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

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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: Christophe Leroy <christophe.leroy@csgroup.eu>
[mpe: Fix CONFIG_PPC_BOOKS_64 -> CONFIG_PPC_BOOK3S_64 typo]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4c36df18b41c988c4512f45d96220486adbe4c99.1634627931.git.christophe.leroy@csgroup.eu
This commit is contained in:
Christophe Leroy 2021-10-19 09:29:19 +02:00 committed by Michael Ellerman
parent 70428da94c
commit 6754862249
7 changed files with 16 additions and 37 deletions
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2
Documentation/admin-guide/kernel-parameters.txt
View File

@ -3378,7 +3378,7 @@
Disable SMAP (Supervisor Mode Access Prevention) Disable SMAP (Supervisor Mode Access Prevention)
even if it is supported by processor. even if it is supported by processor.
nosmep [X86,PPC] nosmep [X86,PPC64s]
Disable SMEP (Supervisor Mode Execution Prevention) Disable SMEP (Supervisor Mode Execution Prevention)
even if it is supported by processor. even if it is supported by processor.

5
arch/powerpc/include/asm/kup.h
View File

@ -33,12 +33,7 @@ extern bool disable_kuap;
#include <linux/pgtable.h> #include <linux/pgtable.h>
void setup_kup(void); void setup_kup(void);
#ifdef CONFIG_PPC_KUEP
void setup_kuep(bool disabled); void setup_kuep(bool disabled);
#else
static inline void setup_kuep(bool disabled) { }
#endif /* CONFIG_PPC_KUEP */
#ifdef CONFIG_PPC_KUAP #ifdef CONFIG_PPC_KUAP
void setup_kuap(bool disabled); void setup_kuap(bool disabled);

1
arch/powerpc/mm/book3s32/Makefile
View File

@ -9,5 +9,4 @@ endif
obj-y += mmu.o mmu_context.o obj-y += mmu.o mmu_context.o
obj-$(CONFIG_PPC_BOOK3S_603) += nohash_low.o obj-$(CONFIG_PPC_BOOK3S_603) += nohash_low.o
obj-$(CONFIG_PPC_BOOK3S_604) += hash_low.o tlb.o obj-$(CONFIG_PPC_BOOK3S_604) += hash_low.o tlb.o
obj-$(CONFIG_PPC_KUEP) += kuep.o
obj-$(CONFIG_PPC_KUAP) += kuap.o obj-$(CONFIG_PPC_KUAP) += kuap.o

13
arch/powerpc/mm/book3s32/kuep.c
View File

@ -1,13 +0,0 @@
// 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");
}

15
arch/powerpc/mm/init-common.c
View File

@ -20,6 +20,7 @@
#include <linux/pgtable.h> #include <linux/pgtable.h>
#include <asm/pgalloc.h> #include <asm/pgalloc.h>
#include <asm/kup.h> #include <asm/kup.h>
#include <asm/smp.h>
phys_addr_t memstart_addr __ro_after_init = (phys_addr_t)~0ull; phys_addr_t memstart_addr __ro_after_init = (phys_addr_t)~0ull;
EXPORT_SYMBOL_GPL(memstart_addr); EXPORT_SYMBOL_GPL(memstart_addr);
@ -33,6 +34,9 @@ bool disable_kuap = !IS_ENABLED(CONFIG_PPC_KUAP);
static int __init parse_nosmep(char *p) static int __init parse_nosmep(char *p)
{ {
if (!IS_ENABLED(CONFIG_PPC_BOOK3S_64))
return 0;
disable_kuep = true; disable_kuep = true;
pr_warn("Disabling Kernel Userspace Execution Prevention\n"); pr_warn("Disabling Kernel Userspace Execution Prevention\n");
return 0; return 0;
@ -47,6 +51,17 @@ static int __init parse_nosmap(char *p)
} }
early_param("nosmap", parse_nosmap); 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) void setup_kup(void)
{ {
setup_kuap(disable_kuap); setup_kuap(disable_kuap);

10
arch/powerpc/mm/nohash/44x.c
View File

@ -240,13 +240,3 @@ void __init mmu_init_secondary(int cpu)
} }
} }
#endif /* CONFIG_SMP */ #endif /* CONFIG_SMP */
#ifdef CONFIG_PPC_KUEP
void setup_kuep(bool disabled)
{
if (smp_processor_id() != boot_cpuid)
return;
pr_info("Activating Kernel Userspace Execution Prevention\n");
}
#endif

7
arch/powerpc/mm/nohash/8xx.c
View File

@ -212,13 +212,6 @@ void __init setup_initial_memory_limit(phys_addr_t first_memblock_base,
memblock_set_current_limit(min_t(u64, first_memblock_size, SZ_32M)); memblock_set_current_limit(min_t(u64, first_memblock_size, SZ_32M));
} }
#ifdef CONFIG_PPC_KUEP
void setup_kuep(bool disabled)
{
pr_info("Activating Kernel Userspace Execution Prevention\n");
}
#endif
#ifdef CONFIG_PPC_KUAP #ifdef CONFIG_PPC_KUAP
struct static_key_false disable_kuap_key; struct static_key_false disable_kuap_key;
EXPORT_SYMBOL(disable_kuap_key); EXPORT_SYMBOL(disable_kuap_key);