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[rtl] Re: Shared memory > 32mb




Was there ever a resolution to the problem described below?   I'm
encountering the exact same problem here.

C. W. Wright


> In my attemps to use shared memory between user and RT task on a 64M
> Pentium, I ran into a problem regarding the base address of the memory
> range.
> When using a base address larger than 32M I got a  segmentation fault
> like following:
> 
> Sep 17 13:21:46 picard kernel: Unable to handle kernel paging request at
> virtual address c3f00000
> Sep 17 13:21:46 picard kernel: current->tss.cr3 = 033d7000, Lr3 =
> 033d7000
> Sep 17 13:21:46 picard kernel: *pde = 00000000
> Sep 17 13:21:46 picard kernel: Oops: 0002
> Sep 17 13:21:46 picard kernel: CPU:    0
> Sep 17 13:21:46 picard kernel: EIP:    0010:[<0403603c>]
> Sep 17 13:21:46 picard kernel: EFLAGS: 00010202
> Sep 17 13:21:46 picard kernel: eax: 00000001   ebx: ffffffff   ecx:
> 040360e4   edx: 00000378
> Sep 17 13:21:46 picard kernel: esi: 7fffffff   edi: 00000000   ebp:
> 02feabc4   esp: 02feabc0
> Sep 17 13:21:46 picard kernel: ds: 0018   es: 0018   fs: 002b   gs:
> 002b   ss: 0018
> Sep 17 13:21:46 picard kernel: Process sshd (pid: 743, process nr: 28,
> stackpage=0319a000)
> Sep 17 13:21:46 picard kernel: Stack: 00000010 040360e4 00000001
> 00000001 00000000 00000000 00000000 00000000
> Sep 17 13:21:46 picard kernel:        00000000 00000000 00000000
> 00000000 00000000 00000000 00000000 00000000
> Sep 17 13:21:46 picard kernel:        00000000 00000000 00000000
> 00000000 00000000 00000000 00000000 00000000
> Sep 17 13:21:46 picard kernel: Call Trace: [<040360e4>]
> Sep 17 13:21:46 picard kernel: Code: a3 00 00 f0 03 e8 ca 12 ff ff eb cc
> 8d 74 26 00 55 89 e5 56
> 
> Does anybody know, whether there is a restriction in principle to use
> only the lower 32M or what else the reason may be ?
> 
> Thank you in advance for your attention and best regards,
> 
> Volker Zahn
> 

--- [rtl] ---
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