Commit 58988b07 authored by Avi Kivity's avatar Avi Kivity

Merge remote branch 'tip/x86/entry' into kvm-updates/2.6.33

Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parents 22763c5c 8e7cac79
......@@ -83,6 +83,13 @@ config KRETPROBES
def_bool y
depends on KPROBES && HAVE_KRETPROBES
config USER_RETURN_NOTIFIER
bool
depends on HAVE_USER_RETURN_NOTIFIER
help
Provide a kernel-internal notification when a cpu is about to
switch to user mode.
config HAVE_IOREMAP_PROT
bool
......@@ -126,4 +133,7 @@ config HAVE_DMA_API_DEBUG
config HAVE_DEFAULT_NO_SPIN_MUTEXES
bool
config HAVE_USER_RETURN_NOTIFIER
bool
source "kernel/gcov/Kconfig"
......@@ -50,6 +50,7 @@ config X86
select HAVE_KERNEL_BZIP2
select HAVE_KERNEL_LZMA
select HAVE_ARCH_KMEMCHECK
select HAVE_USER_RETURN_NOTIFIER
config OUTPUT_FORMAT
string
......
......@@ -83,6 +83,7 @@ struct thread_info {
#define TIF_SYSCALL_AUDIT 7 /* syscall auditing active */
#define TIF_SECCOMP 8 /* secure computing */
#define TIF_MCE_NOTIFY 10 /* notify userspace of an MCE */
#define TIF_USER_RETURN_NOTIFY 11 /* notify kernel of userspace return */
#define TIF_NOTSC 16 /* TSC is not accessible in userland */
#define TIF_IA32 17 /* 32bit process */
#define TIF_FORK 18 /* ret_from_fork */
......@@ -107,6 +108,7 @@ struct thread_info {
#define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT)
#define _TIF_SECCOMP (1 << TIF_SECCOMP)
#define _TIF_MCE_NOTIFY (1 << TIF_MCE_NOTIFY)
#define _TIF_USER_RETURN_NOTIFY (1 << TIF_USER_RETURN_NOTIFY)
#define _TIF_NOTSC (1 << TIF_NOTSC)
#define _TIF_IA32 (1 << TIF_IA32)
#define _TIF_FORK (1 << TIF_FORK)
......@@ -142,13 +144,14 @@ struct thread_info {
/* Only used for 64 bit */
#define _TIF_DO_NOTIFY_MASK \
(_TIF_SIGPENDING|_TIF_MCE_NOTIFY|_TIF_NOTIFY_RESUME)
(_TIF_SIGPENDING | _TIF_MCE_NOTIFY | _TIF_NOTIFY_RESUME | \
_TIF_USER_RETURN_NOTIFY)
/* flags to check in __switch_to() */
#define _TIF_WORK_CTXSW \
(_TIF_IO_BITMAP|_TIF_DEBUGCTLMSR|_TIF_DS_AREA_MSR|_TIF_NOTSC)
#define _TIF_WORK_CTXSW_PREV _TIF_WORK_CTXSW
#define _TIF_WORK_CTXSW_PREV (_TIF_WORK_CTXSW|_TIF_USER_RETURN_NOTIFY)
#define _TIF_WORK_CTXSW_NEXT (_TIF_WORK_CTXSW|_TIF_DEBUG)
#define PREEMPT_ACTIVE 0x10000000
......
......@@ -9,6 +9,7 @@
#include <linux/pm.h>
#include <linux/clockchips.h>
#include <linux/random.h>
#include <linux/user-return-notifier.h>
#include <trace/events/power.h>
#include <asm/system.h>
#include <asm/apic.h>
......@@ -224,6 +225,7 @@ void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
*/
memset(tss->io_bitmap, 0xff, prev->io_bitmap_max);
}
propagate_user_return_notify(prev_p, next_p);
}
int sys_fork(struct pt_regs *regs)
......
......@@ -19,6 +19,7 @@
#include <linux/stddef.h>
#include <linux/personality.h>
#include <linux/uaccess.h>
#include <linux/user-return-notifier.h>
#include <asm/processor.h>
#include <asm/ucontext.h>
......@@ -872,6 +873,8 @@ do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
if (current->replacement_session_keyring)
key_replace_session_keyring();
}
if (thread_info_flags & _TIF_USER_RETURN_NOTIFY)
fire_user_return_notifiers();
#ifdef CONFIG_X86_32
clear_thread_flag(TIF_IRET);
......
