misc: tegra-profiler: fix stop error

Do not verify the existence of profiled process after
start of session.
It fixes the stop error on non-rooted devices when
application is terminated during the profile session.

Bug 1634968

Change-Id: I5384e6de3c7ff9791033d344b02acba9a729157b
Signed-off-by: Igor Nabirushkin <inabirushkin@nvidia.com>
Reviewed-on: http://git-master/r/730898
(cherry picked from commit 79fcedbbf7fbc984ec8b95900ee49af0a9be590b)
Reviewed-on: http://git-master/r/748093
GVS: Gerrit_Virtual_Submit
Reviewed-by: Andrey Trachenko <atrachenko@nvidia.com>
Reviewed-by: Winnie Hsu <whsu@nvidia.com>

4 files changed, 36 insertions, 70 deletions

diff --git a/drivers/misc/tegra-profiler/comm.c b/drivers/misc/tegra-profiler/comm.c
index 2d70f6318d3e..80c84614081a 100644
--- a/drivers/misc/tegra-profiler/comm.c
+++ b/drivers/misc/tegra-profiler/comm.c
@@ -1,7 +1,7 @@
 /*
  * drivers/misc/tegra-profiler/comm.c
  *
- * Copyright (c) 2015, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2013-2015, NVIDIA CORPORATION.  All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -54,8 +54,6 @@ struct quadd_comm_ctx {
 	int nr_users;
 
 	int params_ok;
-	pid_t process_pid;
-	uid_t debug_app_uid;
 
 	wait_queue_head_t read_wait;
 
@@ -251,31 +249,6 @@ static struct quadd_comm_data_interface comm_data = {
 	.is_active = is_active,
 };
 
-static int check_access_permission(void)
-{
-	struct task_struct *task;
-
-	if (capable(CAP_SYS_ADMIN))
-		return 0;
-
-	if (!comm_ctx.params_ok || comm_ctx.process_pid == 0)
-		return -EACCES;
-
-	rcu_read_lock();
-	task = pid_task(find_vpid(comm_ctx.process_pid), PIDTYPE_PID);
-	rcu_read_unlock();
-	if (!task)
-		return -EACCES;
-
-	if (current_fsuid() != task_uid(task) &&
-	    task_uid(task) != comm_ctx.debug_app_uid) {
-		pr_err("Permission denied, owner/task uids: %u/%u\n",
-			   current_fsuid(), task_uid(task));
-		return -EACCES;
-	}
-	return 0;
-}
-
 static struct quadd_mmap_area *
 find_mmap(unsigned long vm_start)
 {
@@ -449,17 +422,18 @@ device_ioctl(struct file *file,
 	struct quadd_sections extabs;
 	struct quadd_mmap_rb_info mmap_rb;
 
+	mutex_lock(&comm_ctx.io_mutex);
+
 	if (ioctl_num != IOCTL_SETUP &&
 	    ioctl_num != IOCTL_GET_CAP &&
 	    ioctl_num != IOCTL_GET_STATE &&
 	    ioctl_num != IOCTL_GET_VERSION) {
-		err = check_access_permission();
-		if (err)
-			return err;
+		if (!comm_ctx.params_ok) {
+			err = -EACCES;
+			goto error_out;
+		}
 	}
 
-	mutex_lock(&comm_ctx.io_mutex);
-
 	switch (ioctl_num) {
 	case IOCTL_SETUP:
 		if (atomic_read(&comm_ctx.active)) {
@@ -467,6 +441,7 @@ device_ioctl(struct file *file,
 			err = -EBUSY;
 			goto error_out;
 		}
+		comm_ctx.params_ok = 0;
 
 		user_params = vmalloc(sizeof(*user_params));
 		if (!user_params) {
@@ -482,15 +457,12 @@ device_ioctl(struct file *file,
 			goto error_out;
 		}
 
-		err = comm_ctx.control->set_parameters(user_params,
-						       &comm_ctx.debug_app_uid);
+		err = comm_ctx.control->set_parameters(user_params);
 		if (err) {
 			pr_err("error: setup failed\n");
 			vfree(user_params);
 			goto error_out;
 		}
-		comm_ctx.params_ok = 1;
-		comm_ctx.process_pid = user_params->pids[0];
 
 		if (user_params->reserved[QUADD_PARAM_IDX_SIZE_OF_RB] == 0) {
 			pr_err("error: too old version of daemon\n");
@@ -499,6 +471,8 @@ device_ioctl(struct file *file,
 			goto error_out;
 		}
 
+		comm_ctx.params_ok = 1;
+
 		pr_info("setup success: freq/mafreq: %u/%u, backtrace: %d, pid: %d\n",
 			user_params->freq,
 			user_params->ma_freq,
@@ -550,13 +524,6 @@ device_ioctl(struct file *file,
 
 	case IOCTL_START:
 		if (!atomic_cmpxchg(&comm_ctx.active, 0, 1)) {
-			if (!comm_ctx.params_ok) {
-				pr_err("error: params failed\n");
-				atomic_set(&comm_ctx.active, 0);
-				err = -EFAULT;
-				goto error_out;
-			}
-
 			err = comm_ctx.control->start();
 			if (err) {
 				pr_err("error: start failed\n");
@@ -824,7 +791,6 @@ static int comm_init(void)
 	atomic_set(&comm_ctx.active, 0);
 
 	comm_ctx.params_ok = 0;
-	comm_ctx.process_pid = 0;
 	comm_ctx.nr_users = 0;
 
