Re: [patch 4/5] x86, ptrace: new ptrace BTS API
* Markus Metzger <[EMAIL PROTECTED]> wrote: > 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? i think we tend to have such signal targets configurable (like in the POSIX timers APIs) - or we could use SIGIO. I've Cc:-ed Ulrich - maybe he has some specific ideas how to structure this. Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[patch 4/5] 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 <[EMAIL PROTECTED]>
---
Index: linux-2.6-x86/arch/x86/kernel/ds.c
===
--- linux-2.6-x86.orig/arch/x86/kernel/ds.c 2007-12-14 15:31:48.%N +0100
+++ linux-2.6-x86/arch/x86/kernel/ds.c 2007-12-14 15:31:48.%N +0100
@@ -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;
Index: linux-2.6-x86/arch/x86/kernel/ptrace.c
===
--- linux-2.6-x86.orig/arch/x86/kernel/ptrace.c 2007-12-14 15:31:48.%N +0100
+++ linux-2.6-x86/arch/x86/kernel/ptrace.c 2007-12-14 17:32:40.%N +0100
@@ -33,12 +33,6 @@
/*
- * The maximal size of a BTS buffer per traced task in number of BTS
- * records.
- */
-#define PTRACE_BTS_BUFFER_MAX 4000
-
-/*
* does not yet catch signals sent when the child dies.
* in exit.c or in signal.c.
*/
@@ -466,17 +460,12 @@
return 0;
}
-static int ptrace_bts_max_buffer_size(void)
-{
- return PTRACE_BTS_BUFFER_MAX;
-}
-
-static int ptrace_bts_get_buffer_size(struct task_struct *child)
+static int ptrace_bts_get_size(struct task_struct *child)
{
if (!child->thread.ds_area_msr)
return -ENXIO;
- return ds_get_bts_size((void *)child->thread.ds_area_msr);
+ return ds_get_bts_index((void *)child->thread.ds_area_msr);
}
static int ptrace_bts_read_record(struct task_struct *child,
@@ -485,7 +474,7 @@
{
struct bts_struct ret;
int retval;
- int bts_size;
+ int bts_end;
int bts_index;
if (!child->thread.ds_area_msr)
@@ -494,15 +483,15 @@
if (index < 0)
return -EINVAL;
- bts_size = ds_get_bts_size((void *)child->thread.ds_area_msr);
- if (bts_size <= index)
+ bts_end = ds_get_bts_end((void *)child->thread.ds_area_msr);
+ if (bts_end <= index)
return -EINVAL;
/* translate the ptrace bts index into the ds bts index */
bts_index = ds_get_bts_index((void *)child->thread.ds_area_msr);
bts_index -= (index + 1);
if (bts_index < 0)
- bts_index += bts_size;
+ bts_index += bts_end;
retval = ds_read_bts((void *)child->thread.ds_area_msr,
bts_index, );
@@ -530,19 +519,97 @@
return sizeof(*in);
}
-static int ptrace_bts_config(struct task_struct *child,
-unsigned long options)
+static int ptrace_bts_clear(struct task_struct *child)
{
- unsigned long debugctl_mask = ds_debugctl_mask();
- int retval;
+ if (!child->thread.ds_area_msr)
+ return -ENXIO;
- retval = ptrace_bts_get_buffer_size(child);
- if
[patch 4/5] 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 [EMAIL PROTECTED]
---
Index: linux-2.6-x86/arch/x86/kernel/ds.c
===
--- linux-2.6-x86.orig/arch/x86/kernel/ds.c 2007-12-14 15:31:48.%N +0100
+++ linux-2.6-x86/arch/x86/kernel/ds.c 2007-12-14 15:31:48.%N +0100
@@ -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;
Index: linux-2.6-x86/arch/x86/kernel/ptrace.c
===
--- linux-2.6-x86.orig/arch/x86/kernel/ptrace.c 2007-12-14 15:31:48.%N +0100
+++ linux-2.6-x86/arch/x86/kernel/ptrace.c 2007-12-14 17:32:40.%N +0100
@@ -33,12 +33,6 @@
/*
- * The maximal size of a BTS buffer per traced task in number of BTS
- * records.
- */
-#define PTRACE_BTS_BUFFER_MAX 4000
-
-/*
* does not yet catch signals sent when the child dies.
* in exit.c or in signal.c.
*/
@@ -466,17 +460,12 @@
return 0;
}
-static int ptrace_bts_max_buffer_size(void)
-{
- return PTRACE_BTS_BUFFER_MAX;
-}
-
-static int ptrace_bts_get_buffer_size(struct task_struct *child)
+static int ptrace_bts_get_size(struct task_struct *child)
{
if (!child-thread.ds_area_msr)
return -ENXIO;
- return ds_get_bts_size((void *)child-thread.ds_area_msr);
+ return ds_get_bts_index((void *)child-thread.ds_area_msr);
}
static int ptrace_bts_read_record(struct task_struct *child,
@@ -485,7 +474,7 @@
{
struct bts_struct ret;
int retval;
- int bts_size;
+ int bts_end;
int bts_index;
if (!child-thread.ds_area_msr)
@@ -494,15 +483,15 @@
if (index 0)
return -EINVAL;
- bts_size = ds_get_bts_size((void *)child-thread.ds_area_msr);
- if (bts_size = index)
+ bts_end = ds_get_bts_end((void *)child-thread.ds_area_msr);
+ if (bts_end = index)
return -EINVAL;
/* translate the ptrace bts index into the ds bts index */
bts_index = ds_get_bts_index((void *)child-thread.ds_area_msr);
bts_index -= (index + 1);
if (bts_index 0)
- bts_index += bts_size;
+ bts_index += bts_end;
retval = ds_read_bts((void *)child-thread.ds_area_msr,
bts_index, ret);
@@ -530,19 +519,97 @@
return sizeof(*in);
}
-static int ptrace_bts_config(struct task_struct *child,
-unsigned long options)
+static int ptrace_bts_clear(struct task_struct *child)
{
- unsigned long debugctl_mask = ds_debugctl_mask();
- int retval;
+ if (!child-thread.ds_area_msr)
+ return -ENXIO;
- retval = ptrace_bts_get_buffer_size(child);
- if (retval 0)
-
Re: [patch 4/5] x86, ptrace: new ptrace BTS API
* Markus Metzger [EMAIL PROTECTED] wrote: 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? i think we tend to have such signal targets configurable (like in the POSIX timers APIs) - or we could use SIGIO. I've Cc:-ed Ulrich - maybe he has some specific ideas how to structure this. Ingo -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
