Revision b5d281f6c16dd432b618bdfd36ddba1a58d5b603 authored by Christian Marangi on 19 June 2022, 22:03:51 UTC, committed by Chanwoo Choi on 29 June 2022, 20:11:17 UTC
On a devfreq PROBE_DEFER, the freq_table in the driver profile struct,
is never reset and may be leaved in an undefined state.

This comes from the fact that we store the freq_table in the driver
profile struct that is commonly defined as static and not reset on
PROBE_DEFER.
We currently skip the reinit of the freq_table if we found
it's already defined since a driver may declare his own freq_table.

This logic is flawed in the case devfreq core generate a freq_table, set
it in the profile struct and then PROBE_DEFER, freeing the freq_table.
In this case devfreq will found a NOT NULL freq_table that has been
freed, skip the freq_table generation and probe the driver based on the
wrong table.

To fix this and correctly handle PROBE_DEFER, use a local freq_table and
max_state in the devfreq struct and never modify the freq_table present
in the profile struct if it does provide it.

Fixes: 0ec09ac2cebe ("PM / devfreq: Set the freq_table of devfreq device")
Cc: stable@vger.kernel.org
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
1 parent f44b799
Raw File
memregion.c
// SPDX-License-Identifier: GPL-2.0-only
/* identifiers for device / performance-differentiated memory regions */
#include <linux/idr.h>
#include <linux/types.h>
#include <linux/memregion.h>

static DEFINE_IDA(memregion_ids);

int memregion_alloc(gfp_t gfp)
{
	return ida_alloc(&memregion_ids, gfp);
}
EXPORT_SYMBOL(memregion_alloc);

void memregion_free(int id)
{
	ida_free(&memregion_ids, id);
}
EXPORT_SYMBOL(memregion_free);
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