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path: root/drivers/platform/x86/tc1100-wmi.c
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/*
 *  HP Compaq TC1100 Tablet WMI Extras Driver
 *
 *  Copyright (C) 2007 Carlos Corbacho <carlos@strangeworlds.co.uk>
 *  Copyright (C) 2004 Jamey Hicks <jamey.hicks@hp.com>
 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or (at
 *  your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful, but
 *  WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/acpi.h>
#include <linux/platform_device.h>

#define GUID "C364AC71-36DB-495A-8494-B439D472A505"

#define TC1100_INSTANCE_WIRELESS		1
#define TC1100_INSTANCE_JOGDIAL		2

MODULE_AUTHOR("Jamey Hicks, Carlos Corbacho");
MODULE_DESCRIPTION("HP Compaq TC1100 Tablet WMI Extras");
MODULE_LICENSE("GPL");
MODULE_ALIAS("wmi:C364AC71-36DB-495A-8494-B439D472A505");

static struct platform_device *tc1100_device;

struct tc1100_data {
	u32 wireless;
	u32 jogdial;
};

#ifdef CONFIG_PM
static struct tc1100_data suspend_data;
#endif

/* --------------------------------------------------------------------------
				Device Management
   -------------------------------------------------------------------------- */

static int get_state(u32 *out, u8 instance)
{
	u32 tmp;
	acpi_status status;
	struct acpi_buffer result = { ACPI_ALLOCATE_BUFFER, NULL };
	union acpi_object *obj;

	if (!out)
		return -EINVAL;

	if (instance > 2)
		return -ENODEV;

	status = wmi_query_block(GUID, instance, &result);
	if (ACPI_FAILURE(status))
		return -ENODEV;

	obj = (union acpi_object *) result.pointer;
	if (obj && obj->type == ACPI_TYPE_INTEGER) {
		tmp = obj->integer.value;
	} else {
		tmp = 0;
	}

	if (result.length > 0)
		kfree(result.pointer);

	switch (instance) {
	case TC1100_INSTANCE_WIRELESS:
		*out = (tmp == 3) ? 1 : 0;
		return 0;
	case TC1100_INSTANCE_JOGDIAL:
		*out = (tmp == 1) ? 0 : 1;
		return 0;
	default:
		return -ENODEV;
	}
}

static int set_state(u32 *in, u8 instance)
{
	u32 value;
	acpi_status status;
	struct acpi_buffer input;

	if (!in)
		return -EINVAL;

	if (instance > 2)
		return -ENODEV;

	switch (instance) {
	case TC1100_INSTANCE_WIRELESS:
		value = (*in) ? 1 : 2;
		break;
	case TC1100_INSTANCE_JOGDIAL:
		value = (*in) ? 0 : 1;
		break;
	default:
		return -ENODEV;
	}

	input.length = sizeof(u32);
	input.pointer = &value;

	status = wmi_set_block(GUID, instance, &input);
	if (ACPI_FAILURE(status))
		return -ENODEV;

	return 0;
}

/* --------------------------------------------------------------------------
				FS Interface (/sys)
   -------------------------------------------------------------------------- */

/*
 * Read/ write bool sysfs macro
 */
#define show_set_bool(value, instance) \
static ssize_t \
show_bool_##value(struct device *dev, struct device_attribute *attr, \
	char *buf) \
{ \
	u32 result; \
	acpi_status status = get_state(&result, instance); \
	if (ACPI_SUCCESS(status)) \
		return sprintf(buf, "%d\n", result); \
	return sprintf(buf, "Read error\n"); \
} \
\
static ssize_t \
set_bool_##value(struct device *dev, struct device_attribute *attr, \
	const char *buf, size_t count) \
{ \
	u32 tmp = simple_strtoul(buf, NULL, 10); \
	acpi_status status = set_state(&tmp, instance); \
		if (ACPI_FAILURE(status)) \
			return -EINVAL; \
	return count; \
} \
static DEVICE_ATTR(value, S_IRUGO | S_IWUSR, \
	show_bool_##value, set_bool_##value);

show_set_bool(wireless, TC1100_INSTANCE_WIRELESS);
show_set_bool(jogdial, TC1100_INSTANCE_JOGDIAL);

static struct attribute *tc1100_attributes[] = {
	&dev_attr_wireless.attr,
	&dev_attr_jogdial.attr,
	NULL
};

static struct attribute_group tc1100_attribute_group = {
	.attrs	= tc1100_attributes,
};

