x86, ptrace: new ptrace BTS API
Here's the new ptrace BTS API that supports two different overflow handling mechanisms (wrap-around and buffer-full-signal) to support two different use cases (debugging and profiling).
It further combines buffer allocation and configuration.
Opens:
- memory rlimit
- overflow signal
What would be the right signal to use?
Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/kernel/ds.c b/arch/x86/kernel/ds.c
index e7855de..6eb5d49 100644
--- a/arch/x86/kernel/ds.c
+++ b/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;