minix/kernel/system/do_update.c

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New RS and new signal handling for system processes. UPDATING INFO: 20100317: /usr/src/etc/system.conf updated to ignore default kernel calls: copy it (or merge it) to /etc/system.conf. The hello driver (/dev/hello) added to the distribution: # cd /usr/src/commands/scripts && make clean install # cd /dev && MAKEDEV hello KERNEL CHANGES: - Generic signal handling support. The kernel no longer assumes PM as a signal manager for every process. The signal manager of a given process can now be specified in its privilege slot. When a signal has to be delivered, the kernel performs the lookup and forwards the signal to the appropriate signal manager. PM is the default signal manager for user processes, RS is the default signal manager for system processes. To enable ptrace()ing for system processes, it is sufficient to change the default signal manager to PM. This will temporarily disable crash recovery, though. - sys_exit() is now split into sys_exit() (i.e. exit() for system processes, which generates a self-termination signal), and sys_clear() (i.e. used by PM to ask the kernel to clear a process slot when a process exits). - Added a new kernel call (i.e. sys_update()) to swap two process slots and implement live update. PM CHANGES: - Posix signal handling is no longer allowed for system processes. System signals are split into two fixed categories: termination and non-termination signals. When a non-termination signaled is processed, PM transforms the signal into an IPC message and delivers the message to the system process. When a termination signal is processed, PM terminates the process. - PM no longer assumes itself as the signal manager for system processes. It now makes sure that every system signal goes through the kernel before being actually processes. The kernel will then dispatch the signal to the appropriate signal manager which may or may not be PM. SYSLIB CHANGES: - Simplified SEF init and LU callbacks. - Added additional predefined SEF callbacks to debug crash recovery and live update. - Fixed a temporary ack in the SEF init protocol. SEF init reply is now completely synchronous. - Added SEF signal event type to provide a uniform interface for system processes to deal with signals. A sef_cb_signal_handler() callback is available for system processes to handle every received signal. A sef_cb_signal_manager() callback is used by signal managers to process system signals on behalf of the kernel. - Fixed a few bugs with memory mapping and DS. VM CHANGES: - Page faults and memory requests coming from the kernel are now implemented using signals. - Added a new VM call to swap two process slots and implement live update. - The call is used by RS at update time and in turn invokes the kernel call sys_update(). RS CHANGES: - RS has been reworked with a better functional decomposition. - Better kernel call masks. com.h now defines the set of very basic kernel calls every system service is allowed to use. This makes system.conf simpler and easier to maintain. In addition, this guarantees a higher level of isolation for system libraries that use one or more kernel calls internally (e.g. printf). - RS is the default signal manager for system processes. By default, RS intercepts every signal delivered to every system process. This makes crash recovery possible before bringing PM and friends in the loop. - RS now supports fast rollback when something goes wrong while initializing the new version during a live update. - Live update is now implemented by keeping the two versions side-by-side and swapping the process slots when the old version is ready to update. - Crash recovery is now implemented by keeping the two versions side-by-side and cleaning up the old version only when the recovery process is complete. DS CHANGES: - Fixed a bug when the process doing ds_publish() or ds_delete() is not known by DS. - Fixed the completely broken support for strings. String publishing is now implemented in the system library and simply wraps publishing of memory ranges. Ideally, we should adopt a similar approach for other data types as well. - Test suite fixed. DRIVER CHANGES: - The hello driver has been added to the Minix distribution to demonstrate basic live update and crash recovery functionalities. - Other drivers have been adapted to conform the new SEF interface.
2010-03-17 02:15:29 +01:00
/* The kernel call implemented in this file:
* m_type: SYS_UPDATE
*
* The parameters for this kernel call are:
* m2_i1: SYS_UPD_SRC_ENDPT (source process endpoint)
* m2_i2: SYS_UPD_DST_ENDPT (destination process endpoint)
*/
#include "../system.h"
#include "../ipc.h"
#include <string.h>
#if USE_UPDATE
#define DEBUG 0
#define proc_is_updatable(p) \
(RTS_ISSET(p, RTS_NO_PRIV) || RTS_ISSET(p, RTS_SIG_PENDING) \
|| (RTS_ISSET(p, RTS_RECEIVING) && !RTS_ISSET(p, RTS_SENDING)))
FORWARD _PROTOTYPE(void adjust_proc_slot, (struct proc *rp,
struct proc *from_rp));
FORWARD _PROTOTYPE(void adjust_priv_slot, (struct priv *privp,
struct priv *from_privp));
FORWARD _PROTOTYPE(void swap_proc_slot_pointer, (struct proc **rpp,
struct proc *src_rp, struct proc *dst_rp));
/*===========================================================================*
* do_update *
*===========================================================================*/
PUBLIC int do_update(struct proc * caller, message * m_ptr)
{
/* Handle sys_update(). Update a process into another by swapping their process
* slots.
