msm: kgsl: Compare pid pointer instead of TGID for a new process

There is a possibility of sharing process_private between two unrelated
processes due to PID wrapping. In kgsl_process_private_new(), instead
of checking numeric TGID, compare the unique pid pointer of the current
process with that of the existing processes in kgsl process list to
allow sharing of process_private data judiciously. Also, in all required
functions get TGID/PID of a process from its struct pid.

Change-Id: I0e3d5d79275cdb3f3c304fb36322ad56b0d0b227
Signed-off-by: Archana Sriram <apsrir@codeaurora.org>
Signed-off-by: Kamal Agrawal <kamaagra@codeaurora.org>

9 files changed, 43 insertions, 34 deletions

diff --git a/drivers/gpu/msm/adreno_debugfs.c b/drivers/gpu/msm/adreno_debugfs.c
index 2027ac66f737..201e63f5e9dc 100644
--- a/drivers/gpu/msm/adreno_debugfs.c
+++ b/drivers/gpu/msm/adreno_debugfs.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2002,2008-2017, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2002,2008-2017,2020, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -281,7 +281,7 @@ static int ctx_print(struct seq_file *s, void *unused)
 		   ctx_type_str(drawctxt->type),
 		   drawctxt->base.priority,
 		   drawctxt->base.proc_priv->comm,
-		   drawctxt->base.proc_priv->pid,
+		   pid_nr(drawctxt->base.proc_priv->pid),
 		   drawctxt->base.tid);
 
 	seq_puts(s, "flags: ");
diff --git a/drivers/gpu/msm/adreno_dispatch.c b/drivers/gpu/msm/adreno_dispatch.c
index 49b14fbf439c..3eca9bdcaaf7 100644
--- a/drivers/gpu/msm/adreno_dispatch.c
+++ b/drivers/gpu/msm/adreno_dispatch.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2013-2019, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2013-2020, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -1695,7 +1695,7 @@ static inline const char *_kgsl_context_comm(struct kgsl_context *context)
 #define pr_fault(_d, _c, fmt, args...) \
 		dev_err((_d)->dev, "%s[%d]: " fmt, \
 		_kgsl_context_comm((_c)->context), \
-		(_c)->context->proc_priv->pid, ##args)
+		pid_nr((_c)->context->proc_priv->pid), ##args)
 
 
 static void adreno_fault_header(struct kgsl_device *device,
diff --git a/drivers/gpu/msm/adreno_profile.c b/drivers/gpu/msm/adreno_profile.c
index e756c82287fd..93501d96ef8e 100644
--- a/drivers/gpu/msm/adreno_profile.c
+++ b/drivers/gpu/msm/adreno_profile.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2013-2016, 2018, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2013-2016, 2018,2020, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -168,7 +168,7 @@ static int _build_pre_ib_cmds(struct adreno_device *adreno_dev,
 	ibcmds += _ib_cmd_mem_write(adreno_dev, ibcmds, gpuaddr + data_offset,
 			drawctxt->base.id, &data_offset);
 	ibcmds += _ib_cmd_mem_write(adreno_dev, ibcmds, gpuaddr + data_offset,
-			drawctxt->base.proc_priv->pid, &data_offset);
+			pid_nr(drawctxt->base.proc_priv->pid), &data_offset);
 	ibcmds += _ib_cmd_mem_write(adreno_dev, ibcmds, gpuaddr + data_offset,
 			drawctxt->base.tid, &data_offset);
 	ibcmds += _ib_cmd_mem_write(adreno_dev, ibcmds, gpuaddr + data_offset,
diff --git a/drivers/gpu/msm/kgsl.c b/drivers/gpu/msm/kgsl.c
index e081e579d142..9d9836052158 100644
--- a/drivers/gpu/msm/kgsl.c
+++ b/drivers/gpu/msm/kgsl.c
@@ -540,7 +540,7 @@ int kgsl_context_init(struct kgsl_device_private *dev_priv,
 	if (atomic_read(&proc_priv->ctxt_count) > KGSL_MAX_CONTEXTS_PER_PROC) {
 		KGSL_DRV_ERR_RATELIMIT(device,
 			"Per process context limit reached for pid %u",
-			dev_priv->process_priv->pid);
+			pid_nr(dev_priv->process_priv->pid));
 		spin_unlock(&proc_priv->ctxt_count_lock);
 		return -ENOSPC;
 	}
@@ -865,6 +865,7 @@ static void kgsl_destroy_process_private(struct kref *kref)
 	struct kgsl_process_private *private = container_of(kref,
 			struct kgsl_process_private, refcount);
 
