diff --git a/arch/x86/include/asm/context_tracking.h b/arch/x86/include/asm/context_tracking.h
index 1616562683e9a50d9a089528a040a1774d6e6438..1fe49704b1464cde5dc2d080cd2509bf208a59c9 100644
--- a/arch/x86/include/asm/context_tracking.h
+++ b/arch/x86/include/asm/context_tracking.h
@@ -1,31 +1,10 @@
#ifndef _ASM_X86_CONTEXT_TRACKING_H
#define _ASM_X86_CONTEXT_TRACKING_H
-#ifndef __ASSEMBLY__
-#include <linux/context_tracking.h>
-#include <asm/ptrace.h>
-
-static inline void exception_enter(struct pt_regs *regs)
-{
- user_exit();
-}
-
-static inline void exception_exit(struct pt_regs *regs)
-{
-#ifdef CONFIG_CONTEXT_TRACKING
- if (user_mode(regs))
- user_enter();
-#endif
-}
-
-#else /* __ASSEMBLY__ */
-
#ifdef CONFIG_CONTEXT_TRACKING
# define SCHEDULE_USER call schedule_user
#else
# define SCHEDULE_USER call schedule
#endif
-#endif /* !__ASSEMBLY__ */
-
#endif
diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index b686a904d7c3b64ce2274fa63fbfe53b691a0736..cd6d9a5a42f60dcb93a528853fe65b8773b0832e 100644
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -20,6 +20,7 @@
* Authors: Anthony Liguori <aliguori@us.ibm.com>
*/
+#include <linux/context_tracking.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/kvm_para.h>
@@ -43,7 +44,6 @@
#include <asm/apicdef.h>
#include <asm/hypervisor.h>
#include <asm/kvm_guest.h>
-#include <asm/context_tracking.h>
static int kvmapf = 1;
@@ -254,16 +254,18 @@ EXPORT_SYMBOL_GPL(kvm_read_and_reset_pf_reason);
dotraplinkage void __kprobes
do_async_page_fault(struct pt_regs *regs, unsigned long error_code)
{
+ enum ctx_state prev_state;
+
switch (kvm_read_and_reset_pf_reason()) {
default:
do_page_fault(regs, error_code);
break;
case KVM_PV_REASON_PAGE_NOT_PRESENT:
/* page is swapped out by the host. */
- exception_enter(regs);
+ prev_state = exception_enter();
exit_idle();
kvm_async_pf_task_wait((u32)read_cr2());
- exception_exit(regs);
+ exception_exit(prev_state);
break;
case KVM_PV_REASON_PAGE_READY:
rcu_irq_enter();
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 68bda7a841597ee1fc06e15b96865d1eff2633ce..ff6d2271cbe25b14272bf3315efa1e44cd9ea0e2 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -12,6 +12,7 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/context_tracking.h>
#include <linux/interrupt.h>
#include <linux/kallsyms.h>
#include <linux/spinlock.h>
@@ -55,8 +56,6 @@
#include <asm/i387.h>
#include <asm/fpu-internal.h>
#include <asm/mce.h>
-#include <asm/context_tracking.h>
-
#include <asm/mach_traps.h>
#ifdef CONFIG_X86_64
@@ -176,34 +175,38 @@ do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
#define DO_ERROR(trapnr, signr, str, name) \
dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \
{ \
- exception_enter(regs); \
+ enum ctx_state prev_state; \
+ \
+ prev_state = exception_enter(); \
if (notify_die(DIE_TRAP, str, regs, error_code, \
trapnr, signr) == NOTIFY_STOP) { \
- exception_exit(regs); \
+ exception_exit(prev_state); \
return; \
} \
conditional_sti(regs); \
do_trap(trapnr, signr, str, regs, error_code, NULL); \
- exception_exit(regs); \
+ exception_exit(prev_state); \
}
#define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \
{ \
siginfo_t info; \
+ enum ctx_state prev_state; \
+ \
info.si_signo = signr; \
info.si_errno = 0; \
