From 7486f9b2e96d3f2e77fed0e4ece9f52737d8ba56 Mon Sep 17 00:00:00 2001
From: Aurabindo Pillai <aurabindo.pillai@amd.com>
Date: Tue, 19 May 2020 16:48:43 -0400
Subject: drm/amd/amdkfd: Fix large framesize for kfd_smi_ev_read()
Git-commit: 6e14adea0ac3037d923a9591d1a094c115d7947c
Patch-mainline: v5.9-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322

The buffer allocated is of 1024 bytes. Allocate this from
heap instead of stack.

Also remove check for stack size since we're allocating from heap

Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com>
Tested-by: Amber Lin <Amber.Lin@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/amd/amdkfd/kfd_smi_events.c | 26 +++++++++++++++------
 1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_smi_events.c b/drivers/gpu/drm/amd/amdkfd/kfd_smi_events.c
index bfc9330df987..7b348bf9df21 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_smi_events.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_smi_events.c
@@ -78,9 +78,11 @@ static ssize_t kfd_smi_ev_read(struct file *filep, char __user *user,
 	int ret;
 	size_t to_copy;
 	struct kfd_smi_client *client = filep->private_data;
-	unsigned char buf[MAX_KFIFO_SIZE];
+	unsigned char *buf;
 
-	BUILD_BUG_ON(MAX_KFIFO_SIZE > 1024);
+	buf = kmalloc(MAX_KFIFO_SIZE * sizeof(*buf), GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
 
 	/* kfifo_to_user can sleep so we can't use spinlock protection around
 	 * it. Instead, we kfifo out as spinlocked then copy them to the user.
@@ -89,19 +91,29 @@ static ssize_t kfd_smi_ev_read(struct file *filep, char __user *user,
 	to_copy = kfifo_len(&client->fifo);
 	if (!to_copy) {
 		spin_unlock(&client->lock);
-		return -EAGAIN;
+		ret = -EAGAIN;
+		goto ret_err;
 	}
 	to_copy = min3(size, sizeof(buf), to_copy);
 	ret = kfifo_out(&client->fifo, buf, to_copy);
 	spin_unlock(&client->lock);
-	if (ret <= 0)
-		return -EAGAIN;
+	if (ret <= 0) {
+		ret = -EAGAIN;
+		goto ret_err;
+	}
 
 	ret = copy_to_user(user, buf, to_copy);
-	if (ret)
-		return -EFAULT;
+	if (ret) {
+		ret = -EFAULT;
+		goto ret_err;
+	}
 
+	kfree(buf);
 	return to_copy;
+
+ret_err:
+	kfree(buf);
+	return ret;
 }
 
 static ssize_t kfd_smi_ev_write(struct file *filep, const char __user *user,
-- 
2.29.2