cpython/Include/fileutils.h
Alexey Izbyshev c1e46e94de bpo-32777: Fix _Py_set_inheritable async-safety in subprocess (GH-5560)
Fix a rare but potential pre-exec child process deadlock in subprocess on POSIX systems when marking file descriptors inheritable on exec in the child process.  This bug appears to have been introduced in 3.4 with the inheritable file descriptors support.

This also changes Python/fileutils.c `set_inheritable` to use the "slow" two `fcntl` syscall path instead of the "fast" single `ioctl` syscall path when asked to be async signal safe (by way of being asked not to raise exceptions).  `ioctl` is not a POSIX async-signal-safe approved function.

ref: http://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html
2018-02-05 22:09:34 -08:00

178 lines
3.6 KiB
C

#ifndef Py_FILEUTILS_H
#define Py_FILEUTILS_H
#ifdef __cplusplus
extern "C" {
#endif
#if !defined(Py_LIMITED_API) || Py_LIMITED_API+0 >= 0x03050000
PyAPI_FUNC(wchar_t *) Py_DecodeLocale(
const char *arg,
size_t *size);
PyAPI_FUNC(char*) Py_EncodeLocale(
const wchar_t *text,
size_t *error_pos);
PyAPI_FUNC(char*) _Py_EncodeLocaleRaw(
const wchar_t *text,
size_t *error_pos);
#endif
#ifdef Py_BUILD_CORE
PyAPI_FUNC(int) _Py_DecodeUTF8Ex(
const char *arg,
Py_ssize_t arglen,
wchar_t **wstr,
size_t *wlen,
const char **reason,
int surrogateescape);
PyAPI_FUNC(int) _Py_EncodeUTF8Ex(
const wchar_t *text,
char **str,
size_t *error_pos,
const char **reason,
int raw_malloc,
int surrogateescape);
PyAPI_FUNC(wchar_t*) _Py_DecodeUTF8_surrogateescape(
const char *arg,
Py_ssize_t arglen);
PyAPI_FUNC(int) _Py_DecodeLocaleEx(
const char *arg,
wchar_t **wstr,
size_t *wlen,
const char **reason,
int current_locale,
int surrogateescape);
PyAPI_FUNC(int) _Py_EncodeLocaleEx(
const wchar_t *text,
char **str,
size_t *error_pos,
const char **reason,
int current_locale,
int surrogateescape);
#endif
#ifndef Py_LIMITED_API
PyAPI_FUNC(PyObject *) _Py_device_encoding(int);
#ifdef MS_WINDOWS
struct _Py_stat_struct {
unsigned long st_dev;
uint64_t st_ino;
unsigned short st_mode;
int st_nlink;
int st_uid;
int st_gid;
unsigned long st_rdev;
__int64 st_size;
time_t st_atime;
int st_atime_nsec;
time_t st_mtime;
int st_mtime_nsec;
time_t st_ctime;
int st_ctime_nsec;
unsigned long st_file_attributes;
};
#else
# define _Py_stat_struct stat
#endif
PyAPI_FUNC(int) _Py_fstat(
int fd,
struct _Py_stat_struct *status);
PyAPI_FUNC(int) _Py_fstat_noraise(
int fd,
struct _Py_stat_struct *status);
PyAPI_FUNC(int) _Py_stat(
PyObject *path,
struct stat *status);
PyAPI_FUNC(int) _Py_open(
const char *pathname,
int flags);
PyAPI_FUNC(int) _Py_open_noraise(
const char *pathname,
int flags);
PyAPI_FUNC(FILE *) _Py_wfopen(
const wchar_t *path,
const wchar_t *mode);
PyAPI_FUNC(FILE*) _Py_fopen(
const char *pathname,
const char *mode);
PyAPI_FUNC(FILE*) _Py_fopen_obj(
PyObject *path,
const char *mode);
PyAPI_FUNC(Py_ssize_t) _Py_read(
int fd,
void *buf,
size_t count);
PyAPI_FUNC(Py_ssize_t) _Py_write(
int fd,
const void *buf,
size_t count);
PyAPI_FUNC(Py_ssize_t) _Py_write_noraise(
int fd,
const void *buf,
size_t count);
#ifdef HAVE_READLINK
PyAPI_FUNC(int) _Py_wreadlink(
const wchar_t *path,
wchar_t *buf,
size_t bufsiz);
#endif
#ifdef HAVE_REALPATH
PyAPI_FUNC(wchar_t*) _Py_wrealpath(
const wchar_t *path,
wchar_t *resolved_path,
size_t resolved_path_size);
#endif
PyAPI_FUNC(wchar_t*) _Py_wgetcwd(
wchar_t *buf,
size_t size);
PyAPI_FUNC(int) _Py_get_inheritable(int fd);
PyAPI_FUNC(int) _Py_set_inheritable(int fd, int inheritable,
int *atomic_flag_works);
PyAPI_FUNC(int) _Py_set_inheritable_async_safe(int fd, int inheritable,
int *atomic_flag_works);
PyAPI_FUNC(int) _Py_dup(int fd);
#ifndef MS_WINDOWS
PyAPI_FUNC(int) _Py_get_blocking(int fd);
PyAPI_FUNC(int) _Py_set_blocking(int fd, int blocking);
#endif /* !MS_WINDOWS */
PyAPI_FUNC(int) _Py_GetLocaleconvNumeric(
PyObject **decimal_point,
PyObject **thousands_sep,
const char **grouping);
#endif /* Py_LIMITED_API */
#ifdef __cplusplus
}
#endif
#endif /* !Py_FILEUTILS_H */