/* --------------------------------------------------------------------------
				Driver Model
   -------------------------------------------------------------------------- */

static int __init tc1100_probe(struct platform_device *device)
{
	return sysfs_create_group(&device->dev.kobj, &tc1100_attribute_group);
}


static int tc1100_remove(struct platform_device *device)
{
	sysfs_remove_group(&device->dev.kobj, &tc1100_attribute_group);

	return 0;
}

#ifdef CONFIG_PM
static int tc1100_suspend(struct device *dev)
{
	int ret;

	ret = get_state(&suspend_data.wireless, TC1100_INSTANCE_WIRELESS);
	if (ret)
		return ret;

	ret = get_state(&suspend_data.jogdial, TC1100_INSTANCE_JOGDIAL);
	if (ret)
		return ret;

	return 0;
}

static int tc1100_resume(struct device *dev)
{
	int ret;

	ret = set_state(&suspend_data.wireless, TC1100_INSTANCE_WIRELESS);
	if (ret)
		return ret;

	ret = set_state(&suspend_data.jogdial, TC1100_INSTANCE_JOGDIAL);
	if (ret)
		return ret;

	return 0;
}

static const struct dev_pm_ops tc1100_pm_ops = {
	.suspend	= tc1100_suspend,
	.resume		= tc1100_resume,
	.freeze		= tc1100_suspend,
	.restore	= tc1100_resume,
};
#endif

static struct platform_driver tc1100_driver = {
	.driver = {
		.name = "tc1100-wmi",
#ifdef CONFIG_PM
		.pm = &tc1100_pm_ops,
#endif
	},
	.remove = tc1100_remove,
};

static int __init tc1100_init(void)
{
	int error;

	if (!wmi_has_guid(GUID))
		return -ENODEV;

	tc1100_device = platform_device_alloc("tc1100-wmi", -1);
	if (!tc1100_device)
		return -ENOMEM;

	error = platform_device_add(tc1100_device);
	if (error)
		goto err_device_put;

	error = platform_driver_probe(&tc1100_driver, tc1100_probe);
	if (error)
		goto err_device_del;

	pr_info("HP Compaq TC1100 Tablet WMI Extras loaded\n");
	return 0;

 err_device_del:
	platform_device_del(tc1100_device);
 err_device_put:
	platform_device_put(tc1100_device);
	return error;
}

static void __exit tc1100_exit(void)
{
	platform_device_unregister(tc1100_device);
	platform_driver_unregister(&tc1100_driver);
}

