Commit 2eb5f31b authored by Anton Ivanov's avatar Anton Ivanov Committed by Richard Weinberger

um: Switch clocksource to hrtimers

UML is using an obsolete itimer call for
all timers and "polls" for kernel space timer firing
in its userspace portion resulting in a long list
of bugs and incorrect behaviour(s). It also uses
ITIMER_VIRTUAL for its timer which results in the
timer being dependent on it running and the cpu
load.

This patch fixes this by moving to posix high resolution
timers firing off CLOCK_MONOTONIC and relaying the timer
correctly to the UML userspace.

Fixes:
 - crashes when hosts suspends/resumes
 - broken userspace timers - effecive ~40Hz instead
   of what they should be. Note - this modifies skas behavior
   by no longer setting an itimer per clone(). Timer events
   are relayed instead.
 - kernel network packet scheduling disciplines
 - tcp behaviour especially under load
 - various timer related corner cases

Finally, overall responsiveness of userspace is better.
Signed-off-by: default avatarThomas Meyer <thomas@m3y3r.de>
Signed-off-by: default avatarAnton Ivanov <aivanov@brocade.com>
[rw: massaged commit message]
Signed-off-by: default avatarRichard Weinberger <richard@nod.at>
parent e17c6d77
...@@ -131,7 +131,7 @@ export LDS_ELF_FORMAT := $(ELF_FORMAT) ...@@ -131,7 +131,7 @@ export LDS_ELF_FORMAT := $(ELF_FORMAT)
# The wrappers will select whether using "malloc" or the kernel allocator. # The wrappers will select whether using "malloc" or the kernel allocator.
LINK_WRAPS = -Wl,--wrap,malloc -Wl,--wrap,free -Wl,--wrap,calloc LINK_WRAPS = -Wl,--wrap,malloc -Wl,--wrap,free -Wl,--wrap,calloc
LD_FLAGS_CMDLINE = $(foreach opt,$(LDFLAGS),-Wl,$(opt)) LD_FLAGS_CMDLINE = $(foreach opt,$(LDFLAGS),-Wl,$(opt)) -lrt
# Used by link-vmlinux.sh which has special support for um link # Used by link-vmlinux.sh which has special support for um link
export CFLAGS_vmlinux := $(LINK-y) $(LINK_WRAPS) $(LD_FLAGS_CMDLINE) export CFLAGS_vmlinux := $(LINK-y) $(LINK_WRAPS) $(LD_FLAGS_CMDLINE)
......
/* /*
* Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk})
* Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
* Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL * Licensed under the GPL
*/ */
...@@ -183,6 +185,7 @@ extern int create_mem_file(unsigned long long len); ...@@ -183,6 +185,7 @@ extern int create_mem_file(unsigned long long len);
/* process.c */ /* process.c */
extern unsigned long os_process_pc(int pid); extern unsigned long os_process_pc(int pid);
extern int os_process_parent(int pid); extern int os_process_parent(int pid);
extern void os_alarm_process(int pid);
extern void os_stop_process(int pid); extern void os_stop_process(int pid);
extern void os_kill_process(int pid, int reap_child); extern void os_kill_process(int pid, int reap_child);
extern void os_kill_ptraced_process(int pid, int reap_child); extern void os_kill_ptraced_process(int pid, int reap_child);
...@@ -217,7 +220,7 @@ extern int set_umid(char *name); ...@@ -217,7 +220,7 @@ extern int set_umid(char *name);
extern char *get_umid(void); extern char *get_umid(void);
/* signal.c */ /* signal.c */
extern void timer_init(void); extern void timer_set_signal_handler(void);
extern void set_sigstack(void *sig_stack, int size); extern void set_sigstack(void *sig_stack, int size);
extern void remove_sigstack(void); extern void remove_sigstack(void);
extern void set_handler(int sig); extern void set_handler(int sig);
...@@ -227,6 +230,7 @@ extern void unblock_signals(void); ...@@ -227,6 +230,7 @@ extern void unblock_signals(void);
extern int get_signals(void); extern int get_signals(void);
extern int set_signals(int enable); extern int set_signals(int enable);
extern int os_is_signal_stack(void); extern int os_is_signal_stack(void);
extern void deliver_alarm(void);
/* util.c */ /* util.c */
extern void stack_protections(unsigned long address); extern void stack_protections(unsigned long address);
...@@ -238,12 +242,16 @@ extern void um_early_printk(const char *s, unsigned int n); ...@@ -238,12 +242,16 @@ extern void um_early_printk(const char *s, unsigned int n);
extern void os_fix_helper_signals(void); extern void os_fix_helper_signals(void);
/* time.c */ /* time.c */
extern void idle_sleep(unsigned long long nsecs); extern void os_idle_sleep(unsigned long long nsecs);
extern int set_interval(void); extern int os_timer_create(void* timer);
extern int timer_one_shot(int ticks); extern int os_timer_set_interval(void* timer, void* its);
extern long long disable_timer(void); extern int os_timer_one_shot(int ticks);
extern long long os_timer_disable(void);
extern long os_timer_remain(void* timer);
extern void uml_idle_timer(void); extern void uml_idle_timer(void);
extern long long os_persistent_clock_emulation(void);
extern long long os_nsecs(void); extern long long os_nsecs(void);
extern long long os_vnsecs(void);
/* skas/mem.c */ /* skas/mem.c */
extern long run_syscall_stub(struct mm_id * mm_idp, extern long run_syscall_stub(struct mm_id * mm_idp,
......
