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
test_hmm_uapi.h
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/*
 * This is a module to test the HMM (Heterogeneous Memory Management) API
 * of the kernel. It allows a userspace program to expose its entire address
 * space through the HMM test module device file.
 */
#ifndef _LIB_TEST_HMM_UAPI_H
#define _LIB_TEST_HMM_UAPI_H

#include <linux/types.h>
#include <linux/ioctl.h>

/*
 * Structure to pass to the HMM test driver to mimic a device accessing
 * system memory and ZONE_DEVICE private memory through device page tables.
 *
 * @addr: (in) user address the device will read/write
 * @ptr: (in) user address where device data is copied to/from
 * @npages: (in) number of pages to read/write
 * @cpages: (out) number of pages copied
 * @faults: (out) number of device page faults seen
 */
struct hmm_dmirror_cmd {
	__u64		addr;
	__u64		ptr;
	__u64		npages;
	__u64		cpages;
	__u64		faults;
};

/* Expose the address space of the calling process through hmm device file */
#define HMM_DMIRROR_READ		_IOWR('H', 0x00, struct hmm_dmirror_cmd)
#define HMM_DMIRROR_WRITE		_IOWR('H', 0x01, struct hmm_dmirror_cmd)
#define HMM_DMIRROR_MIGRATE		_IOWR('H', 0x02, struct hmm_dmirror_cmd)
#define HMM_DMIRROR_SNAPSHOT		_IOWR('H', 0x03, struct hmm_dmirror_cmd)
#define HMM_DMIRROR_EXCLUSIVE		_IOWR('H', 0x04, struct hmm_dmirror_cmd)
#define HMM_DMIRROR_CHECK_EXCLUSIVE	_IOWR('H', 0x05, struct hmm_dmirror_cmd)

/*
 * Values returned in hmm_dmirror_cmd.ptr for HMM_DMIRROR_SNAPSHOT.
 * HMM_DMIRROR_PROT_ERROR: no valid mirror PTE for this page
 * HMM_DMIRROR_PROT_NONE: unpopulated PTE or PTE with no access
 * HMM_DMIRROR_PROT_READ: read-only PTE
 * HMM_DMIRROR_PROT_WRITE: read/write PTE
 * HMM_DMIRROR_PROT_PMD: PMD sized page is fully mapped by same permissions
 * HMM_DMIRROR_PROT_PUD: PUD sized page is fully mapped by same permissions
 * HMM_DMIRROR_PROT_ZERO: special read-only zero page
 * HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL: Migrated device private page on the
 *					device the ioctl() is made
 * HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE: Migrated device private page on some
 *					other device
 */
enum {
	HMM_DMIRROR_PROT_ERROR			= 0xFF,
	HMM_DMIRROR_PROT_NONE			= 0x00,
	HMM_DMIRROR_PROT_READ			= 0x01,
	HMM_DMIRROR_PROT_WRITE			= 0x02,
	HMM_DMIRROR_PROT_PMD			= 0x04,
	HMM_DMIRROR_PROT_PUD			= 0x08,
	HMM_DMIRROR_PROT_ZERO			= 0x10,
	HMM_DMIRROR_PROT_DEV_PRIVATE_LOCAL	= 0x20,
	HMM_DMIRROR_PROT_DEV_PRIVATE_REMOTE	= 0x30,
};

#endif /* _LIB_TEST_HMM_UAPI_H */
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