qemu-e2k/include/qemu/osdep.h
Daniel P. Berrangé 9afa888ce0 osdep: set _FORTIFY_SOURCE=2 when optimization is enabled
Currently we set _FORTIFY_SOURCE=2 as a compiler argument when the
meson 'optimization' setting is non-zero, the compiler is GCC and
the target is Linux.

While the default QEMU optimization level is 2, user could override
this by setting CFLAGS="-O0" or --extra-cflags="-O0" when running
configure and this won't be reflected in the meson 'optimization'
setting. As a result we try to enable _FORTIFY_SOURCE=2 and then the
user gets compile errors as it only works with optimization.

Rather than trying to improve detection in meson, it is simpler to
just check the __OPTIMIZE__ define from osdep.h.

The comment about being incompatible with clang appears to be
outdated, as compilation works fine without excluding clang.

In the coroutine code we must set _FORTIFY_SOURCE=0 to stop the
logic in osdep.h then enabling it.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-id: 20231003091549.223020-1-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2023-10-04 09:52:06 -04:00

787 lines
24 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
#if !defined _FORTIFY_SOURCE && defined __OPTIMIZE__ && __OPTIMIZE__ && defined __linux__
# define _FORTIFY_SOURCE 2
#endif
#include "config-host.h"
#ifdef NEED_CPU_H
#include CONFIG_TARGET
#else
#include "exec/poison.h"
#endif
/*
* HOST_WORDS_BIGENDIAN was replaced with HOST_BIG_ENDIAN. Prevent it from
* creeping back in.
*/
#pragma GCC poison HOST_WORDS_BIGENDIAN
/*
* TARGET_WORDS_BIGENDIAN was replaced with TARGET_BIG_ENDIAN. Prevent it from
* creeping back in.
*/
#pragma GCC poison TARGET_WORDS_BIGENDIAN
#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
QEMU_EXTERN_C int daemon(int, int);
#endif
#ifdef _WIN32
/* as defined in sdkddkver.h */
#ifndef _WIN32_WINNT
#define _WIN32_WINNT 0x0602 /* Windows 8 API (should be >= the one from glib) */
#endif
/* reduces the number of implicitly included headers */
#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif
#endif
/* enable C99/POSIX format strings (needs mingw32-runtime 3.15 or later) */
#ifdef __MINGW32__
#define __USE_MINGW_ANSI_STDIO 1
#endif
/*
* We need the FreeBSD "legacy" definitions. Rust needs the FreeBSD 11 system
* calls since it doesn't use libc at all, so we have to emulate that despite
* FreeBSD 11 being EOL'd.
*/
#ifdef __FreeBSD__
#define _WANT_FREEBSD11_STAT
#define _WANT_FREEBSD11_STATFS
#define _WANT_FREEBSD11_DIRENT
#define _WANT_KERNEL_ERRNO
#define _WANT_SEMUN
#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 <getopt.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 CONFIG_IOVEC
#include <sys/uio.h>
#endif
#if defined(__linux__) && defined(__sparc__)
/* The SPARC definition of QEMU_VMALLOC_ALIGN needs SHMLBA */
#include <sys/shm.h>
#endif
#ifndef _WIN32
#include <sys/wait.h>
#else
#define WIFEXITED(x) 1
#define WEXITSTATUS(x) (x)
#endif
#ifdef __APPLE__
#include <AvailabilityMacros.h>
#endif
/*
* This is somewhat like a system header; it must be outside any extern "C"
* block because it includes system headers itself, including glib.h,
* which will not compile if inside an extern "C" block.
*/
#include "glib-compat.h"
#ifdef _WIN32
#include "sysemu/os-win32.h"
#endif
#ifdef CONFIG_POSIX
#include "sysemu/os-posix.h"
#endif
#ifdef __cplusplus
extern "C" {
#endif
#include "qemu/typedefs.h"
/**
* Mark a function that executes in coroutine context
*
* Functions that execute in coroutine context cannot be called directly from
* normal functions. In the future it would be nice to enable compiler or
* static checker support for catching such errors. This annotation might make
* it possible and in the meantime it serves as documentation.
*
* For example:
*
* static void coroutine_fn foo(void) {
* ....
