Thread (9 messages) 9 messages, 4 authors, 2025-02-26
STALE459d

[PATCH linux-next 1/2] perf: Remove unnecessary parameter of security check

From: Luo Gengkun <hidden>
Date: 2024-12-23 06:57:48
Also in: linux-arm-kernel, linux-perf-users, linux-security-module, lkml, selinux
Subsystem: arm pmu profiling and debugging, performance events subsystem, security subsystem, selinux security module, the rest, tracing, x86 architecture (32-bit and 64-bit) · Maintainers: Will Deacon, Mark Rutland, Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Paul Moore, James Morris, "Serge E. Hallyn", Stephen Smalley, Linus Torvalds, Steven Rostedt, Masami Hiramatsu, Thomas Gleixner, Borislav Petkov, Dave Hansen

It seems that the attr parameter was never been used in security
checks since it was first introduced by:

commit da97e18458fb ("perf_event: Add support for LSM and SELinux checks")

so remove it.

Signed-off-by: Luo Gengkun <redacted>
---
 arch/x86/events/intel/bts.c     |  2 +-
 arch/x86/events/intel/core.c    |  2 +-
 arch/x86/events/intel/p4.c      |  2 +-
 drivers/perf/arm_spe_pmu.c      |  4 ++--
 include/linux/lsm_hook_defs.h   |  2 +-
 include/linux/perf_event.h      | 10 +++++-----
 include/linux/security.h        |  5 ++---
 kernel/events/core.c            | 14 +++++++-------
 kernel/trace/trace_event_perf.c |  4 ++--
 security/security.c             |  5 ++---
 security/selinux/hooks.c        |  2 +-
 11 files changed, 25 insertions(+), 27 deletions(-)
diff --git a/arch/x86/events/intel/bts.c b/arch/x86/events/intel/bts.c
index 8f78b0c900ef..485a09d61adf 100644
--- a/arch/x86/events/intel/bts.c
+++ b/arch/x86/events/intel/bts.c
@@ -559,7 +559,7 @@ static int bts_event_init(struct perf_event *event)
 	 * to the user in a zero-copy fashion.
 	 */
 	if (event->attr.exclude_kernel) {
-		ret = perf_allow_kernel(&event->attr);
+		ret = perf_allow_kernel();
 		if (ret)
 			return ret;
 	}
diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
index 103ee41907c7..3b65df32daee 100644
--- a/arch/x86/events/intel/core.c
+++ b/arch/x86/events/intel/core.c
@@ -4150,7 +4150,7 @@ static int intel_pmu_hw_config(struct perf_event *event)
 	if (x86_pmu.version < 3)
 		return -EINVAL;
 
-	ret = perf_allow_cpu(&event->attr);
+	ret = perf_allow_cpu();
 	if (ret)
 		return ret;
 
diff --git a/arch/x86/events/intel/p4.c b/arch/x86/events/intel/p4.c
index 844bc4fc4724..78d78b8a1530 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) {
-		v = perf_allow_cpu(&event->attr);
+		v = perf_allow_cpu();
 		if (v)
 			return v;
 	}
diff --git a/drivers/perf/arm_spe_pmu.c b/drivers/perf/arm_spe_pmu.c
index fd5b78732603..a55d10956ff6 100644
--- a/drivers/perf/arm_spe_pmu.c
+++ b/drivers/perf/arm_spe_pmu.c
@@ -50,7 +50,7 @@ static_assert((PERF_EVENT_FLAG_ARCH & SPE_PMU_HW_FLAGS_CX) == SPE_PMU_HW_FLAGS_C
 
 static void set_spe_event_has_cx(struct perf_event *event)
 {
-	if (IS_ENABLED(CONFIG_PID_IN_CONTEXTIDR) && !perf_allow_kernel(&event->attr))
+	if (IS_ENABLED(CONFIG_PID_IN_CONTEXTIDR) && !perf_allow_kernel())
 		event->hw.flags |= SPE_PMU_HW_FLAGS_CX;
 }
 
@@ -746,7 +746,7 @@ static int arm_spe_pmu_event_init(struct perf_event *event)
 	set_spe_event_has_cx(event);
 	reg = arm_spe_event_to_pmscr(event);
 	if (reg & (PMSCR_EL1_PA | PMSCR_EL1_PCT))
-		return perf_allow_kernel(&event->attr);
+		return perf_allow_kernel();
 
 	return 0;
 }
diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h
index e2f1ce37c41e..e349e585cc07 100644
--- a/include/linux/lsm_hook_defs.h
+++ b/include/linux/lsm_hook_defs.h
@@ -445,7 +445,7 @@ LSM_HOOK(int, 0, bpf_token_capable, const struct bpf_token *token, int cap)
 LSM_HOOK(int, 0, locked_down, enum lockdown_reason what)
 
 #ifdef CONFIG_PERF_EVENTS
-LSM_HOOK(int, 0, perf_event_open, struct perf_event_attr *attr, int type)
+LSM_HOOK(int, 0, perf_event_open, int type)
 LSM_HOOK(int, 0, perf_event_alloc, struct perf_event *event)
 LSM_HOOK(int, 0, perf_event_read, struct perf_event *event)
 LSM_HOOK(int, 0, perf_event_write, struct perf_event *event)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 8333f132f4a9..5d2ec4283ebf 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -1672,22 +1672,22 @@ static inline int perf_is_paranoid(void)
 	return sysctl_perf_event_paranoid > -1;
 }
 
-int perf_allow_kernel(struct perf_event_attr *attr);
+int perf_allow_kernel(void);
 
-static inline int perf_allow_cpu(struct perf_event_attr *attr)
+static inline int perf_allow_cpu(void)
 {
 	if (sysctl_perf_event_paranoid > 0 && !perfmon_capable())
 		return -EACCES;
 
