freebsd-skq/sys/compat/ndis/subr_hal.c
Rebecca Cran 03225fac13 Fix race condition in KfRaiseIrql().
After getting the current irql, if the kthread gets preempted and
subsequently runs on a different CPU, the saved irql could be wrong.

Also, correct the panic string.

PR:		kern/165630
Submitted by:	Vladislav Movchan <vladislav.movchan at gmail.com>
2012-03-04 17:08:43 +00:00

482 lines
15 KiB
C

/*-
* Copyright (c) 2003
* Bill Paul <wpaul@windriver.com>. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Bill Paul.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL Bill Paul OR THE VOICES IN HIS HEAD
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/types.h>
#include <sys/errno.h>
#include <sys/callout.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/proc.h>
#include <sys/sched.h>
#include <sys/module.h>
#include <sys/systm.h>
#include <machine/bus.h>
#include <sys/bus.h>
#include <sys/rman.h>
#include <compat/ndis/pe_var.h>
#include <compat/ndis/resource_var.h>
#include <compat/ndis/cfg_var.h>
#include <compat/ndis/ntoskrnl_var.h>
#include <compat/ndis/hal_var.h>
static void KeStallExecutionProcessor(uint32_t);
static void WRITE_PORT_BUFFER_ULONG(uint32_t *,
uint32_t *, uint32_t);
static void WRITE_PORT_BUFFER_USHORT(uint16_t *,
uint16_t *, uint32_t);
static void WRITE_PORT_BUFFER_UCHAR(uint8_t *,
uint8_t *, uint32_t);
static void WRITE_PORT_ULONG(uint32_t *, uint32_t);
static void WRITE_PORT_USHORT(uint16_t *, uint16_t);
static void WRITE_PORT_UCHAR(uint8_t *, uint8_t);
static uint32_t READ_PORT_ULONG(uint32_t *);
static uint16_t READ_PORT_USHORT(uint16_t *);
static uint8_t READ_PORT_UCHAR(uint8_t *);
static void READ_PORT_BUFFER_ULONG(uint32_t *,
uint32_t *, uint32_t);
static void READ_PORT_BUFFER_USHORT(uint16_t *,
uint16_t *, uint32_t);
static void READ_PORT_BUFFER_UCHAR(uint8_t *,
uint8_t *, uint32_t);
static uint64_t KeQueryPerformanceCounter(uint64_t *);
static void _KeLowerIrql(uint8_t);
static uint8_t KeRaiseIrqlToDpcLevel(void);
static void dummy (void);
#define NDIS_MAXCPUS 64
static struct mtx disp_lock[NDIS_MAXCPUS];
int
hal_libinit()
{
image_patch_table *patch;
int i;
for (i = 0; i < NDIS_MAXCPUS; i++)
mtx_init(&disp_lock[i], "HAL preemption lock",
"HAL lock", MTX_RECURSE|MTX_DEF);
patch = hal_functbl;
while (patch->ipt_func != NULL) {
windrv_wrap((funcptr)patch->ipt_func,
(funcptr *)&patch->ipt_wrap,
patch->ipt_argcnt, patch->ipt_ftype);
patch++;
}
return (0);
}
int
hal_libfini()
{
image_patch_table *patch;
int i;
for (i = 0; i < NDIS_MAXCPUS; i++)
mtx_destroy(&disp_lock[i]);
patch = hal_functbl;
while (patch->ipt_func != NULL) {
windrv_unwrap(patch->ipt_wrap);
patch++;
}
return (0);
}
static void
KeStallExecutionProcessor(usecs)
uint32_t usecs;
{
DELAY(usecs);
}
static void
WRITE_PORT_ULONG(port, val)
uint32_t *port;
uint32_t val;
{
bus_space_write_4(NDIS_BUS_SPACE_IO, 0x0, (bus_size_t)port, val);
}
static void
WRITE_PORT_USHORT(uint16_t *port, uint16_t val)
{
bus_space_write_2(NDIS_BUS_SPACE_IO, 0x0, (bus_size_t)port, val);
}
static void
WRITE_PORT_UCHAR(uint8_t *port, uint8_t val)
{
bus_space_write_1(NDIS_BUS_SPACE_IO, 0x0, (bus_size_t)port, val);
}
static void
WRITE_PORT_BUFFER_ULONG(port, val, cnt)
uint32_t *port;
uint32_t *val;
uint32_t cnt;
{
bus_space_write_multi_4(NDIS_BUS_SPACE_IO, 0x0,
