From d10f60ae27d26d811e2a1bb39ded47df96d7499f Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Mon, 14 Oct 2019 16:51:28 +0000 Subject: [PATCH] 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: a68c31fc01ef ("powerpc/32s: Implement Kernel Userspace Access Protection") Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/067a1b09f15f421d40797c2d04c22d4049a1cee8.1571071875.git.christophe.leroy@c-s.fr --- arch/powerpc/include/asm/book3s/32/kup.h | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h index 677e9ba..f9dc597 100644 --- a/arch/powerpc/include/asm/book3s/32/kup.h +++ b/arch/powerpc/include/asm/book3s/32/kup.h @@ -91,6 +91,7 @@ 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 */ while (addr < end) { mtsrin(sr, addr); -- 2.7.4