/* /*
* Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
* Copyright (C) 2005 Jeff Dike (jdike@karaya.com) * Copyright (C) 2005 Jeff Dike (jdike@karaya.com)
* Licensed under the GPL * Licensed under the GPL
*/ */
...@@ -6,12 +8,11 @@ ...@@ -6,12 +8,11 @@
#ifndef __STUB_DATA_H #ifndef __STUB_DATA_H
#define __STUB_DATA_H #define __STUB_DATA_H
#include <sys/time.h> #include <time.h>
struct stub_data { struct stub_data {
long offset; unsigned long offset;
int fd; int fd;
struct itimerval timer;
long err; long err;
}; };
......
/*
* Copyright (C) 2012 - 2014 Cisco Systems
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
*/
#ifndef __TIMER_INTERNAL_H__
#define __TIMER_INTERNAL_H__
#define TIMER_MULTIPLIER 256
#define TIMER_MIN_DELTA 500
#endif
/* /*
* Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk})
* Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Copyright 2003 PathScale, Inc. * Copyright 2003 PathScale, Inc.
* Licensed under the GPL * Licensed under the GPL
...@@ -27,6 +29,7 @@ ...@@ -27,6 +29,7 @@
#include <kern_util.h> #include <kern_util.h>
#include <os.h> #include <os.h>
#include <skas.h> #include <skas.h>
#include <timer-internal.h>
/* /*
* This is a per-cpu array. A processor only modifies its entry and it only * This is a per-cpu array. A processor only modifies its entry and it only
...@@ -203,11 +206,8 @@ void initial_thread_cb(void (*proc)(void *), void *arg) ...@@ -203,11 +206,8 @@ void initial_thread_cb(void (*proc)(void *), void *arg)
void arch_cpu_idle(void) void arch_cpu_idle(void)
{ {
unsigned long long nsecs;
cpu_tasks[current_thread_info()->cpu].pid = os_getpid(); cpu_tasks[current_thread_info()->cpu].pid = os_getpid();
nsecs = disable_timer(); os_idle_sleep(UM_NSEC_PER_SEC);
idle_sleep(nsecs);
local_irq_enable(); local_irq_enable();
} }
......
/* /*
* Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
* Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) * Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL * Licensed under the GPL
*/ */
...@@ -35,11 +36,6 @@ stub_clone_handler(void) ...@@ -35,11 +36,6 @@ stub_clone_handler(void)
if (err) if (err)
goto out; goto out;
err = stub_syscall3(__NR_setitimer, ITIMER_VIRTUAL,
(long) &data->timer, 0);
if (err)
goto out;
remap_stack(data->fd, data->offset); remap_stack(data->fd, data->offset);
goto done; goto done;
......
/* /*
* Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
* Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL * Licensed under the GPL
*/ */
...@@ -61,10 +62,12 @@ int init_new_context(struct task_struct *task, struct mm_struct *mm) ...@@ -61,10 +62,12 @@ int init_new_context(struct task_struct *task, struct mm_struct *mm)
if (current->mm != NULL && current->mm != &init_mm) if (current->mm != NULL && current->mm != &init_mm)
from_mm = &current->mm->context; from_mm = &current->mm->context;
block_signals();
if (from_mm) if (from_mm)
to_mm->id.u.pid = copy_context_skas0(stack, to_mm->id.u.pid = copy_context_skas0(stack,
from_mm->id.u.pid); from_mm->id.u.pid);
else to_mm->id.u.pid = start_userspace(stack); else to_mm->id.u.pid = start_userspace(stack);
unblock_signals();
if (to_mm->id.u.pid < 0) { if (to_mm->id.u.pid < 0) {
ret = to_mm->id.u.pid; ret = to_mm->id.u.pid;
......
