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https://github.com/Divested-Mobile/DivestOS-Build.git
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125 lines
3.7 KiB
Diff
125 lines
3.7 KiB
Diff
From 80decd6365deec08c35ecb902a58f9210599b39a Mon Sep 17 00:00:00 2001
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From: ansharma <ansharma@codeaurora.org>
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Date: Fri, 20 Jan 2017 14:43:57 +0530
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Subject: platform: msm: spmi: Fix possible race condition in debugfs
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There is a possible race condition when debugfs files are concurrently
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accessed by multiple threads. Fix this.
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CRs-Fixed: 1106842
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Change-Id: Ifd092143f428db3cf73c45ec4f0aaa96318ae165
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Signed-off-by: ansharma <ansharma@codeaurora.org>
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---
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drivers/platform/msm/spmi/spmi-dbgfs.c | 37 +++++++++++++++++++++++++---------
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1 file changed, 28 insertions(+), 9 deletions(-)
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diff --git a/drivers/platform/msm/spmi/spmi-dbgfs.c b/drivers/platform/msm/spmi/spmi-dbgfs.c
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index b0a354b..86f1b0d 100644
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--- a/drivers/platform/msm/spmi/spmi-dbgfs.c
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+++ b/drivers/platform/msm/spmi/spmi-dbgfs.c
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@@ -1,4 +1,4 @@
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-/* Copyright (c) 2012-2014, The Linux Foundation. All rights reserved.
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+/* Copyright (c) 2012-2014, 2017, The Linux Foundation. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 and
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@@ -69,6 +69,7 @@ struct spmi_trans {
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u32 addr; /* 20-bit address: SID + PID + Register offset */
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u32 offset; /* Offset of last read data */
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bool raw_data; /* Set to true for raw data dump */
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+ struct mutex spmi_dfs_lock; /* Prevent thread concurrency */
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struct spmi_controller *ctrl;
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struct spmi_log_buffer *log; /* log buffer */
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};
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@@ -168,6 +169,7 @@ static int spmi_dfs_open(struct spmi_ctrl_data *ctrl_data, struct file *file)
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trans->addr = ctrl_data->addr;
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trans->ctrl = ctrl_data->ctrl;
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trans->offset = trans->addr;
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+ mutex_init(&trans->spmi_dfs_lock);
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file->private_data = trans;
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return 0;
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@@ -197,6 +199,7 @@ static int spmi_dfs_close(struct inode *inode, struct file *file)
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if (trans && trans->log) {
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file->private_data = NULL;
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+ mutex_destroy(&trans->spmi_dfs_lock);
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kfree(trans->log);
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kfree(trans);
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}
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@@ -473,14 +476,21 @@ static ssize_t spmi_dfs_reg_write(struct file *file, const char __user *buf,
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int cnt = 0;
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u8 *values;
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size_t ret = 0;
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-
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+ u32 offset;
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+ char *kbuf;
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struct spmi_trans *trans = file->private_data;
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- u32 offset = trans->offset;
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+
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+ mutex_lock(&trans->spmi_dfs_lock);
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+
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+ trans = file->private_data;
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+ offset = trans->offset;
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/* Make a copy of the user data */
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- char *kbuf = kmalloc(count + 1, GFP_KERNEL);
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- if (!kbuf)
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- return -ENOMEM;
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+ kbuf = kmalloc(count + 1, GFP_KERNEL);
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+ if (!kbuf) {
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+ ret = -ENOMEM;
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+ goto unlock_mutex;
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+ }
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ret = copy_from_user(kbuf, buf, count);
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if (ret == count) {
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@@ -517,6 +527,8 @@ static ssize_t spmi_dfs_reg_write(struct file *file, const char __user *buf,
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free_buf:
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kfree(kbuf);
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+unlock_mutex:
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+ mutex_unlock(&trans->spmi_dfs_lock);
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return ret;
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}
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@@ -537,10 +549,13 @@ static ssize_t spmi_dfs_reg_read(struct file *file, char __user *buf,
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size_t ret;
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size_t len;
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+ mutex_lock(&trans->spmi_dfs_lock);
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/* Is the the log buffer empty */
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if (log->rpos >= log->wpos) {
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- if (get_log_data(trans) <= 0)
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- return 0;
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+ if (get_log_data(trans) <= 0) {
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+ len = 0;
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+ goto unlock_mutex;
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+ }
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}
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len = min(count, log->wpos - log->rpos);
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@@ -548,7 +563,8 @@ static ssize_t spmi_dfs_reg_read(struct file *file, char __user *buf,
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ret = copy_to_user(buf, &log->data[log->rpos], len);
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if (ret == len) {
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pr_err("error copy SPMI register values to user\n");
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- return -EFAULT;
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+ len = -EFAULT;
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+ goto unlock_mutex;
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}
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/* 'ret' is the number of bytes not copied */
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@@ -556,6 +572,9 @@ static ssize_t spmi_dfs_reg_read(struct file *file, char __user *buf,
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*ppos += len;
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log->rpos += len;
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+
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+unlock_mutex:
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+ mutex_unlock(&trans->spmi_dfs_lock);
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return len;
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}
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--
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cgit v1.1
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