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This pull request contains the following changes for UML: 

- New mode for time travel, external via virtio
 - Fixes for ubd to make sure no requests can get lost
 - Fixes for vector networking
 - Allow CONFIG_STATIC_LINK only when possible
 - Minor cleanups and fixes
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Merge tag 'for-linus-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml

Pull UML updates from Richard Weinberger:

 - New mode for time travel, external via virtio

 - Fixes for ubd to make sure no requests can get lost

 - Fixes for vector networking

 - Allow CONFIG_STATIC_LINK only when possible

 - Minor cleanups and fixes

* tag 'for-linus-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml:
  um: Remove some unnecessary NULL checks in vector_user.c
  um: vector: Avoid NULL ptr deference if transport is unset
  um: Make CONFIG_STATIC_LINK actually static
  um: Implement cpu_relax() as ndelay(1) for time-travel
  um: Implement ndelay/udelay in time-travel mode
  um: Implement time-travel=ext
  um: virtio: Implement VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS
  um: time-travel: Rewrite as an event scheduler
  um: Move timer-internal.h to non-shared
  hostfs: Use kasprintf() instead of fixed buffer formatting
  um: falloc.h needs to be directly included for older libc
  um: ubd: Retry buffer read on any kind of error
  um: ubd: Prevent buffer overrun on command completion
  um: Fix overlapping ELF segments when statically linked
  um: Delete never executed timer
  um: Don't overwrite ethtool driver version
  um: Fix len of file in create_pid_file
  um: Don't use console_drivers directly
  um: Cleanup CONFIG_IOSCHED_CFQ
This commit is contained in:
Linus Torvalds 2020-04-07 12:36:09 -07:00
parent d5d247661e 4a7c46247f
commit 762a9f2f01
26 changed files with 986 additions and 214 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
arch/um/Kconfig
View File

@ -62,9 +62,12 @@ config NR_CPUS
source "arch/$(HEADER_ARCH)/um/Kconfig"
config FORBID_STATIC_LINK
bool
config STATIC_LINK
bool "Force a static link"
default n
depends on !FORBID_STATIC_LINK
help
This option gives you the ability to force a static link of UML.
Normally, UML is linked as a shared binary. This is inconvenient for
@ -73,6 +76,9 @@ config STATIC_LINK
Additionally, this option enables using higher memory spaces (up to
2.75G) for UML.
NOTE: This option is incompatible with some networking features which
depend on features that require being dynamically loaded (like NSS).
config LD_SCRIPT_STATIC
bool
default y
@ -191,6 +197,7 @@ config UML_TIME_TRAVEL_SUPPORT
prompt "Support time-travel mode (e.g. for test execution)"
# inf-cpu mode is incompatible with the benchmarking
depends on !RAID6_PQ_BENCHMARK
depends on !SMP
help
Enable this option to support time travel inside the UML instance.

2
arch/um/configs/i386_defconfig
View File

@ -26,7 +26,7 @@ CONFIG_SLAB=y
CONFIG_MODULES=y
CONFIG_MODULE_UNLOAD=y
# CONFIG_BLK_DEV_BSG is not set
CONFIG_IOSCHED_CFQ=m
CONFIG_IOSCHED_BFQ=m
CONFIG_SSL=y
CONFIG_NULL_CHAN=y
CONFIG_PORT_CHAN=y

2
arch/um/configs/x86_64_defconfig
View File

@ -24,7 +24,7 @@ CONFIG_SLAB=y
CONFIG_MODULES=y
CONFIG_MODULE_UNLOAD=y
# CONFIG_BLK_DEV_BSG is not set
CONFIG_IOSCHED_CFQ=m
CONFIG_IOSCHED_BFQ=m
CONFIG_SSL=y
CONFIG_NULL_CHAN=y
CONFIG_PORT_CHAN=y

3
arch/um/drivers/Kconfig
View File

@ -234,6 +234,7 @@ config UML_NET_DAEMON
config UML_NET_VECTOR
bool "Vector I/O high performance network devices"
depends on UML_NET
select FORBID_STATIC_LINK
help
This User-Mode Linux network driver uses multi-message send
and receive functions. The host running the UML guest must have
@ -245,6 +246,7 @@ config UML_NET_VECTOR
config UML_NET_VDE
bool "VDE transport (obsolete)"
depends on UML_NET
select FORBID_STATIC_LINK
help
This User-Mode Linux network transport allows one or more running
UMLs on a single host to communicate with each other and also
@ -292,6 +294,7 @@ config UML_NET_MCAST
config UML_NET_PCAP
bool "pcap transport (obsolete)"
depends on UML_NET
select FORBID_STATIC_LINK
help
The pcap transport makes a pcap packet stream on the host look
like an ethernet device inside UML. This is useful for making

13
arch/um/drivers/net_kern.c
View File

@ -266,7 +266,6 @@ static void uml_net_get_drvinfo(struct net_device *dev,
struct ethtool_drvinfo *info)
{
strlcpy(info->driver, DRIVER_NAME, sizeof(info->driver));
strlcpy(info->version, "42", sizeof(info->version));
}
static const struct ethtool_ops uml_net_ethtool_ops = {
@ -275,17 +274,6 @@ static const struct ethtool_ops uml_net_ethtool_ops = {
.get_ts_info = ethtool_op_get_ts_info,
};
static void uml_net_user_timer_expire(struct timer_list *t)
{
#ifdef undef
struct uml_net_private *lp = from_timer(lp, t, tl);
struct connection *conn = &lp->user;
dprintk(KERN_INFO "uml_net_user_timer_expire [%p]\n", conn);
do_connect(conn);
#endif
}
void uml_net_setup_etheraddr(struct net_device *dev, char *str)
{
unsigned char *addr = dev->dev_addr;
@ -456,7 +444,6 @@ static void eth_configure(int n, void *init, char *mac,
.add_address = transport->user->add_address,
.delete_address = transport->user->delete_address });
timer_setup(&lp->tl, uml_net_user_timer_expire, 0);
spin_lock_init(&lp->lock);
memcpy(lp->mac, dev->dev_addr, sizeof(lp->mac));

12
arch/um/drivers/ubd_kern.c
View File

@ -1592,11 +1592,11 @@ int io_thread(void *arg)
&io_remainder_size,
UBD_REQ_BUFFER_SIZE
);
if (n < 0) {
if (n == -EAGAIN) {
if (n <= 0) {
if (n == -EAGAIN)
ubd_read_poll(-1);
continue;
}
continue;
}
for (count = 0; count < n/sizeof(struct io_thread_req *); count++) {
@ -1607,7 +1607,9 @@ int io_thread(void *arg)
written = 0;
do {
res = os_write_file(kernel_fd, ((char *) io_req_buffer) + written, n);
res = os_write_file(kernel_fd,
((char *) io_req_buffer) + written,
n - written);
if (res >= 0) {
written += res;
}