 	init_waitqueue_head(&comm_ctx.read_wait);
diff --git a/drivers/misc/tegra-profiler/comm.h b/drivers/misc/tegra-profiler/comm.h
index c89acd7db904..d04e04fdcd22 100644
--- a/drivers/misc/tegra-profiler/comm.h
+++ b/drivers/misc/tegra-profiler/comm.h
@@ -1,7 +1,7 @@
 /*
  * drivers/misc/tegra-profiler/comm.h
  *
- * Copyright (c) 2015, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2013-2015, NVIDIA CORPORATION.  All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -54,8 +54,7 @@ struct quadd_mmap_area {
 struct quadd_comm_control_interface {
 	int (*start)(void);
 	void (*stop)(void);
-	int (*set_parameters)(struct quadd_parameters *param,
-			      uid_t *debug_app_uid);
+	int (*set_parameters)(struct quadd_parameters *param);
 	void (*get_capabilities)(struct quadd_comm_cap *cap);
 	void (*get_state)(struct quadd_module_state *state);
 	int (*set_extab)(struct quadd_sections *extabs,
diff --git a/drivers/misc/tegra-profiler/main.c b/drivers/misc/tegra-profiler/main.c
index d3236970e27a..80a2b7317ac9 100644
--- a/drivers/misc/tegra-profiler/main.c
+++ b/drivers/misc/tegra-profiler/main.c
@@ -1,7 +1,7 @@
 /*
  * drivers/misc/tegra-profiler/main.c
  *
- * Copyright (c) 2015, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2013-2015, NVIDIA CORPORATION.  All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -178,9 +178,10 @@ validate_freq(unsigned int freq)
 }
 
 static int
-set_parameters(struct quadd_parameters *p, uid_t *debug_app_uid)
+set_parameters(struct quadd_parameters *p)
 {
 	int i, err, uid = 0;
+	uid_t task_uid, current_uid;
 	int pmu_events_id[QUADD_MAX_COUNTERS];
 	int pl310_events_id;
 	int nr_pmu = 0, nr_pl310 = 0;
@@ -188,54 +189,54 @@ set_parameters(struct quadd_parameters *p, uid_t *debug_app_uid)
 	u64 *low_addr_p;
 
 	if (!validate_freq(p->freq)) {
-		pr_err("%s: incorrect frequency: %u\n", __func__, p->freq);
+		pr_err("error: incorrect frequency: %u\n", p->freq);
 		return -EINVAL;
 	}
 
-	ctx.param = *p;
-
-	for (i = 0; i < ARRAY_SIZE(p->reserved); i++)
-		ctx.param.reserved[i] = p->reserved[i];
-
 	/* Currently only one process */
 	if (p->nr_pids != 1)
 		return -EINVAL;
 
 	p->package_name[sizeof(p->package_name) - 1] = '\0';
 
+	ctx.param = *p;
+
 	rcu_read_lock();
 	task = pid_task(find_vpid(p->pids[0]), PIDTYPE_PID);
 	rcu_read_unlock();
 	if (!task) {
-		pr_err("Process not found: %u\n", p->pids[0]);
+		pr_err("error: process not found: %u\n", p->pids[0]);
 		return -ESRCH;
 	}
 
-	pr_info("owner/task uids: %u/%u\n", current_fsuid(), task_uid(task));
+	current_uid = current_fsuid();
+	task_uid = task_uid(task);
+	pr_info("owner/task uids: %u/%u\n", current_uid, task_uid);
+
 	if (!capable(CAP_SYS_ADMIN)) {
-		if (current_fsuid() != task_uid(task)) {
+		if (current_uid != task_uid) {
+			pr_info("package: %s\n", p->package_name);
+
 			uid = quadd_auth_is_debuggable((char *)p->package_name);
 			if (uid < 0) {
-				pr_err("Error: QuadD security service\n");
+				pr_err("error: tegra profiler security service\n");
 				return uid;
 			} else if (uid == 0) {
-				pr_err("Error: app is not debuggable\n");
+				pr_err("error: app is not debuggable\n");
 				return -EACCES;
 			}
+			pr_info("app is debuggable, uid: %u\n", uid);
 
-			*debug_app_uid = uid;
-			pr_info("debug_app_uid: %u\n", uid);
+			if (task_uid != uid) {
+				pr_err("error: uids are not matched\n");
+				return -EACCES;
+			}
 		}
 		ctx.collect_kernel_ips = 0;
 	} else {
 		ctx.collect_kernel_ips = 1;
 	}
 
-	for (i = 0; i < p->nr_pids; i++)
-		ctx.param.pids[i] = p->pids[i];
-
-	ctx.param.nr_pids = p->nr_pids;
-
 	for (i = 0; i < p->nr_events; i++) {
 		int event = p->events[i];
 
diff --git a/drivers/misc/tegra-profiler/version.h b/drivers/misc/tegra-profiler/version.h
index 53e1e063e6bc..7fdf4c4bfadf 100644
--- a/drivers/misc/tegra-profiler/version.h
+++ b/drivers/misc/tegra-profiler/version.h
@@ -1,7 +1,7 @@
 /*
  * drivers/misc/tegra-profiler/hrt.h
  *
- * Copyright (c) 2015, NVIDIA CORPORATION.  All rights reserved.
+ * Copyright (c) 2013-2015, NVIDIA CORPORATION.  All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
@@ -18,7 +18,7 @@
 #ifndef __QUADD_VERSION_H
 #define __QUADD_VERSION_H
 
-#define QUADD_MODULE_VERSION		"1.101"
+#define QUADD_MODULE_VERSION		"1.102"
 #define QUADD_MODULE_BRANCH		"Dev"
 
 #endif	/* __QUADD_VERSION_H */