diff options
| author | Markus Metzger <markus.t.metzger@intel.com> | 2009-04-03 16:43:51 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2009-04-07 13:36:35 +0200 |
| commit | 150f5164c1258e05b7dea16f29e592f354c48f34 (patch) | |
| tree | 5b90728e0bc23182ae1a152d9cb8ff4e9e819afa /arch/x86/kernel | |
| parent | 608780a9048efa3e85fbc4d8649b26805cc588aa (diff) | |
| download | lwn-150f5164c1258e05b7dea16f29e592f354c48f34.tar.gz lwn-150f5164c1258e05b7dea16f29e592f354c48f34.zip | |
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')
| -rw-r--r-- | arch/x86/kernel/ds.c | 9 | ||||
| -rw-r--r-- | 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 ebfb0fde8e6f..4e05157506aa 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 a40b2533c71e..5f104a0ace66 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); |