x86, ptrace: new ptrace BTS API

Index: linux-2.6-x86/arch/x86/kernel/ds.c
===================================================================
@@ -177,18 +177,20 @@
 }
 
 
-int ds_allocate(void **dsp, size_t bts_size_in_records)
+int ds_allocate(void **dsp, size_t bts_size_in_bytes)
 {
-	size_t bts_size_in_bytes = 0;
-	void *bts = 0;
-	void *ds = 0;
+	size_t bts_size_in_records;
+	void *bts;
+	void *ds;
 
 	if (!ds_cfg.sizeof_ds || !ds_cfg.sizeof_bts)
 		return -EOPNOTSUPP;
 
-	if (bts_size_in_records < 0)
+	if (bts_size_in_bytes < 0)
 		return -EINVAL;
 
+	bts_size_in_records =
+		bts_size_in_bytes / ds_cfg.sizeof_bts;
 	bts_size_in_bytes =
 		bts_size_in_records * ds_cfg.sizeof_bts;
 

@@ -233,9 +235,21 @@
 	if (!ds_cfg.sizeof_ds || !ds_cfg.sizeof_bts)
 		return -EOPNOTSUPP;
 
+	if (!ds)
+		return 0;
+
 	size_in_bytes =
 		get_bts_absolute_maximum(ds) -
 		get_bts_buffer_base(ds);
+	return size_in_bytes;
+}
+
+int ds_get_bts_end(void *ds)
+{
+	size_t size_in_bytes = ds_get_bts_size(ds);
+
+	if (size_in_bytes <= 0)
+		return size_in_bytes;
 
 	return size_in_bytes / ds_cfg.sizeof_bts;
 }

@@ -254,6 +268,38 @@
 	return index_offset_in_bytes / ds_cfg.sizeof_bts;
 }
 
+int ds_set_overflow(void *ds, int method)
+{
+	switch (method) {
+	case DS_O_SIGNAL:
+		return -EOPNOTSUPP;
+	case DS_O_WRAP:
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+int ds_get_overflow(void *ds)
+{
+	return DS_O_WRAP;
+}
+
+int ds_clear(void *ds)
+{
+	int bts_size = ds_get_bts_size(ds);
+	void *bts_base;
+
+	if (bts_size <= 0)
+		return bts_size;
+
+	bts_base = get_bts_buffer_base(ds);
+	memset(bts_base, 0, bts_size);
+
+	set_bts_index(ds, bts_base);
+	return 0;
+}
+
 int ds_read_bts(void *ds, size_t index, struct bts_struct *out)
 {
 	void *bts;

317 lines not on this page · raw message

Index: linux-2.6-x86/include/asm-x86/ds.h
===================================================================
@@ -52,11 +52,18 @@
 	} variant;
 };
 
+/* Overflow handling mechanisms */
+#define DS_O_SIGNAL	1 /* send overflow signal */
+#define DS_O_WRAP	2 /* wrap around */
 
 extern int ds_allocate(void **, size_t);
 extern int ds_free(void **);
 extern int ds_get_bts_size(void *);
+extern int ds_get_bts_end(void *);
 extern int ds_get_bts_index(void *);
+extern int ds_set_overflow(void *, int);
+extern int ds_get_overflow(void *);
+extern int ds_clear(void *);
 extern int ds_read_bts(void *, size_t, struct bts_struct *);
 extern int ds_write_bts(void *, const struct bts_struct *);
 extern unsigned long ds_debugctl_mask(void);

99 lines not on this page · raw message

Index: linux-2.6-x86/include/asm-x86/ptrace.h
===================================================================
@@ -9,6 +9,7 @@
 
 #ifdef __KERNEL__
 
+/* the DS BTS struct is used for ptrace as well */
 #include <asm/ds.h>
 
 struct task_struct;