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Subject[RFC 2/5] perf: Pass pmu pointer to perf_paranoid_* helpers
Date
From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

To enable per-PMU access controls in a following patch we need to start
passing in the PMU object pointer to perf_paranoid_* helpers.

This patch only changes the API across the code base without changing the
behaviour.

v2:
* Correct errors in core-book3s.c as reported by kbuild test robot.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.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: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Alexey Budankov <alexey.budankov@linux.intel.com>
Cc: linux-kernel@vger.kernel.org
Cc: x86@kernel.org
---
arch/powerpc/perf/core-book3s.c | 31 ++++++++++++++++++++++---------
arch/x86/events/intel/bts.c | 2 +-
arch/x86/events/intel/core.c | 2 +-
arch/x86/events/intel/p4.c | 2 +-
include/linux/perf_event.h | 6 +++---
kernel/events/core.c | 15 ++++++++-------
kernel/trace/trace_event_perf.c | 6 ++++--
7 files changed, 40 insertions(+), 24 deletions(-)

diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c
index 81f8a0c838ae..1e8b1aed6e81 100644
--- a/arch/powerpc/perf/core-book3s.c
+++ b/arch/powerpc/perf/core-book3s.c
@@ -95,7 +95,13 @@ static inline unsigned long perf_ip_adjust(struct pt_regs *regs)
{
return 0;
}
-static inline void perf_get_data_addr(struct pt_regs *regs, u64 *addrp) { }
+
+static inline void
+perf_get_data_addr(struct pmu *pmu, struct pt_regs *regs, u64 *addrp)
+{
+
+}
+
static inline u32 perf_get_misc_flags(struct pt_regs *regs)
{
return 0;
@@ -126,7 +132,13 @@ static unsigned long ebb_switch_in(bool ebb, struct cpu_hw_events *cpuhw)
static inline void power_pmu_bhrb_enable(struct perf_event *event) {}
static inline void power_pmu_bhrb_disable(struct perf_event *event) {}
static void power_pmu_sched_task(struct perf_event_context *ctx, bool sched_in) {}
-static inline void power_pmu_bhrb_read(struct cpu_hw_events *cpuhw) {}
+
+static inline void
+power_pmu_bhrb_read(struct pmu *pmu,struct cpu_hw_events *cpuhw)
+{
+
+}
+
static void pmao_restore_workaround(bool ebb) { }
#endif /* CONFIG_PPC32 */

@@ -170,7 +182,8 @@ static inline unsigned long perf_ip_adjust(struct pt_regs *regs)
* pointed to by SIAR; this is indicated by the [POWER6_]MMCRA_SDSYNC, the
* [POWER7P_]MMCRA_SDAR_VALID bit in MMCRA, or the SDAR_VALID bit in SIER.
*/
-static inline void perf_get_data_addr(struct pt_regs *regs, u64 *addrp)
+static inline void
+perf_get_data_addr(struct pmu *pmu, struct pt_regs *regs, u64 *addrp)
{
unsigned long mmcra = regs->dsisr;
bool sdar_valid;
@@ -195,7 +208,7 @@ static inline void perf_get_data_addr(struct pt_regs *regs, u64 *addrp)
if (!(mmcra & MMCRA_SAMPLE_ENABLE) || sdar_valid)
*addrp = mfspr(SPRN_SDAR);

- if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN) &&
+ if (perf_paranoid_kernel(pmu) && !capable(CAP_SYS_ADMIN) &&
is_kernel_addr(mfspr(SPRN_SDAR)))
*addrp = 0;
}
@@ -435,7 +448,7 @@ static __u64 power_pmu_bhrb_to(u64 addr)
}

/* Processing BHRB entries */
-static void power_pmu_bhrb_read(struct cpu_hw_events *cpuhw)
+static void power_pmu_bhrb_read(struct pmu *pmu, struct cpu_hw_events *cpuhw)
{
u64 val;
u64 addr;
@@ -463,8 +476,8 @@ static void power_pmu_bhrb_read(struct cpu_hw_events *cpuhw)
* exporting it to userspace (avoid exposure of regions
* where we could have speculative execution)
*/
- if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN) &&
- is_kernel_addr(addr))
+ if (perf_paranoid_kernel(pmu) &&
+ !capable(CAP_SYS_ADMIN) && is_kernel_addr(addr))
continue;

/* Branches are read most recent first (ie. mfbhrb 0 is
@@ -2066,12 +2079,12 @@ static void record_and_restart(struct perf_event *event, unsigned long val,

if (event->attr.sample_type &
(PERF_SAMPLE_ADDR | PERF_SAMPLE_PHYS_ADDR))
- perf_get_data_addr(regs, &data.addr);
+ perf_get_data_addr(event->pmu, regs, &data.addr);

if (event->attr.sample_type & PERF_SAMPLE_BRANCH_STACK) {
struct cpu_hw_events *cpuhw;
cpuhw = this_cpu_ptr(&cpu_hw_events);
- power_pmu_bhrb_read(cpuhw);
+ power_pmu_bhrb_read(event->pmu, cpuhw);
data.br_stack = &cpuhw->bhrb_stack;
}

diff --git a/arch/x86/events/intel/bts.c b/arch/x86/events/intel/bts.c
index 24ffa1e88cf9..e416c9e2400a 100644
--- a/arch/x86/events/intel/bts.c
+++ b/arch/x86/events/intel/bts.c
@@ -555,7 +555,7 @@ static int bts_event_init(struct perf_event *event)
* Note that the default paranoia setting permits unprivileged
* users to profile the kernel.
*/
- if (event->attr.exclude_kernel && perf_paranoid_kernel() &&
+ if (event->attr.exclude_kernel && perf_paranoid_kernel(event->pmu) &&
!capable(CAP_SYS_ADMIN))
return -EACCES;

diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 035c37481f57..40ccb4dbbadf 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -3033,7 +3033,7 @@ static int intel_pmu_hw_config(struct perf_event *event)
if (x86_pmu.version < 3)
return -EINVAL;