5
arch/um/drivers/vector_kern.c
View File

@ -46,7 +46,6 @@
#define DRIVER_NAME "uml-vector"
#define DRIVER_VERSION "01"
struct vector_cmd_line_arg {
struct list_head list;
int unit;
@ -198,6 +197,9 @@ static int get_transport_options(struct arglist *def)
long parsed;
int result = 0;
if (transport == NULL)
return -EINVAL;
if (vector != NULL) {
if (kstrtoul(vector, 10, &parsed) == 0) {
if (parsed == 0) {
@ -1378,7 +1380,6 @@ static void vector_net_get_drvinfo(struct net_device *dev,
struct ethtool_drvinfo *info)
{
strlcpy(info->driver, DRIVER_NAME, sizeof(info->driver));
strlcpy(info->version, DRIVER_VERSION, sizeof(info->version));
}
static int vector_net_load_bpf_flash(struct net_device *dev,

15
arch/um/drivers/vector_user.c
View File

@ -221,8 +221,7 @@ static struct vector_fds *user_init_tap_fds(struct arglist *ifspec)
return result;
tap_cleanup:
printk(UM_KERN_ERR "user_init_tap: init failed, error %d", fd);
if (result != NULL)
kfree(result);
kfree(result);
return NULL;
}
@ -266,8 +265,7 @@ static struct vector_fds *user_init_hybrid_fds(struct arglist *ifspec)
return result;
hybrid_cleanup:
printk(UM_KERN_ERR "user_init_hybrid: init failed");
if (result != NULL)
kfree(result);
kfree(result);
return NULL;
}
@ -344,10 +342,8 @@ static struct vector_fds *user_init_unix_fds(struct arglist *ifspec, int id)
unix_cleanup:
if (fd >= 0)
os_close_file(fd);
if (remote_addr != NULL)
kfree(remote_addr);
if (result != NULL)
kfree(result);
kfree(remote_addr);
kfree(result);
return NULL;
}
@ -382,8 +378,7 @@ static struct vector_fds *user_init_raw_fds(struct arglist *ifspec)
return result;
raw_cleanup:
printk(UM_KERN_ERR "user_init_raw: init failed, error %d", err);
if (result != NULL)
kfree(result);
kfree(result);
return NULL;
}

12
arch/um/drivers/vhost_user.h
View File

@ -10,9 +10,10 @@
/* Feature bits */
#define VHOST_USER_F_PROTOCOL_FEATURES 30
/* Protocol feature bits */
#define VHOST_USER_PROTOCOL_F_REPLY_ACK 3
#define VHOST_USER_PROTOCOL_F_SLAVE_REQ 5
#define VHOST_USER_PROTOCOL_F_CONFIG 9
#define VHOST_USER_PROTOCOL_F_REPLY_ACK 3
#define VHOST_USER_PROTOCOL_F_SLAVE_REQ 5
#define VHOST_USER_PROTOCOL_F_CONFIG 9
#define VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS 14
/* Vring state index masks */
#define VHOST_USER_VRING_INDEX_MASK 0xff
#define VHOST_USER_VRING_POLL_MASK BIT(8)
@ -24,7 +25,8 @@
/* Supported protocol features */
#define VHOST_USER_SUPPORTED_PROTOCOL_F (BIT_ULL(VHOST_USER_PROTOCOL_F_REPLY_ACK) | \
BIT_ULL(VHOST_USER_PROTOCOL_F_SLAVE_REQ) | \
BIT_ULL(VHOST_USER_PROTOCOL_F_CONFIG))
BIT_ULL(VHOST_USER_PROTOCOL_F_CONFIG) | \
BIT_ULL(VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS))
enum vhost_user_request {
VHOST_USER_GET_FEATURES = 1,
@ -52,12 +54,14 @@ enum vhost_user_request {
VHOST_USER_SET_VRING_ENDIAN = 23,
VHOST_USER_GET_CONFIG = 24,
VHOST_USER_SET_CONFIG = 25,
VHOST_USER_VRING_KICK = 35,
};
enum vhost_user_slave_request {
VHOST_USER_SLAVE_IOTLB_MSG = 1,
VHOST_USER_SLAVE_CONFIG_CHANGE_MSG = 2,
VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG = 3,
VHOST_USER_SLAVE_VRING_CALL = 4,
};
struct vhost_user_header {