* }
*/
#ifdef __clang__
#define coroutine_fn QEMU_ANNOTATE("coroutine_fn")
#else
#define coroutine_fn
#endif
/**
* Mark a function that can suspend when executed in coroutine context,
* but can handle running in non-coroutine context too.
*/
#ifdef __clang__
#define coroutine_mixed_fn QEMU_ANNOTATE("coroutine_mixed_fn")
#else
#define coroutine_mixed_fn
#endif
/**
* Mark a function that should not be called from a coroutine context.
* Usually there will be an analogous, coroutine_fn function that should
* be used instead.
*
* When the function is also marked as coroutine_mixed_fn, the function should
* only be called if the caller does not know whether it is in coroutine
* context.
*
* Functions that are only no_coroutine_fn, on the other hand, should not
* be called from within coroutines at all. This for example includes
* functions that block.
*
* In the future it would be nice to enable compiler or static checker
* support for catching such errors. This annotation is the first step
* towards this, and in the meantime it serves as documentation.
*
* For example:
*
* static void no_coroutine_fn foo(void) {
* ....
* }
*/
#ifdef __clang__
#define no_coroutine_fn QEMU_ANNOTATE("no_coroutine_fn")
#else
#define no_coroutine_fn
#endif
/*
* For mingw, as of v6.0.0, the function implementing the assert macro is
* not marked as noreturn, so the compiler cannot delete code following an
* assert(false) as unused. We rely on this within the code base to delete
* code that is unreachable when features are disabled.
* All supported versions of Glib's g_assert() satisfy this requirement.
*/
#ifdef __MINGW32__
#undef assert
#define assert(x) g_assert(x)
#endif
/**
* qemu_build_not_reached()
*
* The compiler, during optimization, is expected to prove that a call
* to this function cannot be reached and remove it. If the compiler
* supports QEMU_ERROR, this will be reported at compile time; otherwise
* this will be reported at link time due to the missing symbol.
*/
G_NORETURN
void QEMU_ERROR("code path is reachable")
qemu_build_not_reached_always(void);
#if defined(__OPTIMIZE__) && !defined(__NO_INLINE__)
#define qemu_build_not_reached() qemu_build_not_reached_always()
#else
#define qemu_build_not_reached() g_assert_not_reached()
#endif
/**
* qemu_build_assert()
*
* The compiler, during optimization, is expected to prove that the
* assertion is true.
*/
#define qemu_build_assert(test) while (!(test)) qemu_build_not_reached()
/*
* According to waitpid man page:
* WCOREDUMP
* This macro is not specified in POSIX.1-2001 and is not
* available on some UNIX implementations (e.g., AIX, SunOS).
* Therefore, enclose its use inside #ifdef WCOREDUMP ... #endif.
*/
#ifndef WCOREDUMP
#define WCOREDUMP(status) 0
#endif
/*
* We have a lot of unaudited code that may fail in strange ways, or
* even be a security risk during migration, if you disable assertions
* at compile-time. You may comment out these safety checks if you
* absolutely want to disable assertion overhead, but it is not
* supported upstream so the risk is all yours. Meanwhile, please
* submit patches to remove any side-effects inside an assertion, or
* fixing error handling that should use Error instead of assert.
*/
#ifdef NDEBUG
#error building with NDEBUG is not supported
#endif
#ifdef G_DISABLE_ASSERT
#error building with G_DISABLE_ASSERT is not supported
#endif
#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 MAP_NORESERVE
#define MAP_NORESERVE 0
#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
#if !defined(ESHUTDOWN)
#define ESHUTDOWN 4099
#endif
#define RETRY_ON_EINTR(expr) \
(__extension__ \
({ typeof(expr) __result; \
do { \
__result = (expr); \
} while (__result == -1 && errno == EINTR); \
__result; }))
/* time_t may be either 32 or 64 bits depending on the host OS, and
* can be either signed or unsigned, so we can't just hardcode a
* specific maximum value. This is not a C preprocessor constant,
* so you can't use TIME_MAX in an #ifdef, but for our purposes
* this isn't a problem.
*/
/* The macros TYPE_SIGNED, TYPE_WIDTH, and TYPE_MAXIMUM are from
* Gnulib, and are under the LGPL v2.1 or (at your option) any
* later version.