/* /*
* Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk})
* 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) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL * Licensed under the GPL
*/ */
...@@ -7,11 +10,15 @@ ...@@ -7,11 +10,15 @@
#include <linux/init.h> #include <linux/init.h>
#include <linux/interrupt.h> #include <linux/interrupt.h>
#include <linux/jiffies.h> #include <linux/jiffies.h>
#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/threads.h> #include <linux/threads.h>
#include <asm/irq.h> #include <asm/irq.h>
#include <asm/param.h> #include <asm/param.h>
#include <kern_util.h> #include <kern_util.h>
#include <os.h> #include <os.h>
#include <timer-internal.h>
void timer_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs) void timer_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
{ {
...@@ -24,81 +31,97 @@ void timer_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs) ...@@ -24,81 +31,97 @@ void timer_handler(int sig, struct siginfo *unused_si, struct uml_pt_regs *regs)
static int itimer_shutdown(struct clock_event_device *evt) static int itimer_shutdown(struct clock_event_device *evt)
{ {
disable_timer(); os_timer_disable();
return 0; return 0;
} }
static int itimer_set_periodic(struct clock_event_device *evt) static int itimer_set_periodic(struct clock_event_device *evt)
{ {
set_interval(); os_timer_set_interval(NULL, NULL);
return 0; return 0;
} }
static int itimer_next_event(unsigned long delta, static int itimer_next_event(unsigned long delta,
struct clock_event_device *evt) struct clock_event_device *evt)
{ {
return timer_one_shot(delta + 1); return os_timer_one_shot(delta);
} }
static struct clock_event_device itimer_clockevent = { static int itimer_one_shot(struct clock_event_device *evt)
.name = "itimer", {
os_timer_one_shot(1);
return 0;
}
static struct clock_event_device timer_clockevent = {
.name = "posix-timer",
.rating = 250, .rating = 250,
.cpumask = cpu_all_mask, .cpumask = cpu_all_mask,
.features = CLOCK_EVT_FEAT_PERIODIC | .features = CLOCK_EVT_FEAT_PERIODIC |
CLOCK_EVT_FEAT_ONESHOT, CLOCK_EVT_FEAT_ONESHOT,
.set_state_shutdown = itimer_shutdown, .set_state_shutdown = itimer_shutdown,
.set_state_periodic = itimer_set_periodic, .set_state_periodic = itimer_set_periodic,
.set_state_oneshot = itimer_shutdown, .set_state_oneshot = itimer_one_shot,
.set_next_event = itimer_next_event, .set_next_event = itimer_next_event,
.shift = 32, .shift = 0,
.max_delta_ns = 0xffffffff,
.min_delta_ns = TIMER_MIN_DELTA, //microsecond resolution should be enough for anyone, same as 640K RAM
.irq = 0, .irq = 0,
.mult = 1,
}; };
static irqreturn_t um_timer(int irq, void *dev) static irqreturn_t um_timer(int irq, void *dev)
{ {
(*itimer_clockevent.event_handler)(&itimer_clockevent); if (get_current()->mm != NULL)
{
/* userspace - relay signal, results in correct userspace timers */
os_alarm_process(get_current()->mm->context.id.u.pid);
}
(*timer_clockevent.event_handler)(&timer_clockevent);
return IRQ_HANDLED; return IRQ_HANDLED;
} }
static cycle_t itimer_read(struct clocksource *cs) static cycle_t timer_read(struct clocksource *cs)
{ {
return os_nsecs() / 1000; return os_nsecs() / TIMER_MULTIPLIER;
} }
static struct clocksource itimer_clocksource = { static struct clocksource timer_clocksource = {
.name = "itimer", .name = "timer",
.rating = 300, .rating = 300,
.read = itimer_read, .read = timer_read,
.mask = CLOCKSOURCE_MASK(64), .mask = CLOCKSOURCE_MASK(64),
.flags = CLOCK_SOURCE_IS_CONTINUOUS, .flags = CLOCK_SOURCE_IS_CONTINUOUS,
}; };
static void __init setup_itimer(void) static void __init timer_setup(void)
{ {
int err; int err;
err = request_irq(TIMER_IRQ, um_timer, 0, "timer", NULL); err = request_irq(TIMER_IRQ, um_timer, IRQF_TIMER, "hr timer", NULL);
if (err != 0) if (err != 0)
printk(KERN_ERR "register_timer : request_irq failed - " printk(KERN_ERR "register_timer : request_irq failed - "
"errno = %d\n", -err); "errno = %d\n", -err);
itimer_clockevent.mult = div_sc(HZ, NSEC_PER_SEC, 32); err = os_timer_create(NULL);
itimer_clockevent.max_delta_ns = if (err != 0) {
clockevent_delta2ns(60 * HZ, &itimer_clockevent); printk(KERN_ERR "creation of timer failed - errno = %d\n", -err);
itimer_clockevent.min_delta_ns = return;
clockevent_delta2ns(1, &itimer_clockevent); }
err = clocksource_register_hz(&itimer_clocksource, USEC_PER_SEC);
err = clocksource_register_hz(&timer_clocksource, NSEC_PER_SEC/TIMER_MULTIPLIER);
if (err) { if (err) {
printk(KERN_ERR "clocksource_register_hz returned %d\n", err); printk(KERN_ERR "clocksource_register_hz returned %d\n", err);
return; return;
} }
clockevents_register_device(&itimer_clockevent); clockevents_register_device(&timer_clockevent);
} }
void read_persistent_clock(struct timespec *ts) void read_persistent_clock(struct timespec *ts)
{ {
long long nsecs = os_nsecs(); long long nsecs = os_persistent_clock_emulation();
set_normalized_timespec(ts, nsecs / NSEC_PER_SEC, set_normalized_timespec(ts, nsecs / NSEC_PER_SEC,
nsecs % NSEC_PER_SEC); nsecs % NSEC_PER_SEC);
...@@ -106,6 +129,6 @@ void read_persistent_clock(struct timespec *ts) ...@@ -106,6 +129,6 @@ void read_persistent_clock(struct timespec *ts)
void __init time_init(void) void __init time_init(void)
{ {
timer_init(); timer_set_signal_handler();
late_time_init = setup_itimer; late_time_init = timer_setup;
} }
void alarm_handler(int sig, struct siginfo *unused_si, mcontext_t *mc);
/* /*
* Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL * Licensed under the GPL
*/ */
...@@ -163,13 +164,13 @@ int __init main(int argc, char **argv, char **envp) ...@@ -163,13 +164,13 @@ int __init main(int argc, char **argv, char **envp)
/* /*
* This signal stuff used to be in the reboot case. However, * This signal stuff used to be in the reboot case. However,
* sometimes a SIGVTALRM can come in when we're halting (reproducably * sometimes a timer signal can come in when we're halting (reproducably
* when writing out gcov information, presumably because that takes * when writing out gcov information, presumably because that takes
* some time) and cause a segfault. * some time) and cause a segfault.