153
arch/um/drivers/virtio_uml.c
View File

@ -26,6 +26,7 @@
#include <linux/virtio.h>
#include <linux/virtio_config.h>
#include <linux/virtio_ring.h>
#include <linux/time-internal.h>
#include <shared/as-layout.h>
#include <irq_kern.h>
#include <init.h>
@ -53,6 +54,7 @@ struct virtio_uml_device {
struct virtio_device vdev;
struct platform_device *pdev;
spinlock_t sock_lock;
int sock, req_fd;
u64 features;
u64 protocol_features;
@ -63,6 +65,11 @@ struct virtio_uml_device {
struct virtio_uml_vq_info {
int kick_fd, call_fd;
char name[32];
#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
struct virtqueue *vq;
vq_callback_t *callback;
struct time_travel_event defer;
#endif
};
extern unsigned long long physmem_size, highmem;
@ -117,10 +124,27 @@ static int vhost_user_recv_header(int fd, struct vhost_user_msg *msg)
static int vhost_user_recv(struct virtio_uml_device *vu_dev,
int fd, struct vhost_user_msg *msg,
size_t max_payload_size)
size_t max_payload_size, bool wait)
{
size_t size;
int rc = vhost_user_recv_header(fd, msg);
int rc;
/*
* In virtio time-travel mode, we're handling all the vhost-user
* FDs by polling them whenever appropriate. However, we may get
* into a situation where we're sending out an interrupt message
* to a device (e.g. a net device) and need to handle a simulation
* time message while doing so, e.g. one that tells us to update
* our idea of how long we can run without scheduling.
*
* Thus, we need to not just read() from the given fd, but need
* to also handle messages for the simulation time - this function
* does that for us while waiting for the given fd to be readable.
*/
if (wait)
time_travel_wait_readable(fd);
rc = vhost_user_recv_header(fd, msg);
if (rc == -ECONNRESET && vu_dev->registered) {
struct virtio_uml_platform_data *pdata;
@ -142,7 +166,8 @@ static int vhost_user_recv_resp(struct virtio_uml_device *vu_dev,
struct vhost_user_msg *msg,
size_t max_payload_size)
{
int rc = vhost_user_recv(vu_dev, vu_dev->sock, msg, max_payload_size);
int rc = vhost_user_recv(vu_dev, vu_dev->sock, msg,
max_payload_size, true);
if (rc)
return rc;
@ -172,7 +197,8 @@ static int vhost_user_recv_req(struct virtio_uml_device *vu_dev,
struct vhost_user_msg *msg,
size_t max_payload_size)
{
int rc = vhost_user_recv(vu_dev, vu_dev->req_fd, msg, max_payload_size);
int rc = vhost_user_recv(vu_dev, vu_dev->req_fd, msg,
max_payload_size, false);
if (rc)
return rc;
@ -189,6 +215,7 @@ static int vhost_user_send(struct virtio_uml_device *vu_dev,
int *fds, size_t num_fds)
{
size_t size = sizeof(msg->header) + msg->header.size;
unsigned long flags;
bool request_ack;
int rc;
@ -207,24 +234,28 @@ static int vhost_user_send(struct virtio_uml_device *vu_dev,
if (request_ack)
msg->header.flags |= VHOST_USER_FLAG_NEED_REPLY;
spin_lock_irqsave(&vu_dev->sock_lock, flags);
rc = full_sendmsg_fds(vu_dev->sock, msg, size, fds, num_fds);
if (rc < 0)
return rc;
goto out;
if (request_ack) {
uint64_t status;
rc = vhost_user_recv_u64(vu_dev, &status);
if (rc)
return rc;
goto out;
if (status) {
vu_err(vu_dev, "slave reports error: %llu\n", status);
return -EIO;
rc = -EIO;
goto out;
}
}
return 0;
out:
spin_unlock_irqrestore(&vu_dev->sock_lock, flags);
return rc;
}
static int vhost_user_send_no_payload(struct virtio_uml_device *vu_dev,
@ -324,6 +355,7 @@ static void vhost_user_reply(struct virtio_uml_device *vu_dev,
static irqreturn_t vu_req_interrupt(int irq, void *data)
{
struct virtio_uml_device *vu_dev = data;
struct virtqueue *vq;
int response = 1;
struct {
struct vhost_user_msg msg;
@ -343,6 +375,15 @@ static irqreturn_t vu_req_interrupt(int irq, void *data)
virtio_config_changed(&vu_dev->vdev);
response = 0;
break;
case VHOST_USER_SLAVE_VRING_CALL:
virtio_device_for_each_vq((&vu_dev->vdev), vq) {
if (vq->index == msg.msg.payload.vring_state.index) {
response = 0;
vring_interrupt(0 /* ignored */, vq);
break;
}
}
break;
case VHOST_USER_SLAVE_IOTLB_MSG:
/* not supported - VIRTIO_F_IOMMU_PLATFORM */
case VHOST_USER_SLAVE_VRING_HOST_NOTIFIER_MSG:
@ -684,6 +725,17 @@ static bool vu_notify(struct virtqueue *vq)
const uint64_t n = 1;
int rc;
time_travel_propagate_time();
if (info->kick_fd < 0) {
struct virtio_uml_device *vu_dev;
vu_dev = to_virtio_uml_device(vq->vdev);
return vhost_user_set_vring_state(vu_dev, VHOST_USER_VRING_KICK,
vq->index, 0) == 0;
}
do {
rc = os_write_file(info->kick_fd, &n, sizeof(n));
} while (rc == -EINTR);
@ -749,10 +801,13 @@ static void vu_del_vq(struct virtqueue *vq)
{
struct virtio_uml_vq_info *info = vq->priv;
um_free_irq(VIRTIO_IRQ, vq);
if (info->call_fd >= 0) {
um_free_irq(VIRTIO_IRQ, vq);
os_close_file(info->call_fd);
}
os_close_file(info->call_fd);
os_close_file(info->kick_fd);
if (info->kick_fd >= 0)
os_close_file(info->kick_fd);
vring_del_virtqueue(vq);
kfree(info);
@ -782,6 +837,15 @@ static int vu_setup_vq_call_fd(struct virtio_uml_device *vu_dev,
int call_fds[2];
int rc;
/* no call FD needed/desired in this case */
if (vu_dev->protocol_features &
BIT_ULL(VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS) &&
vu_dev->protocol_features &
BIT_ULL(VHOST_USER_PROTOCOL_F_SLAVE_REQ)) {
info->call_fd = -1;
return 0;
}
/* Use a pipe for call fd, since SIGIO is not supported for eventfd */
rc = os_pipe(call_fds, true, true);
if (rc < 0)
@ -810,6 +874,23 @@ out:
return rc;
}
#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
static void vu_defer_irq_handle(struct time_travel_event *d)
{
struct virtio_uml_vq_info *info;
info = container_of(d, struct virtio_uml_vq_info, defer);
info->callback(info->vq);
}
static void vu_defer_irq_callback(struct virtqueue *vq)
{
struct virtio_uml_vq_info *info = vq->priv;
time_travel_add_irq_event(&info->defer);
}
#endif
static struct virtqueue *vu_setup_vq(struct virtio_device *vdev,
unsigned index, vq_callback_t *callback,
const char *name, bool ctx)
@ -829,6 +910,19 @@ static struct virtqueue *vu_setup_vq(struct virtio_device *vdev,
snprintf(info->name, sizeof(info->name), "%s.%d-%s", pdev->name,
pdev->id, name);
#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
/*
* When we get an interrupt, we must bounce it through the simulation
* calendar (the simtime device), except for the simtime device itself
* since that's part of the simulation control.
*/
if (time_travel_mode == TT_MODE_EXTERNAL && callback) {
info->callback = callback;
callback = vu_defer_irq_callback;
time_travel_set_event_fn(&info->defer, vu_defer_irq_handle);
}
#endif
vq = vring_create_virtqueue(index, num, PAGE_SIZE, vdev, true, true,
ctx, vu_notify, callback, info->name);
if (!vq) {
@ -837,11 +931,19 @@ static struct virtqueue *vu_setup_vq(struct virtio_device *vdev,
}
vq->priv = info;
num = virtqueue_get_vring_size(vq);
#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
info->vq = vq;
#endif
rc = os_eventfd(0, 0);
if (rc < 0)
goto error_kick;
info->kick_fd = rc;
if (vu_dev->protocol_features &
BIT_ULL(VHOST_USER_PROTOCOL_F_INBAND_NOTIFICATIONS)) {
info->kick_fd = -1;
} else {
rc = os_eventfd(0, 0);
if (rc < 0)
goto error_kick;
info->kick_fd = rc;
}
rc = vu_setup_vq_call_fd(vu_dev, vq);
if (rc)
@ -866,10 +968,13 @@ static struct virtqueue *vu_setup_vq(struct virtio_device *vdev,
return vq;
error_setup:
um_free_irq(VIRTIO_IRQ, vq);
os_close_file(info->call_fd);
if (info->call_fd >= 0) {
um_free_irq(VIRTIO_IRQ, vq);
os_close_file(info->call_fd);
}
error_call:
os_close_file(info->kick_fd);
if (info->kick_fd >= 0)
os_close_file(info->kick_fd);
error_kick:
vring_del_virtqueue(vq);
error_create:
@ -908,10 +1013,12 @@ static int vu_find_vqs(struct virtio_device *vdev, unsigned nvqs,
list_for_each_entry(vq, &vdev->vqs, list) {
struct virtio_uml_vq_info *info = vq->priv;
rc = vhost_user_set_vring_kick(vu_dev, vq->index,
info->kick_fd);
if (rc)
goto error_setup;
if (info->kick_fd >= 0) {
rc = vhost_user_set_vring_kick(vu_dev, vq->index,
info->kick_fd);
if (rc)
goto error_setup;
}
rc = vhost_user_set_vring_enable(vu_dev, vq->index, true);
if (rc)
@ -1008,6 +1115,8 @@ static int virtio_uml_probe(struct platform_device *pdev)
return rc;
vu_dev->sock = rc;
spin_lock_init(&vu_dev->sock_lock);
rc = vhost_user_init(vu_dev);
if (rc)
goto error_init;

1
arch/um/include/asm/Kbuild
View File

@ -3,7 +3,6 @@ generic-y += bpf_perf_event.h
generic-y += bug.h
generic-y += compat.h
generic-y += current.h
generic-y += delay.h
generic-y += device.h
generic-y += emergency-restart.h
generic-y += exec.h

