLE QEMU_MADV_INVALID
#define QEMU_MADV_DODUMP QEMU_MADV_INVALID
#define QEMU_MADV_DONTDUMP QEMU_MADV_INVALID
#define QEMU_MADV_HUGEPAGE QEMU_MADV_INVALID
#define QEMU_MADV_NOHUGEPAGE QEMU_MADV_INVALID
#endif
#if defined(__linux__) && \
(defined(__x86_64__) || defined(__arm__) || defined(__aarch64__))
/* Use 2 MiB alignment so transparent hugepages can be used by KVM.
Valgrind does not support alignments larger than 1 MiB,
therefore we need special code which handles running on Valgrind. */
# define QEMU_VMALLOC_ALIGN (512 * 4096)
#elif defined(__linux__) && defined(__s390x__)
/* Use 1 MiB (segment size) alignment so gmap can be used by KVM. */
# define QEMU_VMALLOC_ALIGN (256 * 4096)
#else
# define QEMU_VMALLOC_ALIGN getpagesize()
#endif
int qemu_madvise(void *addr, size_t len, int advice);
int qemu_open(const char *name, int flags, ...);
int qemu_close(int fd);
#ifndef _WIN32
int qemu_dup(int fd);
#endif
#if defined(__HAIKU__) && defined(__i386__)
#define FMT_pid "%ld"
#elif defined(WIN64)
#define FMT_pid "%" PRId64
#else
#define FMT_pid "%d"
#endif
int qemu_create_pidfile(const char *filename);
int qemu_get_thread_id(void);
#ifndef CONFIG_IOVEC
struct iovec {
void *iov_base;
size_t iov_len;
};
/*
* Use the same value as Linux for now.
*/
#define IOV_MAX 1024
ssize_t readv(int fd, const struct iovec *iov, int iov_cnt);
ssize_t writev(int fd, const struct iovec *iov, int iov_cnt);
#else
#include <sys/uio.h>
#endif
#ifdef _WIN32
static inline void qemu_timersub(const struct timeval *val1,
const struct timeval *val2,
struct timeval *res)
{
res->tv_sec = val1->tv_sec - val2->tv_sec;
if (val1->tv_usec < val2->tv_usec) {
res->tv_sec--;
res->tv_usec = val1->tv_usec - val2->tv_usec + 1000 * 1000;
} else {
res->tv_usec = val1->tv_usec - val2->tv_usec;
}
}
#else
#define qemu_timersub timersub
#endif
void qemu_set_cloexec(int fd);
/* Starting on QEMU 2.5, qemu_hw_version() returns "2.5+" by default
* instead of QEMU_VERSION, so setting hw_version on MachineClass
* is no longer mandatory.
*
* Do NOT change this string, or it will break compatibility on all
* machine classes that don't set hw_version.
*/
#define QEMU_HW_VERSION "2.5+"
/* QEMU "hardware version" setting. Used to replace code that exposed
* QEMU_VERSION to guests in the past and need to keep compatibility.
* Do not use qemu_hw_version() in new code.
*/
void qemu_set_hw_version(const char *);
const char *qemu_hw_version(void);
void fips_set_state(bool requested);
bool fips_get_state(void);
/* Return a dynamically allocated pathname denoting a file or directory that is
* appropriate for storing local state.
*
* @relative_pathname need not start with a directory separator; one will be
* added automatically.
*
* The caller is responsible for releasing the value returned with g_free()
* after use.
*/
char *qemu_get_local_state_pathname(const char *relative_pathname);
/* Find program directory, and save it for later usage with
* qemu_get_exec_dir().
* Try OS specific API first, if not working, parse from argv0. */
void qemu_init_exec_dir(const char *argv0);
/* Get the saved exec dir.
* Caller needs to release the returned string by g_free() */
char *qemu_get_exec_dir(void);
/**
* qemu_getauxval:
* @type: the auxiliary vector key to lookup
*
* Search the auxiliary vector for @type, returning the value
* or 0 if @type is not present.
*/
unsigned long qemu_getauxval(unsigned long type);
void qemu_set_tty_echo(int fd, bool echo);
void os_mem_prealloc(int fd, char *area, size_t sz, Error **errp);
int qemu_read_password(char *buf, int buf_size);
/**
* qemu_get_pid_name:
* @pid: pid of a process
*
* For given @pid fetch its name. Caller is responsible for
* freeing the string when no longer needed.
* Returns allocated string on success, NULL on failure.
*/
char *qemu_get_pid_name(pid_t pid);
/**
* qemu_fork:
*
* A version of fork that avoids signal handler race
* conditions that can lead to child process getting
* signals that are otherwise only expected by the
* parent. It also resets all signal handlers to the
* default settings.
*
* Returns 0 to child process, pid number to parent
* or -1 on failure.
*/
pid_t qemu_fork(Error **errp);
#endif