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authorMarkus Metzger <markus.t.metzger@intel.com>2009-04-03 16:43:51 +0200
committerIngo Molnar <mingo@elte.hu>2009-04-07 13:36:35 +0200
commit150f5164c1258e05b7dea16f29e592f354c48f34 (patch)
tree5b90728e0bc23182ae1a152d9cb8ff4e9e819afa /arch/x86/kernel/ds.c
parent608780a9048efa3e85fbc4d8649b26805cc588aa (diff)
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@googlemail.com> Signed-off-by: Markus Metzger <markus.t.metzger@intel.com> Cc: roland@redhat.com Cc: eranian@googlemail.com Cc: oleg@redhat.com Cc: juan.villacis@intel.com Cc: ak@linux.jf.intel.com LKML-Reference: <20090403144606.139137000@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/ds.c')
-rw-r--r--arch/x86/kernel/ds.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/arch/x86/kernel/ds.c b/arch/x86/kernel/ds.c
index ebfb0fde8e6..4e05157506a 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) {