mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-26 01:35:35 +07:00
297d716f62
Change the ownership of power_supply structure from each driver implementing the class to the power supply core. The patch changes power_supply_register() function thus all drivers implementing power supply class are adjusted. Each driver provides the implementation of power supply. However it should not be the owner of power supply class instance because it is exposed by core to other subsystems with power_supply_get_by_name(). These other subsystems have no knowledge when the driver will unregister the power supply. This leads to several issues when driver is unbound - mostly because user of power supply accesses freed memory. Instead let the core own the instance of struct 'power_supply'. Other users of this power supply will still access valid memory because it will be freed when device reference count reaches 0. Currently this means "it will leak" but power_supply_put() call in next patches will solve it. This solves invalid memory references in following race condition scenario: Thread 1: charger manager Thread 2: power supply driver, used by charger manager THREAD 1 (charger manager) THREAD 2 (power supply driver) ========================== ============================== psy = power_supply_get_by_name() Driver unbind, .remove power_supply_unregister() Device fully removed psy->get_property() The 'get_property' call is executed in invalid context because the driver was unbound and struct 'power_supply' memory was freed. This could be observed easily with charger manager driver (here compiled with max17040 fuel gauge): $ cat /sys/devices/virtual/power_supply/cm-battery/capacity & $ echo "1-0036" > /sys/bus/i2c/drivers/max17040/unbind [ 55.725123] Unable to handle kernel NULL pointer dereference at virtual address 00000000 [ 55.732584] pgd = d98d4000 [ 55.734060] [00000000] *pgd=5afa2831, *pte=00000000, *ppte=00000000 [ 55.740318] Internal error: Oops: 80000007 [#1] PREEMPT SMP ARM [ 55.746210] Modules linked in: [ 55.749259] CPU: 1 PID: 2936 Comm: cat Tainted: G W 3.19.0-rc1-next-20141226-00048-gf79f475f3c44-dirty #1496 [ 55.760190] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [ 55.766270] task: d9b76f00 ti: daf54000 task.ti: daf54000 [ 55.771647] PC is at 0x0 [ 55.774182] LR is at charger_get_property+0x2f4/0x36c [ 55.779201] pc : [<00000000>] lr : [<c034b0b4>] psr: 60000013 [ 55.779201] sp : daf55e90 ip : 00000003 fp : 00000000 [ 55.790657] r10: 00000000 r9 : c06e2878 r8 : d9b26c68 [ 55.795865] r7 : dad81610 r6 : daec7410 r5 : daf55ebc r4 : 00000000 [ 55.802367] r3 : 00000000 r2 : daf55ebc r1 : 0000002a r0 : d9b26c68 [ 55.808879] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment user [ 55.815994] Control: 10c5387d Table: 598d406a DAC: 00000015 [ 55.821723] Process cat (pid: 2936, stack limit = 0xdaf54210) [ 55.827451] Stack: (0xdaf55e90 to 0xdaf56000) [ 55.831795] 5e80: 60000013 c01459c4 0000002a c06f8ef8 [ 55.839956] 5ea0: db651000 c06f8ef8 daebac00 c04cb668 daebac08 c0346864 00000000 c01459c4 [ 55.848115] 5ec0: d99eaa80 c06f8ef8 00000fff 00001000 db651000 c027f25c c027f240 d99eaa80 [ 55.856274] 5ee0: d9a06c00 c0146218 daf55f18 00001000 d99eaa80 db4c18c0 00000001 00000001 [ 55.864468] 5f00: daf55f80 c0144c78 c0144c54 c0107f90 00015000 d99eaab0 00000000 00000000 [ 55.872603] 5f20: 000051c7 00000000 db4c18c0 c04a9370 00015000 00001000 daf55f80 00001000 [ 55.880763] 5f40: daf54000 00015000 00000000 c00e53dc db4c18c0 c00e548c 0000000d 00008124 [ 55.888937] 5f60: 00000001 00000000 00000000 db4c18c0 db4c18c0 00001000 00015000 c00e5550 [ 55.897099] 5f80: 00000000 00000000 00001000 00001000 00015000 00000003 00000003 c000f364 [ 55.905239] 5fa0: 00000000 c000f1a0 00001000 00015000 00000003 00015000 00001000 0001333c [ 55.913399] 5fc0: 00001000 00015000 00000003 00000003 00000002 00000000 00000000 