diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/Kconfig | 10 | ||||
| -rw-r--r-- | arch/x86/Kconfig | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/thread_info.h | 7 | ||||
| -rw-r--r-- | arch/x86/kernel/process.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/signal.c | 3 |
5 files changed, 21 insertions, 2 deletions
diff --git a/arch/Kconfig b/arch/Kconfig index 7f418bbc261..4e312fffbfd 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -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" diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 8da93745c08..1df175d15aa 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/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 diff --git a/arch/x86/include/asm/thread_info.h b/arch/x86/include/asm/thread_info.h index d27d0a2fec4..375c917c37d 100644 --- a/arch/x86/include/asm/thread_info.h +++ b/arch/x86/include/asm/thread_info.h @@ -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 diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 5284cd2b577..e51b056fc88 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -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) diff --git a/arch/x86/kernel/signal.c b/arch/x86/kernel/signal.c index 6a44a76055a..c49f90f7957 100644 --- a/arch/x86/kernel/signal.c +++ b/arch/x86/kernel/signal.c @@ -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); |