From: Nathan_Lynch@mentor•com (Nathan Lynch)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH v2 4/4] remoteproc: debugfs: Add ability to boot remote processor using debugfs
Date: Fri, 28 Aug 2015 10:23:14 -0500 [thread overview]
Message-ID: <55E07CE2.2050704@mentor.com> (raw)
In-Reply-To: <1440757911-9120-5-git-send-email-lee.jones@linaro.org>
On 08/28/2015 05:31 AM, Lee Jones wrote:
> +static ssize_t rproc_state_write(struct file *filp, const char __user *userbuf,
> + size_t count, loff_t *ppos)
> +{
> + struct rproc *rproc = filp->private_data;
> + char buf[2];
> + int ret;
> +
> + ret = copy_from_user(buf, userbuf, 1);
> + if (ret)
> + return -EFAULT;
> +
> + switch (buf[0]) {
> + case '0':
> + rproc_shutdown(rproc);
> + break;
> + case '1':
> + ret = rproc_boot(rproc);
> + if (ret)
> + dev_warn(&rproc->dev, "Boot failed: %d\n", ret);
> + break;
> + default:
> + dev_err(&rproc->dev, "Unrecognised option: %x\n", buf[1]);
> + return -EINVAL;
This prints uninitialized kernel stack contents instead of what was
copied from user space.
Is the dev_err statement really necessary anyway?
> + }
> +
> + return count;
> +}
If rproc_boot fails, that should be reflected in the syscall result.
This interface is essentially exposing the remoteproc->power refcount to
user space; is that okay? Seems like it makes it easy to underflow
remoteproc->power through successive shutdown calls.
The other debugfs interface in remoteproc that has a write method
(recovery) accepts more expressive string commands as opposed to 0/1.
It would be more consistent for this interface to take commands such as
"boot" and "shutdown" IMO.
next prev parent reply other threads:[~2015-08-28 15:23 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-08-28 10:31 [PATCH v2 0/4] remoteproc: Add driver for STMicroelectronics platforms Lee Jones
2015-08-28 10:31 ` [PATCH v2 1/4] ARM: STiH407: Add nodes for RemoteProc Lee Jones
2015-09-01 8:28 ` [STLinux Kernel] " Peter Griffin
2015-09-01 9:11 ` Lee Jones
2015-09-01 9:17 ` Peter Griffin
2015-08-28 10:31 ` [PATCH v2 2/4] remoteproc: dt: Provide bindings for ST's Remote Processor Controller driver Lee Jones
2015-08-31 15:28 ` Rob Herring
2015-09-01 10:41 ` Lee Jones
2015-09-01 11:49 ` Rob Herring
2015-09-01 8:58 ` [STLinux Kernel] " Peter Griffin
2015-09-01 9:14 ` Lee Jones
2015-09-01 12:54 ` Lee Jones
2015-08-28 10:31 ` [PATCH v2 3/4] remoteproc: Supply controller driver for ST's Remote Processors Lee Jones
2015-08-28 16:24 ` Nathan Lynch
2015-09-01 7:55 ` Lee Jones
2015-09-01 8:17 ` [STLinux Kernel] " Peter Griffin
2015-09-01 9:12 ` Lee Jones
2015-08-28 10:31 ` [PATCH v2 4/4] remoteproc: debugfs: Add ability to boot remote processor using debugfs Lee Jones
2015-08-28 15:23 ` Nathan Lynch [this message]
2015-09-01 7:48 ` Lee Jones
2015-08-28 17:17 ` Florian Fainelli
2015-09-01 7:41 ` Lee Jones
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