info.si_code = sicode; \
info.si_addr = (void __user *)siaddr; \
- exception_enter(regs); \
+ prev_state = exception_enter(); \
if (notify_die(DIE_TRAP, str, regs, error_code, \
trapnr, signr) == NOTIFY_STOP) { \
- exception_exit(regs); \
+ exception_exit(prev_state); \
return; \
} \
conditional_sti(regs); \
do_trap(trapnr, signr, str, regs, error_code, &info); \
- exception_exit(regs); \
+ exception_exit(prev_state); \
}
DO_ERROR_INFO(X86_TRAP_DE, SIGFPE, "divide error", divide_error, FPE_INTDIV,
@@ -226,14 +229,16 @@ DO_ERROR_INFO(X86_TRAP_AC, SIGBUS, "alignment check", alignment_check,
/* Runs on IST stack */
dotraplinkage void do_stack_segment(struct pt_regs *regs, long error_code)
{
- exception_enter(regs);
+ enum ctx_state prev_state;
+
+ prev_state = exception_enter();
if (notify_die(DIE_TRAP, "stack segment", regs, error_code,
X86_TRAP_SS, SIGBUS) != NOTIFY_STOP) {
preempt_conditional_sti(regs);
do_trap(X86_TRAP_SS, SIGBUS, "stack segment", regs, error_code, NULL);
preempt_conditional_cli(regs);
}
- exception_exit(regs);
+ exception_exit(prev_state);
}
dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code)
@@ -241,7 +246,7 @@ dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code)
static const char str[] = "double fault";
struct task_struct *tsk = current;
- exception_enter(regs);
+ exception_enter();
/* Return not checked because double check cannot be ignored */
notify_die(DIE_TRAP, str, regs, error_code, X86_TRAP_DF, SIGSEGV);
@@ -261,8 +266,9 @@ dotraplinkage void __kprobes
do_general_protection(struct pt_regs *regs, long error_code)
{
struct task_struct *tsk;
+ enum ctx_state prev_state;
- exception_enter(regs);
+ prev_state = exception_enter();
conditional_sti(regs);
#ifdef CONFIG_X86_32
@@ -300,12 +306,14 @@ do_general_protection(struct pt_regs *regs, long error_code)
force_sig(SIGSEGV, tsk);
exit:
- exception_exit(regs);
+ exception_exit(prev_state);
}
/* May run on IST stack. */
dotraplinkage void __kprobes notrace do_int3(struct pt_regs *regs, long error_code)
{
+ enum ctx_state prev_state;
+
#ifdef CONFIG_DYNAMIC_FTRACE
/*
* ftrace must be first, everything else may cause a recursive crash.
@@ -315,7 +323,7 @@ dotraplinkage void __kprobes notrace do_int3(struct pt_regs *regs, long error_co
ftrace_int3_handler(regs))
return;
#endif
- exception_enter(regs);
+ prev_state = exception_enter();
#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP,
SIGTRAP) == NOTIFY_STOP)
@@ -336,7 +344,7 @@ dotraplinkage void __kprobes notrace do_int3(struct pt_regs *regs, long error_co
preempt_conditional_cli(regs);
debug_stack_usage_dec();
exit:
- exception_exit(regs);
+ exception_exit(prev_state);
}
#ifdef CONFIG_X86_64
@@ -393,11 +401,12 @@ asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs)
dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
{
struct task_struct *tsk = current;
+ enum ctx_state prev_state;
int user_icebp = 0;
unsigned long dr6;
int si_code;
- exception_enter(regs);
+ prev_state = exception_enter();
get_debugreg(dr6, 6);
@@ -467,7 +476,7 @@ dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
debug_stack_usage_dec();
exit:
- exception_exit(regs);
+ exception_exit(prev_state);
}
/*
@@ -561,17 +570,21 @@ void math_error(struct pt_regs *regs, int error_code, int trapnr)
dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code)
{
- exception_enter(regs);
+ enum ctx_state prev_state;
+
+ prev_state = exception_enter();
math_error(regs, error_code, X86_TRAP_MF);
- exception_exit(regs);
+ exception_exit(prev_state);
}
dotraplinkage void
do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
{
- exception_enter(regs);
+ enum ctx_state prev_state;
+
+ prev_state = exception_enter();
math_error(regs, error_code, X86_TRAP_XF);
- exception_exit(regs);
+ exception_exit(prev_state);
}
dotraplinkage void
@@ -639,7 +652,9 @@ EXPORT_SYMBOL_GPL(math_state_restore);
dotraplinkage void __kprobes
do_device_not_available(struct pt_regs *regs, long error_code)
{
- exception_enter(regs);
+ enum ctx_state prev_state;
+
+ prev_state = exception_enter();
BUG_ON(use_eager_fpu());
#ifdef CONFIG_MATH_EMULATION
@@ -650,7 +665,7 @@ do_device_not_available(struct pt_regs *regs, long error_code)
info.regs = regs;
math_emulate(&info);
- exception_exit(regs);
+ exception_exit(prev_state);
return;
}
#endif
@@ -658,15 +673,16 @@ do_device_not_available(struct pt_regs *regs, long error_code)
#ifdef CONFIG_X86_32
conditional_sti(regs);
#endif
- exception_exit(regs);
+ exception_exit(prev_state);
}
#ifdef CONFIG_X86_32
dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code)
{
siginfo_t info;
+ enum ctx_state prev_state;
- exception_enter(regs);
+ prev_state = exception_enter();
local_irq_enable();
info.si_signo = SIGILL;
@@ -678,7 +694,7 @@ dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code)
do_trap(X86_TRAP_IRET, SIGILL, "iret exception", regs, error_code,
&info);
}
- exception_exit(regs);
+ exception_exit(prev_state);
}
#endif
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 2b97525246d43c3397f9d2149adf859b24b2842b..fa8c02de0d259ad7b1e5f869627cc442733b9738 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -13,12 +13,12 @@
#include <linux/perf_event.h> /* perf_sw_event */
#include <linux/hugetlb.h> /* hstate_index_to_shift */
#include <linux/prefetch.h> /* prefetchw */
+#include <linux/context_tracking.h> /* exception_enter(), ... */
#include <asm/traps.h> /* dotraplinkage, ... */
#include <asm/pgalloc.h> /* pgd_*(), ... */
#include <asm/kmemcheck.h> /* kmemcheck_*(), ... */
#include <asm/fixmap.h> /* VSYSCALL_START */
-#include <asm/context_tracking.h> /* exception_enter(), ... */
/*
* Page fault error code bits:
@@ -1222,7 +1222,9 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code)
dotraplinkage void __kprobes
do_page_fault(struct pt_regs *regs, unsigned long error_code)
{
- exception_enter(regs);
+ enum ctx_state prev_state;
+
+ prev_state = exception_enter();
__do_page_fault(regs, error_code);
- exception_exit(regs);
+ exception_exit(prev_state);
}
diff --git a/include/linux/context_tracking.h b/include/linux/context_tracking.h
index b28d161c1091908b9395df4e3ad73e6d88518966..365f4a61bf0408c12b3b3dbeb1743c8a2b616c35 100644
--- a/include/linux/context_tracking.h
+++ b/include/linux/context_tracking.h
@@ -1,9 +1,9 @@
#ifndef _LINUX_CONTEXT_TRACKING_H
#define _LINUX_CONTEXT_TRACKING_H
-#ifdef CONFIG_CONTEXT_TRACKING
#include <linux/sched.h>
#include <linux/percpu.h>
+#include <asm/ptrace.h>
struct context_tracking {
/*
@@ -13,12 +13,13 @@ struct context_tracking {
* may be further optimized using static keys.
