31062da1b0
3 Commits
| Author | SHA1 | Message | Date | |
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Bill Paul
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9b307fe2be |
This commit makes a bunch of changes, some big, some not so big.
- Remove the old task threads from kern_ndis.c and reimplement them in subr_ntoskrnl.c, in order to more properly emulate the Windows DPC API. Each CPU gets its own DPC queue/thread, and each queue can have low, medium and high importance DPCs. New APIs implemented: KeSetTargetProcessorDpc(), KeSetImportanceDpc() and KeFlushQueuedDpcs(). (This is the biggest change.) - Fix a bug in NdisMInitializeTimer(): the k_dpc pointer in the nmt_timer embedded in the ndis_miniport_timer struct must be set to point to the DPC, also embedded in the struct. Failing to do this breaks dequeueing of DPCs submitted via timers, and in turn breaks cancelling timers. - Fix a bug in KeCancelTimer(): if the timer is interted in the timer queue (i.e. the timeout callback is still pending), we have to both untimeout() the timer _and_ call KeRemoveQueueDpc() to nuke the DPC that might be pending. Failing to do this breaks cancellation of periodic timers, which always appear to be inserted in the timer queue. - Make use of the nmt_nexttimer field in ndis_miniport_timer: keep a queue of pending timers and cancel them all in ndis_halt_nic(), prior to calling MiniportHalt(). Also call KeFlushQueuedDpcs() to make sure any DPCs queued by the timers have expired. - Modify NdisMAllocateSharedMemory() and NdisMFreeSharedMemory() to keep track of both the virtual and physical addresses of the shared memory buffers that get handed out. The AirGo MIMO driver appears to have a bug in it: for one of the segments is allocates, it returns the wrong virtual address. This would confuse NdisMFreeSharedMemory() and cause a crash. Why it doesn't crash Windows too I have no idea (from reading the documentation for NdisMFreeSharedMemory(), it appears to be a violation of the API). - Implement strstr(), strchr() and MmIsAddressValid(). - Implement IoAllocateWorkItem(), IoFreeWorkItem(), IoQueueWorkItem() and ExQueueWorkItem(). (This is the second biggest change.) - Make NdisScheduleWorkItem() call ExQueueWorkItem(). (Note that the ExQueueWorkItem() API is deprecated by Microsoft, but NDIS still uses it, since NdisScheduleWorkItem() is incompatible with the IoXXXWorkItem() API.) - Change if_ndis.c to use the NdisScheduleWorkItem() interface for scheduling tasks. With all these changes and fixes, the AirGo MIMO driver for the Belkin F5D8010 Pre-N card now works. Special thanks to Paul Robinson (paul dawt robinson at pwermedia dawt net) for the loan of a card for testing. |
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Bill Paul
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d02239a3af |
Create new i386 windows/bsd thunking layer, similar to the amd64 thunking
layer, but with a twist. The twist has to do with the fact that Microsoft supports structured exception handling in kernel mode. On the i386 arch, exception handling is implemented by hanging an exception registration list off the Thread Environment Block (TEB), and the TEB is accessed via the %fs register. The problem is, we use %fs as a pointer to the pcpu stucture, which means any driver that tries to write through %fs:0 will overwrite the curthread pointer and make a serious mess of things. To get around this, Project Evil now creates a special entry in the GDT on each processor. When we call into Windows code, a context switch routine will fix up %fs so it points to our new descriptor, which in turn points to a fake TEB. When the Windows code returns, or calls out to an external routine, we swap %fs back again. Currently, Project Evil makes use of GDT slot 7, which is all 0s by default. I fully expect someone to jump up and say I can't do that, but I couldn't find any code that makes use of this entry anywhere. Sadly, this was the only method I could come up with that worked on both UP and SMP. (Modifying the LDT works on UP, but becomes incredibly complicated on SMP.) If necessary, the context switching stuff can be yanked out while preserving the convention calling wrappers. (Fortunately, it looks like Microsoft uses some special epilog/prolog code on amd64 to implement exception handling, so the same nastiness won't be necessary on that arch.) The advantages are: - Any driver that uses %fs as though it were a TEB pointer won't clobber pcpu. - All the __stdcall/__fastcall/__regparm stuff that's specific to gcc goes away. Also, while I'm here, switch NdisGetSystemUpTime() back to using nanouptime() again. It turns out nanouptime() is way more accurate than just using ticks(). On slower machines, the Atheros drivers I tested seem to take a long time to associate due to the loss in accuracy. |
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Bill Paul
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63ba67b69c |
- Correct one aspect of the driver_object/device_object/IRP framework:
when we create a PDO, the driver_object associated with it is that of the parent driver, not the driver we're trying to attach. For example, if we attach a PCI device, the PDO we pass to the NdisAddDevice() function should contain a pointer to fake_pci_driver, not to the NDIS driver itself. For PCI or PCMCIA devices this doesn't matter because the child never needs to talk to the parent bus driver, but for USB, the child needs to be able to send IRPs to the parent USB bus driver, and for that to work the parent USB bus driver has to be hung off the PDO. This involves modifying windrv_lookup() so that we can search for bus drivers by name, if necessary. Our fake bus drivers attach themselves as "PCI Bus," "PCCARD Bus" and "USB Bus," so we can search for them using those names. The individual attachment stubs now create and attach PDOs to the parent bus drivers instead of hanging them off the NDIS driver's object, and in if_ndis.c, we now search for the correct driver object depending on the bus type, and use that to find the correct PDO. With this fix, I can get my sample USB ethernet driver to deliver an IRP to my fake parent USB bus driver's dispatch routines. - Add stub modules for USB support: subr_usbd.c, usbd_var.h and if_ndis_usb.c. The subr_usbd.c module is hooked up the build but currently doesn't do very much. It provides the stub USB parent driver object and a dispatch routine for IRM_MJ_INTERNAL_DEVICE_CONTROL. The only exported function at the moment is USBD_GetUSBDIVersion(). The if_ndis_usb.c stub compiles, but is not hooked up to the build yet. I'm putting these here so I can keep them under source code control as I flesh them out. |