powerpc: Add set_memory_{p/np}() and remove set_memory_attr()
commit f222ab83 upstream. set_memory_attr() was implemented by commit 4d1755b6 ("powerpc/mm: implement set_memory_attr()") because the set_memory_xx() couldn't be used at that time to modify memory "on the fly" as explained it the commit. But set_memory_attr() uses set_pte_at() which leads to warnings when CONFIG_DEBUG_VM is selected, because set_pte_at() is unexpected for updating existing page table entries. The check could be bypassed by using __set_pte_at() instead, as it was the case before commit c988cfd3 ("powerpc/32: use set_memory_attr()") but since commit 9f7853d7 ("powerpc/mm: Fix set_memory_*() against concurrent accesses") it is now possible to use set_memory_xx() functions to update page table entries "on the fly" because the update is now atomic. For DEBUG_PAGEALLOC we need to clear and set back _PAGE_PRESENT. Add set_memory_np() and set_memory_p() for that. Replace all uses of set_memory_attr() by the relevant set_memory_xx() and remove set_memory_attr(). Fixes: c988cfd3 ("powerpc/32: use set_memory_attr()") Cc: stable@vger.kernel.org Reported-by:Maxime Bizon <mbizon@freebox.fr> Signed-off-by:
Christophe Leroy <christophe.leroy@csgroup.eu> Tested-by:
Maxime Bizon <mbizon@freebox.fr> Reviewed-by:
Russell Currey <ruscur@russell.cc> Depends-on: 9f7853d7 ("powerpc/mm: Fix set_memory_*() against concurrent accesses") Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/cda2b44b55c96f9ac69fa92e68c01084ec9495c5.1640344012.git.christophe.leroy@csgroup.eu Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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