*/ */
/* stop timers and set SIGVTALRM to be ignored */ /* stop timers and set timer signal to be ignored */
disable_timer(); os_timer_disable();
/* disable SIGIO for the fds and set SIGIO to be ignored */ /* disable SIGIO for the fds and set SIGIO to be ignored */
err = deactivate_all_fds(); err = deactivate_all_fds();
......
/* /*
* Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
* Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL * Licensed under the GPL
*/ */
...@@ -89,6 +90,11 @@ int os_process_parent(int pid) ...@@ -89,6 +90,11 @@ int os_process_parent(int pid)
return parent; return parent;
} }
void os_alarm_process(int pid)
{
kill(pid, SIGALRM);
}
void os_stop_process(int pid) void os_stop_process(int pid)
{ {
kill(pid, SIGSTOP); kill(pid, SIGSTOP);
......
/* /*
* Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk})
* Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
* Copyright (C) 2004 PathScale, Inc * Copyright (C) 2004 PathScale, Inc
* Copyright (C) 2004 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) * Copyright (C) 2004 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL * Licensed under the GPL
...@@ -13,7 +15,6 @@ ...@@ -13,7 +15,6 @@
#include <kern_util.h> #include <kern_util.h>
#include <os.h> #include <os.h>
#include <sysdep/mcontext.h> #include <sysdep/mcontext.h>
#include "internal.h"
void (*sig_info[NSIG])(int, struct siginfo *, struct uml_pt_regs *) = { void (*sig_info[NSIG])(int, struct siginfo *, struct uml_pt_regs *) = {
[SIGTRAP] = relay_signal, [SIGTRAP] = relay_signal,
...@@ -23,7 +24,8 @@ void (*sig_info[NSIG])(int, struct siginfo *, struct uml_pt_regs *) = { ...@@ -23,7 +24,8 @@ void (*sig_info[NSIG])(int, struct siginfo *, struct uml_pt_regs *) = {
[SIGBUS] = bus_handler, [SIGBUS] = bus_handler,
[SIGSEGV] = segv_handler, [SIGSEGV] = segv_handler,
[SIGIO] = sigio_handler, [SIGIO] = sigio_handler,
[SIGVTALRM] = timer_handler }; [SIGALRM] = timer_handler
};
static void sig_handler_common(int sig, struct siginfo *si, mcontext_t *mc) static void sig_handler_common(int sig, struct siginfo *si, mcontext_t *mc)
{ {
...@@ -38,7 +40,7 @@ static void sig_handler_common(int sig, struct siginfo *si, mcontext_t *mc) ...@@ -38,7 +40,7 @@ static void sig_handler_common(int sig, struct siginfo *si, mcontext_t *mc)
} }
/* enable signals if sig isn't IRQ signal */ /* enable signals if sig isn't IRQ signal */
if ((sig != SIGIO) && (sig != SIGWINCH) && (sig != SIGVTALRM)) if ((sig != SIGIO) && (sig != SIGWINCH) && (sig != SIGALRM))
unblock_signals(); unblock_signals();
(*sig_info[sig])(sig, si, &r); (*sig_info[sig])(sig, si, &r);
...@@ -55,8 +57,8 @@ static void sig_handler_common(int sig, struct siginfo *si, mcontext_t *mc) ...@@ -55,8 +57,8 @@ static void sig_handler_common(int sig, struct siginfo *si, mcontext_t *mc)
#define SIGIO_BIT 0 #define SIGIO_BIT 0
#define SIGIO_MASK (1 << SIGIO_BIT) #define SIGIO_MASK (1 << SIGIO_BIT)
#define SIGVTALRM_BIT 1 #define SIGALRM_BIT 1
#define SIGVTALRM_MASK (1 << SIGVTALRM_BIT) #define SIGALRM_MASK (1 << SIGALRM_BIT)
static int signals_enabled; static int signals_enabled;
static unsigned int signals_pending; static unsigned int signals_pending;
...@@ -78,36 +80,38 @@ void sig_handler(int sig, struct siginfo *si, mcontext_t *mc) ...@@ -78,36 +80,38 @@ void sig_handler(int sig, struct siginfo *si, mcontext_t *mc)