-	return security_perf_event_open(attr, PERF_SECURITY_CPU);
+	return security_perf_event_open(PERF_SECURITY_CPU);
 }
 
-static inline int perf_allow_tracepoint(struct perf_event_attr *attr)
+static inline int perf_allow_tracepoint(void)
 {
 	if (sysctl_perf_event_paranoid > -1 && !perfmon_capable())
 		return -EPERM;
 
-	return security_perf_event_open(attr, PERF_SECURITY_TRACEPOINT);
+	return security_perf_event_open(PERF_SECURITY_TRACEPOINT);
 }
 
 extern int perf_exclude_event(struct perf_event *event, struct pt_regs *regs);
diff --git a/include/linux/security.h b/include/linux/security.h
index 980b6c207cad..a3b35a699256 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -2324,14 +2324,13 @@ struct perf_event_attr;
 struct perf_event;
 
 #ifdef CONFIG_SECURITY
-extern int security_perf_event_open(struct perf_event_attr *attr, int type);
+extern int security_perf_event_open(int type);
 extern int security_perf_event_alloc(struct perf_event *event);
 extern void security_perf_event_free(struct perf_event *event);
 extern int security_perf_event_read(struct perf_event *event);
 extern int security_perf_event_write(struct perf_event *event);
 #else
-static inline int security_perf_event_open(struct perf_event_attr *attr,
-					   int type)
+static inline int security_perf_event_open(int type)
 {
 	return 0;
 }
diff --git a/kernel/events/core.c b/kernel/events/core.c
index b2bc67791f84..f2cb450eb134 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4883,7 +4883,7 @@ find_get_context(struct task_struct *task, struct perf_event *event)
 
 	if (!task) {
 		/* Must be root to operate on a CPU event: */
-		err = perf_allow_cpu(&event->attr);
+		err = perf_allow_cpu();
 		if (err)
 			return ERR_PTR(err);
 
@@ -12488,7 +12488,7 @@ static int perf_copy_attr(struct perf_event_attr __user *uattr,
 		}
 		/* privileged levels capture (kernel, hv): check permissions */
 		if (mask & PERF_SAMPLE_BRANCH_PERM_PLM) {
-			ret = perf_allow_kernel(attr);
+			ret = perf_allow_kernel();
 			if (ret)
 				return ret;
 		}
@@ -12745,12 +12745,12 @@ SYSCALL_DEFINE5(perf_event_open,
 		return err;
 
 	/* Do we allow access to perf_event_open(2) ? */
-	err = security_perf_event_open(&attr, PERF_SECURITY_OPEN);
+	err = security_perf_event_open(PERF_SECURITY_OPEN);
 	if (err)
 		return err;
 
 	if (!attr.exclude_kernel) {
-		err = perf_allow_kernel(&attr);
+		err = perf_allow_kernel();
 		if (err)
 			return err;
 	}
@@ -12770,7 +12770,7 @@ SYSCALL_DEFINE5(perf_event_open,
 
 	/* Only privileged users can get physical addresses */
 	if ((attr.sample_type & PERF_SAMPLE_PHYS_ADDR)) {
-		err = perf_allow_kernel(&attr);
+		err = perf_allow_kernel();
 		if (err)
 			return err;
 	}
@@ -13603,12 +13603,12 @@ const struct perf_event_attr *perf_event_attrs(struct perf_event *event)
 	return &event->attr;
 }
 
-int perf_allow_kernel(struct perf_event_attr *attr)
+int perf_allow_kernel(void)
 {
 	if (sysctl_perf_event_paranoid > 1 && !perfmon_capable())
 		return -EACCES;
 
-	return security_perf_event_open(attr, PERF_SECURITY_KERNEL);
+	return security_perf_event_open(PERF_SECURITY_KERNEL);
 }
 EXPORT_SYMBOL_GPL(perf_allow_kernel);
 
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 3ff9caa4a71b..a6bb7577e8c5 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -49,7 +49,7 @@ 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)) {
-		ret = perf_allow_tracepoint(&p_event->attr);
+		ret = perf_allow_tracepoint();
 		if (ret)
 			return ret;
 
@@ -86,7 +86,7 @@ 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.
 	 */
-	ret = perf_allow_tracepoint(&p_event->attr);
+	ret = perf_allow_tracepoint();
 	if (ret)
 		return ret;
 
diff --git a/security/security.c b/security/security.c
index 1db835c05a78..ad9655aa1322 100644
--- a/security/security.c
+++ b/security/security.c
@@ -5885,16 +5885,15 @@ EXPORT_SYMBOL(security_bdev_setintegrity);
 #ifdef CONFIG_PERF_EVENTS
 /**
  * security_perf_event_open() - Check if a perf event open is allowed
- * @attr: perf event attribute
  * @type: type of event
  *
  * Check whether the @type of perf_event_open syscall is allowed.
  *
  * Return: Returns 0 if permission is granted.
  */
-int security_perf_event_open(struct perf_event_attr *attr, int type)
+int security_perf_event_open(int type)
 {
-	return call_int_hook(perf_event_open, attr, type);
+	return call_int_hook(perf_event_open, type);
 }
 
 /**
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index a503b8fd6611..14c7d331c3b6 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -7040,7 +7040,7 @@ struct lsm_blob_sizes selinux_blob_sizes __ro_after_init = {
 };
 
 #ifdef CONFIG_PERF_EVENTS
-static int selinux_perf_event_open(struct perf_event_attr *attr, int type)
+static int selinux_perf_event_open(int type)
 {
 	u32 requested, sid = current_sid();
 
-- 
2.34.1
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