*/
bool active;
- enum {
+ enum ctx_state {
IN_KERNEL = 0,
IN_USER,
} state;
};
+#ifdef CONFIG_CONTEXT_TRACKING
DECLARE_PER_CPU(struct context_tracking, context_tracking);
static inline bool context_tracking_in_user(void)
@@ -33,12 +34,31 @@ static inline bool context_tracking_active(void)
extern void user_enter(void);
extern void user_exit(void);
+
+static inline enum ctx_state exception_enter(void)
+{
+ enum ctx_state prev_ctx;
+
+ prev_ctx = this_cpu_read(context_tracking.state);
+ user_exit();
+
+ return prev_ctx;
+}
+
+static inline void exception_exit(enum ctx_state prev_ctx)
+{
+ if (prev_ctx == IN_USER)
+ user_enter();
+}
+
extern void context_tracking_task_switch(struct task_struct *prev,
struct task_struct *next);
#else
static inline bool context_tracking_in_user(void) { return false; }
static inline void user_enter(void) { }
static inline void user_exit(void) { }
+static inline enum ctx_state exception_enter(void) { return 0; }
+static inline void exception_exit(enum ctx_state prev_ctx) { }
static inline void context_tracking_task_switch(struct task_struct *prev,
struct task_struct *next) { }
#endif /* !CONFIG_CONTEXT_TRACKING */
diff --git a/include/linux/sched.h b/include/linux/sched.h
index fc039ceccbeae08d99b0543b18115b7ea1a7a0b1..9004f6e19eacc462ba719e6bc9a4639bdea16928 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -558,7 +558,7 @@ struct signal_struct {
cputime_t utime, stime, cutime, cstime;
cputime_t gtime;
cputime_t cgtime;
-#ifndef CONFIG_VIRT_CPU_ACCOUNTING
+#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
struct cputime prev_cputime;
#endif
unsigned long nvcsw, nivcsw, cnvcsw, cnivcsw;
@@ -1158,7 +1158,7 @@ struct task_struct {
cputime_t utime, stime, utimescaled, stimescaled;
cputime_t gtime;
-#ifndef CONFIG_VIRT_CPU_ACCOUNTING
+#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
struct cputime prev_cputime;
#endif
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
diff --git a/init/Kconfig b/init/Kconfig
index 22616cd434bc7d91d157074eb0cf9c9ce9b9f0f0..8a1dac2f80a98c268a571d7609038095fd126e0e 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -509,6 +509,7 @@ config RCU_USER_QS
config CONTEXT_TRACKING_FORCE
bool "Force context tracking"
depends on CONTEXT_TRACKING
+ default CONTEXT_TRACKING
help
Probe on user/kernel boundaries by default in order to
test the features that rely on it such as userspace RCU extended
diff --git a/kernel/fork.c b/kernel/fork.c
index 8d932b1c9056af738e2903bf813bcbd035ed3892..f3146ed490746037657c03d2bb305eccec6918a1 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1230,7 +1230,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
p->utime = p->stime = p->gtime = 0;
p->utimescaled = p->stimescaled = 0;
-#ifndef CONFIG_VIRT_CPU_ACCOUNTING
+#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
p->prev_cputime.utime = p->prev_cputime.stime = 0;
#endif
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 42ecbcb735166fc06cd599406e52f6d2e7c325e1..b36635e7404e3cc8a6df4d56a83ab4a8c5466066 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3082,11 +3082,13 @@ EXPORT_SYMBOL(preempt_schedule);
asmlinkage void __sched preempt_schedule_irq(void)
{
struct thread_info *ti = current_thread_info();
+ enum ctx_state prev_state;
/* Catch callers which need to be fixed */
BUG_ON(ti->preempt_count || !irqs_disabled());
- user_exit();
+ prev_state = exception_enter();
+
do {
add_preempt_count(PREEMPT_ACTIVE);
local_irq_enable();
@@ -3100,6 +3102,8 @@ asmlinkage void __sched preempt_schedule_irq(void)
*/
barrier();
} while (need_resched());
+
+ exception_exit(prev_state);
}
#endif /* CONFIG_PREEMPT */
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index ed12cbb135f4b8ded0d3c7be26a67d1df8d2ffc2..024fe1998ad54be7110776cdb855fab2e1d73084 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -388,82 +388,10 @@ static inline void irqtime_account_process_tick(struct task_struct *p, int user_
struct rq *rq) {}
#endif /* CONFIG_IRQ_TIME_ACCOUNTING */
-#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
-/*
- * Account a single tick of cpu time.
- * @p: the process that the cpu time gets accounted to
- * @user_tick: indicates if the tick is a user or a system tick
- */
-void account_process_tick(struct task_struct *p, int user_tick)
-{
- cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy);
- struct rq *rq = this_rq();
-
- if (vtime_accounting_enabled())
- return;
-
- if (sched_clock_irqtime) {
- irqtime_account_process_tick(p, user_tick, rq);
- return;
- }
-
- if (steal_account_process_tick())
- return;
-
- if (user_tick)
- account_user_time(p, cputime_one_jiffy, one_jiffy_scaled);
- else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET))
- account_system_time(p, HARDIRQ_OFFSET, cputime_one_jiffy,
- one_jiffy_scaled);
- else
- account_idle_time(cputime_one_jiffy);
-}
-
-/*
- * Account multiple ticks of steal time.