30
arch/um/include/asm/delay.h Normal file
View File

@ -0,0 +1,30 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __UM_DELAY_H
#define __UM_DELAY_H
#include <asm-generic/delay.h>
#include <linux/time-internal.h>
static inline void um_ndelay(unsigned long nsecs)
{
if (time_travel_mode == TT_MODE_INFCPU ||
time_travel_mode == TT_MODE_EXTERNAL) {
time_travel_ndelay(nsecs);
return;
}
ndelay(nsecs);
}
#undef ndelay
#define ndelay um_ndelay
static inline void um_udelay(unsigned long usecs)
{
if (time_travel_mode == TT_MODE_INFCPU ||
time_travel_mode == TT_MODE_EXTERNAL) {
time_travel_ndelay(1000 * usecs);
return;
}
udelay(usecs);
}
#undef udelay
#define udelay um_udelay
#endif /* __UM_DELAY_H */

84
arch/um/include/linux/time-internal.h Normal file
View File

@ -0,0 +1,84 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2012 - 2014 Cisco Systems
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
*/
#ifndef __TIMER_INTERNAL_H__
#define __TIMER_INTERNAL_H__
#include <linux/list.h>
#define TIMER_MULTIPLIER 256
#define TIMER_MIN_DELTA 500
enum time_travel_mode {
TT_MODE_OFF,
TT_MODE_BASIC,
TT_MODE_INFCPU,
TT_MODE_EXTERNAL,
};
#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
struct time_travel_event {
unsigned long long time;
void (*fn)(struct time_travel_event *d);
struct list_head list;
bool pending, onstack;
};
extern enum time_travel_mode time_travel_mode;
void time_travel_sleep(unsigned long long duration);
static inline void
time_travel_set_event_fn(struct time_travel_event *e,
void (*fn)(struct time_travel_event *d))
{
e->fn = fn;
}
void __time_travel_propagate_time(void);
static inline void time_travel_propagate_time(void)
{
if (time_travel_mode == TT_MODE_EXTERNAL)
__time_travel_propagate_time();
}
void __time_travel_wait_readable(int fd);
static inline void time_travel_wait_readable(int fd)
{
if (time_travel_mode == TT_MODE_EXTERNAL)
__time_travel_wait_readable(fd);
}
void time_travel_add_irq_event(struct time_travel_event *e);
#else
struct time_travel_event {
};
#define time_travel_mode TT_MODE_OFF
static inline void time_travel_sleep(unsigned long long duration)
{
}
/* this is a macro so the event/function need not exist */
#define time_travel_set_event_fn(e, fn) do {} while (0)
static inline void time_travel_propagate_time(void)
{
}
static inline void time_travel_wait_readable(int fd)
{
}
#endif /* CONFIG_UML_TIME_TRAVEL_SUPPORT */
/*
* Without CONFIG_UML_TIME_TRAVEL_SUPPORT this is a linker error if used,
* which is intentional since we really shouldn't link it in that case.
*/
void time_travel_ndelay(unsigned long nsec);
#endif /* __TIMER_INTERNAL_H__ */

1
arch/um/include/shared/os.h
View File

@ -181,6 +181,7 @@ extern int os_falloc_punch(int fd, unsigned long long offset, int count);
extern int os_eventfd(unsigned int initval, int flags);
extern int os_sendmsg_fds(int fd, const void *buf, unsigned int len,
const int *fds, unsigned int fds_num);
int os_poll(unsigned int n, const int *fds);
/* start_up.c */
extern void os_early_checks(void);

76
arch/um/include/shared/timer-internal.h
View File

@ -1,76 +0,0 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2012 - 2014 Cisco Systems
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
*/
#ifndef __TIMER_INTERNAL_H__
#define __TIMER_INTERNAL_H__
#define TIMER_MULTIPLIER 256
#define TIMER_MIN_DELTA 500
enum time_travel_mode {
TT_MODE_OFF,
TT_MODE_BASIC,
TT_MODE_INFCPU,
};
enum time_travel_timer_mode {
TT_TMR_DISABLED,
TT_TMR_ONESHOT,
TT_TMR_PERIODIC,
};
#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
extern enum time_travel_mode time_travel_mode;
extern unsigned long long time_travel_time;
extern enum time_travel_timer_mode time_travel_timer_mode;
extern unsigned long long time_travel_timer_expiry;
extern unsigned long long time_travel_timer_interval;
static inline void time_travel_set_time(unsigned long long ns)
{
time_travel_time = ns;
}
static inline void time_travel_set_timer_mode(enum time_travel_timer_mode mode)
{
time_travel_timer_mode = mode;
}
static inline void time_travel_set_timer_expiry(unsigned long long expiry)
{
time_travel_timer_expiry = expiry;
}
static inline void time_travel_set_timer_interval(unsigned long long interval)
{
time_travel_timer_interval = interval;
}
#else
#define time_travel_mode TT_MODE_OFF
#define time_travel_time 0
#define time_travel_timer_expiry 0
#define time_travel_timer_interval 0
static inline void time_travel_set_time(unsigned long long ns)
{
}
static inline void time_travel_set_timer_mode(enum time_travel_timer_mode mode)
{
}
static inline void time_travel_set_timer_expiry(unsigned long long expiry)
{
}
static inline void time_travel_set_timer_interval(unsigned long long interval)
{
}
#define time_travel_timer_mode TT_TMR_DISABLED
#endif
#endif

9
arch/um/kernel/kmsg_dump.c
View File

@ -9,20 +9,19 @@ static void kmsg_dumper_stdout(struct kmsg_dumper *dumper,
enum kmsg_dump_reason reason)
{
static char line[1024];
struct console *con;
size_t len = 0;
bool con_available = false;
/* only dump kmsg when no console is available */
if (!console_trylock())
return;
if (console_drivers != NULL)
con_available = true;
for_each_console(con)
break;
console_unlock();
if (con_available == true)
if (con)
return;
printf("kmsg_dump:\n");

39
arch/um/kernel/process.c
View File

@ -32,7 +32,7 @@
#include <kern_util.h>
#include <os.h>
#include <skas.h>
#include <timer-internal.h>
#include <linux/time-internal.h>
/*
* This is a per-cpu array. A processor only modifies its entry and it only
@ -203,43 +203,6 @@ void initial_thread_cb(void (*proc)(void *), void *arg)
kmalloc_ok = save_kmalloc_ok;
}
static void time_travel_sleep(unsigned long long duration)
{
unsigned long long next = time_travel_time + duration;
if (time_travel_mode != TT_MODE_INFCPU)
os_timer_disable();
while (time_travel_timer_mode == TT_TMR_PERIODIC &&
time_travel_timer_expiry < time_travel_time)
time_travel_set_timer_expiry(time_travel_timer_expiry +
time_travel_timer_interval);
if (time_travel_timer_mode != TT_TMR_DISABLED &&
time_travel_timer_expiry < next) {
if (time_travel_timer_mode == TT_TMR_ONESHOT)
time_travel_set_timer_mode(TT_TMR_DISABLED);
/*
* In basic mode, time_travel_time will be adjusted in
* the timer IRQ handler so it works even when the signal
* comes from the OS timer, see there.
*/
if (time_travel_mode != TT_MODE_BASIC)
time_travel_set_time(time_travel_timer_expiry);
deliver_alarm();
} else {
time_travel_set_time(next);
}
if (time_travel_mode != TT_MODE_INFCPU) {
if (time_travel_timer_mode == TT_TMR_PERIODIC)
os_timer_set_interval(time_travel_timer_interval);
else if (time_travel_timer_mode == TT_TMR_ONESHOT)
os_timer_one_shot(time_travel_timer_expiry - next);
}
}
static void um_idle_sleep(void)
{
unsigned long long duration = UM_NSEC_PER_SEC;

