c684613e19
Specifically these functions are now supported:
signalfd4(), eventfd(), timerfd_create(),
pipe(), and inotify_init1()
Modified syscall_portable() to call signalfd4_portable(),
eventfd_portable(), eventfd2_portable(), and timerfd_create().
These system calls enable the read system calls to access
kernel data structures.
The signalfd4() enables read to return a signalfd_siginfo structure
which have the signal number and errno mapped until an execve().
This is similar to the maintaining a table of signal handlers to
map the signal numbers done earlier. This mapping is extended to
the process after an execve() by passing the final set of mapped
file descriptors via a pair of environment variables.
Disabling signal and file descriptor read mapping in parent
if the child would break the mapping algorithms.
This code passes at least all of the non-POSIX LTP tests,
including an updated LTP signalfd4 test that posts SIGNALS
and uses this read() mechanism to get signal info.
inotify_init1 is similar to signalfd(), timerfd() and other
filefd functions which map read() calls. Unlike signalfd(), and
similar to timerfd(), the reads don't appear to need to be mapped.
The members of the inotify_event structure appear to be generic.
The mask bits like IN_MOVE_FROM and IN_MOVE_TO are defined in
generic files. The LTP test in testcases/kernel/syscalls/inotify
test for the inotify_event structure being inotify_event structure
being read and does seem to check it contents being correct.
Change-Id: I3f2dcd4e33437ac953cd9f67f56dccc6ec6e5e6f
Signed-off-by: Pete Delaney <piet.delaney@imgtec.com>
Signed-off-by: Chris Dearman <chris.dearman@imgtec.com>
Signed-off-by: Paul Lind <paul.lind@imgtec.com>
140 lines
4.9 KiB
C
140 lines
4.9 KiB
C
/*
|
|
* Copyright 2012, The Android Open Source Project
|
|
*
|
|
* Licensed under the Apache License, Version 2.0 (the "License");
|
|
* you may not use this file except in compliance with the License.
|
|
* You may obtain a copy of the License at
|
|
*
|
|
* http://www.apache.org/licenses/LICENSE-2.0
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
|
|
#define _GNU_SOURCE
|
|
#include <sched.h>
|
|
#include <stdarg.h>
|
|
#include <stdlib.h>
|
|
#include <signal.h>
|
|
#include <signal_portable.h>
|
|
#include <portability.h>
|
|
#include <stdio.h>
|
|
#include <errno.h>
|
|
#include <filefd_portable.h>
|
|
|
|
#define PORTABLE_TAG "clone_portable"
|
|
#include <log_portable.h>
|
|
|
|
|
|
/*
|
|
* This function maps the clone function call defined in:
|
|
* $TOP/bionic/libc/bionic/bionic_clone.c
|
|
*
|
|
* which calls the __bionic_clone() system call which is defined in:
|
|
* $TOP/bionic/libc/unistd/arch-mips/bionic/clone.S
|
|
*
|
|
* We have to map the low byte of the 'flags' parameter which
|
|
* contains the number of the termination signal sent to the
|
|
* parent when the child dies.
|
|
*
|
|
* Note that if this signal is specified as anything other than
|
|
* SIGCHLD, then the parent process must specify the __WALL or
|
|
* __WCLONE options when waiting for the child with wait(2).
|
|
*
|
|
* If no signal is specified, then the parent process is not
|
|
* signaled when the child terminates.
|
|
*/
|
|
int clone_portable(int (*fn)(void *), void *child_stack, int port_flags, void *arg, ...)
