Commit 67548622 authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/kuep: Remove 'nosmep' boot time parameter except for book3s/64 



Deactivating KUEP at boot time is unrelevant for PPC32 and BOOK3E/64.

Remove it.

It allows to refactor setup_kuep() via a __weak function
that only PPC64s will overide for now.

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Fix CONFIG_PPC_BOOKS_64 -> CONFIG_PPC_BOOK3S_64 typo]
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4c36df18b41c988c4512f45d96220486adbe4c99.1634627931.git.christophe.leroy@csgroup.eu
parent 70428da9

Documentation/admin-guide/kernel-parameters.txt

+1 −1
Original line number Diff line number Diff line
@@ -3378,7 +3378,7 @@ 
			Disable SMAP (Supervisor Mode Access Prevention)

			even if it is supported by processor.



	nosmep		[X86,PPC]

	nosmep		[X86,PPC64s]

			Disable SMEP (Supervisor Mode Execution Prevention)

			even if it is supported by processor.

arch/powerpc/include/asm/kup.h

+0 −5
Original line number Diff line number Diff line
@@ -33,12 +33,7 @@ extern bool disable_kuap; 
#include <linux/pgtable.h>



void setup_kup(void);



#ifdef CONFIG_PPC_KUEP

void setup_kuep(bool disabled);

#else

static inline void setup_kuep(bool disabled) { }

#endif /* CONFIG_PPC_KUEP */



#ifdef CONFIG_PPC_KUAP

void setup_kuap(bool disabled);

arch/powerpc/mm/book3s32/Makefile

+0 −1
Original line number Diff line number Diff line
@@ -9,5 +9,4 @@ endif 
obj-y += mmu.o mmu_context.o

obj-$(CONFIG_PPC_BOOK3S_603) += nohash_low.o

obj-$(CONFIG_PPC_BOOK3S_604) += hash_low.o tlb.o

obj-$(CONFIG_PPC_KUEP) += kuep.o

obj-$(CONFIG_PPC_KUAP) += kuap.o

arch/powerpc/mm/book3s32/kuep.c

deleted100644 → 0
+0 −13
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-or-later



#include <asm/code-patching.h>

#include <asm/kup.h>

#include <asm/smp.h>



void setup_kuep(bool disabled)

{

	if (smp_processor_id() != boot_cpuid)

		return;



	pr_info("Activating Kernel Userspace Execution Prevention\n");

}

arch/powerpc/mm/init-common.c

+15 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ 
#include <linux/pgtable.h>

#include <asm/pgalloc.h>

#include <asm/kup.h>

#include <asm/smp.h>



phys_addr_t memstart_addr __ro_after_init = (phys_addr_t)~0ull;

EXPORT_SYMBOL_GPL(memstart_addr);
@@ -33,6 +34,9 @@ bool disable_kuap = !IS_ENABLED(CONFIG_PPC_KUAP); 


static int __init parse_nosmep(char *p)

{

	if (!IS_ENABLED(CONFIG_PPC_BOOK3S_64))

		return 0;



	disable_kuep = true;

	pr_warn("Disabling Kernel Userspace Execution Prevention\n");

	return 0;
@@ -47,6 +51,17 @@ static int __init parse_nosmap(char *p) 
}

early_param("nosmap", parse_nosmap);



void __weak setup_kuep(bool disabled)

{

	if (!IS_ENABLED(CONFIG_PPC_KUEP) || disabled)

		return;



	if (smp_processor_id() != boot_cpuid)

		return;



	pr_info("Activating Kernel Userspace Execution Prevention\n");

}



void setup_kup(void)

{

	setup_kuap(disable_kuap);