set_signals(enabled); set_signals(enabled);
} }
static void real_alarm_handler(mcontext_t *mc) static void timer_real_alarm_handler(mcontext_t *mc)
{ {
struct uml_pt_regs regs; struct uml_pt_regs regs;
if (mc != NULL) if (mc != NULL)
get_regs_from_mc(&regs, mc); get_regs_from_mc(&regs, mc);
regs.is_user = 0; timer_handler(SIGALRM, NULL, &regs);
unblock_signals();
timer_handler(SIGVTALRM, NULL, &regs);
} }
void alarm_handler(int sig, struct siginfo *unused_si, mcontext_t *mc) void timer_alarm_handler(int sig, struct siginfo *unused_si, mcontext_t *mc)
{ {
int enabled; int enabled;
enabled = signals_enabled; enabled = signals_enabled;
if (!signals_enabled) { if (!signals_enabled) {
signals_pending |= SIGVTALRM_MASK; signals_pending |= SIGALRM_MASK;
return; return;
} }
block_signals(); block_signals();
real_alarm_handler(mc); timer_real_alarm_handler(mc);
set_signals(enabled); set_signals(enabled);
} }
void timer_init(void) void deliver_alarm(void) {
timer_alarm_handler(SIGALRM, NULL, NULL);
}
void timer_set_signal_handler(void)
{ {
set_handler(SIGVTALRM); set_handler(SIGALRM);
} }
void set_sigstack(void *sig_stack, int size) void set_sigstack(void *sig_stack, int size)
...@@ -131,10 +135,9 @@ static void (*handlers[_NSIG])(int sig, struct siginfo *si, mcontext_t *mc) = { ...@@ -131,10 +135,9 @@ static void (*handlers[_NSIG])(int sig, struct siginfo *si, mcontext_t *mc) = {
[SIGIO] = sig_handler, [SIGIO] = sig_handler,
[SIGWINCH] = sig_handler, [SIGWINCH] = sig_handler,
[SIGVTALRM] = alarm_handler [SIGALRM] = timer_alarm_handler
}; };
static void hard_handler(int sig, siginfo_t *si, void *p) static void hard_handler(int sig, siginfo_t *si, void *p)
{ {
struct ucontext *uc = p; struct ucontext *uc = p;
...@@ -188,9 +191,9 @@ void set_handler(int sig) ...@@ -188,9 +191,9 @@ void set_handler(int sig)
/* block irq ones */ /* block irq ones */
sigemptyset(&action.sa_mask); sigemptyset(&action.sa_mask);
sigaddset(&action.sa_mask, SIGVTALRM);
sigaddset(&action.sa_mask, SIGIO); sigaddset(&action.sa_mask, SIGIO);
sigaddset(&action.sa_mask, SIGWINCH); sigaddset(&action.sa_mask, SIGWINCH);
sigaddset(&action.sa_mask, SIGALRM);
if (sig == SIGSEGV) if (sig == SIGSEGV)
flags |= SA_NODEFER; flags |= SA_NODEFER;
...@@ -283,8 +286,8 @@ void unblock_signals(void) ...@@ -283,8 +286,8 @@ void unblock_signals(void)
if (save_pending & SIGIO_MASK) if (save_pending & SIGIO_MASK)
sig_handler_common(SIGIO, NULL, NULL); sig_handler_common(SIGIO, NULL, NULL);
if (save_pending & SIGVTALRM_MASK) if (save_pending & SIGALRM_MASK)
real_alarm_handler(NULL); timer_real_alarm_handler(NULL);
} }
} }
......
/* /*
* Copyright (C) 2015 Thomas Meyer (thomas@m3y3r.de)
* Copyright (C) 2002- 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) * Copyright (C) 2002- 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL * Licensed under the GPL
*/ */
...@@ -45,7 +46,7 @@ static int ptrace_dump_regs(int pid) ...@@ -45,7 +46,7 @@ static int ptrace_dump_regs(int pid)
* Signals that are OK to receive in the stub - we'll just continue it. * Signals that are OK to receive in the stub - we'll just continue it.
* SIGWINCH will happen when UML is inside a detached screen. * SIGWINCH will happen when UML is inside a detached screen.