#ifndef _LINUX_USER_RETURN_NOTIFIER_H
#define _LINUX_USER_RETURN_NOTIFIER_H
#ifdef CONFIG_USER_RETURN_NOTIFIER
#include <linux/list.h>
#include <linux/sched.h>
struct user_return_notifier {
void (*on_user_return)(struct user_return_notifier *urn);
struct hlist_node link;
};
void user_return_notifier_register(struct user_return_notifier *urn);
void user_return_notifier_unregister(struct user_return_notifier *urn);
static inline void propagate_user_return_notify(struct task_struct *prev,
struct task_struct *next)
{
if (test_tsk_thread_flag(prev, TIF_USER_RETURN_NOTIFY)) {
clear_tsk_thread_flag(prev, TIF_USER_RETURN_NOTIFY);
set_tsk_thread_flag(next, TIF_USER_RETURN_NOTIFY);
}
}
void fire_user_return_notifiers(void);
static inline void clear_user_return_notifier(struct task_struct *p)
{
clear_tsk_thread_flag(p, TIF_USER_RETURN_NOTIFY);
}
#else
struct user_return_notifier {};
static inline void propagate_user_return_notify(struct task_struct *prev,
struct task_struct *next)
{
}
static inline void fire_user_return_notifiers(void) {}
static inline void clear_user_return_notifier(struct task_struct *p) {}
#endif
#endif
......@@ -96,6 +96,7 @@ obj-$(CONFIG_SMP) += sched_cpupri.o
obj-$(CONFIG_SLOW_WORK) += slow-work.o
obj-$(CONFIG_SLOW_WORK_DEBUG) += slow-work-debugfs.o
obj-$(CONFIG_PERF_EVENTS) += perf_event.o
obj-$(CONFIG_USER_RETURN_NOTIFIER) += user-return-notifier.o
ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y)
# According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is
......
......@@ -64,6 +64,7 @@
#include <linux/magic.h>
#include <linux/perf_event.h>
#include <linux/posix-timers.h>
#include <linux/user-return-notifier.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
......@@ -249,6 +250,7 @@ static struct task_struct *dup_task_struct(struct task_struct *orig)
goto out;
setup_thread_stack(tsk, orig);
clear_user_return_notifier(tsk);
stackend = end_of_stack(tsk);
*stackend = STACK_END_MAGIC; /* for overflow detection */
......
#include <linux/user-return-notifier.h>
#include <linux/percpu.h>
#include <linux/sched.h>
#include <linux/module.h>
static DEFINE_PER_CPU(struct hlist_head, return_notifier_list);
#define URN_LIST_HEAD per_cpu(return_notifier_list, raw_smp_processor_id())
/*
* Request a notification when the current cpu returns to userspace. Must be
* called in atomic context. The notifier will also be called in atomic
* context.
*/
void user_return_notifier_register(struct user_return_notifier *urn)
{
set_tsk_thread_flag(current, TIF_USER_RETURN_NOTIFY);
hlist_add_head(&urn->link, &URN_LIST_HEAD);
}
EXPORT_SYMBOL_GPL(user_return_notifier_register);
/*
* Removes a registered user return notifier. Must be called from atomic
* context, and from the same cpu registration occured in.
*/
void user_return_notifier_unregister(struct user_return_notifier *urn)
{
hlist_del(&urn->link);
if (hlist_empty(&URN_LIST_HEAD))
clear_tsk_thread_flag(current, TIF_USER_RETURN_NOTIFY);
}
EXPORT_SYMBOL_GPL(user_return_notifier_unregister);
/* Calls registered user return notifiers */
void fire_user_return_notifiers(void)
{
struct user_return_notifier *urn;
struct hlist_node *tmp1, *tmp2;
struct hlist_head *head;
head = &get_cpu_var(return_notifier_list);
hlist_for_each_entry_safe(urn, tmp1, tmp2, head, link)
urn->on_user_return(urn);
put_cpu_var(return_notifier_list);
}
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