Iam trying to find a way to get the physical addr given the user virtual
addr.
i thought the following would get the virtual to physical mapping but what i
find is current->mm is NULL
all the time.
user program obtains memory using malloc()
addr = malloc(size);
then passes this to a kernel module for translation to physical addr
pgd = pgd_offset(current->mm, addr);
pmd = pmd_offset(pgd, addr);
pte = pte_offset(pmd, addr);
if (pte_present(*pte))
page = pte_page(*pte);
i have seen that always the current->mm is NULL.
I have tried to do the same to a mmap addr returned by the kernel and
passing it back to kernel
for translation. That did not work either.
addr = mmap(...) // driver maps some register set to user space
still i notice that the mm is NULL, i thought that i should probably use
init_mm instead of current->mm since
this is a kernel mm, but still pte_present returns FALSE.
Am i missing something here?
thanks for any help.
Cheers,
ashokr
Plug-and-Play is really nice, unfortunately it only works 50% of the time.
To be specific the "Plug" almost always works.
--unknown source
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Ashok Raj Phone : (503)-677-6928
NGIO Division Fax : (503)-690-4302
Core Software Group email : ashok.raj@intel.com
M/S : CO3-208
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