* [RFC 1/2] perf/pmu: Allow PMU providers to override system-wide security settings
@ 2017-11-17 13:57 ` Tvrtko Ursulin
0 siblings, 0 replies; 4+ messages in thread
From: Tvrtko Ursulin @ 2017-11-17 13:57 UTC (permalink / raw)
To: Intel-gfx
Cc: Peter Zijlstra, linux-kernel, Arnaldo Carvalho de Melo,
Alexander Shishkin, Ingo Molnar, Namhyung Kim, Jiri Olsa
From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
To allow system administrators finer-grained control over security
settings, we add an optional pmu->is_privileged(pmu, event) callback
which is consulted when unprivileged system-wide uncore event collection
is disabled.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-kernel@vger.kernel.org
Cc: Dmitry Rogozhkin <dmitry.v.rogozhkin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
---
include/linux/perf_event.h | 6 ++++++
kernel/events/core.c | 12 +++++++++++-
2 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 8e22f24ded6a..a93630cad6b9 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -446,6 +446,12 @@ struct pmu {
* Filter events for PMU-specific reasons.
*/
int (*filter_match) (struct perf_event *event); /* optional */
+
+ /*
+ * Returns true if the event needs CAP_SYS_ADMIN privilege in system-
+ * wide mode.
+ */
+ bool (*is_privileged) (struct perf_event *event); /* optional */
};
/**
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 1811dd5aa2e2..adec28c879e8 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3847,6 +3847,16 @@ find_lively_task_by_vpid(pid_t vpid)
return task;
}
+static bool cpu_is_privileged(struct pmu *pmu, struct perf_event *event)
+{
+ bool privileged = perf_paranoid_cpu();
+
+ if (privileged && pmu->is_privileged)
+ privileged = pmu->is_privileged(event);
+
+ return privileged;
+}
+
/*
* Returns a matching context with refcount and pincount.
*/
@@ -3863,7 +3873,7 @@ find_get_context(struct pmu *pmu, struct task_struct *task,
if (!task) {
/* Must be root to operate on a CPU event: */
- if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
+ if (cpu_is_privileged(pmu, event) && !capable(CAP_SYS_ADMIN))
return ERR_PTR(-EACCES);
cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
--
2.14.1
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [RFC 1/2] perf/pmu: Allow PMU providers to override system-wide security settings
@ 2017-11-17 13:57 ` Tvrtko Ursulin
0 siblings, 0 replies; 4+ messages in thread
From: Tvrtko Ursulin @ 2017-11-17 13:57 UTC (permalink / raw)
To: Intel-gfx
Cc: linux-kernel, Tvrtko Ursulin, Peter Zijlstra, Ingo Molnar,
Arnaldo Carvalho de Melo, Alexander Shishkin, Jiri Olsa,
Namhyung Kim, Dmitry Rogozhkin, Chris Wilson
From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
To allow system administrators finer-grained control over security
settings, we add an optional pmu->is_privileged(pmu, event) callback
which is consulted when unprivileged system-wide uncore event collection
is disabled.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linux-kernel@vger.kernel.org
Cc: Dmitry Rogozhkin <dmitry.v.rogozhkin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
---
include/linux/perf_event.h | 6 ++++++
kernel/events/core.c | 12 +++++++++++-
2 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 8e22f24ded6a..a93630cad6b9 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -446,6 +446,12 @@ struct pmu {
* Filter events for PMU-specific reasons.
*/
int (*filter_match) (struct perf_event *event); /* optional */
+
+ /*
+ * Returns true if the event needs CAP_SYS_ADMIN privilege in system-
+ * wide mode.
+ */
+ bool (*is_privileged) (struct perf_event *event); /* optional */
};
/**
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 1811dd5aa2e2..adec28c879e8 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3847,6 +3847,16 @@ find_lively_task_by_vpid(pid_t vpid)
return task;
}
+static bool cpu_is_privileged(struct pmu *pmu, struct perf_event *event)
+{
+ bool privileged = perf_paranoid_cpu();
+
+ if (privileged && pmu->is_privileged)
+ privileged = pmu->is_privileged(event);
+
+ return privileged;
+}
+
/*
* Returns a matching context with refcount and pincount.