+	put_pid(private->pid);
 	idr_destroy(&private->mem_idr);
 	idr_destroy(&private->syncsource_idr);
 
@@ -895,7 +896,7 @@ struct kgsl_process_private *kgsl_process_private_find(pid_t pid)
 
 	mutex_lock(&kgsl_driver.process_mutex);
 	list_for_each_entry(p, &kgsl_driver.process_list, list) {
-		if (p->pid == pid) {
+		if (pid_nr(p->pid) == pid) {
 			if (kgsl_process_private_get(p))
 				private = p;
 			break;
@@ -909,13 +910,15 @@ static struct kgsl_process_private *kgsl_process_private_new(
 		struct kgsl_device *device)
 {
 	struct kgsl_process_private *private;
-	pid_t tgid = task_tgid_nr(current);
+	struct pid *cur_pid = get_task_pid(current->group_leader, PIDTYPE_PID);
 
 	/* Search in the process list */
 	list_for_each_entry(private, &kgsl_driver.process_list, list) {
-		if (private->pid == tgid) {
-			if (!kgsl_process_private_get(private))
+		if (private->pid == cur_pid) {
+			if (!kgsl_process_private_get(private)) {
+				put_pid(cur_pid);
 				private = ERR_PTR(-EINVAL);
+			}
 			return private;
 		}
 	}
@@ -927,7 +930,7 @@ static struct kgsl_process_private *kgsl_process_private_new(
 
 	kref_init(&private->refcount);
 
-	private->pid = tgid;
+	private->pid = cur_pid;
 	get_task_comm(private->comm, current->group_leader);
 
 	spin_lock_init(&private->mem_lock);
@@ -938,12 +941,14 @@ static struct kgsl_process_private *kgsl_process_private_new(
 	idr_init(&private->syncsource_idr);
 
 	/* Allocate a pagetable for the new process object */
-	private->pagetable = kgsl_mmu_getpagetable(&device->mmu, tgid);
+	private->pagetable = kgsl_mmu_getpagetable(&device->mmu,
+							pid_nr(cur_pid));
 	if (IS_ERR(private->pagetable)) {
 		int err = PTR_ERR(private->pagetable);
 
 		idr_destroy(&private->mem_idr);
 		idr_destroy(&private->syncsource_idr);
+		put_pid(private->pid);
 
 		kfree(private);
 		private = ERR_PTR(err);
@@ -1877,8 +1882,9 @@ static long gpumem_free_entry(struct kgsl_mem_entry *entry)
 	if (entry->memdesc.pagetable != NULL)
 		ptname = entry->memdesc.pagetable->name;
 
-	kgsl_memfree_add(entry->priv->pid, ptname, entry->memdesc.gpuaddr,
-		entry->memdesc.size, entry->memdesc.flags);
+	kgsl_memfree_add(pid_nr(entry->priv->pid), ptname,
+			entry->memdesc.gpuaddr,	entry->memdesc.size,
+			entry->memdesc.flags);
 
 	kgsl_mem_entry_put(entry);
 
@@ -4529,13 +4535,15 @@ kgsl_get_unmapped_area(struct file *file, unsigned long addr,
 		if (IS_ERR_VALUE(val))
 			KGSL_DRV_ERR_RATELIMIT(device,
 				"get_unmapped_area: pid %d addr %lx pgoff %lx len %ld failed error %d\n",
-				private->pid, addr, pgoff, len, (int) val);
+				pid_nr(private->pid), addr,
+				pgoff, len, (int) val);
 	} else {
 		 val = _get_svm_area(private, entry, addr, len, flags);
 		 if (IS_ERR_VALUE(val))
 			KGSL_DRV_ERR_RATELIMIT(device,
 				"_get_svm_area: pid %d mmap_base %lx addr %lx pgoff %lx len %ld failed error %d\n",
-				private->pid, current->mm->mmap_base, addr,
+				pid_nr(private->pid),
+				current->mm->mmap_base, addr,
 				pgoff, len, (int) val);
 	}
 