*/ */
#define STUB_SIG_MASK ((1 << SIGVTALRM) | (1 << SIGWINCH)) #define STUB_SIG_MASK ((1 << SIGALRM) | (1 << SIGWINCH))
/* Signals that the stub will finish with - anything else is an error */ /* Signals that the stub will finish with - anything else is an error */
#define STUB_DONE_MASK (1 << SIGTRAP) #define STUB_DONE_MASK (1 << SIGTRAP)
...@@ -183,19 +184,13 @@ extern char __syscall_stub_start[]; ...@@ -183,19 +184,13 @@ extern char __syscall_stub_start[];
static int userspace_tramp(void *stack) static int userspace_tramp(void *stack)
{ {
void *addr; void *addr;
int err, fd; int fd;
unsigned long long offset; unsigned long long offset;
ptrace(PTRACE_TRACEME, 0, 0, 0); ptrace(PTRACE_TRACEME, 0, 0, 0);
signal(SIGTERM, SIG_DFL); signal(SIGTERM, SIG_DFL);
signal(SIGWINCH, SIG_IGN); signal(SIGWINCH, SIG_IGN);
err = set_interval();
if (err) {
printk(UM_KERN_ERR "userspace_tramp - setting timer failed, "
"errno = %d\n", err);
exit(1);
}
/* /*
* This has a pte, but it can't be mapped in with the usual * This has a pte, but it can't be mapped in with the usual
...@@ -286,7 +281,7 @@ int start_userspace(unsigned long stub_stack) ...@@ -286,7 +281,7 @@ int start_userspace(unsigned long stub_stack)
"errno = %d\n", errno); "errno = %d\n", errno);
goto out_kill; goto out_kill;
} }
} while (WIFSTOPPED(status) && (WSTOPSIG(status) == SIGVTALRM)); } while (WIFSTOPPED(status) && (WSTOPSIG(status) == SIGALRM));
if (!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP)) { if (!WIFSTOPPED(status) || (WSTOPSIG(status) != SIGSTOP)) {
err = -EINVAL; err = -EINVAL;
...@@ -319,8 +314,6 @@ int start_userspace(unsigned long stub_stack) ...@@ -319,8 +314,6 @@ int start_userspace(unsigned long stub_stack)
void userspace(struct uml_pt_regs *regs) void userspace(struct uml_pt_regs *regs)
{ {
struct itimerval timer;
unsigned long long nsecs, now;
int err, status, op, pid = userspace_pid[0]; int err, status, op, pid = userspace_pid[0];
/* To prevent races if using_sysemu changes under us.*/ /* To prevent races if using_sysemu changes under us.*/
int local_using_sysemu; int local_using_sysemu;
...@@ -329,13 +322,8 @@ void userspace(struct uml_pt_regs *regs) ...@@ -329,13 +322,8 @@ void userspace(struct uml_pt_regs *regs)
/* Handle any immediate reschedules or signals */ /* Handle any immediate reschedules or signals */
interrupt_end(); interrupt_end();
if (getitimer(ITIMER_VIRTUAL, &timer))
printk(UM_KERN_ERR "Failed to get itimer, errno = %d\n", errno);
nsecs = timer.it_value.tv_sec * UM_NSEC_PER_SEC +
timer.it_value.tv_usec * UM_NSEC_PER_USEC;
nsecs += os_nsecs();
while (1) { while (1) {
/* /*
* This can legitimately fail if the process loads a * This can legitimately fail if the process loads a
* bogus value into a segment register. It will * bogus value into a segment register. It will
...@@ -405,18 +393,7 @@ void userspace(struct uml_pt_regs *regs) ...@@ -405,18 +393,7 @@ void userspace(struct uml_pt_regs *regs)
case SIGTRAP: case SIGTRAP:
relay_signal(SIGTRAP, (struct siginfo *)&si, regs); relay_signal(SIGTRAP, (struct siginfo *)&si, regs);
break; break;
case SIGVTALRM: case SIGALRM:
now = os_nsecs();
if (now < nsecs)
break;
block_signals();
(*sig_info[sig])(sig, (struct siginfo *)&si, regs);
unblock_signals();
nsecs = timer.it_value.tv_sec *
UM_NSEC_PER_SEC +
timer.it_value.tv_usec *
UM_NSEC_PER_USEC;
nsecs += os_nsecs();
break; break;
case SIGIO: case SIGIO:
case SIGILL: case SIGILL:
...@@ -464,7 +441,6 @@ __initcall(init_thread_regs); ...@@ -464,7 +441,6 @@ __initcall(init_thread_regs);
int copy_context_skas0(unsigned long new_stack, int pid) int copy_context_skas0(unsigned long new_stack, int pid)
{ {
struct timeval tv = { .tv_sec = 0, .tv_usec = UM_USEC_PER_SEC / UM_HZ };
int err; int err;
unsigned long current_stack = current_stub_stack(); unsigned long current_stack = current_stub_stack();
struct stub_data *data = (struct stub_data *) current_stack; struct stub_data *data = (struct stub_data *) current_stack;
...@@ -476,11 +452,10 @@ int copy_context_skas0(unsigned long new_stack, int pid) ...@@ -476,11 +452,10 @@ int copy_context_skas0(unsigned long new_stack, int pid)
* prepare offset and fd of child's stack as argument for parent's * prepare offset and fd of child's stack as argument for parent's
* and child's mmap2 calls * and child's mmap2 calls
*/ */
*data = ((struct stub_data) { .offset = MMAP_OFFSET(new_offset), *data = ((struct stub_data) {
.fd = new_fd, .offset = MMAP_OFFSET(new_offset),
.timer = ((struct itimerval) .fd = new_fd
{ .it_value = tv, });
.it_interval = tv }) });
err = ptrace_setregs(pid, thread_regs); err = ptrace_setregs(pid, thread_regs);
if (err < 0) { if (err < 0) {
......
