Re: [PATCH] drm/amd/amdkfd: Fix large framesize for kfd_smi_ev_read()

On Wed, May 20, 2020 at 9:53 AM Aurabindo Pillai aurabindo.pillai@amd.com wrote:

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: Alex Deucher alexander.deucher@amd.com

---

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 f5fd18eacf0d..5aebe169f8c6 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_smi_events.c +++ b/drivers/gpu/drm/amd/amdkfd/kfd_smi_events.c @@ -77,9 +77,11 @@ 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 = kzalloc(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.
  

@@ -88,19 +90,29 @@ 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,

2.25.1

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