5
arch/um/kernel/skas/syscall.c
View File

@ -10,7 +10,7 @@
#include <sysdep/ptrace.h>
#include <sysdep/ptrace_user.h>
#include <sysdep/syscalls.h>
#include <shared/timer-internal.h>
#include <linux/time-internal.h>
void handle_syscall(struct uml_pt_regs *r)
{
@ -24,7 +24,8 @@ void handle_syscall(struct uml_pt_regs *r)
* went to sleep, even if said userspace interacts with the kernel in
* various ways.
*/
if (time_travel_mode == TT_MODE_INFCPU)
if (time_travel_mode == TT_MODE_INFCPU ||
time_travel_mode == TT_MODE_EXTERNAL)
schedule();
/* Initialize the syscall number and default return value. */

538
arch/um/kernel/time.c
View File

@ -4,6 +4,7 @@
* Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
* Copyright (C) 2012-2014 Cisco Systems
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Copyright (C) 2019 Intel Corporation
*/
#include <linux/clockchips.h>
@ -18,21 +19,484 @@
#include <asm/param.h>
#include <kern_util.h>
#include <os.h>
#include <timer-internal.h>
#include <linux/time-internal.h>
#include <linux/um_timetravel.h>
#include <shared/init.h>
#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
enum time_travel_mode time_travel_mode;
unsigned long long time_travel_time;
enum time_travel_timer_mode time_travel_timer_mode;
unsigned long long time_travel_timer_expiry;
unsigned long long time_travel_timer_interval;
EXPORT_SYMBOL_GPL(time_travel_mode);
static bool time_travel_start_set;
static unsigned long long time_travel_start;
#else
static unsigned long long time_travel_time;
static LIST_HEAD(time_travel_events);
static unsigned long long time_travel_timer_interval;
static unsigned long long time_travel_next_event;
static struct time_travel_event time_travel_timer_event;
static int time_travel_ext_fd = -1;
static unsigned int time_travel_ext_waiting;
static bool time_travel_ext_prev_request_valid;
static unsigned long long time_travel_ext_prev_request;
static bool time_travel_ext_free_until_valid;
static unsigned long long time_travel_ext_free_until;
static void time_travel_set_time(unsigned long long ns)
{
if (unlikely(ns < time_travel_time))
panic("time-travel: time goes backwards %lld -> %lld\n",
time_travel_time, ns);
time_travel_time = ns;
}
enum time_travel_message_handling {
TTMH_IDLE,
TTMH_POLL,
TTMH_READ,
};
static void time_travel_handle_message(struct um_timetravel_msg *msg,
enum time_travel_message_handling mode)
{
struct um_timetravel_msg resp = {
.op = UM_TIMETRAVEL_ACK,
};
int ret;
/*
* Poll outside the locked section (if we're not called to only read
* the response) so we can get interrupts for e.g. virtio while we're
* here, but then we need to lock to not get interrupted between the
* read of the message and write of the ACK.
*/
if (mode != TTMH_READ) {
while (os_poll(1, &time_travel_ext_fd) != 0) {
if (mode == TTMH_IDLE) {
BUG_ON(!irqs_disabled());
local_irq_enable();
local_irq_disable();
}
}
}
ret = os_read_file(time_travel_ext_fd, msg, sizeof(*msg));
if (ret == 0)
panic("time-travel external link is broken\n");
if (ret != sizeof(*msg))
panic("invalid time-travel message - %d bytes\n", ret);
switch (msg->op) {
default:
WARN_ONCE(1, "time-travel: unexpected message %lld\n",
(unsigned long long)msg->op);
break;
case UM_TIMETRAVEL_ACK:
return;
case UM_TIMETRAVEL_RUN:
time_travel_set_time(msg->time);
break;
case UM_TIMETRAVEL_FREE_UNTIL:
time_travel_ext_free_until_valid = true;
time_travel_ext_free_until = msg->time;
break;
}
os_write_file(time_travel_ext_fd, &resp, sizeof(resp));
}
static u64 time_travel_ext_req(u32 op, u64 time)
{
static int seq;
int mseq = ++seq;
struct um_timetravel_msg msg = {
.op = op,
.time = time,
.seq = mseq,
};
unsigned long flags;
/*
* We need to save interrupts here and only restore when we
* got the ACK - otherwise we can get interrupted and send
* another request while we're still waiting for an ACK, but
* the peer doesn't know we got interrupted and will send
* the ACKs in the same order as the message, but we'd need
* to see them in the opposite order ...
*
* This wouldn't matter *too* much, but some ACKs carry the
* current time (for UM_TIMETRAVEL_GET) and getting another
* ACK without a time would confuse us a lot!
*
* The sequence number assignment that happens here lets us
* debug such message handling issues more easily.
*/
local_irq_save(flags);
os_write_file(time_travel_ext_fd, &msg, sizeof(msg));
while (msg.op != UM_TIMETRAVEL_ACK)
time_travel_handle_message(&msg, TTMH_READ);
if (msg.seq != mseq)
panic("time-travel: ACK message has different seqno! op=%d, seq=%d != %d time=%lld\n",
msg.op, msg.seq, mseq, msg.time);
if (op == UM_TIMETRAVEL_GET)
time_travel_set_time(msg.time);
local_irq_restore(flags);
return msg.time;
}
void __time_travel_wait_readable(int fd)
{
int fds[2] = { fd, time_travel_ext_fd };
int ret;
if (time_travel_mode != TT_MODE_EXTERNAL)
return;
while ((ret = os_poll(2, fds))) {
struct um_timetravel_msg msg;
if (ret == 1)
time_travel_handle_message(&msg, TTMH_READ);
}
}
EXPORT_SYMBOL_GPL(__time_travel_wait_readable);
static void time_travel_ext_update_request(unsigned long long time)
{
if (time_travel_mode != TT_MODE_EXTERNAL)
return;
/* asked for exactly this time previously */
if (time_travel_ext_prev_request_valid &&
time == time_travel_ext_prev_request)
return;
time_travel_ext_prev_request = time;
time_travel_ext_prev_request_valid = true;
time_travel_ext_req(UM_TIMETRAVEL_REQUEST, time);
}
void __time_travel_propagate_time(void)
{
time_travel_ext_req(UM_TIMETRAVEL_UPDATE, time_travel_time);
}
EXPORT_SYMBOL_GPL(__time_travel_propagate_time);
/* returns true if we must do a wait to the simtime device */
static bool time_travel_ext_request(unsigned long long time)
{
/*
* If we received an external sync point ("free until") then we
* don't have to request/wait for anything until then, unless
* we're already waiting.
*/
if (!time_travel_ext_waiting && time_travel_ext_free_until_valid &&
time < time_travel_ext_free_until)
return false;
time_travel_ext_update_request(time);
return true;
}
static void time_travel_ext_wait(bool idle)
{
struct um_timetravel_msg msg = {
.op = UM_TIMETRAVEL_ACK,
};
time_travel_ext_prev_request_valid = false;
time_travel_ext_waiting++;
time_travel_ext_req(UM_TIMETRAVEL_WAIT, -1);
/*
* Here we are deep in the idle loop, so we have to break out of the
* kernel abstraction in a sense and implement this in terms of the
* UML system waiting on the VQ interrupt while sleeping, when we get
* the signal it'll call time_travel_ext_vq_notify_done() completing the
* call.
*/
while (msg.op != UM_TIMETRAVEL_RUN)
time_travel_handle_message(&msg, idle ? TTMH_IDLE : TTMH_POLL);
time_travel_ext_waiting--;
/* we might request more stuff while polling - reset when we run */
time_travel_ext_prev_request_valid = false;
}
static void time_travel_ext_get_time(void)
{
time_travel_ext_req(UM_TIMETRAVEL_GET, -1);
}
static void __time_travel_update_time(unsigned long long ns, bool idle)
{
if (time_travel_mode == TT_MODE_EXTERNAL && time_travel_ext_request(ns))
time_travel_ext_wait(idle);
else
time_travel_set_time(ns);
}
static struct time_travel_event *time_travel_first_event(void)
{
return list_first_entry_or_null(&time_travel_events,
struct time_travel_event,
list);
}
static void __time_travel_add_event(struct time_travel_event *e,
unsigned long long time)
{
struct time_travel_event *tmp;
bool inserted = false;
if (WARN(time_travel_mode == TT_MODE_BASIC &&
e != &time_travel_timer_event,
"only timer events can be handled in basic mode"))
return;
if (e->pending)
return;
e->pending = true;
e->time = time;
list_for_each_entry(tmp, &time_travel_events, list) {
/*
* Add the new entry before one with higher time,
* or if they're equal and both on stack, because
* in that case we need to unwind the stack in the
* right order, and the later event (timer sleep
* or such) must be dequeued first.
*/
if ((tmp->time > e->time) ||
(tmp->time == e->time && tmp->onstack && e->onstack)) {
list_add_tail(&e->list, &tmp->list);
inserted = true;
break;
}
}
if (!inserted)
list_add_tail(&e->list, &time_travel_events);
tmp = time_travel_first_event();
time_travel_ext_update_request(tmp->time);
time_travel_next_event = tmp->time;
}
static void time_travel_add_event(struct time_travel_event *e,
unsigned long long time)
{
if (WARN_ON(!e->fn))
return;
__time_travel_add_event(e, time);
}
void time_travel_periodic_timer(struct time_travel_event *e)
{
time_travel_add_event(&time_travel_timer_event,
time_travel_time + time_travel_timer_interval);
deliver_alarm();
}
static void time_travel_deliver_event(struct time_travel_event *e)
{
if (e == &time_travel_timer_event) {
/*
* deliver_alarm() does the irq_enter/irq_exit
* by itself, so must handle it specially here
*/
e->fn(e);
} else {
unsigned long flags;
local_irq_save(flags);
irq_enter();
