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From: Russell Currey <ruscur@russell.cc>
To: linuxppc-dev@lists.ozlabs.org
Cc: mikey@neuling.org, kernel-hardening@lists.openwall.com,
	Russell Currey <ruscur@russell.cc>,
	npiggin@gmail.com
Subject: [PATCH v2 1/3] powerpc/mm/radix: Use KUEP API for Radix MMU
Date: Mon, 10 Dec 2018 18:00:42 +1100	[thread overview]
Message-ID: <20181210070044.27503-2-ruscur@russell.cc> (raw)
In-Reply-To: <20181210070044.27503-1-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        | 11 ++++++++---
 arch/powerpc/platforms/Kconfig.cputype |  1 +
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
index 931156069a81..3565e266994b 100644
--- a/arch/powerpc/mm/pgtable-radix.c
+++ b/arch/powerpc/mm/pgtable-radix.c
@@ -535,8 +535,14 @@ 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;
+
+	pr_warn("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 +550,7 @@ static void radix_init_iamr(void)
 	 */
 	mtspr(SPRN_IAMR, (1ul << 62));
 }
+#endif
 
 void __init radix__early_init_mmu(void)
 {
@@ -605,7 +612,6 @@ 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 +633,6 @@ 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 9997b5ea5693..48cc8df0fdd2 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -335,6 +335,7 @@ 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
-- 
2.19.2


WARNING: multiple messages have this Message-ID (diff)
From: Russell Currey <ruscur@russell.cc>
To: linuxppc-dev@lists.ozlabs.org
Cc: mikey@neuling.org, mpe@ellerman.id.au, benh@kernel.crashing.org,
	npiggin@gmail.com, christophe.leroy@c-s.fr,
	kernel-hardening@lists.openwall.com,
	Russell Currey <ruscur@russell.cc>
Subject: [PATCH v2 1/3] powerpc/mm/radix: Use KUEP API for Radix MMU
Date: Mon, 10 Dec 2018 18:00:42 +1100	[thread overview]
Message-ID: <20181210070044.27503-2-ruscur@russell.cc> (raw)
In-Reply-To: <20181210070044.27503-1-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        | 11 ++++++++---
 arch/powerpc/platforms/Kconfig.cputype |  1 +
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
index 931156069a81..3565e266994b 100644
--- a/arch/powerpc/mm/pgtable-radix.c
+++ b/arch/powerpc/mm/pgtable-radix.c
@@ -535,8 +535,14 @@ 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;
+
+	pr_warn("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 +550,7 @@ static void radix_init_iamr(void)
 	 */
 	mtspr(SPRN_IAMR, (1ul << 62));
 }
+#endif
 
 void __init radix__early_init_mmu(void)
 {
@@ -605,7 +612,6 @@ 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 +633,6 @@ 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 9997b5ea5693..48cc8df0fdd2 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -335,6 +335,7 @@ 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
-- 
2.19.2

  reply	other threads:[~2018-12-10  7:05 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-12-10  7:00 [PATCH v2 0/3] [PATCH v2 0/3] Kernel Userspace Protection for Radix MMU Russell Currey
2018-12-10  7:00 ` Russell Currey
2018-12-10  7:00 ` Russell Currey [this message]
2018-12-10  7:00   ` [PATCH v2 1/3] powerpc/mm/radix: Use KUEP API " Russell Currey
2018-12-10  7:00 ` [PATCH v2 2/3] powerpc/lib: Refactor __patch_instruction() to use __put_user_asm() Russell Currey
2018-12-10  7:00   ` Russell Currey
2018-12-17  7:09   ` Christophe Leroy
2018-12-17  7:09     ` Christophe Leroy
2019-01-25 11:45     ` Christophe Leroy
2019-01-25 11:45       ` Christophe Leroy
2019-02-20 11:57       ` Russell Currey
2019-02-20 11:57         ` Russell Currey
2018-12-10  7:00 ` [PATCH v2 3/3] powerpc/64s: Implement KUAP for Radix MMU Russell Currey
2018-12-10  7:00   ` Russell Currey

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