*/
/* True if the real type T is signed. */
#define TYPE_SIGNED(t) (!((t)0 < (t)-1))
/* The width in bits of the integer type or expression T.
* Padding bits are not supported.
*/
#define TYPE_WIDTH(t) (sizeof(t) * CHAR_BIT)
/* The maximum and minimum values for the integer type T. */
#define TYPE_MAXIMUM(t) \
((t) (!TYPE_SIGNED(t) \
? (t)-1 \
: ((((t)1 << (TYPE_WIDTH(t) - 2)) - 1) * 2 + 1)))
#ifndef TIME_MAX
#define TIME_MAX TYPE_MAXIMUM(time_t)
#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. */
#ifdef HAVE_BROKEN_SIZE_MAX
#undef SIZE_MAX
#define SIZE_MAX ((size_t)-1)
#endif
/*
* Two variations of MIN/MAX macros. The first is for runtime use, and
* evaluates arguments only once (so it is safe even with side
* effects), but will not work in constant contexts (such as array
* size declarations) because of the '{}'. The second is for constant
* expression use, where evaluating arguments twice is safe because
* the result is going to be constant anyway, but will not work in a
* runtime context because of a void expression where a value is
* expected. Thus, both gcc and clang will fail to compile if you use
* the wrong macro (even if the error may seem a bit cryptic).
*
* Note that neither form is usable as an #if condition; if you truly
* need to write conditional code that depends on a minimum or maximum
* determined by the pre-processor instead of the compiler, you'll
* have to open-code it. Sadly, Coverity is severely confused by the
* constant variants, so we have to dumb things down there.
*
* Preprocessor sorcery ahead: use different identifiers for the local
* variables in each expansion, so we can nest macro calls without
* shadowing variables.
*/
#define MIN_INTERNAL(a, b, _a, _b) \
({ \
typeof(1 ? (a) : (b)) _a = (a), _b = (b); \
_a < _b ? _a : _b; \
})
#undef MIN
#define MIN(a, b) \
MIN_INTERNAL((a), (b), MAKE_IDENTFIER(_a), MAKE_IDENTFIER(_b))
#define MAX_INTERNAL(a, b, _a, _b) \
({ \
typeof(1 ? (a) : (b)) _a = (a), _b = (b); \
_a > _b ? _a : _b; \
})
#undef MAX
#define MAX(a, b) \
MAX_INTERNAL((a), (b), MAKE_IDENTFIER(_a), MAKE_IDENTFIER(_b))
#ifdef __COVERITY__
# define MIN_CONST(a, b) ((a) < (b) ? (a) : (b))
# define MAX_CONST(a, b) ((a) > (b) ? (a) : (b))
#else
# define MIN_CONST(a, b) \
__builtin_choose_expr( \
__builtin_constant_p(a) && __builtin_constant_p(b), \
(a) < (b) ? (a) : (b), \
((void)0))
# define MAX_CONST(a, b) \
__builtin_choose_expr( \
__builtin_constant_p(a) && __builtin_constant_p(b), \
(a) > (b) ? (a) : (b), \
((void)0))
#endif
/*
* Minimum function that returns zero only if both values are zero.
* Intended for use with unsigned values only.
*
* Preprocessor sorcery ahead: use different identifiers for the local
* variables in each expansion, so we can nest macro calls without
* shadowing variables.
*/
#define MIN_NON_ZERO_INTERNAL(a, b, _a, _b) \
({ \
typeof(1 ? (a) : (b)) _a = (a), _b = (b); \
_a == 0 ? _b : (_b == 0 || _b > _a) ? _a : _b; \
})
#define MIN_NON_ZERO(a, b) \
MIN_NON_ZERO_INTERNAL((a), (b), MAKE_IDENTFIER(_a), MAKE_IDENTFIER(_b))
/*
* Round number down to multiple. Safe when m is not a power of 2 (see
* ROUND_DOWN for a faster version when a power of 2 is guaranteed).
*/
#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 down to multiple. Requires that d be a power of 2 (see
* QEMU_ALIGN_UP for a safer but slower version on arbitrary
* numbers); works even if d is a smaller type than n.