e->fn(e);
irq_exit();
local_irq_restore(flags);
}
}
static bool time_travel_del_event(struct time_travel_event *e)
{
if (!e->pending)
return false;
list_del(&e->list);
e->pending = false;
return true;
}
static void time_travel_update_time(unsigned long long next, bool idle)
{
struct time_travel_event ne = {
.onstack = true,
};
struct time_travel_event *e;
bool finished = idle;
/* add it without a handler - we deal with that specifically below */
__time_travel_add_event(&ne, next);
do {
e = time_travel_first_event();
BUG_ON(!e);
__time_travel_update_time(e->time, idle);
/* new events may have been inserted while we were waiting */
if (e == time_travel_first_event()) {
BUG_ON(!time_travel_del_event(e));
BUG_ON(time_travel_time != e->time);
if (e == &ne) {
finished = true;
} else {
if (e->onstack)
panic("On-stack event dequeued outside of the stack! time=%lld, event time=%lld, event=%pS\n",
time_travel_time, e->time, e);
time_travel_deliver_event(e);
}
}
e = time_travel_first_event();
if (e)
time_travel_ext_update_request(e->time);
} while (ne.pending && !finished);
time_travel_del_event(&ne);
}
void time_travel_ndelay(unsigned long nsec)
{
time_travel_update_time(time_travel_time + nsec, false);
}
EXPORT_SYMBOL(time_travel_ndelay);
void time_travel_add_irq_event(struct time_travel_event *e)
{
BUG_ON(time_travel_mode != TT_MODE_EXTERNAL);
time_travel_ext_get_time();
/*
* We could model interrupt latency here, for now just
* don't have any latency at all and request the exact
* same time (again) to run the interrupt...
*/
time_travel_add_event(e, time_travel_time);
}
EXPORT_SYMBOL_GPL(time_travel_add_irq_event);
static void time_travel_oneshot_timer(struct time_travel_event *e)
{
deliver_alarm();
}
void time_travel_sleep(unsigned long long duration)
{
unsigned long long next = time_travel_time + duration;
if (time_travel_mode == TT_MODE_BASIC)
os_timer_disable();
time_travel_update_time(next, true);
if (time_travel_mode == TT_MODE_BASIC &&
time_travel_timer_event.pending) {
if (time_travel_timer_event.fn == time_travel_periodic_timer) {
/*
* This is somewhat wrong - we should get the first
* one sooner like the os_timer_one_shot() below...
*/
os_timer_set_interval(time_travel_timer_interval);
} else {
os_timer_one_shot(time_travel_timer_event.time - next);
}
}
}
static void time_travel_handle_real_alarm(void)
{
time_travel_set_time(time_travel_next_event);
time_travel_del_event(&time_travel_timer_event);
if (time_travel_timer_event.fn == time_travel_periodic_timer)
time_travel_add_event(&time_travel_timer_event,
time_travel_time +
time_travel_timer_interval);
}
static void time_travel_set_interval(unsigned long long interval)
{
time_travel_timer_interval = interval;
}
static int time_travel_connect_external(const char *socket)
{
const char *sep;
unsigned long long id = (unsigned long long)-1;
int rc;
if ((sep = strchr(socket, ':'))) {
char buf[25] = {};
if (sep - socket > sizeof(buf) - 1)
goto invalid_number;
memcpy(buf, socket, sep - socket);
if (kstrtoull(buf, 0, &id)) {
invalid_number:
panic("time-travel: invalid external ID in string '%s'\n",
socket);
return -EINVAL;
}
socket = sep + 1;
}
rc = os_connect_socket(socket);
if (rc < 0) {
panic("time-travel: failed to connect to external socket %s\n",
socket);
return rc;
}
time_travel_ext_fd = rc;
time_travel_ext_req(UM_TIMETRAVEL_START, id);
return 1;
}
#else /* CONFIG_UML_TIME_TRAVEL_SUPPORT */
#define time_travel_start_set 0
#define time_travel_start 0
#define time_travel_time 0
static inline void time_travel_update_time(unsigned long long ns, bool retearly)
{
}
static inline void time_travel_handle_real_alarm(void)
{
}
static void time_travel_set_interval(unsigned long long interval)
{
}
/* fail link if this actually gets used */
extern u64 time_travel_ext_req(u32 op, u64 time);
/* these are empty macros so the struct/fn need not exist */
#define time_travel_add_event(e, time) do { } while (0)
#define time_travel_del_event(e) do { } while (0)
#endif
void timer_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
@ -48,7 +512,7 @@ void timer_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
* never get any real signals from the OS.
*/
if (time_travel_mode == TT_MODE_BASIC)
time_travel_set_time(time_travel_timer_expiry);
time_travel_handle_real_alarm();
local_irq_save(flags);
do_IRQ(TIMER_IRQ, regs);
@ -58,9 +522,10 @@ void timer_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
static int itimer_shutdown(struct clock_event_device *evt)
{
if (time_travel_mode != TT_MODE_OFF)
time_travel_set_timer_mode(TT_TMR_DISABLED);
time_travel_del_event(&time_travel_timer_event);
if (time_travel_mode != TT_MODE_INFCPU)
if (time_travel_mode != TT_MODE_INFCPU &&
time_travel_mode != TT_MODE_EXTERNAL)
os_timer_disable();
return 0;
@ -71,12 +536,16 @@ static int itimer_set_periodic(struct clock_event_device *evt)
unsigned long long interval = NSEC_PER_SEC / HZ;
if (time_travel_mode != TT_MODE_OFF) {
time_travel_set_timer_mode(TT_TMR_PERIODIC);
time_travel_set_timer_expiry(time_travel_time + interval);
time_travel_set_timer_interval(interval);
time_travel_del_event(&time_travel_timer_event);
time_travel_set_event_fn(&time_travel_timer_event,
time_travel_periodic_timer);
time_travel_set_interval(interval);
time_travel_add_event(&time_travel_timer_event,
time_travel_time + interval);
}
if (time_travel_mode != TT_MODE_INFCPU)
if (time_travel_mode != TT_MODE_INFCPU &&
time_travel_mode != TT_MODE_EXTERNAL)
os_timer_set_interval(interval);
return 0;
@ -88,11 +557,15 @@ static int itimer_next_event(unsigned long delta,
delta += 1;
if (time_travel_mode != TT_MODE_OFF) {
time_travel_set_timer_mode(TT_TMR_ONESHOT);
time_travel_set_timer_expiry(time_travel_time + delta);
time_travel_del_event(&time_travel_timer_event);
time_travel_set_event_fn(&time_travel_timer_event,
time_travel_oneshot_timer);
time_travel_add_event(&time_travel_timer_event,
time_travel_time + delta);
}
if (time_travel_mode != TT_MODE_INFCPU)
if (time_travel_mode != TT_MODE_INFCPU &&
time_travel_mode != TT_MODE_EXTERNAL)
return os_timer_one_shot(delta);
return 0;
@ -143,8 +616,17 @@ static u64 timer_read(struct clocksource *cs)
* stuck in loops that expect time to move more than the
* exact requested sleep amount, e.g. python's socket server,
* see https://bugs.python.org/issue37026.
*
* However, don't do that when we're in interrupt or such as
* then we might recurse into our own processing, and get to
* even more waiting, and that's not good - it messes up the
* "what do I do next" and onstack event we use to know when
* to return from time_travel_update_time().
*/
time_travel_set_time(time_travel_time + TIMER_MULTIPLIER);
if (!irqs_disabled() && !in_interrupt() && !in_softirq())
time_travel_update_time(time_travel_time +
TIMER_MULTIPLIER,
false);
return time_travel_time / TIMER_MULTIPLIER;
}
@ -188,6 +670,8 @@ void read_persistent_clock64(struct timespec64 *ts)
if (time_travel_start_set)
nsecs = time_travel_start + time_travel_time;
else if (time_travel_mode == TT_MODE_EXTERNAL)
nsecs = time_travel_ext_req(UM_TIMETRAVEL_GET_TOD, -1);
else
nsecs = os_persistent_clock_emulation();
@ -204,7 +688,8 @@ void __init time_init(void)
#ifdef CONFIG_UML_TIME_TRAVEL_SUPPORT
unsigned long calibrate_delay_is_known(void)
{
if (time_travel_mode == TT_MODE_INFCPU)
if (time_travel_mode == TT_MODE_INFCPU ||
time_travel_mode == TT_MODE_EXTERNAL)
return 1;
return 0;
}
@ -218,6 +703,13 @@ int setup_time_travel(char *str)
return 1;
}
if (strncmp(str, "=ext:", 5) == 0) {
time_travel_mode = TT_MODE_EXTERNAL;
timer_clockevent.name = "time-travel-timer-external";
timer_clocksource.name = "time-travel-clock-external";
return time_travel_connect_external(str + 5);
}
if (!*str) {
time_travel_mode = TT_MODE_BASIC;
timer_clockevent.name = "time-travel-timer";
@ -242,7 +734,15 @@ __uml_help(setup_time_travel,
"are no wall clock timers, and any CPU processing happens - as seen from the\n"
"guest - instantly. This can be useful for accurate simulation regardless of\n"
"debug overhead, physical CPU speed, etc. but is somewhat dangerous as it can\n"
"easily lead to getting stuck (e.g. if anything in the system busy loops).\n");
"easily lead to getting stuck (e.g. if anything in the system busy loops).\n"
"\n"
"time-travel=ext:[ID:]/path/to/socket\n"
"This enables time travel mode similar to =inf-cpu, except the system will\n"
"use the given socket to coordinate with a central scheduler, in order to\n"
"have more than one system simultaneously be on simulated time. The virtio\n"
"driver code in UML knows about this so you can also simulate networks and\n"
"devices using it, assuming the device has the right capabilities.\n"
"The optional ID is a 64-bit integer that's sent to the central scheduler.\n");
int setup_time_travel_start(char *str)
{