00000000 [ 55.921560] 5fe0: 7fffe000 be999850 0000a225 b6f3c19c 60000010 00000003 00000000 00000000 [ 55.929744] [<c034b0b4>] (charger_get_property) from [<c0346864>] (power_supply_show_property+0x48/0x20c) [ 55.939286] [<c0346864>] (power_supply_show_property) from [<c027f25c>] (dev_attr_show+0x1c/0x48) [ 55.948130] [<c027f25c>] (dev_attr_show) from [<c0146218>] (sysfs_kf_seq_show+0x84/0x104) [ 55.956298] [<c0146218>] (sysfs_kf_seq_show) from [<c0144c78>] (kernfs_seq_show+0x24/0x28) [ 55.964536] [<c0144c78>] (kernfs_seq_show) from [<c0107f90>] (seq_read+0x1b0/0x484) [ 55.972172] [<c0107f90>] (seq_read) from [<c00e53dc>] (__vfs_read+0x18/0x4c) [ 55.979188] [<c00e53dc>] (__vfs_read) from [<c00e548c>] (vfs_read+0x7c/0x100) [ 55.986304] [<c00e548c>] (vfs_read) from [<c00e5550>] (SyS_read+0x40/0x8c) [ 55.993164] [<c00e5550>] (SyS_read) from [<c000f1a0>] (ret_fast_syscall+0x0/0x48) [ 56.000626] Code: bad PC value [ 56.011652] ---[ end trace 7b64343fbdae8ef1 ]--- Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> [for the nvec part] Reviewed-by: Marc Dietrich <marvin24@gmx.de> [for compal-laptop.c] Acked-by: Darren Hart <dvhart@linux.intel.com> [for the mfd part] Acked-by: Lee Jones <lee.jones@linaro.org> [for the hid part] Acked-by: Jiri Kosina <jkosina@suse.cz> [for the acpi part] Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Sebastian Reichel <sre@kernel.org>
234 lines
5.3 KiB
C
234 lines
5.3 KiB
C
/*
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* Support for OLPC XO-1.5 System Control Interrupts (SCI)
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*
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* Copyright (C) 2009-2010 One Laptop per Child
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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 as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#include <linux/device.h>
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#include <linux/slab.h>
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#include <linux/workqueue.h>
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#include <linux/power_supply.h>
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#include <linux/olpc-ec.h>
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#include <linux/acpi.h>
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#include <asm/olpc.h>
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#define DRV_NAME "olpc-xo15-sci"
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#define PFX DRV_NAME ": "
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#define XO15_SCI_CLASS DRV_NAME
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#define XO15_SCI_DEVICE_NAME "OLPC XO-1.5 SCI"
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static unsigned long xo15_sci_gpe;
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static bool lid_wake_on_close;
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/*
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* The normal ACPI LID wakeup behavior is wake-on-open, but not
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* wake-on-close. This is implemented as standard by the XO-1.5 DSDT.
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*
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* We provide here a sysfs attribute that will additionally enable
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* wake-on-close behavior. This is useful (e.g.) when we oportunistically
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* suspend with the display running; if the lid is then closed, we want to
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* wake up to turn the display off.
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*
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* This is controlled through a custom method in the XO-1.5 DSDT.