- * @p: the process from which the cpu time has been stolen
- * @ticks: number of stolen ticks
- */
-void account_steal_ticks(unsigned long ticks)
-{
- account_steal_time(jiffies_to_cputime(ticks));
-}
-
-/*
- * Account multiple ticks of idle time.
- * @ticks: number of stolen ticks
- */
-void account_idle_ticks(unsigned long ticks)
-{
-
- if (sched_clock_irqtime) {
- irqtime_account_idle_ticks(ticks);
- return;
- }
-
- account_idle_time(jiffies_to_cputime(ticks));
-}
-#endif /* !CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
-
/*
* Use precise platform statistics if available:
*/
#ifdef CONFIG_VIRT_CPU_ACCOUNTING
-void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st)
-{
- *ut = p->utime;
- *st = p->stime;
-}
-
-void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st)
-{
- struct task_cputime cputime;
-
- thread_group_cputime(p, &cputime);
-
- *ut = cputime.utime;
- *st = cputime.stime;
-}
#ifndef __ARCH_HAS_VTIME_TASK_SWITCH
void vtime_task_switch(struct task_struct *prev)
@@ -518,8 +446,80 @@ void vtime_account_irq_enter(struct task_struct *tsk)
}
EXPORT_SYMBOL_GPL(vtime_account_irq_enter);
#endif /* __ARCH_HAS_VTIME_ACCOUNT */
+#endif /* CONFIG_VIRT_CPU_ACCOUNTING */
+
+
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
+void task_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st)
+{
+ *ut = p->utime;
+ *st = p->stime;
+}
-#else /* !CONFIG_VIRT_CPU_ACCOUNTING */
+void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime_t *st)
+{
+ struct task_cputime cputime;
+
+ thread_group_cputime(p, &cputime);
+
+ *ut = cputime.utime;
+ *st = cputime.stime;
+}
+#else /* !CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
+/*
+ * Account a single tick of cpu time.
+ * @p: the process that the cpu time gets accounted to
+ * @user_tick: indicates if the tick is a user or a system tick
+ */
+void account_process_tick(struct task_struct *p, int user_tick)
+{
+ cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy);
+ struct rq *rq = this_rq();
+
+ if (vtime_accounting_enabled())
+ return;
+
+ if (sched_clock_irqtime) {
+ irqtime_account_process_tick(p, user_tick, rq);
+ return;
+ }
+
+ if (steal_account_process_tick())
+ return;
+
+ if (user_tick)
+ account_user_time(p, cputime_one_jiffy, one_jiffy_scaled);
+ else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET))
+ account_system_time(p, HARDIRQ_OFFSET, cputime_one_jiffy,
+ one_jiffy_scaled);
+ else
+ account_idle_time(cputime_one_jiffy);
+}
+
+/*
+ * Account multiple ticks of steal time.
+ * @p: the process from which the cpu time has been stolen
+ * @ticks: number of stolen ticks
+ */
+void account_steal_ticks(unsigned long ticks)
+{
+ account_steal_time(jiffies_to_cputime(ticks));
+}
+
+/*
+ * Account multiple ticks of idle time.
+ * @ticks: number of stolen ticks
+ */
+void account_idle_ticks(unsigned long ticks)
+{
+
+ if (sched_clock_irqtime) {
+ irqtime_account_idle_ticks(ticks);
+ return;
+ }
+
+ account_idle_time(jiffies_to_cputime(ticks));
+}
static cputime_t scale_stime(cputime_t stime, cputime_t rtime, cputime_t total)
{
@@ -545,6 +545,12 @@ static void cputime_adjust(struct task_cputime *curr,
{
cputime_t rtime, stime, total;
+ if (vtime_accounting_enabled()) {
+ *ut = curr->utime;
+ *st = curr->stime;
+ return;
+ }
+
stime = curr->stime;
total = stime + curr->utime;
@@ -597,7 +603,7 @@ void thread_group_cputime_adjusted(struct task_struct *p, cputime_t *ut, cputime
thread_group_cputime(p, &cputime);
cputime_adjust(&cputime, &p->signal->prev_cputime, ut, st);
}
-#endif /* !CONFIG_VIRT_CPU_ACCOUNTING */
+#endif /* !CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
static unsigned long long vtime_delta(struct task_struct *tsk)