- if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
+ if (perf_paranoid_cpu(event->pmu) && !capable(CAP_SYS_ADMIN))
return -EACCES;

event->hw.config |= ARCH_PERFMON_EVENTSEL_ANY;
diff --git a/arch/x86/events/intel/p4.c b/arch/x86/events/intel/p4.c
index d32c0eed38ca..878451ef1ace 100644
--- a/arch/x86/events/intel/p4.c
+++ b/arch/x86/events/intel/p4.c
@@ -776,7 +776,7 @@ static int p4_validate_raw_event(struct perf_event *event)
* the user needs special permissions to be able to use it
*/
if (p4_ht_active() && p4_event_bind_map[v].shared) {
- if (perf_paranoid_cpu() && !capable(CAP_SYS_ADMIN))
+ if (perf_paranoid_cpu(event->pmu) && !capable(CAP_SYS_ADMIN))
return -EACCES;
}

diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 53c500f0ca79..22906bcc1bcd 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -1179,17 +1179,17 @@ extern int perf_cpu_time_max_percent_handler(struct ctl_table *table, int write,
int perf_event_max_stack_handler(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp, loff_t *ppos);

-static inline bool perf_paranoid_tracepoint_raw(void)
+static inline bool perf_paranoid_tracepoint_raw(const struct pmu *pmu)
{
return sysctl_perf_event_paranoid > -1;
}

-static inline bool perf_paranoid_cpu(void)
+static inline bool perf_paranoid_cpu(const struct pmu *pmu)
{
return sysctl_perf_event_paranoid > 0;
}

-static inline bool perf_paranoid_kernel(void)
+static inline bool perf_paranoid_kernel(const struct pmu *pmu)
{
return sysctl_perf_event_paranoid > 1;
}
diff --git a/kernel/events/core.c b/kernel/events/core.c
index adcd9eae13fb..f556144bc0c5 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4108,7 +4108,7 @@ 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 (perf_paranoid_cpu(pmu) && !capable(CAP_SYS_ADMIN))
return ERR_PTR(-EACCES);

cpuctx = per_cpu_ptr(pmu->pmu_cpu_context, cpu);
@@ -5676,7 +5676,7 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma)
lock_limit >>= PAGE_SHIFT;
locked = vma->vm_mm->pinned_vm + extra;

- if ((locked > lock_limit) && perf_paranoid_tracepoint_raw() &&
+ if ((locked > lock_limit) && perf_paranoid_tracepoint_raw(event->pmu) &&
!capable(CAP_IPC_LOCK)) {
ret = -EPERM;
goto unlock;
@@ -10492,8 +10492,10 @@ SYSCALL_DEFINE5(perf_event_open,
goto err_cred;
}

+ pmu = event->pmu;
+
if (!attr.exclude_kernel) {
- if (perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) {
+ if (perf_paranoid_kernel(pmu) && !capable(CAP_SYS_ADMIN)) {
err = -EACCES;
goto err_alloc;
}
@@ -10501,7 +10503,7 @@ SYSCALL_DEFINE5(perf_event_open,

/* Only privileged users can get physical addresses */
if ((attr.sample_type & PERF_SAMPLE_PHYS_ADDR) &&
- perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) {
+ perf_paranoid_kernel(pmu) && !capable(CAP_SYS_ADMIN)) {
err = -EACCES;
goto err_alloc;
}
@@ -10509,13 +10511,13 @@ SYSCALL_DEFINE5(perf_event_open,
/* privileged levels capture (kernel, hv): check permissions */
if ((attr.sample_type & PERF_SAMPLE_BRANCH_STACK) &&
(attr.branch_sample_type & PERF_SAMPLE_BRANCH_PERM_PLM) &&
- perf_paranoid_kernel() && !capable(CAP_SYS_ADMIN)) {
+ perf_paranoid_kernel(pmu) && !capable(CAP_SYS_ADMIN)) {
err = -EACCES;
goto err_alloc;
}

if (is_sampling_event(event)) {
- if (event->pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) {
+ if (pmu->capabilities & PERF_PMU_CAP_NO_INTERRUPT) {
err = -EOPNOTSUPP;
goto err_alloc;
}
@@ -10525,7 +10527,6 @@ SYSCALL_DEFINE5(perf_event_open,
* Special case software events and allow them to be part of
* any hardware group.
*/
- pmu = event->pmu;

if (attr.use_clockid) {
err = perf_event_set_clock(event, attr.clockid);
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 69a3fe926e8c..04ea3afec5b2 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -46,7 +46,8 @@ static int perf_trace_event_perm(struct trace_event_call *tp_event,

/* The ftrace function trace is allowed only for root. */
if (ftrace_event_is_function(tp_event)) {
- if (perf_paranoid_tracepoint_raw() && !capable(CAP_SYS_ADMIN))
+ if (perf_paranoid_tracepoint_raw(p_event->pmu) &&
+ !capable(CAP_SYS_ADMIN))
return -EPERM;

if (!is_sampling_event(p_event))
@@ -82,7 +83,8 @@ static int perf_trace_event_perm(struct trace_event_call *tp_event,
* ...otherwise raw tracepoint data can be a severe data leak,
* only allow root to have these.
*/
- if (perf_paranoid_tracepoint_raw() && !capable(CAP_SYS_ADMIN))
+ if (perf_paranoid_tracepoint_raw(p_event->pmu) &&
+ !capable(CAP_SYS_ADMIN))
return -EPERM;

return 0;
--
2.17.1
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