/* /*
* Copyright (C) 2015 Anton Ivanov (aivanov@{brocade.com,kot-begemot.co.uk})
* 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) 2000 - 2007 Jeff Dike (jdike{addtoit,linux.intel}.com)
* Licensed under the GPL * Licensed under the GPL
*/ */
...@@ -10,177 +13,177 @@ ...@@ -10,177 +13,177 @@
#include <sys/time.h> #include <sys/time.h>
#include <kern_util.h> #include <kern_util.h>
#include <os.h> #include <os.h>
#include "internal.h" #include <string.h>
#include <timer-internal.h>
int set_interval(void) static timer_t event_high_res_timer = 0;
{
int usec = UM_USEC_PER_SEC / UM_HZ;
struct itimerval interval = ((struct itimerval) { { 0, usec },
{ 0, usec } });
if (setitimer(ITIMER_VIRTUAL, &interval, NULL) == -1)
return -errno;
return 0; static inline long long timeval_to_ns(const struct timeval *tv)
{
return ((long long) tv->tv_sec * UM_NSEC_PER_SEC) +
tv->tv_usec * UM_NSEC_PER_USEC;
} }
int timer_one_shot(int ticks) static inline long long timespec_to_ns(const struct timespec *ts)
{ {
unsigned long usec = ticks * UM_USEC_PER_SEC / UM_HZ; return ((long long) ts->tv_sec * UM_NSEC_PER_SEC) +
unsigned long sec = usec / UM_USEC_PER_SEC; ts->tv_nsec;
struct itimerval interval; }
usec %= UM_USEC_PER_SEC;
interval = ((struct itimerval) { { 0, 0 }, { sec, usec } });
if (setitimer(ITIMER_VIRTUAL, &interval, NULL) == -1) long long os_persistent_clock_emulation (void) {
return -errno; struct timespec realtime_tp;
return 0; clock_gettime(CLOCK_REALTIME, &realtime_tp);
return timespec_to_ns(&realtime_tp);
} }
/** /**
* timeval_to_ns - Convert timeval to nanoseconds * os_timer_create() - create an new posix (interval) timer
* @ts: pointer to the timeval variable to be converted
*
* Returns the scalar nanosecond representation of the timeval
* parameter.
*
* Ripped from linux/time.h because it's a kernel header, and thus
* unusable from here.
*/ */
static inline long long timeval_to_ns(const struct timeval *tv) int os_timer_create(void* timer) {
{
return ((long long) tv->tv_sec * UM_NSEC_PER_SEC) + timer_t* t = timer;
tv->tv_usec * UM_NSEC_PER_USEC;
if(t == NULL) {
t = &event_high_res_timer;
}
if (timer_create(
CLOCK_MONOTONIC,
NULL,
t) == -1) {
return -1;
}
return 0;
} }
long long disable_timer(void) int os_timer_set_interval(void* timer, void* i)
{ {
struct itimerval time = ((struct itimerval) { { 0, 0 }, { 0, 0 } }); struct itimerspec its;
long long remain, max = UM_NSEC_PER_SEC / UM_HZ; unsigned long long nsec;
timer_t* t = timer;
struct itimerspec* its_in = i;
if (setitimer(ITIMER_VIRTUAL, &time, &time) < 0) if(t == NULL) {
printk(UM_KERN_ERR "disable_timer - setitimer failed, " t = &event_high_res_timer;
"errno = %d\n", errno); }
remain = timeval_to_ns(&time.it_value); nsec = UM_NSEC_PER_SEC / UM_HZ;
if (remain > max)
remain = max;
return remain; if(its_in != NULL) {
} its.it_value.tv_sec = its_in->it_value.tv_sec;
its.it_value.tv_nsec = its_in->it_value.tv_nsec;
} else {
its.it_value.tv_sec = 0;
its.it_value.tv_nsec = nsec;
}
long long os_nsecs(void) its.it_interval.tv_sec = 0;
{ its.it_interval.tv_nsec = nsec;
struct timeval tv;
gettimeofday(&tv, NULL); if(timer_settime(*t, 0, &its, NULL) == -1) {
return timeval_to_ns(&tv); return -errno;
} }
#ifdef UML_CONFIG_NO_HZ_COMMON
static int after_sleep_interval(struct timespec *ts)
{
return 0; return 0;
} }
static void deliver_alarm(void) /**
* os_timer_remain() - returns the remaining nano seconds of the given interval
* timer
* Because this is the remaining time of an interval timer, which correspondends
* to HZ, this value can never be bigger than one second. Just
* the nanosecond part of the timer is returned.
