| Message ID | 20190424165955.23718-6-julien.grall@arm.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | xen/arm: Provide a generic function to update Xen PT | expand |
On 24.04.19 19:59, Julien Grall wrote: > Currently, the MFN will be incremented even if it is invalid. This will > result to have a valid MFN after the first iteration. > > While this is not a major problem today, this will be in the future if > the code expect an invalid MFN at every iteration. > > Such behavior is prevented by avoiding to increment an invalid MFN. > > Signed-off-by: Julien Grall <julien.grall@arm.com> Reviewed-by: Andrii Anisov <andrii_anisov@epam.com>
diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c index b61217abd0..eee7122c88 100644 --- a/xen/arch/arm/mm.c +++ b/xen/arch/arm/mm.c @@ -1046,11 +1046,14 @@ static int xen_pt_update(enum xenmap_operation op, spin_lock(&xen_pt_lock); - for(; addr < addr_end; addr += PAGE_SIZE, mfn = mfn_add(mfn, 1)) + for( ; addr < addr_end; addr += PAGE_SIZE ) { rc = xen_pt_update_entry(op, addr, mfn, flags); if ( rc ) break; + + if ( !mfn_eq(mfn, INVALID_MFN) ) + mfn = mfn_add(mfn, 1); } /*
Currently, the MFN will be incremented even if it is invalid. This will result to have a valid MFN after the first iteration. While this is not a major problem today, this will be in the future if the code expect an invalid MFN at every iteration. Such behavior is prevented by avoiding to increment an invalid MFN. Signed-off-by: Julien Grall <julien.grall@arm.com> --- xen/arch/arm/mm.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)