|
|
{
|
|
va_list args;
|
|
int ret;
|
|
int mips_flags;
|
|
void *new_tls = NULL;
|
|
int *child_tidptr = NULL;
|
|
int *parent_tidptr = NULL;
|
|
int mips_term_signum;
|
|
char *mips_term_signame;
|
|
int portable_term_signum;
|
|
char *portable_term_signame;
|
|
int cloning_vm = ((port_flags & CLONE_VM) == CLONE_VM);
|
|
int cloning_files = ((port_flags & CLONE_FILES) == CLONE_FILES);
|
|
int cloning_sighand = ((port_flags & CLONE_SIGHAND) == CLONE_SIGHAND);
|
|
|
|
ALOGV(" ");
|
|
ALOGV("%s(fn:%p, child_stack:%p, port_flags:0x%x, arg:%p, ...) {", __func__,
|
|
fn, child_stack, port_flags, arg);
|
|
|
|
/* Shared file descriptor table requires shared memory. */
|
|
if (cloning_files != cloning_vm) {
|
|
ALOGE("%s: cloning_files:%d != cloning_vm:%d) ...", __func__,
|
|
cloning_files, cloning_vm);
|
|
|
|
ALOGE("%s: ... port_flags:0x%x Not Supported by Lib-Portable!", __func__,
|
|
port_flags);
|
|
}
|
|
|
|
/* Shared signal handler table requires shared memory. */
|
|
if (cloning_sighand != cloning_vm) {
|
|
ALOGE("%s: cloning_sighand:%d != cloning_vm:%d) ...", __func__,
|
|
cloning_sighand, cloning_vm);
|
|
|
|
ALOGE("%s: ... port_flags:0x%x Not Supported by Lib-Portable!", __func__,
|
|
port_flags);
|
|
}
|
|
|
|
/* Extract optional parameters - they are cumulative. */
|
|
va_start(args, arg);
|
|
if (port_flags & (CLONE_PARENT_SETTID|CLONE_SETTLS|CLONE_CHILD_SETTID)) {
|
|
parent_tidptr = va_arg(args, int*);
|
|
}
|
|
if (port_flags & (CLONE_SETTLS|CLONE_CHILD_SETTID)) {
|
|
new_tls = va_arg(args, void*);
|
|
}
|
|
if (port_flags & CLONE_CHILD_SETTID) {
|
|
child_tidptr = va_arg(args, int*);
|
|
}
|
|
va_end(args);
|
|
|
|
/*
|
|
* Map the LSB of the flags as explained above.
|
|
*/
|
|
portable_term_signum = port_flags & 0xFF;
|
|
if (portable_term_signum == 0) {
|
|
mips_flags = port_flags;
|
|
} else {
|
|
portable_term_signame = map_portable_signum_to_name(portable_term_signum);
|
|
ALOGV("%s: portable_term_signum:0x%x:'%s'", __func__,
|
|
portable_term_signum, portable_term_signame);
|
|
mips_term_signum = signum_pton(portable_term_signum);
|
|
mips_term_signame = map_mips_signum_to_name(mips_term_signum);
|
|
ALOGV("%s: mips_term_signum:0x%x:'%s'", __func__,
|
|
mips_term_signum, mips_term_signame);
|
|
mips_flags = (port_flags & ~0xFF) | (mips_term_signum & 0xFF);
|
|
}
|
|
ALOGV("%s: clone(%p, %p, 0x%x, %p, %p, %p, %p);", __func__,
|
|
fn, child_stack, mips_flags, arg, parent_tidptr, new_tls, child_tidptr);
|
|
|
|
ret = clone(fn, child_stack, mips_flags, arg, parent_tidptr,
|
|
new_tls, child_tidptr);
|
|
|
|
if (ret > 0) {
|
|
/*
|
|
* Disable mapping in the parent if the child could interfere
|
|
* and make things even worse than skipping the signal and
|
|
* file read mapping.
|
|
*/
|
|
if (cloning_files != cloning_vm) {
|
|
filefd_disable_mapping();
|
|
}
|
|
if (cloning_sighand != cloning_vm) {
|
|
signal_disable_mapping();
|
|
}
|
|
}
|
|
|
|
ALOGV("%s: return(ret:%d); }", __func__, ret);
|
|
return ret;
|
|
}
|