*/
#ifndef ROUND_DOWN
#define ROUND_DOWN(n, d) ((n) & -(0 ? (n) : (d)))
#endif
/*
* 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); works even if d is a smaller type than n.
*/
#ifndef ROUND_UP
#define ROUND_UP(n, d) ROUND_DOWN((n) + (d) - 1, (d))
#endif
#ifndef DIV_ROUND_UP
#define DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
#endif
/*
* &(x)[0] is always a pointer - if it's same type as x then the argument is a
* pointer, not an array.
*/
#define QEMU_IS_ARRAY(x) (!__builtin_types_compatible_p(typeof(x), \
typeof(&(x)[0])))
#ifndef ARRAY_SIZE
#define ARRAY_SIZE(x) ((sizeof(x) / sizeof((x)[0])) + \
QEMU_BUILD_BUG_ON_ZERO(!QEMU_IS_ARRAY(x)))
#endif
int qemu_daemon(int nochdir, int noclose);
void *qemu_anon_ram_alloc(size_t size, uint64_t *align, bool shared,
bool noreserve);
void qemu_anon_ram_free(void *ptr, size_t size);
#ifdef _WIN32
#define HAVE_CHARDEV_SERIAL 1
#elif defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \
|| defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) \
|| defined(__GLIBC__) || defined(__APPLE__)
#define HAVE_CHARDEV_SERIAL 1
#endif
#if defined(__HAIKU__)
#define SIGIO SIGPOLL
#endif
#ifdef HAVE_MADVISE_WITHOUT_PROTOTYPE
/*
* See MySQL bug #7156 (http://bugs.mysql.com/bug.php?id=7156) for discussion
* about Solaris missing the madvise() prototype.
*/
int madvise(char *, size_t, int);
#endif
#if defined(CONFIG_LINUX)
#ifndef BUS_MCEERR_AR
#define BUS_MCEERR_AR 4
#endif
#ifndef BUS_MCEERR_AO
#define BUS_MCEERR_AO 5
#endif
#endif
#if defined(__linux__) && \
(defined(__x86_64__) || defined(__arm__) || defined(__aarch64__) \
|| defined(__powerpc64__))
/* 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)
#elif defined(__linux__) && defined(__sparc__)
# define QEMU_VMALLOC_ALIGN MAX(qemu_real_host_page_size(), SHMLBA)
#else
# define QEMU_VMALLOC_ALIGN qemu_real_host_page_size()
#endif
#ifdef CONFIG_POSIX
struct qemu_signalfd_siginfo {
uint32_t ssi_signo; /* Signal number */
int32_t ssi_errno; /* Error number (unused) */
int32_t ssi_code; /* Signal code */
uint32_t ssi_pid; /* PID of sender */
uint32_t ssi_uid; /* Real UID of sender */
int32_t ssi_fd; /* File descriptor (SIGIO) */
uint32_t ssi_tid; /* Kernel timer ID (POSIX timers) */
uint32_t ssi_band; /* Band event (SIGIO) */
uint32_t ssi_overrun; /* POSIX timer overrun count */
uint32_t ssi_trapno; /* Trap number that caused signal */
int32_t ssi_status; /* Exit status or signal (SIGCHLD) */
int32_t ssi_int; /* Integer sent by sigqueue(2) */
uint64_t ssi_ptr; /* Pointer sent by sigqueue(2) */
uint64_t ssi_utime; /* User CPU time consumed (SIGCHLD) */
uint64_t ssi_stime; /* System CPU time consumed (SIGCHLD) */
uint64_t ssi_addr; /* Address that generated signal
(for hardware-generated signals) */
uint8_t pad[48]; /* Pad size to 128 bytes (allow for
additional fields in the future) */
};
int qemu_signalfd(const sigset_t *mask);
void sigaction_invoke(struct sigaction *action,
struct qemu_signalfd_siginfo *info);
#endif
/*
* Don't introduce new usage of this function, prefer the following
* qemu_open/qemu_create that take an "Error **errp"
*/
int qemu_open_old(const char *name, int flags, ...);
int qemu_open(const char *name, int flags, Error **errp);
int qemu_create(const char *name, int flags, mode_t mode, Error **errp);
int qemu_close(int fd);
int qemu_unlink(const char *name);
#ifndef _WIN32
int qemu_dup_flags(int fd, int flags);
int qemu_dup(int fd);
int qemu_lock_fd(int fd, int64_t start, int64_t len, bool exclusive);
int qemu_unlock_fd(int fd, int64_t start, int64_t len);
int qemu_lock_fd_test(int fd, int64_t start, int64_t len, bool exclusive);
bool qemu_has_ofd_lock(void);
#endif
#if defined(__HAIKU__) && defined(__i386__)
#define FMT_pid "%ld"
#elif defined(WIN64)
#define FMT_pid "%" PRId64
#else
#define FMT_pid "%d"
#endif
bool qemu_write_pidfile(const char *pidfile, Error **errp);
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);
#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
ssize_t qemu_write_full(int fd, const void *buf, size_t count)
G_GNUC_WARN_UNUSED_RESULT;
void qemu_set_cloexec(int fd);
/* Return a dynamically allocated directory path that is appropriate for storing
* local state.