*/
@@ -3863,7 +3873,7 @@ find_get_context(struct pmu *pmu, struct task_struct *task,
if (!task) {
/* Must be root to operate on a CPU event: */
- if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
+ if (cpu_is_privileged(pmu, event) && !capable(CAP_SYS_ADMIN))
return ERR_PTR(-EACCES);
cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
--
2.14.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [RFC 2/2] drm/i915/pmu: Allow fine-grained PMU access control
2017-11-17 13:57 ` Tvrtko Ursulin
@ 2017-11-17 13:57 ` Tvrtko Ursulin
-1 siblings, 0 replies; 4+ messages in thread
From: Tvrtko Ursulin @ 2017-11-17 13:57 UTC (permalink / raw)
To: Intel-gfx; +Cc: linux-kernel
From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
We implement the new pmu->is_privileged callback and add our own sysctl
as /proc/sys/dev/i915/pmu_stream_paranoid (defaulting to true), which
enables system administrators to override the global
/proc/sys/kernel/perf_event_paranoid setting for i915 PMU only.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Dmitry Rogozhkin <dmitry.v.rogozhkin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
---
drivers/gpu/drm/i915/i915_pmu.c | 55 +++++++++++++++++++++++++++++++++++++++--
drivers/gpu/drm/i915/i915_pmu.h | 4 +++
2 files changed, 57 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c
index baa663641bb7..a8eca7303b7e 100644
--- a/drivers/gpu/drm/i915/i915_pmu.c
+++ b/drivers/gpu/drm/i915/i915_pmu.c
@@ -43,6 +43,11 @@
static cpumask_t i915_pmu_cpumask = CPU_MASK_NONE;
+/* for sysctl proc_dointvec_minmax of dev.i915.pmu_stream_paranoid */
+static int zero;
+static int one = 1;
+static u32 i915_pmu_stream_paranoid = true;
+
static u8 engine_config_sample(u64 config)
{
return config & I915_PMU_SAMPLE_MASK;
@@ -647,6 +652,11 @@ static int i915_pmu_event_event_idx(struct perf_event *event)
return 0;
}
+static bool i915_pmu_is_privileged(struct perf_event *event)
+{
+ return i915_pmu_stream_paranoid;
+}
+
static ssize_t i915_pmu_format_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -834,11 +844,44 @@ static void i915_pmu_unregister_cpuhp_state(struct drm_i915_private *i915)
#endif
}
+static struct ctl_table pmu_table[] = {
+ {
+ .procname = "pmu_stream_paranoid",
+ .data = &i915_pmu_stream_paranoid,
+ .maxlen = sizeof(i915_pmu_stream_paranoid),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &one,
+ },
+ {}
+};
+
+static struct ctl_table i915_root[] = {
+ {
+ .procname = "i915",
+ .maxlen = 0,
+ .mode = 0555,
+ .child = pmu_table,
+ },
+ {}
+};
+
+static struct ctl_table dev_root[] = {
+ {
+ .procname = "dev",
+ .maxlen = 0,
+ .mode = 0555,
+ .child = i915_root,
+ },
+ {}
+};
+
void i915_pmu_register(struct drm_i915_private *i915)
{
struct intel_engine_cs *engine;
enum intel_engine_id id;
- int ret;
+ int ret = -EINVAL;
if (INTEL_GEN(i915) <= 2) {
DRM_INFO("PMU not supported for this GPU.");
@@ -854,6 +897,7 @@ void i915_pmu_register(struct drm_i915_private *i915)
i915->pmu.base.stop = i915_pmu_event_stop;
i915->pmu.base.read = i915_pmu_event_read;
i915->pmu.base.event_idx = i915_pmu_event_event_idx;
+ i915->pmu.base.is_privileged = i915_pmu_is_privileged;
spin_lock_init(&i915->pmu.lock);
