Hi all, It's a good idea to clarify some points before announcing Mellanox patch for WDK porting and __ptr64 problems. Hope, these explanations will be informative enough and not so long.
1. __ptr64 problem Briefly speaking, this problem arises when copying 32bit len pointer into 64bit len pointer. In this case, signed pointer extension will take place. How it's applicable to WinOF ? A lot of pointer were declared to be __ptr64 (i.e., to be always "long", even in 32bit kernel systems), that's to preserve on unique size of structs used in IOCTL calls. The main problem it will cause is between 32bit user applications and 64bit kernel application. When user code do operation like s_ptr = &my_struct; my_type* __ptr64 ptr = s_ptr; Than kernel will receive ptr with invalid upper bits data (4 bytes FF). To avoid signed pointer extension, PtrToPtr64() function should be used. Also, I found some other places where dangerous signed pointer extension took place, even on 32bit kernel. Yet another problem that arises with __ptr64 attribute is internal compiler error (C1001) in WDK when using __ptr64 pointer to function (callback) This problem was described in ofw discussion, you can see also : http://blogs.msdn.com/texblog/archive/2005/10/31/487436.aspx http://lists.openfabrics.org/pipermail/ofw/2007-July/001613.html (posted by Jan from OFW) Our solution: 1. Initially, we decided to remove all __ptr64 attributes except those ones inside IOCTL structures. After, put PtrToPtr64() conversion on every assignment to long pointer. (like my_type* __ptr64 ptr = PtrToPtr64(s_ptr); ) During this solution, we changed a huge amount of code, so patch became unreadable. And it was difficult to validate that all long pointer (with __ptr64 attribute) were used in a proper manner 2. So, we decided about another solution: All __ptr64 occurrences were replaced by either: i) TO_LONG_PTR(type, field) macro, when occurred inside structure ii) VOID_PTR64 macro otherwise (defined as void macro) #define CONCAT(str1, str2) str1##str2 #define TO_LONG_PTR(type,member_name) \ union { type member_name; uint64_t CONCAT(member_name,_padding) ; } Thus, we can both preserve on a uniform shapes of structs in user and kernel and to avoid unsafe pointer arithmetic ! The patch now is much more readable, but it sill consist of thousands lines. 2. Migration to WDK Main issue here was to preserve on backward compatibility with DDK We were able to compile our stack with WDK, while the main problems we found were : 1. WDK uses newer version of SDK (SDK Vista). So, when using 2 or more versions of SDK on the same build machine, one has to update PLATFORM_SDK_PATH variable to point on the proper version of SDK (for example, PLATFORM_SDK_PATH=%sysdrive%:\PROGRA~1\MI2578~1\windows\v6.1) 2.verify.src script in WDK (new add-on) checks if your SOURCES file is in appropriate format. For example, you can't set implicitly path to system .dll in TARGETLIBS, but to use USE_<MODULE_NAME> =1 macro Example: Old code : .... TARGETLIBS= \ $(CRT_LIB_PATH)\msvcprt.lib\ $(SDK_LIB_PATH)\Ws2_32.lib\ $(TARGETPATH)\*\mtcr.lib New code : USE_MSVCRT=1 USE_NTDLL=1 TARGETLIBS= \ $(SDK_LIB_PATH)\Ws2_32.lib\ $(TARGETPATH)\*\mtcr.lib 3. Some other problems, like mulitple includes error in .rc files, or problem with substituing more than one symbol constant into string in Makefiles (some version of WDK) Currently, we continue testing and will advertise these patches right after the testing will finish Naslednikov Alexander (a.k.a XaleX) Windows Team Mellanox Technologies -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Smith, Stan Sent: Tuesday, April 08, 2008 4:10 PM To: Ishai Rabinovitz Cc: [email protected] Subject: [ofw] WDK build environment migration thoughts Hello, I strongly believe it would help the WinOF community in transitioning to the WDK build environment if the connectX branch (svn:gen1\branches\ConnectX) was used as a WDK build environment staging grounds prior to merging the WDK modifications into the mainline trunk. This has been talked about before although it still (as of last Friday) does not build using the latest WDK version. One week prior to merging the WDK fixes into the mainline trunk, if you were to push all the WDK fixes into the ConnectX branch and then advertise on the ofw mailing list the availability of a WDK build branch along with 1) how to build in the WDK environment, which version of the WDK is required + a URL link where to get the WDK. 2) An explanation of why and how the __ptr64 attributes were removed along with how others should correct their codes containing __ptr64 attributes. 3) updates to the WinOF wiki page describing how to build in the WDK env. Let this branch exist for one week, receiving feedback from the list and then merge into the mainline trunk. Using this approach is certainly community friendly and may prevent developer surprises. ConnectX branch availability dates plus when the actual WDK fixes would be merged into the mainline trunk would be published beforehand. Thanks for your consideration, Stan. _______________________________________________ ofw mailing list [email protected] http://lists.openfabrics.org/cgi-bin/mailman/listinfo/ofw
_______________________________________________ ofw mailing list [email protected] http://lists.openfabrics.org/cgi-bin/mailman/listinfo/ofw
