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Revision efb55222d31c8c2af8b4ba42bb56b0b0beedf98e authored by Vladimir Oltean on 30 August 2019, 01:07:21 UTC, committed by David S. Miller on 01 September 2019, 01:45:34 UTC 
taprio: Fix kernel panic in taprio_destroy
 
taprio_init may fail earlier than this line:

	list_add(&q->taprio_list, &taprio_list);

i.e. due to the net device not being multi queue.

Attempting to remove q from the global taprio_list when it is not part
of it will result in a kernel panic.

Fix it by matching list_add and list_del better to one another in the
order of operations. This way we can keep the deletion unconditional
and with lower complexity - O(1).

Cc: Leandro Dorileo <leandro.maciel.dorileo@intel.com>
Fixes: 7b9eba7ba0c1 ("net/sched: taprio: fix picos_per_byte miscalculation")
Signed-off-by: Vladimir Oltean <olteanv@gmail.com>
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent 5f81d54
Raw File
console_64.c 
// SPDX-License-Identifier: GPL-2.0
/* console.c: Routines that deal with sending and receiving IO
 *            to/from the current console device using the PROM.
 *
 * Copyright (C) 1995 David S. Miller (davem@davemloft.net)
 * Copyright (C) 1996,1997 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <asm/openprom.h>
#include <asm/oplib.h>
#include <linux/string.h>

static int __prom_console_write_buf(const char *buf, int len)
{
	unsigned long args[7];
	int ret;

	args[0] = (unsigned long) "write";
	args[1] = 3;
	args[2] = 1;
	args[3] = (unsigned int) prom_stdout;
	args[4] = (unsigned long) buf;
	args[5] = (unsigned int) len;
	args[6] = (unsigned long) -1;

	p1275_cmd_direct(args);

	ret = (int) args[6];
	if (ret < 0)
		return -1;
	return ret;
}

void prom_console_write_buf(const char *buf, int len)
{
	while (len) {
		int n = __prom_console_write_buf(buf, len);
		if (n < 0)
			continue;
		len -= n;
		buf += len;
	}
}
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