diff --git a/drivers/gpu/msm/kgsl_debugfs.c b/drivers/gpu/msm/kgsl_debugfs.c
index 592257a332d1..30769de41a70 100644
--- a/drivers/gpu/msm/kgsl_debugfs.c
+++ b/drivers/gpu/msm/kgsl_debugfs.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2002,2008-2017, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2002,2008-2017,2020, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -393,7 +393,7 @@ void kgsl_process_init_debugfs(struct kgsl_process_private *private)
 	unsigned char name[16];
 	struct dentry *dentry;
 
-	snprintf(name, sizeof(name), "%d", private->pid);
+	snprintf(name, sizeof(name), "%d", pid_nr(private->pid));
 
 	private->debug_root = debugfs_create_dir(name, proc_d_debugfs);
 
@@ -413,14 +413,15 @@ void kgsl_process_init_debugfs(struct kgsl_process_private *private)
 	}
 
 	dentry = debugfs_create_file("mem", 0444, private->debug_root,
-		(void *) ((unsigned long) private->pid), &process_mem_fops);
+		(void *) ((unsigned long) pid_nr(private->pid)),
+		&process_mem_fops);
 
 	if (IS_ERR_OR_NULL(dentry))
 		WARN((dentry == NULL),
 			"Unable to create 'mem' file for %s\n", name);
 
 	dentry = debugfs_create_file("sparse_mem", 0444, private->debug_root,
-		(void *) ((unsigned long) private->pid),
+		(void *) ((unsigned long) pid_nr(private->pid)),
 		&process_sparse_mem_fops);
 
 	if (IS_ERR_OR_NULL(dentry))
diff --git a/drivers/gpu/msm/kgsl_device.h b/drivers/gpu/msm/kgsl_device.h
index 0ab6041b3bbd..14852326116c 100644
--- a/drivers/gpu/msm/kgsl_device.h
+++ b/drivers/gpu/msm/kgsl_device.h
@@ -1,4 +1,4 @@
-/* Copyright (c) 2002,2007-2019, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2002,2007-2020, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -405,13 +405,13 @@ struct kgsl_context {
 #define pr_context(_d, _c, fmt, args...) \
 		dev_err((_d)->dev, "%s[%d]: " fmt, \
 		_context_comm((_c)), \
-		(_c)->proc_priv->pid, ##args)
+		pid_nr((_c)->proc_priv->pid), ##args)
 
 /**
  * struct kgsl_process_private -  Private structure for a KGSL process (across
  * all devices)
  * @priv: Internal flags, use KGSL_PROCESS_* values
- * @pid: ID for the task owner of the process
+ * @pid: Identification structure for the task owner of the process
  * @comm: task name of the process
  * @mem_lock: Spinlock to protect the process memory lists
  * @refcount: kref object for reference counting the process
@@ -428,7 +428,7 @@ struct kgsl_context {
  */
 struct kgsl_process_private {
 	unsigned long priv;
-	pid_t pid;
+	struct pid *pid;
 	char comm[TASK_COMM_LEN];
 	spinlock_t mem_lock;
 	struct kref refcount;
diff --git a/drivers/gpu/msm/kgsl_iommu.c b/drivers/gpu/msm/kgsl_iommu.c
index f6ff4658c93b..aff54105474a 100644
--- a/drivers/gpu/msm/kgsl_iommu.c
+++ b/drivers/gpu/msm/kgsl_iommu.c
@@ -692,7 +692,7 @@ static void _get_entries(struct kgsl_process_private *private,
 		prev->flags = p->memdesc.flags;
 		prev->priv = p->memdesc.priv;
 		prev->pending_free = p->pending_free;
-		prev->pid = private->pid;
+		prev->pid = pid_nr(private->pid);
 		__kgsl_get_memory_usage(prev);
 	}
 