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*/
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static int set_lid_wake_behavior(bool wake_on_close)
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{
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acpi_status status;
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status = acpi_execute_simple_method(NULL, "\\_SB.PCI0.LID.LIDW", wake_on_close);
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if (ACPI_FAILURE(status)) {
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pr_warning(PFX "failed to set lid behavior\n");
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return 1;
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}
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lid_wake_on_close = wake_on_close;
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return 0;
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}
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static ssize_t
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lid_wake_on_close_show(struct kobject *s, struct kobj_attribute *attr, char *buf)
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{
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return sprintf(buf, "%u\n", lid_wake_on_close);
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}
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static ssize_t lid_wake_on_close_store(struct kobject *s,
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struct kobj_attribute *attr,
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const char *buf, size_t n)
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{
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unsigned int val;
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if (sscanf(buf, "%u", &val) != 1)
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return -EINVAL;
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set_lid_wake_behavior(!!val);
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return n;
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}
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static struct kobj_attribute lid_wake_on_close_attr =
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__ATTR(lid_wake_on_close, 0644,
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lid_wake_on_close_show,
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lid_wake_on_close_store);
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static void battery_status_changed(void)
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{
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struct power_supply *psy = power_supply_get_by_name("olpc-battery");
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if (psy) {
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power_supply_changed(psy);
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put_device(&psy->dev);
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}
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}
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static void ac_status_changed(void)
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{
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struct power_supply *psy = power_supply_get_by_name("olpc-ac");
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if (psy) {
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power_supply_changed(psy);
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put_device(&psy->dev);
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}
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}
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static void process_sci_queue(void)
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{
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u16 data;
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int r;
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do {
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r = olpc_ec_sci_query(&data);
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if (r || !data)
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break;
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pr_debug(PFX "SCI 0x%x received\n", data);
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switch (data) {
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case EC_SCI_SRC_BATERR:
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case EC_SCI_SRC_BATSOC:
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case EC_SCI_SRC_BATTERY:
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case EC_SCI_SRC_BATCRIT:
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battery_status_changed();
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break;
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case EC_SCI_SRC_ACPWR:
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ac_status_changed();
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break;
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}
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} while (data);
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if (r)
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pr_err(PFX "Failed to clear SCI queue");
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}
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static void process_sci_queue_work(struct work_struct *work)
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{
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process_sci_queue();
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}
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static DECLARE_WORK(sci_work, process_sci_queue_work);
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static u32 xo15_sci_gpe_handler(acpi_handle gpe_device, u32 gpe, void *context)
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{
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schedule_work(&sci_work);
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return ACPI_INTERRUPT_HANDLED | ACPI_REENABLE_GPE;
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}
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static int xo15_sci_add(struct acpi_device *device)
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{
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unsigned long long tmp;
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acpi_status status;
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int r;
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if (!device)
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return -EINVAL;
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strcpy(acpi_device_name(device), XO15_SCI_DEVICE_NAME);
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strcpy(acpi_device_class(device), XO15_SCI_CLASS);
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/* Get GPE bit assignment (EC events). */
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status = acpi_evaluate_integer(device->handle, "_GPE", NULL, &tmp);
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if (ACPI_FAILURE(status))
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return -EINVAL;
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xo15_sci_gpe = tmp;
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status = acpi_install_gpe_handler(NULL, xo15_sci_gpe,
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ACPI_GPE_EDGE_TRIGGERED,
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xo15_sci_gpe_handler, device);
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if (ACPI_FAILURE(status))
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return -ENODEV;
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dev_info(&device->dev, "Initialized, GPE = 0x%lx\n", xo15_sci_gpe);
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r = sysfs_create_file(&device->dev.kobj, &lid_wake_on_close_attr.attr);
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if (r)
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goto err_sysfs;
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/* Flush queue, and enable all SCI events */
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process_sci_queue();
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olpc_ec_mask_write(EC_SCI_SRC_ALL);
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acpi_enable_gpe(NULL, xo15_sci_gpe);
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/* Enable wake-on-EC */
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if (device->wakeup.flags.valid)
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device_init_wakeup(&device->dev, true);
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return 0;
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err_sysfs:
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acpi_remove_gpe_handler(NULL, xo15_sci_gpe, xo15_sci_gpe_handler);
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cancel_work_sync(&sci_work);
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return r;
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}
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static int xo15_sci_remove(struct acpi_device *device)
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{
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acpi_disable_gpe(NULL, xo15_sci_gpe);
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acpi_remove_gpe_handler(NULL, xo15_sci_gpe, xo15_sci_gpe_handler);
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cancel_work_sync(&sci_work);
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sysfs_remove_file(&device->dev.kobj, &lid_wake_on_close_attr.attr);
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return 0;
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}
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static int xo15_sci_resume(struct device *dev)
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{
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/* Enable all EC events */
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olpc_ec_mask_write(EC_SCI_SRC_ALL);
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/* Power/battery status might have changed */
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battery_status_changed();
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ac_status_changed();
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return 0;
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}
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static SIMPLE_DEV_PM_OPS(xo15_sci_pm, NULL, xo15_sci_resume);
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static const struct acpi_device_id xo15_sci_device_ids[] = {
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{"XO15EC", 0},
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{"", 0},
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};
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static struct acpi_driver xo15_sci_drv = {
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.name = DRV_NAME,
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.class = XO15_SCI_CLASS,
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.ids = xo15_sci_device_ids,
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.ops = {
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.add = xo15_sci_add,
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.remove = xo15_sci_remove,
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},
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.drv.pm = &xo15_sci_pm,
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};
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static int __init xo15_sci_init(void)
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{
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return acpi_bus_register_driver(&xo15_sci_drv);
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}
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device_initcall(xo15_sci_init);
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