(bus_size_t)port, val, cnt);
}
static void
WRITE_PORT_BUFFER_USHORT(port, val, cnt)
uint16_t *port;
uint16_t *val;
uint32_t cnt;
{
bus_space_write_multi_2(NDIS_BUS_SPACE_IO, 0x0,
(bus_size_t)port, val, cnt);
}
static void
WRITE_PORT_BUFFER_UCHAR(port, val, cnt)
uint8_t *port;
uint8_t *val;
uint32_t cnt;
{
bus_space_write_multi_1(NDIS_BUS_SPACE_IO, 0x0,
(bus_size_t)port, val, cnt);
}
static uint16_t
READ_PORT_USHORT(port)
uint16_t *port;
{
return (bus_space_read_2(NDIS_BUS_SPACE_IO, 0x0, (bus_size_t)port));
}
static uint32_t
READ_PORT_ULONG(port)
uint32_t *port;
{
return (bus_space_read_4(NDIS_BUS_SPACE_IO, 0x0, (bus_size_t)port));
}
static uint8_t
READ_PORT_UCHAR(port)
uint8_t *port;
{
return (bus_space_read_1(NDIS_BUS_SPACE_IO, 0x0, (bus_size_t)port));
}
static void
READ_PORT_BUFFER_ULONG(port, val, cnt)
uint32_t *port;
uint32_t *val;
uint32_t cnt;
{
bus_space_read_multi_4(NDIS_BUS_SPACE_IO, 0x0,
(bus_size_t)port, val, cnt);
}
static void
READ_PORT_BUFFER_USHORT(port, val, cnt)
uint16_t *port;
uint16_t *val;
uint32_t cnt;
{
bus_space_read_multi_2(NDIS_BUS_SPACE_IO, 0x0,
(bus_size_t)port, val, cnt);
}
static void
READ_PORT_BUFFER_UCHAR(port, val, cnt)
uint8_t *port;
uint8_t *val;
uint32_t cnt;
{
bus_space_read_multi_1(NDIS_BUS_SPACE_IO, 0x0,
(bus_size_t)port, val, cnt);
}
/*
* The spinlock implementation in Windows differs from that of FreeBSD.
* The basic operation of spinlocks involves two steps: 1) spin in a
* tight loop while trying to acquire a lock, 2) after obtaining the
* lock, disable preemption. (Note that on uniprocessor systems, you're
* allowed to skip the first step and just lock out pre-emption, since
* it's not possible for you to be in contention with another running
* thread.) Later, you release the lock then re-enable preemption.
* The difference between Windows and FreeBSD lies in how preemption
* is disabled. In FreeBSD, it's done using critical_enter(), which on
* the x86 arch translates to a cli instruction. This masks off all
* interrupts, and effectively stops the scheduler from ever running
* so _nothing_ can execute except the current thread. In Windows,
* preemption is disabled by raising the processor IRQL to DISPATCH_LEVEL.
* This stops other threads from running, but does _not_ block device
* interrupts. This means ISRs can still run, and they can make other
* threads runable, but those other threads won't be able to execute
* until the current thread lowers the IRQL to something less than
* DISPATCH_LEVEL.
*
* There's another commonly used IRQL in Windows, which is APC_LEVEL.
* An APC is an Asynchronous Procedure Call, which differs from a DPC
* (Defered Procedure Call) in that a DPC is queued up to run in
* another thread, while an APC runs in the thread that scheduled
* it (similar to a signal handler in a UNIX process). We don't
* actually support the notion of APCs in FreeBSD, so for now, the
* only IRQLs we're interested in are DISPATCH_LEVEL and PASSIVE_LEVEL.
*
* To simulate DISPATCH_LEVEL, we raise the current thread's priority
* to PI_REALTIME, which is the highest we can give it. This should,
* if I understand things correctly, prevent anything except for an
* interrupt thread from preempting us. PASSIVE_LEVEL is basically
* everything else.
