> > I don't know if that has anything to do with failure.
> The snippet of code that returns failure in vm_fault() is
> the following:
> >
> > if (fs.pindex >= fs.object->size) {
> >
> unlock_and_deallocate(&fs);
> > return
> (KERN_PROTECTION_FAILURE);
> > }
> >
> > Any help would be appreciated.
>
> This might be a bug fixed in r191810, but I am not sure.
>
I tried that fix but it didn't work. What seems to happen is that libm is
mmap'ed beyond the size of the file. From truss o/p, I see the following:
open("/lib/libm.so.5",O_RDONLY,030577200) = 3 (0x3)
fstat(3,{ mode=-r--r--r-- ,inode=918533,size=115560,blksize=4096 }) = 0 (0x0)
read(3,"\^?ELF\^B\^A\^A\t\0\0\0\0\0\0\0"...,4096) = 4096 (0x1000)
mmap(0x0,1155072,PROT_READ|PROT_EXEC,MAP_PRIVATE|MAP_NOCORE,3,0x0) =
34366242816 (0x800634000)
So the size of the file is 115560 but mmap() length is 1155072. The memory map
of the file corresponding to libm as seen from running 'cat /proc/<mypid>/map'
is the following:
0x800634000 0x80064c000 24 0 0xffffff002553eca8 r-x 108 54 0x0 COW NC vnode
/lib/libm.so.5
0x80064c000 0x80064d000 1 0 0xffffff01d79b0a20 r-x 1 0 0x3100 COW NNC vnode
/lib/libm.so.5
0x80064d000 0x80074c000 3 0 0xffffff002553eca8 r-x 108 54 0x0 COW NC vnode
/lib/libm.so.5
0x80074c000 0x80074e000 2 0 0xffffff01d79f1288 rw- 1 0 0x3100 COW NNC vnode
/lib/libm.so.5
when the program tries to fault-in all the pages as part of call to mlockall(),
the following check in vm_fault() fails when trying to fault-in 0x800651000.
if (fs.pindex >= fs.object->size) {
unlock_and_deallocate(&fs);
return (KERN_PROTECTION_FAILURE);
}
since the object size corresponds to size of libm and fault address is one page
beyond the object size. Is this a bug ?
Thanks,
Sushanth
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