Commit-ID: 150f5164c1258e05b7dea16f29e592f354c48f34
Gitweb: http://git.kernel.org/tip/150f5164c1258e05b7dea16f29e592f354c48f34
Author: Markus Metzger <markus.t.metzger@xxxxxxxxx>
AuthorDate: Fri, 3 Apr 2009 16:43:51 +0200
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Tue, 7 Apr 2009 13:36:35 +0200
x86, ds: allow small debug store buffers
Check the buffer size more precisely to allow buffers for exactly
one element provided the base address is already properly aligned.
Add a debug store selftest.
Reported-by: Stephane Eranian <eranian@xxxxxxxxxxxxxx>
Signed-off-by: Markus Metzger <markus.t.metzger@xxxxxxxxx>
Cc: roland@xxxxxxxxxx
Cc: eranian@xxxxxxxxxxxxxx
Cc: oleg@xxxxxxxxxx
Cc: juan.villacis@xxxxxxxxx
Cc: ak@xxxxxxxxxxxxxxxxxx
LKML-Reference: <20090403144606.139137000@xxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
arch/x86/kernel/ds.c | 9 +++++++--
arch/x86/kernel/ds_selftest.c | 6 +++---
2 files changed, 10 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kernel/ds.c b/arch/x86/kernel/ds.c
index ebfb0fd..4e05157 100644
--- a/arch/x86/kernel/ds.c
+++ b/arch/x86/kernel/ds.c
@@ -656,6 +656,7 @@ static int ds_request(struct ds_tracer *tracer, struct ds_trace *trace,
{
struct ds_context *context;
int error;
+ size_t req_size;
error = -EOPNOTSUPP;
if (!ds_cfg.sizeof_rec[qual])
@@ -665,9 +666,13 @@ static int ds_request(struct ds_tracer *tracer, struct ds_trace *trace,
if (!base)
goto out;
- /* We need space for alignment adjustments in ds_init_ds_trace(). */
+ req_size = ds_cfg.sizeof_rec[qual];
+ /* We might need space for alignment adjustments. */
+ if (!IS_ALIGNED((unsigned long)base, DS_ALIGNMENT))
+ req_size += DS_ALIGNMENT;
+
error = -EINVAL;
- if (size < (DS_ALIGNMENT + ds_cfg.sizeof_rec[qual]))
+ if (size < req_size)
goto out;
if (th != (size_t)-1) {
diff --git a/arch/x86/kernel/ds_selftest.c b/arch/x86/kernel/ds_selftest.c
index a40b253..5f104a0 100644
--- a/arch/x86/kernel/ds_selftest.c
+++ b/arch/x86/kernel/ds_selftest.c
@@ -16,8 +16,8 @@
#include <asm/ds.h>
-#define BUFFER_SIZE 521 /* Intentionally chose an odd size. */
-
+#define BUFFER_SIZE 521 /* Intentionally chose an odd size. */
+#define SMALL_BUFFER_SIZE 24 /* A single bts entry. */
struct ds_selftest_bts_conf {
struct bts_tracer *tracer;
@@ -381,7 +381,7 @@ int ds_selftest_bts(void)
conf.suspend = ds_suspend_bts_noirq;
conf.resume = ds_resume_bts_noirq;
conf.tracer =
- ds_request_bts_task(current, buffer, BUFFER_SIZE,
+ ds_request_bts_task(current, buffer, SMALL_BUFFER_SIZE,
NULL, (size_t)-1, BTS_KERNEL);
local_irq_save(irq);
ds_selftest_bts_cpu(&conf);
--
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