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Commit b89a9575 authored by Ravi Aravamudhan's avatar Ravi Aravamudhan
Browse files

diag: Prevent memory leak when switching from Memory Device Mode 



When diag switches from Memory device mode to any other mode,
buffers are not freed for Local Diag data. This can lead to memory
pool exhaustion resulting in Diag packet drops.

Change-Id: Icfeb00dd6c11091a7b9106fbefcdcc9d028782c8
Signed-off-by: default avatarRavi Aravamudhan <aravamud@codeaurora.org>
parent 72bd72cf

drivers/char/diag/diagchar_core.c

+25 −9
Original line number Diff line number Diff line
@@ -117,6 +117,8 @@ static uint16_t diag_get_next_delayed_rsp_id(void) 
	return rsp_id;

}



static int diag_switch_logging(int requested_mode);



#define COPY_USER_SPACE_OR_EXIT(buf, data, length)		\

do {								\

	if ((count < ret+length) || (copy_to_user(buf,		\
@@ -164,6 +166,20 @@ void check_drain_timer(void) 
	}

}



static void diag_clear_local_tbl(void)

{

	int i;



	for (i = 0; i < driver->buf_tbl_size; i++) {

		if (driver->buf_tbl[i].buf) {

			diagmem_free(driver, (unsigned char *)

				     driver->buf_tbl[i].buf, POOL_TYPE_HDLC);

			driver->buf_tbl[i].buf = 0;

		}

		driver->buf_tbl[i].length = 0;

	}

}



#ifdef CONFIG_DIAGFWD_BRIDGE_CODE

void diag_clear_hsic_tbl(void)

{
@@ -311,15 +327,9 @@ static int diagchar_close(struct inode *inode, struct file *file) 
#ifdef CONFIG_DIAG_OVER_USB

	/* If the SD logging process exits, change logging to USB mode */

	if (driver->logging_process_id == current->tgid) {

		driver->logging_mode = USB_MODE;

		diag_update_proc_vote(DIAG_PROC_MEMORY_DEVICE, VOTE_DOWN,

				      ALL_PROC);

		diagfwd_connect();

#ifdef CONFIG_DIAGFWD_BRIDGE_CODE

		diag_clear_hsic_tbl();

		diagfwd_cancel_hsic(REOPEN_HSIC);

		diagfwd_connect_bridge(0);

#endif

		diag_switch_logging(USB_MODE);

	}

#endif /* DIAG over USB */

	/* Delete the pkt response table entry for the exiting process */
@@ -793,6 +803,7 @@ void diag_cmp_logging_modes_diagfwd_bridge(int old_mode, int new_mode) 
	if (old_mode == MEMORY_DEVICE_MODE && new_mode

					== NO_LOGGING_MODE) {

		diagfwd_disconnect_bridge(0);

		diag_clear_local_tbl();

		diag_clear_hsic_tbl();

	} else if (old_mode == NO_LOGGING_MODE && new_mode

					== MEMORY_DEVICE_MODE) {
@@ -817,6 +828,7 @@ void diag_cmp_logging_modes_diagfwd_bridge(int old_mode, int new_mode) 
		diagfwd_connect_bridge(0);

	} else if (old_mode == MEMORY_DEVICE_MODE && new_mode

					== USB_MODE) {

		diag_clear_local_tbl();

		diag_clear_hsic_tbl();

		diagfwd_cancel_hsic(REOPEN_HSIC);

		diagfwd_connect_bridge(0);
@@ -856,10 +868,12 @@ static int diag_switch_logging(int requested_mode) 
		return 0;

	}



	diag_update_proc_vote(DIAG_PROC_MEMORY_DEVICE, VOTE_UP, ALL_PROC);

	if (requested_mode != MEMORY_DEVICE_MODE)

		diag_update_real_time_vote(DIAG_PROC_MEMORY_DEVICE,

					   MODE_REALTIME, ALL_PROC);

	else

		diag_update_proc_vote(DIAG_PROC_MEMORY_DEVICE, VOTE_UP,

				      ALL_PROC);



	if (!(requested_mode == MEMORY_DEVICE_MODE &&

					driver->logging_mode == USB_MODE))
@@ -871,6 +885,7 @@ static int diag_switch_logging(int requested_mode) 
	driver->logging_mode = requested_mode;



	if (driver->logging_mode == MEMORY_DEVICE_MODE) {

		diag_clear_local_tbl();

		diag_clear_hsic_tbl();

		driver->mask_check = 1;

		if (driver->socket_process) {
@@ -896,13 +911,13 @@ static int diag_switch_logging(int requested_mode) 
	if (driver->logging_mode == UART_MODE ||

				driver->logging_mode == SOCKET_MODE ||

				driver->logging_mode == CALLBACK_MODE) {

		diag_clear_local_tbl();

		diag_clear_hsic_tbl();

		driver->mask_check = 0;

		driver->logging_mode = MEMORY_DEVICE_MODE;

	}



	driver->logging_process_id = current->tgid;

	mutex_unlock(&driver->diagchar_mutex);



	if (temp == MEMORY_DEVICE_MODE && driver->logging_mode

						== NO_LOGGING_MODE) {
@@ -936,6 +951,7 @@ static int diag_switch_logging(int requested_mode) 
		diag_cmp_logging_modes_diagfwd_bridge(temp,

						driver->logging_mode);

	}

	mutex_unlock(&driver->diagchar_mutex);

	success = 1;

	return success;

}