*
* Be aware that, at least on the x86 arch, the Windows spinlock
* functions are divided up in peculiar ways. The actual spinlock
* functions are KfAcquireSpinLock() and KfReleaseSpinLock(), and
* they live in HAL.dll. Meanwhile, KeInitializeSpinLock(),
* KefAcquireSpinLockAtDpcLevel() and KefReleaseSpinLockFromDpcLevel()
* live in ntoskrnl.exe. Most Windows source code will call
* KeAcquireSpinLock() and KeReleaseSpinLock(), but these are just
* macros that call KfAcquireSpinLock() and KfReleaseSpinLock().
* KefAcquireSpinLockAtDpcLevel() and KefReleaseSpinLockFromDpcLevel()
* perform the lock aquisition/release functions without doing the
* IRQL manipulation, and are used when one is already running at
* DISPATCH_LEVEL. Make sense? Good.
*
* According to the Microsoft documentation, any thread that calls
* KeAcquireSpinLock() must be running at IRQL <= DISPATCH_LEVEL. If
* we detect someone trying to acquire a spinlock from DEVICE_LEVEL
* or HIGH_LEVEL, we panic.
*
* Alternate sleep-lock-based spinlock implementation
* --------------------------------------------------
*
* The earlier spinlock implementation was arguably a bit of a hack
* and presented several problems. It was basically designed to provide
* the functionality of spinlocks without incurring the wrath of
* WITNESS. We could get away with using both our spinlock implementation
* and FreeBSD sleep locks at the same time, but if WITNESS knew what
* we were really up to, it would have spanked us rather severely.
*
* There's another method we can use based entirely on sleep locks.
* First, it's important to realize that everything we're locking
* resides inside Project Evil itself: any critical data being locked
* by drivers belongs to the drivers, and should not be referenced
* by any other OS code outside of the NDISulator. The priority-based
* locking scheme has system-wide effects, just like real spinlocks
* (blocking preemption affects the whole CPU), but since we keep all
* our critical data private, we can use a simpler mechanism that
* affects only code/threads directly related to Project Evil.
*
* The idea is to create a sleep lock mutex for each CPU in the system.
* When a CPU running in the NDISulator wants to acquire a spinlock, it
* does the following:
* - Pin ourselves to the current CPU
* - Acquire the mutex for the current CPU
* - Spin on the spinlock variable using atomic test and set, just like
* a real spinlock.
* - Once we have the lock, we execute our critical code
*
* To give up the lock, we do:
* - Clear the spinlock variable with an atomic op
* - Release the per-CPU mutex
* - Unpin ourselves from the current CPU.
*
* On a uniprocessor system, this means all threads that access protected
* data are serialized through the per-CPU mutex. After one thread
* acquires the 'spinlock,' any other thread that uses a spinlock on the
* current CPU will block on the per-CPU mutex, which has the same general
* effect of blocking pre-emption, but _only_ for those threads that are
* running NDISulator code.
*
* On a multiprocessor system, threads on different CPUs all block on
* their respective per-CPU mutex, and the atomic test/set operation
* on the spinlock variable provides inter-CPU synchronization, though
* only for threads running NDISulator code.
*
* This method solves an important problem. In Windows, you're allowed
* to do an ExAllocatePoolWithTag() with a spinlock held, provided you
* allocate from NonPagedPool. This implies an atomic heap allocation
* that will not cause the current thread to sleep. (You can't sleep
* while holding real spinlock: clowns will eat you.) But in FreeBSD,
* malloc(9) _always_ triggers the acquisition of a sleep lock, even
* when you use M_NOWAIT. This is not a problem for FreeBSD native
* code: you're allowed to sleep in things like interrupt threads. But
* it is a problem with the old priority-based spinlock implementation:
* even though we get away with it most of the time, we really can't
* do a malloc(9) after doing a KeAcquireSpinLock() or KeRaiseIrql().
* With the new implementation, it's not a problem: you're allowed to
* acquire more than one sleep lock (as long as you avoid lock order
* reversals).
*
* The one drawback to this approach is that now we have a lot of
* contention on one per-CPU mutex within the NDISulator code. Whether
* or not this is preferable to the expected Windows spinlock behavior
* of blocking pre-emption is debatable.
