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From: Russell Currey <ruscur@russell.cc>
To: linuxppc-dev@lists.ozlabs.org
Cc: mpe@ellerman.id.au, npiggin@gmail.com, christophe.leroy@c-s.fr,
	kernel-hardening@lists.openwall.com,
	Russell Currey <ruscur@russell.cc>
Subject: [PATCH 5/7] powerpc/mm/radix: Use KUEP API for Radix MMU
Date: Thu, 21 Feb 2019 20:35:59 +1100	[thread overview]
Message-ID: <20190221093601.27920-6-ruscur@russell.cc> (raw)
In-Reply-To: <20190221093601.27920-1-ruscur@russell.cc>

Execution protection already exists on radix, this just refactors
the radix init to provide the KUEP setup function instead.

Thus, the only functional change is that it can now be disabled.

Signed-off-by: Russell Currey <ruscur@russell.cc>
---
 arch/powerpc/mm/pgtable-radix.c        | 12 +++++++++---
 arch/powerpc/platforms/Kconfig.cputype |  1 +
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
index 931156069a81..224bcd4be5ae 100644
--- a/arch/powerpc/mm/pgtable-radix.c
+++ b/arch/powerpc/mm/pgtable-radix.c
@@ -535,8 +535,15 @@ static void radix_init_amor(void)
 	mtspr(SPRN_AMOR, (3ul << 62));
 }
 
-static void radix_init_iamr(void)
+#ifdef CONFIG_PPC_KUEP
+void __init setup_kuep(bool disabled)
 {
+	if (disabled || !early_radix_enabled())
+		return;
+
+	if (smp_processor_id() == boot_cpuid)
+		pr_info("Activating Kernel Userspace Execution Prevention\n");
+
 	/*
 	 * Radix always uses key0 of the IAMR to determine if an access is
 	 * allowed. We set bit 0 (IBM bit 1) of key0, to prevent instruction
@@ -544,6 +551,7 @@ static void radix_init_iamr(void)
 	 */
 	mtspr(SPRN_IAMR, (1ul << 62));
 }
+#endif
 
 void __init radix__early_init_mmu(void)
 {
@@ -605,7 +613,6 @@ void __init radix__early_init_mmu(void)
 
 	memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE);
 
-	radix_init_iamr();
 	radix_init_pgtable();
 	/* Switch to the guard PID before turning on MMU */
 	radix__switch_mmu_context(NULL, &init_mm);
@@ -627,7 +634,6 @@ void radix__early_init_mmu_secondary(void)
 		      __pa(partition_tb) | (PATB_SIZE_SHIFT - 12));
 		radix_init_amor();
 	}
-	radix_init_iamr();
 
 	radix__switch_mmu_context(NULL, &init_mm);
 	if (cpu_has_feature(CPU_FTR_HVMODE))
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 7fa5ddbdce12..25cc7d36b27d 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -320,6 +320,7 @@ config PPC_RADIX_MMU
 	bool "Radix MMU Support"
 	depends on PPC_BOOK3S_64
 	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
+	select PPC_HAVE_KUEP
 	default y
 	help
 	  Enable support for the Power ISA 3.0 Radix style MMU. Currently this
-- 
2.20.1

  parent reply	other threads:[~2019-02-21  9:35 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-21  9:35 [PATCH 0/7] Kernel Userspace Protection for radix Russell Currey
2019-02-21  9:35 ` [PATCH 1/7] powerpc: Add framework for Kernel Userspace Protection Russell Currey
2019-02-21  9:35 ` [PATCH 2/7] powerpc: Add skeleton for Kernel Userspace Execution Prevention Russell Currey
2019-02-21  9:35 ` [PATCH 3/7] powerpc/mm: Add a framework for Kernel Userspace Access Protection Russell Currey
2019-02-21 10:46   ` Christophe Leroy
2019-02-21 14:48     ` Mark Rutland
2019-02-22  0:11       ` Russell Currey
2019-02-21 12:56   ` kbuild test robot
2019-02-21  9:35 ` [PATCH 4/7] powerpc/64: Setup KUP on secondary CPUs Russell Currey
2019-02-21  9:35 ` Russell Currey [this message]
2019-02-21  9:36 ` [PATCH 6/7] powerpc/lib: Refactor __patch_instruction() to use __put_user_asm() Russell Currey
2019-02-21  9:36 ` [PATCH 7/7] powerpc/64s: Implement KUAP for Radix MMU Russell Currey
2019-02-22  5:14   ` Nicholas Piggin
2019-02-21 16:07 ` [PATCH 0/7] Kernel Userspace Protection for radix Kees Cook
2019-02-22  0:09   ` Russell Currey
2019-02-22  0:16     ` Kees Cook
2019-02-22  3:46       ` Michael Ellerman

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