/* For asynchronous cancellation we use a signal. This is the handler. */
static void
sighandler_setxid (int sig, siginfo_t *si, void *ctx)
{
/* Safety check. It would be possible to call this function for
other signals and send a signal from another process. This is not
correct and might even be a security problem. Try to catch as
many incorrect invocations as possible. */
if (sig != SIGSETXID
#ifdef __ASSUME_CORRECT_SI_PID
/* Kernels before 2.5.75 stored the thread ID and not the process
ID in si_pid so we skip this test. */
|| si->si_pid != THREAD_GETMEM (THREAD_SELF, pid)
#endif
|| si->si_code != SI_TKILL)
return;
INTERNAL_SYSCALL_DECL (err);
INTERNAL_SYSCALL_NCS (__xidcmd->syscall_no, err, 3, __xidcmd->id[0],
__xidcmd->id[1], __xidcmd->id[2]);
if (atomic_decrement_val (&__xidcmd->cntr) == 0)
lll_futex_wake (&__xidcmd->cntr, 1);
/* Reset the SETXID flag. */
struct pthread *self = THREAD_SELF;
int flags = THREAD_GETMEM (self, cancelhandling);
THREAD_SETMEM (self, cancelhandling, flags & ~SETXID_BITMASK);
/* And release the futex. */
self->setxid_futex = 1;
lll_futex_wake (&self->setxid_futex, 1);
}
long int
syscall (long int syscall_number, long int arg1, long int arg2, long int arg3,
long int arg4, long int arg5, long int arg6, long int arg7)
{
long int ret;
INTERNAL_SYSCALL_DECL (err);
ret = INTERNAL_SYSCALL_NCS (syscall_number, err, 7, arg1, arg2, arg3, arg4,
arg5, arg6, arg7);
if (INTERNAL_SYSCALL_ERROR_P (ret, err))
return __syscall_error (ret);
return ret;
}
long syscall (long syscall_number, long arg1, long arg2, long arg3,
long arg4, long arg5, long arg6, long arg7)
{
long ret, err;
ret = INTERNAL_SYSCALL_NCS(syscall_number, err, 7, arg1, arg2, arg3, arg4,
arg5, arg6, arg7);
if (INTERNAL_SYSCALL_ERROR_P (ret, err))
{
extern long __syscall_error() attribute_hidden;
return __syscall_error();
}
return ret;
}
/* For asynchronous cancellation we use a signal. This is the handler. */
static void
sighandler_setxid (int sig, siginfo_t *si, void *ctx)
{
#ifdef __ASSUME_CORRECT_SI_PID
/* Determine the process ID. It might be negative if the thread is
in the middle of a fork() call. */
pid_t pid = THREAD_GETMEM (THREAD_SELF, pid);
if (__builtin_expect (pid < 0, 0))
pid = -pid;
#endif
/* Safety check. It would be possible to call this function for
other signals and send a signal from another process. This is not
correct and might even be a security problem. Try to catch as
many incorrect invocations as possible. */
if (sig != SIGSETXID
#ifdef __ASSUME_CORRECT_SI_PID
/* Kernels before 2.5.75 stored the thread ID and not the process
ID in si_pid so we skip this test. */
|| si->si_pid != pid
#endif
|| si->si_code != SI_TKILL)
return;
INTERNAL_SYSCALL_DECL (err);
INTERNAL_SYSCALL_NCS (__xidcmd->syscall_no, err, 3, __xidcmd->id[0],
__xidcmd->id[1], __xidcmd->id[2]);
/* Reset the SETXID flag. */
struct pthread *self = THREAD_SELF;
int flags, newval;
do
{
flags = THREAD_GETMEM (self, cancelhandling);
newval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling,
flags & ~SETXID_BITMASK, flags);
}
while (flags != newval);
/* And release the futex. */
self->setxid_futex = 1;
lll_futex_wake (&self->setxid_futex, 1, LLL_PRIVATE);
if (atomic_decrement_val (&__xidcmd->cntr) == 0)
lll_futex_wake (&__xidcmd->cntr, 1, LLL_PRIVATE);
}
/* We use the SIGSETXID signal in the setuid, setgid, etc. implementations to
tell each thread to call the respective setxid syscall on itself. This is
the handler. */
static void
sighandler_setxid (int sig, siginfo_t *si, void *ctx)
{
/* Determine the process ID. It might be negative if the thread is
in the middle of a fork() call. */
pid_t pid = THREAD_GETMEM (THREAD_SELF, pid);
int result;
if (__glibc_unlikely (pid < 0))
pid = -pid;
/* Safety check. It would be possible to call this function for
other signals and send a signal from another process. This is not
correct and might even be a security problem. Try to catch as
many incorrect invocations as possible. */
if (sig != SIGSETXID
|| si->si_pid != pid
|| si->si_code != SI_TKILL)
return;
INTERNAL_SYSCALL_DECL (err);
result = INTERNAL_SYSCALL_NCS (__xidcmd->syscall_no, err, 3, __xidcmd->id[0],
__xidcmd->id[1], __xidcmd->id[2]);
int error = 0;
if (__glibc_unlikely (INTERNAL_SYSCALL_ERROR_P (result, err)))
error = INTERNAL_SYSCALL_ERRNO (result, err);
__nptl_setxid_error (__xidcmd, error);
/* Reset the SETXID flag. */
struct pthread *self = THREAD_SELF;
int flags, newval;
do
{
flags = THREAD_GETMEM (self, cancelhandling);
newval = THREAD_ATOMIC_CMPXCHG_VAL (self, cancelhandling,
flags & ~SETXID_BITMASK, flags);
}
while (flags != newval);
/* And release the futex. */
self->setxid_futex = 1;
futex_wake (&self->setxid_futex, 1, FUTEX_PRIVATE);
if (atomic_decrement_val (&__xidcmd->cntr) == 0)
futex_wake ((unsigned int *) &__xidcmd->cntr, 1, FUTEX_PRIVATE);
}