@@ -702,7 +702,7 @@ static void _get_entries(struct kgsl_process_private *private,
 		next->flags = n->memdesc.flags;
 		next->priv = n->memdesc.priv;
 		next->pending_free = n->pending_free;
-		next->pid = private->pid;
+		next->pid = pid_nr(private->pid);
 		__kgsl_get_memory_usage(next);
 	}
 }
diff --git a/drivers/gpu/msm/kgsl_sharedmem.c b/drivers/gpu/msm/kgsl_sharedmem.c
index 4c54553e9977..b233211620da 100644
--- a/drivers/gpu/msm/kgsl_sharedmem.c
+++ b/drivers/gpu/msm/kgsl_sharedmem.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2002,2007-2017 The Linux Foundation. All rights reserved.
+/* Copyright (c) 2002,2007-2017,2020, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -202,7 +202,7 @@ void kgsl_process_init_sysfs(struct kgsl_device *device,
 	/* Keep private valid until the sysfs enries are removed. */
 	kgsl_process_private_get(private);
 
-	snprintf(name, sizeof(name), "%d", private->pid);
+	snprintf(name, sizeof(name), "%d", pid_nr(private->pid));
 
 	if (kobject_init_and_add(&private->kobj, &ktype_mem_entry,
 		kgsl_driver.prockobj, name)) {
diff --git a/drivers/gpu/msm/kgsl_trace.h b/drivers/gpu/msm/kgsl_trace.h
index 6438c6e65b97..2d9bca7e7d7f 100644
--- a/drivers/gpu/msm/kgsl_trace.h
+++ b/drivers/gpu/msm/kgsl_trace.h
@@ -1,4 +1,4 @@
-/* Copyright (c) 2011-2016, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2011-2016,2020, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -417,7 +417,7 @@ TRACE_EVENT(kgsl_mem_alloc,
 	TP_fast_assign(
 		__entry->gpuaddr = mem_entry->memdesc.gpuaddr;
 		__entry->size = mem_entry->memdesc.size;
-		__entry->tgid = mem_entry->priv->pid;
+		__entry->tgid = pid_nr(mem_entry->priv->pid);
 		kgsl_get_memory_usage(__entry->usage, sizeof(__entry->usage),
 				     mem_entry->memdesc.flags);
 		__entry->id = mem_entry->id;
@@ -510,7 +510,7 @@ TRACE_EVENT(kgsl_mem_map,
 		__entry->size = mem_entry->memdesc.size;
 		__entry->fd = fd;
 		__entry->type = kgsl_memdesc_usermem_type(&mem_entry->memdesc);
-		__entry->tgid = mem_entry->priv->pid;
+		__entry->tgid = pid_nr(mem_entry->priv->pid);
 		kgsl_get_memory_usage(__entry->usage, sizeof(__entry->usage),
 				     mem_entry->memdesc.flags);
 		__entry->id = mem_entry->id;
@@ -545,7 +545,7 @@ TRACE_EVENT(kgsl_mem_free,
 		__entry->gpuaddr = mem_entry->memdesc.gpuaddr;
 		__entry->size = mem_entry->memdesc.size;
 		__entry->type = kgsl_memdesc_usermem_type(&mem_entry->memdesc);
-		__entry->tgid = mem_entry->priv->pid;
+		__entry->tgid = pid_nr(mem_entry->priv->pid);
 		kgsl_get_memory_usage(__entry->usage, sizeof(__entry->usage),
 				     mem_entry->memdesc.flags);
 		__entry->id = mem_entry->id;
@@ -580,7 +580,7 @@ TRACE_EVENT(kgsl_mem_sync_cache,
 		__entry->gpuaddr = mem_entry->memdesc.gpuaddr;
 		kgsl_get_memory_usage(__entry->usage, sizeof(__entry->usage),
 				     mem_entry->memdesc.flags);
-		__entry->tgid = mem_entry->priv->pid;
+		__entry->tgid = pid_nr(mem_entry->priv->pid);
 		__entry->id = mem_entry->id;
 		__entry->op = op;
 		__entry->offset = offset;