*/
endpoint_t src_e, dst_e;
int src_p, dst_p;
struct proc *src_rp, *dst_rp;
New RS and new signal handling for system processes. UPDATING INFO: 20100317: /usr/src/etc/system.conf updated to ignore default kernel calls: copy it (or merge it) to /etc/system.conf. The hello driver (/dev/hello) added to the distribution: # cd /usr/src/commands/scripts && make clean install # cd /dev && MAKEDEV hello KERNEL CHANGES: - Generic signal handling support. The kernel no longer assumes PM as a signal manager for every process. The signal manager of a given process can now be specified in its privilege slot. When a signal has to be delivered, the kernel performs the lookup and forwards the signal to the appropriate signal manager. PM is the default signal manager for user processes, RS is the default signal manager for system processes. To enable ptrace()ing for system processes, it is sufficient to change the default signal manager to PM. This will temporarily disable crash recovery, though. - sys_exit() is now split into sys_exit() (i.e. exit() for system processes, which generates a self-termination signal), and sys_clear() (i.e. used by PM to ask the kernel to clear a process slot when a process exits). - Added a new kernel call (i.e. sys_update()) to swap two process slots and implement live update. PM CHANGES: - Posix signal handling is no longer allowed for system processes. System signals are split into two fixed categories: termination and non-termination signals. When a non-termination signaled is processed, PM transforms the signal into an IPC message and delivers the message to the system process. When a termination signal is processed, PM terminates the process. - PM no longer assumes itself as the signal manager for system processes. It now makes sure that every system signal goes through the kernel before being actually processes. The kernel will then dispatch the signal to the appropriate signal manager which may or may not be PM. SYSLIB CHANGES: - Simplified SEF init and LU callbacks. - Added additional predefined SEF callbacks to debug crash recovery and live update. - Fixed a temporary ack in the SEF init protocol. SEF init reply is now completely synchronous. - Added SEF signal event type to provide a uniform interface for system processes to deal with signals. A sef_cb_signal_handler() callback is available for system processes to handle every received signal. A sef_cb_signal_manager() callback is used by signal managers to process system signals on behalf of the kernel. - Fixed a few bugs with memory mapping and DS. VM CHANGES: - Page faults and memory requests coming from the kernel are now implemented using signals. - Added a new VM call to swap two process slots and implement live update. - The call is used by RS at update time and in turn invokes the kernel call sys_update(). RS CHANGES: - RS has been reworked with a better functional decomposition. - Better kernel call masks. com.h now defines the set of very basic kernel calls every system service is allowed to use. This makes system.conf simpler and easier to maintain. In addition, this guarantees a higher level of isolation for system libraries that use one or more kernel calls internally (e.g. printf). - RS is the default signal manager for system processes. By default, RS intercepts every signal delivered to every system process. This makes crash recovery possible before bringing PM and friends in the loop. - RS now supports fast rollback when something goes wrong while initializing the new version during a live update. - Live update is now implemented by keeping the two versions side-by-side and swapping the process slots when the old version is ready to update. - Crash recovery is now implemented by keeping the two versions side-by-side and cleaning up the old version only when the recovery process is complete. DS CHANGES: - Fixed a bug when the process doing ds_publish() or ds_delete() is not known by DS. - Fixed the completely broken support for strings. String publishing is now implemented in the system library and simply wraps publishing of memory ranges. Ideally, we should adopt a similar approach for other data types as well. - Test suite fixed. DRIVER CHANGES: - The hello driver has been added to the Minix distribution to demonstrate basic live update and crash recovery functionalities. - Other drivers have been adapted to conform the new SEF interface.