hrtimer_init(&i915->pmu.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
@@ -863,9 +907,12 @@ void i915_pmu_register(struct drm_i915_private *i915)
INIT_DELAYED_WORK(&engine->pmu.disable_busy_stats,
__disable_busy_stats);
+ if (!(i915->pmu.sysctl_header = register_sysctl_table(dev_root)))
+ goto err;
+
ret = perf_pmu_register(&i915->pmu.base, "i915", -1);
if (ret)
- goto err;
+ goto err_pmu;
ret = i915_pmu_register_cpuhp_state(i915);
if (ret)
@@ -875,6 +922,8 @@ void i915_pmu_register(struct drm_i915_private *i915)
err_unreg:
perf_pmu_unregister(&i915->pmu.base);
+err_pmu:
+ unregister_sysctl_table(i915->pmu.sysctl_header);
err:
i915->pmu.base.event_init = NULL;
DRM_NOTE("Failed to register PMU! (err=%d)\n", ret);
@@ -899,6 +948,8 @@ void i915_pmu_unregister(struct drm_i915_private *i915)
i915_pmu_unregister_cpuhp_state(i915);
+ unregister_sysctl_table(i915->pmu.sysctl_header);
+
perf_pmu_unregister(&i915->pmu.base);
i915->pmu.base.event_init = NULL;
}
diff --git a/drivers/gpu/drm/i915/i915_pmu.h b/drivers/gpu/drm/i915/i915_pmu.h
index e209783a4c5f..30e2192b4218 100644
--- a/drivers/gpu/drm/i915/i915_pmu.h
+++ b/drivers/gpu/drm/i915/i915_pmu.h
@@ -61,6 +61,10 @@ struct i915_pmu {
* @timer: Timer for internal i915 PMU sampling.
*/
struct hrtimer timer;
+ /**
+ * @sysctl_header: Sysctl table header.
+ */
+ struct ctl_table_header *sysctl_header;
/**
* @enable: Bitmask of all currently enabled events.
*
--
2.14.1
_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
^ permalink raw reply related [flat|nested] 4+ messages in thread
* [RFC 2/2] drm/i915/pmu: Allow fine-grained PMU access control
@ 2017-11-17 13:57 ` Tvrtko Ursulin
0 siblings, 0 replies; 4+ messages in thread
From: Tvrtko Ursulin @ 2017-11-17 13:57 UTC (permalink / raw)
To: Intel-gfx; +Cc: linux-kernel, Tvrtko Ursulin, Dmitry Rogozhkin, Chris Wilson
From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
We implement the new pmu->is_privileged callback and add our own sysctl
as /proc/sys/dev/i915/pmu_stream_paranoid (defaulting to true), which
enables system administrators to override the global
/proc/sys/kernel/perf_event_paranoid setting for i915 PMU only.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Dmitry Rogozhkin <dmitry.v.rogozhkin@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
---
drivers/gpu/drm/i915/i915_pmu.c | 55 +++++++++++++++++++++++++++++++++++++++--
drivers/gpu/drm/i915/i915_pmu.h | 4 +++
2 files changed, 57 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_pmu.c b/drivers/gpu/drm/i915/i915_pmu.c
index baa663641bb7..a8eca7303b7e 100644
--- a/drivers/gpu/drm/i915/i915_pmu.c
+++ b/drivers/gpu/drm/i915/i915_pmu.c
@@ -43,6 +43,11 @@
static cpumask_t i915_pmu_cpumask = CPU_MASK_NONE;
+/* for sysctl proc_dointvec_minmax of dev.i915.pmu_stream_paranoid */
+static int zero;
+static int one = 1;
+static u32 i915_pmu_stream_paranoid = true;
+
static u8 engine_config_sample(u64 config)
{
return config & I915_PMU_SAMPLE_MASK;
@@ -647,6 +652,11 @@ static int i915_pmu_event_event_idx(struct perf_event *event)
return 0;
}
+static bool i915_pmu_is_privileged(struct perf_event *event)
+{
+ return i915_pmu_stream_paranoid;