* The returned time is relative to the start time of the interval timer.
* Return an negative value in an error case.
*/
long os_timer_remain(void* timer)
{ {
alarm_handler(SIGVTALRM, NULL, NULL); struct itimerspec its;
} timer_t* t = timer;
static unsigned long long sleep_time(unsigned long long nsecs) if(t == NULL) {
{ t = &event_high_res_timer;
return nsecs; }
}
#else if(timer_gettime(t, &its) == -1) {
unsigned long long last_tick; return -errno;
unsigned long long skew; }
static void deliver_alarm(void) return its.it_value.tv_nsec;
{ }
unsigned long long this_tick = os_nsecs();
int one_tick = UM_NSEC_PER_SEC / UM_HZ;
/* Protection against the host's time going backwards */ int os_timer_one_shot(int ticks)
if ((last_tick != 0) && (this_tick < last_tick)) {
this_tick = last_tick; struct itimerspec its;
unsigned long long nsec;
unsigned long sec;
if (last_tick == 0) nsec = (ticks + 1);
last_tick = this_tick - one_tick; sec = nsec / UM_NSEC_PER_SEC;
nsec = nsec % UM_NSEC_PER_SEC;
skew += this_tick - last_tick; its.it_value.tv_sec = nsec / UM_NSEC_PER_SEC;
its.it_value.tv_nsec = nsec;
while (skew >= one_tick) { its.it_interval.tv_sec = 0;
alarm_handler(SIGVTALRM, NULL, NULL); its.it_interval.tv_nsec = 0; // we cheat here
skew -= one_tick;
}
last_tick = this_tick; timer_settime(event_high_res_timer, 0, &its, NULL);
return 0;
} }
static unsigned long long sleep_time(unsigned long long nsecs) /**
* os_timer_disable() - disable the posix (interval) timer
* Returns the remaining interval timer time in nanoseconds
*/
long long os_timer_disable(void)
{ {
return nsecs > skew ? nsecs - skew : 0; struct itimerspec its;
}
static inline long long timespec_to_us(const struct timespec *ts) memset(&its, 0, sizeof(struct itimerspec));
{ timer_settime(event_high_res_timer, 0, &its, &its);
return ((long long) ts->tv_sec * UM_USEC_PER_SEC) +
ts->tv_nsec / UM_NSEC_PER_USEC; return its.it_value.tv_sec * UM_NSEC_PER_SEC + its.it_value.tv_nsec;
} }
static int after_sleep_interval(struct timespec *ts) long long os_vnsecs(void)
{ {
int usec = UM_USEC_PER_SEC / UM_HZ; struct timespec ts;
long long start_usecs = timespec_to_us(ts);
struct timeval tv;
struct itimerval interval;
/*
* It seems that rounding can increase the value returned from
* setitimer to larger than the one passed in. Over time,
* this will cause the remaining time to be greater than the
* tick interval. If this happens, then just reduce the first
* tick to the interval value.
*/
if (start_usecs > usec)
start_usecs = usec;
start_usecs -= skew / UM_NSEC_PER_USEC;
if (start_usecs < 0)
start_usecs = 0;
tv = ((struct timeval) { .tv_sec = start_usecs / UM_USEC_PER_SEC, clock_gettime(CLOCK_PROCESS_CPUTIME_ID,&ts);
.tv_usec = start_usecs % UM_USEC_PER_SEC }); return timespec_to_ns(&ts);
interval = ((struct itimerval) { { 0, usec }, tv }); }
if (setitimer(ITIMER_VIRTUAL, &interval, NULL) == -1) long long os_nsecs(void)
return -errno; {
struct timespec ts;
return 0; clock_gettime(CLOCK_MONOTONIC,&ts);
return timespec_to_ns(&ts);
} }
#endif
void idle_sleep(unsigned long long nsecs) /**
* os_idle_sleep() - sleep for a given time of nsecs
* @nsecs: nanoseconds to sleep
*/
void os_idle_sleep(unsigned long long nsecs)
{ {
struct timespec ts; struct timespec ts;
/* if (nsecs <= 0) {
* nsecs can come in as zero, in which case, this starts a return;
* busy loop. To prevent this, reset nsecs to the tick }
* interval if it is zero.
*/
if (nsecs == 0)
nsecs = UM_NSEC_PER_SEC / UM_HZ;
nsecs = sleep_time(nsecs); ts = ((struct timespec) {
ts = ((struct timespec) { .tv_sec = nsecs / UM_NSEC_PER_SEC, .tv_sec = nsecs / UM_NSEC_PER_SEC,
.tv_nsec = nsecs % UM_NSEC_PER_SEC }); .tv_nsec = nsecs % UM_NSEC_PER_SEC
});
if (nanosleep(&ts, &ts) == 0) /*
* Relay the signal if clock_nanosleep is interrupted.
*/
if (clock_nanosleep(CLOCK_MONOTONIC, 0, &ts, NULL)) {
deliver_alarm(); deliver_alarm();
after_sleep_interval(&ts); }
} }
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