From 1791ebd131c46539b024c0f2ebf12b6c88a265b9 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Mon, 14 Dec 2020 21:56:16 +1100 Subject: [PATCH] powerpc: Inline setup_kup() setup_kup() is used by both 64-bit and 32-bit code. However on 64-bit it must not be __init, because it's used for CPU hotplug, whereas on 32-bit it should be __init because it calls setup_kuap/kuep() which are __init. We worked around that problem in the past by marking it __ref, see commit 67d53f30e23e ("powerpc/mm: fix section mismatch for setup_kup()"). Marking it __ref basically just omits it from section mismatch checking, which can lead to bugs, and in fact it did, see commit 44b4c4450f8d ("powerpc/64s: Mark the kuap/kuep functions non __init") We can avoid all these problems by just making it static inline. Because all it does is call other functions, making it inline actually shrinks the 32-bit vmlinux by ~76 bytes. Make it __always_inline as pointed out by Christophe. Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201214123011.311024-1-mpe@ellerman.id.au --- arch/powerpc/include/asm/kup.h | 8 ++++++-- arch/powerpc/mm/init-common.c | 6 ------ 2 files changed, 6 insertions(+), 8 deletions(-) diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h index 5a9820c54da92..bf221a2a523e7 100644 --- a/arch/powerpc/include/asm/kup.h +++ b/arch/powerpc/include/asm/kup.h @@ -49,8 +49,6 @@ extern bool disable_kuap; #include -void setup_kup(void); - #ifdef CONFIG_PPC_KUEP void setup_kuep(bool disabled); #else @@ -85,6 +83,12 @@ static inline void restore_user_access(unsigned long flags) { } #endif /* CONFIG_PPC_BOOK3S_64 */ #endif /* CONFIG_PPC_KUAP */ +static __always_inline void setup_kup(void) +{ + setup_kuep(disable_kuep); + setup_kuap(disable_kuap); +} + static inline void allow_read_from_user(const void __user *from, unsigned long size) { allow_user_access(NULL, from, size, KUAP_READ); diff --git a/arch/powerpc/mm/init-common.c b/arch/powerpc/mm/init-common.c index afdebb95bcae1..3a82f89827a51 100644 --- a/arch/powerpc/mm/init-common.c +++ b/arch/powerpc/mm/init-common.c @@ -47,12 +47,6 @@ static int __init parse_nosmap(char *p) } early_param("nosmap", parse_nosmap); -void __ref setup_kup(void) -{ - setup_kuep(disable_kuep); - setup_kuap(disable_kuap); -} - #define CTOR(shift) static void ctor_##shift(void *addr) \ { \ memset(addr, 0, sizeof(void *) << (shift)); \ -- 2.30.2