[S390] ptrace cleanup

Overhaul program event recording and the code dealing with the ptrace
user space interface.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

4 files changed, 60 insertions, 5 deletions

diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h
index 8d6f87169577..1988807d415e 100644
--- a/arch/s390/include/asm/processor.h
+++ b/arch/s390/include/asm/processor.h
@@ -81,7 +81,8 @@ struct thread_struct {
 	mm_segment_t mm_segment;
         unsigned long prot_addr;        /* address of protection-excep.     */
         unsigned int trap_no;
-        per_struct per_info;
+	struct per_regs per_user;	/* User specified PER registers */
+	struct per_event per_event;	/* Cause of the last PER trap */
         /* pfault_wait is used to block the process on a pfault event */
 	unsigned long pfault_wait;
 };
diff --git a/arch/s390/include/asm/ptrace.h b/arch/s390/include/asm/ptrace.h
index d9d42b1e46fa..9ad628a8574a 100644
--- a/arch/s390/include/asm/ptrace.h
+++ b/arch/s390/include/asm/ptrace.h
@@ -331,10 +331,60 @@ struct pt_regs
 	unsigned short ilc;
 	unsigned short svcnr;
 };
+
+/*
+ * Program event recording (PER) register set.
+ */
+struct per_regs {
+	unsigned long control;		/* PER control bits */
+	unsigned long start;		/* PER starting address */
+	unsigned long end;		/* PER ending address */
+};
+
+/*
+ * PER event contains information about the cause of the last PER exception.
+ */
+struct per_event {
+	unsigned short cause;		/* PER code, ATMID and AI */
+	unsigned long address;		/* PER address */
+	unsigned char paid;		/* PER access identification */
+};
+
+/*
+ * Simplified per_info structure used to decode the ptrace user space ABI.
+ */
+struct per_struct_kernel {
+	unsigned long cr9;		/* PER control bits */
+	unsigned long cr10;		/* PER starting address */
+	unsigned long cr11;		/* PER ending address */
+	unsigned long bits;		/* Obsolete software bits */
+	unsigned long starting_addr;	/* User specified start address */
+	unsigned long ending_addr;	/* User specified end address */
+	unsigned short perc_atmid;	/* PER trap ATMID */
+	unsigned long address;		/* PER trap instruction address */
+	unsigned char access_id;	/* PER trap access identification */
+};
+
+#define PER_EVENT_MASK			0xE9000000UL
+
+#define PER_EVENT_BRANCH		0x80000000UL
+#define PER_EVENT_IFETCH		0x40000000UL
+#define PER_EVENT_STORE			0x20000000UL
+#define PER_EVENT_STORE_REAL		0x08000000UL
+#define PER_EVENT_NULLIFICATION		0x01000000UL
+
+#define PER_CONTROL_MASK		0x00a00000UL
+
+#define PER_CONTROL_BRANCH_ADDRESS	0x00800000UL
+#define PER_CONTROL_ALTERATION		0x00200000UL
+
 #endif
 
 /*
- * Now for the program event recording (trace) definitions.
+ * Now for the user space program event recording (trace) definitions.
+ * The following structures are used only for the ptrace interface, don't
+ * touch or even look at it if you don't want to modify the user-space
+ * ptrace interface. In particular stay away from it for in-kernel PER.
  */
 typedef struct
 {
diff --git a/arch/s390/include/asm/system.h b/arch/s390/include/asm/system.h
index 4ab2779fdb02..6710b0eac165 100644
--- a/arch/s390/include/asm/system.h
+++ b/arch/s390/include/asm/system.h
@@ -20,6 +20,7 @@
 struct task_struct;
 
 extern struct task_struct *__switch_to(void *, void *);
+extern void update_per_regs(struct task_struct *task);
 
 static inline void save_fp_regs(s390_fp_regs *fpregs)
 {
@@ -93,6 +94,7 @@ static inline void restore_access_regs(unsigned int *acrs)
 	if (next->mm) {							\
 		restore_fp_regs(&next->thread.fp_regs);			\
 		restore_access_regs(&next->thread.acrs[0]);		\
+		update_per_regs(next);					\
 	}								\
 	prev = __switch_to(prev,next);					\
 } while (0)
diff --git a/arch/s390/include/asm/thread_info.h b/arch/s390/include/asm/thread_info.h
index 814520217945..ebc77091466f 100644
--- a/arch/s390/include/asm/thread_info.h
+++ b/arch/s390/include/asm/thread_info.h
@@ -88,7 +88,7 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_SIGPENDING		2	/* signal pending */
 #define TIF_NEED_RESCHED	3	/* rescheduling necessary */
 #define TIF_RESTART_SVC		4	/* restart svc with new svc number */
-#define TIF_SINGLE_STEP		6	/* deliver sigtrap on return to user */
+#define TIF_PER_TRAP		6	/* deliver sigtrap on return to user */
 #define TIF_MCCK_PENDING	7	/* machine check handling is pending */
 #define TIF_SYSCALL_TRACE	8	/* syscall trace active */
 #define TIF_SYSCALL_AUDIT	9	/* syscall auditing active */
@@ -99,14 +99,15 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_31BIT		17	/* 32bit process */
 #define TIF_MEMDIE		18	/* is terminating due to OOM killer */
 #define TIF_RESTORE_SIGMASK	19	/* restore signal mask in do_signal() */
-#define TIF_FREEZE		20	/* thread is freezing for suspend */
+#define TIF_SINGLE_STEP		20	/* This task is single stepped */
+#define TIF_FREEZE		21	/* thread is freezing for suspend */
 
 #define _TIF_NOTIFY_RESUME	(1<<TIF_NOTIFY_RESUME)
 #define _TIF_RESTORE_SIGMASK	(1<<TIF_RESTORE_SIGMASK)
 #define _TIF_SIGPENDING		(1<<TIF_SIGPENDING)
 #define _TIF_NEED_RESCHED	(1<<TIF_NEED_RESCHED)
 #define _TIF_RESTART_SVC	(1<<TIF_RESTART_SVC)
-#define _TIF_SINGLE_STEP	(1<<TIF_SINGLE_STEP)
+#define _TIF_PER_TRAP		(1<<TIF_PER_TRAP)
 #define _TIF_MCCK_PENDING	(1<<TIF_MCCK_PENDING)
 #define _TIF_SYSCALL_TRACE	(1<<TIF_SYSCALL_TRACE)
 #define _TIF_SYSCALL_AUDIT	(1<<TIF_SYSCALL_AUDIT)
@@ -114,6 +115,7 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_SYSCALL_TRACEPOINT	(1<<TIF_SYSCALL_TRACEPOINT)
 #define _TIF_POLLING_NRFLAG	(1<<TIF_POLLING_NRFLAG)
 #define _TIF_31BIT		(1<<TIF_31BIT)
+#define _TIF_SINGLE_STEP	(1<<TIF_FREEZE)
 #define _TIF_FREEZE		(1<<TIF_FREEZE)
 
 #endif /* __KERNEL__ */