+}
+
static ssize_t i915_pmu_format_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -834,11 +844,44 @@ static void i915_pmu_unregister_cpuhp_state(struct drm_i915_private *i915)
#endif
}
+static struct ctl_table pmu_table[] = {
+ {
+ .procname = "pmu_stream_paranoid",
+ .data = &i915_pmu_stream_paranoid,
+ .maxlen = sizeof(i915_pmu_stream_paranoid),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &one,
+ },
+ {}
+};
+
+static struct ctl_table i915_root[] = {
+ {
+ .procname = "i915",
+ .maxlen = 0,
+ .mode = 0555,
+ .child = pmu_table,
+ },
+ {}
+};
+
+static struct ctl_table dev_root[] = {
+ {
+ .procname = "dev",
+ .maxlen = 0,
+ .mode = 0555,
+ .child = i915_root,
+ },
+ {}
+};
+
void i915_pmu_register(struct drm_i915_private *i915)
{
struct intel_engine_cs *engine;
enum intel_engine_id id;
- int ret;
+ int ret = -EINVAL;
if (INTEL_GEN(i915) <= 2) {
DRM_INFO("PMU not supported for this GPU.");
@@ -854,6 +897,7 @@ void i915_pmu_register(struct drm_i915_private *i915)
i915->pmu.base.stop = i915_pmu_event_stop;
i915->pmu.base.read = i915_pmu_event_read;
i915->pmu.base.event_idx = i915_pmu_event_event_idx;
+ i915->pmu.base.is_privileged = i915_pmu_is_privileged;
spin_lock_init(&i915->pmu.lock);
hrtimer_init(&i915->pmu.timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
@@ -863,9 +907,12 @@ void i915_pmu_register(struct drm_i915_private *i915)
INIT_DELAYED_WORK(&engine->pmu.disable_busy_stats,
__disable_busy_stats);
+ if (!(i915->pmu.sysctl_header = register_sysctl_table(dev_root)))
+ goto err;
+
ret = perf_pmu_register(&i915->pmu.base, "i915", -1);
if (ret)
- goto err;
+ goto err_pmu;
ret = i915_pmu_register_cpuhp_state(i915);
if (ret)
@@ -875,6 +922,8 @@ void i915_pmu_register(struct drm_i915_private *i915)
err_unreg:
perf_pmu_unregister(&i915->pmu.base);
+err_pmu:
+ unregister_sysctl_table(i915->pmu.sysctl_header);
err:
i915->pmu.base.event_init = NULL;
DRM_NOTE("Failed to register PMU! (err=%d)\n", ret);
@@ -899,6 +948,8 @@ void i915_pmu_unregister(struct drm_i915_private *i915)
i915_pmu_unregister_cpuhp_state(i915);
+ unregister_sysctl_table(i915->pmu.sysctl_header);
+
perf_pmu_unregister(&i915->pmu.base);
i915->pmu.base.event_init = NULL;
}
diff --git a/drivers/gpu/drm/i915/i915_pmu.h b/drivers/gpu/drm/i915/i915_pmu.h
index e209783a4c5f..30e2192b4218 100644
--- a/drivers/gpu/drm/i915/i915_pmu.h
+++ b/drivers/gpu/drm/i915/i915_pmu.h
@@ -61,6 +61,10 @@ struct i915_pmu {
* @timer: Timer for internal i915 PMU sampling.
*/
struct hrtimer timer;
+ /**
+ * @sysctl_header: Sysctl table header.
+ */
+ struct ctl_table_header *sysctl_header;
/**
* @enable: Bitmask of all currently enabled events.
*
--
2.14.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
end of thread, other threads:[~2017-11-17 13:57 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2017-11-17 13:57 [RFC 1/2] perf/pmu: Allow PMU providers to override system-wide security settings Tvrtko Ursulin
2017-11-17 13:57 ` Tvrtko Ursulin
2017-11-17 13:57 ` [RFC 2/2] drm/i915/pmu: Allow fine-grained PMU access control Tvrtko Ursulin
2017-11-17 13:57 ` Tvrtko Ursulin
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