2
arch/um/kernel/uml.lds.S
View File

@ -19,10 +19,10 @@ SECTIONS
__binary_start = START;
. = START + SIZEOF_HEADERS;
. = ALIGN(PAGE_SIZE);
_text = .;
INIT_TEXT_SECTION(0)
. = ALIGN(PAGE_SIZE);
.text :
{

31
arch/um/os-Linux/file.c
View File

@ -5,9 +5,11 @@
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <linux/falloc.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/socket.h>
@ -16,6 +18,7 @@
#include <sys/un.h>
#include <sys/types.h>
#include <sys/eventfd.h>
#include <poll.h>
#include <os.h>
static void copy_stat(struct uml_stat *dst, const struct stat64 *src)
@ -664,3 +667,31 @@ int os_sendmsg_fds(int fd, const void *buf, unsigned int len, const int *fds,
return -errno;
return err;
}
int os_poll(unsigned int n, const int *fds)
{
/* currently need 2 FDs at most so avoid dynamic allocation */
struct pollfd pollfds[2] = {};
unsigned int i;
int ret;
if (n > ARRAY_SIZE(pollfds))
return -EINVAL;
for (i = 0; i < n; i++) {
pollfds[i].fd = fds[i];
pollfds[i].events = POLLIN;
}
ret = poll(pollfds, n, -1);
if (ret < 0)
return -errno;
/* Return the index of the available FD */
for (i = 0; i < n; i++) {
if (pollfds[i].revents)
return i;
}
return -EIO;
}