*
* The caller is responsible for releasing the value returned with g_free()
* after use.
*/
char *qemu_get_local_state_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);
typedef struct ThreadContext ThreadContext;
/**
* qemu_prealloc_mem:
* @fd: the fd mapped into the area, -1 for anonymous memory
* @area: start address of the are to preallocate
* @sz: the size of the area to preallocate
* @max_threads: maximum number of threads to use
* @errp: returns an error if this function fails
*
* Preallocate memory (populate/prefault page tables writable) for the virtual
* memory area starting at @area with the size of @sz. After a successful call,
* each page in the area was faulted in writable at least once, for example,
* after allocating file blocks for mapped files.
*/
void qemu_prealloc_mem(int fd, char *area, size_t sz, int max_threads,
ThreadContext *tc, Error **errp);
/**
* 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);
/* Using intptr_t ensures that qemu_*_page_mask is sign-extended even
* when intptr_t is 32-bit and we are aligning a long long.
*/
static inline uintptr_t qemu_real_host_page_size(void)
{
return getpagesize();
}
static inline intptr_t qemu_real_host_page_mask(void)
{
return -(intptr_t)qemu_real_host_page_size();
}
/*
* After using getopt or getopt_long, if you need to parse another set
* of options, then you must reset optind. Unfortunately the way to
* do this varies between implementations of getopt.
*/
static inline void qemu_reset_optind(void)
{
#ifdef HAVE_OPTRESET
optind = 1;
optreset = 1;
#else
optind = 0;
#endif
}
int qemu_fdatasync(int fd);
/**
* Sync changes made to the memory mapped file back to the backing
* storage. For POSIX compliant systems this will fallback
* to regular msync call. Otherwise it will trigger whole file sync
* (including the metadata case there is no support to skip that otherwise)
*
* @addr - start of the memory area to be synced
* @length - length of the are to be synced
* @fd - file descriptor for the file to be synced
* (mandatory only for POSIX non-compliant systems)
*/
int qemu_msync(void *addr, size_t length, int fd);
/**
* qemu_get_host_physmem:
*
* Operating system agnostic way of querying host memory.
*
* Returns amount of physical memory on the system. This is purely
* advisery and may return 0 if we can't work it out. At the other
* end we saturate to SIZE_MAX if you are lucky enough to have that
* much memory.
*/
size_t qemu_get_host_physmem(void);
/*
* Toggle write/execute on the pages marked MAP_JIT
* for the current thread.
*/
#if defined(MAC_OS_VERSION_11_0) && \
MAC_OS_X_VERSION_MIN_REQUIRED >= MAC_OS_VERSION_11_0
static inline void qemu_thread_jit_execute(void)
{
pthread_jit_write_protect_np(true);
}
static inline void qemu_thread_jit_write(void)
{
pthread_jit_write_protect_np(false);
}
#else
static inline void qemu_thread_jit_write(void) {}
static inline void qemu_thread_jit_execute(void) {}
#endif
/**
* Platforms which do not support system() return ENOSYS
*/
#ifndef HAVE_SYSTEM_FUNCTION
#define system platform_does_not_support_system
static inline int platform_does_not_support_system(const char *command)
{
errno = ENOSYS;
return -1;
}
#endif /* !HAVE_SYSTEM_FUNCTION */
#ifdef __cplusplus
}
#endif
#endif