module_init(tc1100_init);
module_exit(tc1100_exit);
n> BPF_S_MISC_TXA: case BPF_S_ALU_DIV_K: case BPF_S_LD_MEM: case BPF_S_LDX_MEM: case BPF_S_ST: case BPF_S_STX: case BPF_S_JMP_JA: case BPF_S_JMP_JEQ_K: case BPF_S_JMP_JEQ_X: case BPF_S_JMP_JGE_K: case BPF_S_JMP_JGE_X: case BPF_S_JMP_JGT_K: case BPF_S_JMP_JGT_X: case BPF_S_JMP_JSET_K: case BPF_S_JMP_JSET_X: continue; default: return -EINVAL; } } return 0; } /** * seccomp_run_filters - evaluates all seccomp filters against @syscall * @syscall: number of the current system call * * Returns valid seccomp BPF response codes. */ static u32 seccomp_run_filters(int syscall) { struct seccomp_filter *f; u32 ret = SECCOMP_RET_ALLOW; /* Ensure unexpected behavior doesn't result in failing open. */ if (WARN_ON(current->seccomp.filter == NULL)) return SECCOMP_RET_KILL; /* * All filters in the list are evaluated and the lowest BPF return * value always takes priority (ignoring the DATA). */ for (f = current->seccomp.filter; f; f = f->prev) { u32 cur_ret = sk_run_filter(NULL, f->insns); if ((cur_ret & SECCOMP_RET_ACTION) < (ret & SECCOMP_RET_ACTION)) ret = cur_ret; } return ret; } /** * seccomp_attach_filter: Attaches a seccomp filter to current. * @fprog: BPF program to install * * Returns 0 on success or an errno on failure. */ static long seccomp_attach_filter(struct sock_fprog *fprog) { struct seccomp_filter *filter; unsigned long fp_size = fprog->len * sizeof(struct sock_filter); unsigned long total_insns = fprog->len; long ret; if (fprog->len == 0 || fprog->len > BPF_MAXINSNS) return -EINVAL; for (filter = current->seccomp.filter; filter; filter = filter->prev) total_insns += filter->len + 4; /* include a 4 instr penalty */ if (total_insns > MAX_INSNS_PER_PATH) return -ENOMEM; /* * Installing a seccomp filter requires that the task have * CAP_SYS_ADMIN in its namespace or be running with no_new_privs. * This avoids scenarios where unprivileged tasks can affect the * behavior of privileged children. */ if (!current->no_new_privs && security_capable_noaudit(current_cred(), current_user_ns(), CAP_SYS_ADMIN) != 0) return -EACCES; /* Allocate a new seccomp_filter */ filter = kzalloc(sizeof(struct seccomp_filter) + fp_size, GFP_KERNEL|__GFP_NOWARN); if (!filter) return -ENOMEM; atomic_set(&filter->usage, 1); filter->len = fprog->len; /* Copy the instructions from fprog. */ ret = -EFAULT; if (copy_from_user(filter->insns, fprog->filter, fp_size)) goto fail; /* Check and rewrite the fprog via the skb checker */ ret = sk_chk_filter(filter->insns, filter->len); if (ret) goto fail; /* Check and rewrite the fprog for seccomp use */ ret = seccomp_check_filter(filter->insns, filter->len); if (ret) goto fail; /* * If there is an existing filter, make it the prev and don't drop its * task reference. */ filter->prev = current->seccomp.filter; current->seccomp.filter = filter; return 0; fail: kfree(filter); return ret; } /** * seccomp_attach_user_filter - attaches a user-supplied sock_fprog * @user_filter: pointer to the user data containing a sock_fprog. * * Returns 0 on success and non-zero otherwise. */ long seccomp_attach_user_filter(char __user *user_filter) { struct sock_fprog fprog; long ret = -EFAULT; #ifdef CONFIG_COMPAT if (is_compat_task()) { struct compat_sock_fprog fprog32; if (copy_from_user(&fprog32, user_filter, sizeof(fprog32))) goto out; fprog.len = fprog32.len; fprog.filter = compat_ptr(fprog32.filter); } else /* falls through to the if below. */ #endif if (copy_from_user(&fprog, user_filter, sizeof(fprog))) goto out; ret = seccomp_attach_filter(&fprog); out: return ret; } /* get_seccomp_filter - increments the reference count of the filter on @tsk */ void get_seccomp_filter(struct task_struct *tsk) { struct seccomp_filter *orig = tsk->seccomp.filter; if (!orig) return; /* Reference count is bounded by the number of total processes. */ atomic_inc(&orig->usage); } /* put_seccomp_filter - decrements the ref count of tsk->seccomp.filter */ void put_seccomp_filter(struct task_struct *tsk) { struct seccomp_filter *orig = tsk->seccomp.filter; /* Clean up single-reference branches iteratively. */ while (orig && atomic_dec_and_test(&orig->usage)) { struct seccomp_filter *freeme = orig; orig = orig->prev; kfree(freeme); } } /** * seccomp_send_sigsys - signals the task to allow in-process syscall emulation * @syscall: syscall number to send to userland * @reason: filter-supplied reason code to send to userland (via si_errno) * * Forces a SIGSYS with a code of SYS_SECCOMP and related sigsys info. */ static void seccomp_send_sigsys(int syscall, int reason) { struct siginfo info; memset(&info, 0, sizeof(info)); info.si_signo = SIGSYS; info.si_code = SYS_SECCOMP; info.si_call_addr = (void __user *)KSTK_EIP(current); info.si_errno = reason; info.si_arch = syscall_get_arch(current, task_pt_regs(current)); info.si_syscall = syscall; force_sig_info(SIGSYS, &info, current); } #endif /* CONFIG_SECCOMP_FILTER */ /* * Secure computing mode 1 allows only read/write/exit/sigreturn. * To be fully secure this must be combined with rlimit * to limit the stack allocations too. */ static int mode1_syscalls[] = { __NR_seccomp_read, __NR_seccomp_write, __NR_seccomp_exit, __NR_seccomp_sigreturn, 0, /* null terminated */ }; #ifdef CONFIG_COMPAT static int mode1_syscalls_32[] = { __NR_seccomp_read_32, __NR_seccomp_write_32, __NR_seccomp_exit_32, __NR_seccomp_sigreturn_32, 0, /* null terminated */ }; #endif int __secure_computing(int this_syscall) { int mode = current->seccomp.mode; int exit_sig = 0; int *syscall; u32 ret; switch (mode) { case SECCOMP_MODE_STRICT: syscall = mode1_syscalls; #ifdef CONFIG_COMPAT if (is_compat_task()) syscall = mode1_syscalls_32; #endif do { if (*syscall == this_syscall) return 0; } while (*++syscall); exit_sig = SIGKILL; ret = SECCOMP_RET_KILL; break; #ifdef CONFIG_SECCOMP_FILTER case SECCOMP_MODE_FILTER: { int data; struct pt_regs *regs = task_pt_regs(current); ret = seccomp_run_filters(this_syscall); data = ret & SECCOMP_RET_DATA; ret &= SECCOMP_RET_ACTION; switch (ret) { case SECCOMP_RET_ERRNO: /* Set the low-order 16-bits as a errno. */ syscall_set_return_value(current, regs, -data, 0); goto skip; case SECCOMP_RET_TRAP: /* Show the handler the original registers. */ syscall_rollback(current, regs); /* Let the filter pass back 16 bits of data. */ seccomp_send_sigsys(this_syscall, data); goto skip; case SECCOMP_RET_TRACE: /* Skip these calls if there is no tracer. */ if (!ptrace_event_enabled(current, PTRACE_EVENT_SECCOMP)) { syscall_set_return_value(current, regs, -ENOSYS, 0); goto skip; } /* Allow the BPF to provide the event message */ ptrace_event(PTRACE_EVENT_SECCOMP, data); /* * The delivery of a fatal signal during event * notification may silently skip tracer notification. * Terminating the task now avoids executing a system * call that may not be intended. */ if (fatal_signal_pending(current)) break; if (syscall_get_nr(current, regs) < 0) goto skip; /* Explicit request to skip. */ return 0; case SECCOMP_RET_ALLOW: return 0; case SECCOMP_RET_KILL: default: break; } exit_sig = SIGSYS; break; } #endif default: BUG(); } #ifdef SECCOMP_DEBUG dump_stack(); #endif audit_seccomp(this_syscall, exit_sig, ret); do_exit(exit_sig); #ifdef CONFIG_SECCOMP_FILTER skip: audit_seccomp(this_syscall, exit_sig, ret); #endif return -1; } long prctl_get_seccomp(void) { return current->seccomp.mode; } /** * prctl_set_seccomp: configures current->seccomp.mode * @seccomp_mode: requested mode to use * @filter: optional struct sock_fprog for use with SECCOMP_MODE_FILTER * * This function may be called repeatedly with a @seccomp_mode of * SECCOMP_MODE_FILTER to install additional filters. Every filter * successfully installed will be evaluated (in reverse order) for each system * call the task makes. * * Once current->seccomp.mode is non-zero, it may not be changed. * * Returns 0 on success or -EINVAL on failure. */ long prctl_set_seccomp(unsigned long seccomp_mode, char __user *filter) { long ret = -EINVAL; if (current->seccomp.mode && current->seccomp.mode != seccomp_mode) goto out; switch (seccomp_mode) { case SECCOMP_MODE_STRICT: ret = 0; #ifdef TIF_NOTSC disable_TSC(); #endif break; #ifdef CONFIG_SECCOMP_FILTER case SECCOMP_MODE_FILTER: ret = seccomp_attach_user_filter(filter); if (ret) goto out; break; #endif default: goto out; } current->seccomp.mode = seccomp_mode; set_thread_flag(TIF_SECCOMP); out: return ret; }