2010-03-17 02:15:29 +01:00
struct priv *src_privp, *dst_privp;
struct proc orig_src_proc;
struct proc orig_dst_proc;
struct priv orig_src_priv;
struct priv orig_dst_priv;
/* Lookup slots for source and destination process. */
src_e = m_ptr->SYS_UPD_SRC_ENDPT;
if(!isokendpt(src_e, &src_p)) {
return EINVAL;
}
src_rp = proc_addr(src_p);
src_privp = priv(src_rp);
if(!(src_privp->s_flags & SYS_PROC)) {
return EPERM;
}
dst_e = m_ptr->SYS_UPD_DST_ENDPT;
if(!isokendpt(dst_e, &dst_p)) {
return EINVAL;
}
dst_rp = proc_addr(dst_p);
dst_privp = priv(dst_rp);
if(!(dst_privp->s_flags & SYS_PROC)) {
return EPERM;
}
/* Check if processes are updatable. */
if(!proc_is_updatable(src_rp) || !proc_is_updatable(dst_rp)) {
return EBUSY;
}
#if DEBUG
printf("do_update: updating %d (%s, %d, %d) into %d (%s, %d, %d)\n",
src_rp->p_endpoint, src_rp->p_name, src_rp->p_nr, priv(src_rp)->s_proc_nr,
dst_rp->p_endpoint, dst_rp->p_name, dst_rp->p_nr, priv(dst_rp)->s_proc_nr);
proc_stacktrace(src_rp);
proc_stacktrace(dst_rp);
printf("do_update: curr ptproc %d\n", ptproc->p_endpoint);
#endif
/* Save existing data. */
orig_src_proc = *src_rp;
orig_src_priv = *(priv(src_rp));
orig_dst_proc = *dst_rp;
orig_dst_priv = *(priv(dst_rp));
/* Swap slots. */
*src_rp = orig_dst_proc;
*src_privp = orig_dst_priv;
*dst_rp = orig_src_proc;
*dst_privp = orig_src_priv;
/* Adjust process slots. */
adjust_proc_slot(src_rp, &orig_src_proc);
adjust_proc_slot(dst_rp, &orig_dst_proc);
/* Adjust privilege slots. */
adjust_priv_slot(priv(src_rp), &orig_src_priv);
adjust_priv_slot(priv(dst_rp), &orig_dst_priv);
/* Swap global process slot addresses. */
swap_proc_slot_pointer(&ptproc, src_rp, dst_rp);
/* Fix segments. */
alloc_segments(src_rp);
alloc_segments(dst_rp);
prot_init();
#if DEBUG
printf("do_update: updated %d (%s, %d, %d) into %d (%s, %d, %d)\n",
src_rp->p_endpoint, src_rp->p_name, src_rp->p_nr, priv(src_rp)->s_proc_nr,
dst_rp->p_endpoint, dst_rp->p_name, dst_rp->p_nr, priv(dst_rp)->s_proc_nr);
proc_stacktrace(src_rp);
proc_stacktrace(dst_rp);
printf("do_update: curr ptproc %d\n", ptproc->p_endpoint);
#endif
return OK;
}
/*===========================================================================*
* adjust_proc_slot *
*===========================================================================*/
PRIVATE void adjust_proc_slot(struct proc *rp, struct proc *from_rp)
{
/* Preserve endpoints, slot numbers, priv structure. */
rp->p_endpoint = from_rp->p_endpoint;
rp->p_nr = from_rp->p_nr;
rp->p_priv = from_rp->p_priv;
priv(rp)->s_proc_nr = from_rp->p_nr;
}
/*===========================================================================*
* adjust_priv_slot *
*===========================================================================*/
PRIVATE void adjust_priv_slot(struct priv *privp, struct priv *from_privp)
{
/* Preserve privilege ids and non-privilege stuff in the priv structure. */
privp->s_id = from_privp->s_id;
privp->s_notify_pending = from_privp->s_notify_pending;
privp->s_int_pending = from_privp->s_int_pending;
privp->s_sig_pending = from_privp->s_sig_pending;
privp->s_alarm_timer = from_privp->s_alarm_timer;
memcpy(privp->s_farmem, from_privp->s_farmem, sizeof(privp->s_farmem));
}
/*===========================================================================*
* swap_proc_slot_pointer *
*===========================================================================*/
PRIVATE void swap_proc_slot_pointer(struct proc **rpp, struct proc *src_rp,
struct proc *dst_rp)
{
if(*rpp == src_rp) {
*rpp = dst_rp;
}
else if(*rpp == dst_rp) {
*rpp = src_rp;
}
}
#endif /* USE_UPDATE */