On Tue, Dec 16, 2008 at 04:51:55PM -0500, [email protected] wrote: > Thank you for pointing this out. I can't look at this in detail at the moment, > but what probably should be changed is the part of getSyscallArg that the ISA > provides. It should probably truncate the register values as they're retrieved > for the system call emulation function if it's from a 32 bit application. I'll > try to look at this more closely soon to give you a more definitive answer and > hopefully a patch.
Thanks very much for your response. This fix sounds like the right thing. I'm in no hurry for an official fix, because I have written a temporary hack to fix it, but it will break 64 bit SPARC applications so it's no use to you. However, when you do have time to look at this problem, I think I may have found a related issue. Values *returned* by system calls should *also* be truncated for 32 bit applications, when M5 has been compiled for x86_64. Here, for example, are two instructions that are run immediately after the lseek system call completes. This is a diff of two traces from the same program, one produced on a 64 bit machine (<) and the other produced on a 32 bit machine (>). The system call has left some data in the top 32 bits (in %o0). 60842,60843c60842,60843 < 30466500: system.cpu T0 : @__libc_lseek+40 : mov %o0, %i0 : IntAlu : D=0x00c4c5bc00bcc5c4 < 30467000: system.cpu T0 : @__libc_lseek+48 : add %i0, 0xff, %g1 : IntAlu : D=0x00c4c5bc00bcc6c3 --- > 30466500: system.cpu T0 : @__libc_lseek+40 : mov %o0, %i0 > : IntAlu : D=0x0000000000bcc5c4 > 30467000: system.cpu T0 : @__libc_lseek+48 : add %i0, 0xff, %g1 > : IntAlu : D=0x0000000000bcc6c3 -- Jack Whitham [email protected] _______________________________________________ m5-users mailing list [email protected] http://m5sim.org/cgi-bin/mailman/listinfo/m5-users
