Commit d10f60ae authored Oct 14, 2019 by Christophe Leroy Committed by Michael Ellerman Oct 17, 2019

powerpc/32s: fix allow/prevent_user_access() when crossing segment boundaries.

Make sure starting addr is aligned to segment boundary so that when
incrementing the segment, the starting address of the new segment is
below the end address. Otherwise the last segment might get missed.

Fixes: a68c31fc ("powerpc/32s: Implement Kernel Userspace Access Protection")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/067a1b09f15f421d40797c2d04c22d4049a1cee8.1571071875.git.christophe.leroy@c-s.fr

parent 2272905a

arch/powerpc/include/asm/book3s/32/kup.h

+1 −0

Original line number	Original line	Diff line number	Diff line
	@@ -91,6 +91,7 @@

	static inline void kuap_update_sr(u32 sr, u32 addr, u32 end)		static inline void kuap_update_sr(u32 sr, u32 addr, u32 end)
	{		{
			addr &= 0xf0000000; /* align addr to start of segment */
	barrier(); /* make sure thread.kuap is updated before playing with SRs */		barrier(); /* make sure thread.kuap is updated before playing with SRs */
	while (addr < end) {		while (addr < end) {
	mtsrin(sr, addr);		mtsrin(sr, addr);