*/
uint8_t
KfAcquireSpinLock(lock)
kspin_lock *lock;
{
uint8_t oldirql;
KeRaiseIrql(DISPATCH_LEVEL, &oldirql);
KeAcquireSpinLockAtDpcLevel(lock);
return (oldirql);
}
void
KfReleaseSpinLock(kspin_lock *lock, uint8_t newirql)
{
KeReleaseSpinLockFromDpcLevel(lock);
KeLowerIrql(newirql);
}
uint8_t
KeGetCurrentIrql()
{
if (mtx_owned(&disp_lock[curthread->td_oncpu]))
return (DISPATCH_LEVEL);
return (PASSIVE_LEVEL);
}
static uint64_t
KeQueryPerformanceCounter(freq)
uint64_t *freq;
{
if (freq != NULL)
*freq = hz;
return ((uint64_t)ticks);
}
uint8_t
KfRaiseIrql(uint8_t irql)
{
uint8_t oldirql;
sched_pin();
oldirql = KeGetCurrentIrql();
/* I am so going to hell for this. */
if (oldirql > irql)
panic("IRQL_NOT_LESS_THAN_OR_EQUAL");
if (oldirql != DISPATCH_LEVEL)
mtx_lock(&disp_lock[curthread->td_oncpu]);
else
sched_unpin();
/*printf("RAISE IRQL: %d %d\n", irql, oldirql);*/
return (oldirql);
}
void
KfLowerIrql(uint8_t oldirql)
{
if (oldirql == DISPATCH_LEVEL)
return;
if (KeGetCurrentIrql() != DISPATCH_LEVEL)
panic("IRQL_NOT_GREATER_THAN");
mtx_unlock(&disp_lock[curthread->td_oncpu]);
sched_unpin();
}
static uint8_t
KeRaiseIrqlToDpcLevel(void)
{
uint8_t irql;
KeRaiseIrql(DISPATCH_LEVEL, &irql);
return (irql);
}
static void
_KeLowerIrql(uint8_t oldirql)
{
KeLowerIrql(oldirql);
}
static void dummy()
{
printf("hal dummy called...\n");
}
image_patch_table hal_functbl[] = {
IMPORT_SFUNC(KeStallExecutionProcessor, 1),
IMPORT_SFUNC(WRITE_PORT_ULONG, 2),
IMPORT_SFUNC(WRITE_PORT_USHORT, 2),
IMPORT_SFUNC(WRITE_PORT_UCHAR, 2),
IMPORT_SFUNC(WRITE_PORT_BUFFER_ULONG, 3),
IMPORT_SFUNC(WRITE_PORT_BUFFER_USHORT, 3),
IMPORT_SFUNC(WRITE_PORT_BUFFER_UCHAR, 3),
IMPORT_SFUNC(READ_PORT_ULONG, 1),
IMPORT_SFUNC(READ_PORT_USHORT, 1),
IMPORT_SFUNC(READ_PORT_UCHAR, 1),
IMPORT_SFUNC(READ_PORT_BUFFER_ULONG, 3),
IMPORT_SFUNC(READ_PORT_BUFFER_USHORT, 3),
IMPORT_SFUNC(READ_PORT_BUFFER_UCHAR, 3),
IMPORT_FFUNC(KfAcquireSpinLock, 1),
IMPORT_FFUNC(KfReleaseSpinLock, 1),
IMPORT_SFUNC(KeGetCurrentIrql, 0),
IMPORT_SFUNC(KeQueryPerformanceCounter, 1),
IMPORT_FFUNC(KfLowerIrql, 1),
IMPORT_FFUNC(KfRaiseIrql, 1),
IMPORT_SFUNC(KeRaiseIrqlToDpcLevel, 0),
#undef KeLowerIrql
IMPORT_SFUNC_MAP(KeLowerIrql, _KeLowerIrql, 1),
/*
* This last entry is a catch-all for any function we haven't
* implemented yet. The PE import list patching routine will
* use it for any function that doesn't have an explicit match
* in this table.
*/
{ NULL, (FUNC)dummy, NULL, 0, WINDRV_WRAP_STDCALL },
/* End of list. */
{ NULL, NULL, NULL }
};