1
arch/um/os-Linux/time.c
View File

@ -14,7 +14,6 @@
#include <kern_util.h>
#include <os.h>
#include <string.h>
#include <timer-internal.h>
static timer_t event_high_res_timer = 0;

5
arch/um/os-Linux/umid.c
View File

@ -220,11 +220,12 @@ static void __init create_pid_file(void)
char pid[sizeof("nnnnn\0")], *file;
int fd, n;
file = malloc(strlen(uml_dir) + UMID_LEN + sizeof("/pid\0"));
n = strlen(uml_dir) + UMID_LEN + sizeof("/pid\0");
file = malloc(n);
if (!file)
return;
if (umid_file_name("pid", file, sizeof(file)))
if (umid_file_name("pid", file, n))
goto out;
fd = open(file, O_RDWR | O_CREAT | O_EXCL, 0644);

12
arch/x86/um/asm/processor.h
View File

@ -1,6 +1,7 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __UM_PROCESSOR_H
#define __UM_PROCESSOR_H
#include <linux/time-internal.h>
/* include faultinfo structure */
#include <sysdep/faultinfo.h>
@ -21,12 +22,19 @@
#include <asm/user.h>
/* REP NOP (PAUSE) is a good thing to insert into busy-wait loops. */
static inline void rep_nop(void)
static __always_inline void rep_nop(void)
{
__asm__ __volatile__("rep;nop": : :"memory");
}
#define cpu_relax() rep_nop()
static __always_inline void cpu_relax(void)
{
if (time_travel_mode == TT_MODE_INFCPU ||
time_travel_mode == TT_MODE_EXTERNAL)
time_travel_ndelay(1);
else
rep_nop();
}
#define task_pt_regs(t) (&(t)->thread.regs)

12
fs/hostfs/hostfs_kern.c
View File

@ -139,8 +139,8 @@ static char *inode_name(struct inode *ino)
static char *follow_link(char *link)
{
int len, n;
char *name, *resolved, *end;
int n;
name = __getname();
if (!name) {
@ -164,15 +164,13 @@ static char *follow_link(char *link)
return name;
*(end + 1) = '\0';
len = strlen(link) + strlen(name) + 1;
resolved = kmalloc(len, GFP_KERNEL);
resolved = kasprintf(GFP_KERNEL, "%s%s", link, name);
if (resolved == NULL) {
n = -ENOMEM;
goto out_free;
}
sprintf(resolved, "%s%s", link, name);
__putname(name);
kfree(link);
return resolved;
@ -921,18 +919,16 @@ static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent)
sb->s_d_op = &simple_dentry_operations;
sb->s_maxbytes = MAX_LFS_FILESIZE;
/* NULL is printed as <NULL> by sprintf: avoid that. */
/* NULL is printed as '(null)' by printf(): avoid that. */
if (req_root == NULL)
req_root = "";
err = -ENOMEM;
sb->s_fs_info = host_root_path =
kmalloc(strlen(root_ino) + strlen(req_root) + 2, GFP_KERNEL);
kasprintf(GFP_KERNEL, "%s/%s", root_ino, req_root);
if (host_root_path == NULL)
goto out;
sprintf(host_root_path, "%s/%s", root_ino, req_root);
root_inode = new_inode(sb);
if (!root_inode)
goto out;

128
include/uapi/linux/um_timetravel.h Normal file
View File

@ -0,0 +1,128 @@
/*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* Copyright (C) 2019 Intel Corporation
*/
#ifndef _UAPI_LINUX_UM_TIMETRAVEL_H
#define _UAPI_LINUX_UM_TIMETRAVEL_H
#include <linux/types.h>
/**
* struct um_timetravel_msg - UM time travel message
*
* This is the basic message type, going in both directions.
*
* This is the message passed between the host (user-mode Linux instance)
* and the calendar (the application on the other side of the socket) in
* order to implement common scheduling.
*
* Whenever UML has an event it will request runtime for it from the
* calendar, and then wait for its turn until it can run, etc. Note
* that it will only ever request the single next runtime, i.e. multiple
* REQUEST messages override each other.
*/
struct um_timetravel_msg {
/**
* @op: operation value from &enum um_timetravel_ops
*/
__u32 op;
/**
* @seq: sequence number for the message - shall be reflected in
* the ACK response, and should be checked while processing
* the response to see if it matches
*/
__u32 seq;
/**
* @time: time in nanoseconds
*/
__u64 time;
};
/**
* enum um_timetravel_ops - Operation codes
*/
enum um_timetravel_ops {
/**
* @UM_TIMETRAVEL_ACK: response (ACK) to any previous message,
* this usually doesn't carry any data in the 'time' field
* unless otherwise specified below
*/
UM_TIMETRAVEL_ACK = 0,
/**
* @UM_TIMETRAVEL_START: initialize the connection, the time
* field contains an (arbitrary) ID to possibly be able
* to distinguish the connections.
*/
UM_TIMETRAVEL_START = 1,
/**
* @UM_TIMETRAVEL_REQUEST: request to run at the given time
* (host -> calendar)
*/
UM_TIMETRAVEL_REQUEST = 2,
/**
* @UM_TIMETRAVEL_WAIT: Indicate waiting for the previously requested
* runtime, new requests may be made while waiting (e.g. due to
* interrupts); the time field is ignored. The calendar must process
* this message and later send a %UM_TIMETRAVEL_RUN message when
* the host can run again.
* (host -> calendar)
*/
UM_TIMETRAVEL_WAIT = 3,
/**
* @UM_TIMETRAVEL_GET: return the current time from the calendar in the
* ACK message, the time in the request message is ignored
* (host -> calendar)
*/
UM_TIMETRAVEL_GET = 4,
/**
* @UM_TIMETRAVEL_UPDATE: time update to the calendar, must be sent e.g.
* before kicking an interrupt to another calendar
* (host -> calendar)
*/
UM_TIMETRAVEL_UPDATE = 5,
/**
* @UM_TIMETRAVEL_RUN: run time request granted, current time is in
* the time field
* (calendar -> host)
*/
UM_TIMETRAVEL_RUN = 6,
/**
* @UM_TIMETRAVEL_FREE_UNTIL: Enable free-running until the given time,
* this is a message from the calendar telling the host that it can
* freely do its own scheduling for anything before the indicated
* time.
* Note that if a calendar sends this message once, the host may
* assume that it will also do so in the future, if it implements
* wraparound semantics for the time field.
* (calendar -> host)
*/
UM_TIMETRAVEL_FREE_UNTIL = 7,
/**
* @UM_TIMETRAVEL_GET_TOD: Return time of day, typically used once at
* boot by the virtual machines to get a synchronized time from
* the simulation.
*/
UM_TIMETRAVEL_GET_TOD = 8,
};
#endif /* _UAPI_LINUX_UM_TIMETRAVEL_H */