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Message-Id: <24591ca480d14a62ef910e38a5273d551262c4a2.1622708530.git.christophe.leroy@csgroup.eu>
Date: Thu, 3 Jun 2021 08:41:37 +0000 (UTC)
From: Christophe Leroy <christophe.leroy@...roup.eu>
To: Benjamin Herrenschmidt <benh@...nel.crashing.org>,
Paul Mackerras <paulus@...ba.org>,
Michael Ellerman <mpe@...erman.id.au>
Cc: linux-kernel@...r.kernel.org, linuxppc-dev@...ts.ozlabs.org
Subject: [PATCH v2 02/12] powerpc/32s: Refactor update of user segment
registers
KUEP implements the update of user segment registers.
Move it into mmu-hash.h in order to use it from other places.
And inline kuep_lock() and kuep_unlock(). Inlining kuep_lock() is
important for system_call_exception(), otherwise system_call_exception()
has to save into stack the system call parameters that are used just
after, and doing that takes more instructions than kuep_lock() itself.
Signed-off-by: Christophe Leroy <christophe.leroy@...roup.eu>
---
arch/powerpc/include/asm/book3s/32/kup.h | 21 +++++++++++
arch/powerpc/include/asm/book3s/32/mmu-hash.h | 27 ++++++++++++++
arch/powerpc/include/asm/kup.h | 5 +--
arch/powerpc/mm/book3s32/kuep.c | 37 -------------------
4 files changed, 49 insertions(+), 41 deletions(-)
diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h
index c1f7c2e625a6..83aa0dde50d6 100644
--- a/arch/powerpc/include/asm/book3s/32/kup.h
+++ b/arch/powerpc/include/asm/book3s/32/kup.h
@@ -7,6 +7,27 @@
#ifndef __ASSEMBLY__
+static __always_inline bool kuep_is_disabled(void)
+{
+ return !IS_ENABLED(CONFIG_PPC_KUEP);
+}
+
+static inline void kuep_lock(void)
+{
+ if (kuep_is_disabled())
+ return;
+
+ update_user_segments(mfsr(0) | SR_NX);
+}
+
+static inline void kuep_unlock(void)
+{
+ if (kuep_is_disabled())
+ return;
+
+ update_user_segments(mfsr(0) & ~SR_NX);
+}
+
#ifdef CONFIG_PPC_KUAP
#include <linux/sched.h>
diff --git a/arch/powerpc/include/asm/book3s/32/mmu-hash.h b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
index b85f8e114a9c..cc0284bbac86 100644
--- a/arch/powerpc/include/asm/book3s/32/mmu-hash.h
+++ b/arch/powerpc/include/asm/book3s/32/mmu-hash.h
@@ -102,6 +102,33 @@ extern s32 patch__hash_page_B, patch__hash_page_C;
extern s32 patch__flush_hash_A0, patch__flush_hash_A1, patch__flush_hash_A2;
extern s32 patch__flush_hash_B;
+#include <asm/reg.h>
+#include <asm/task_size_32.h>
+
+#define UPDATE_TWO_USER_SEGMENTS(n) do { \
+ if (TASK_SIZE > ((n) << 28)) \
+ mtsr(val1, (n) << 28); \
+ if (TASK_SIZE > (((n) + 1) << 28)) \
+ mtsr(val2, ((n) + 1) << 28); \
+ val1 = (val1 + 0x222) & 0xf0ffffff; \
+ val2 = (val2 + 0x222) & 0xf0ffffff; \
+} while (0)
+
+static __always_inline void update_user_segments(u32 val)
+{
+ int val1 = val;
+ int val2 = (val + 0x111) & 0xf0ffffff;
+
+ UPDATE_TWO_USER_SEGMENTS(0);
+ UPDATE_TWO_USER_SEGMENTS(2);
+ UPDATE_TWO_USER_SEGMENTS(4);
+ UPDATE_TWO_USER_SEGMENTS(6);
+ UPDATE_TWO_USER_SEGMENTS(8);
+ UPDATE_TWO_USER_SEGMENTS(10);
+ UPDATE_TWO_USER_SEGMENTS(12);
+ UPDATE_TWO_USER_SEGMENTS(14);
+}
+
#endif /* !__ASSEMBLY__ */
/* We happily ignore the smaller BATs on 601, we don't actually use
diff --git a/arch/powerpc/include/asm/kup.h b/arch/powerpc/include/asm/kup.h
index ec96232529ac..4b94d4293777 100644
--- a/arch/powerpc/include/asm/kup.h
+++ b/arch/powerpc/include/asm/kup.h
@@ -46,10 +46,7 @@ void setup_kuep(bool disabled);
static inline void setup_kuep(bool disabled) { }
#endif /* CONFIG_PPC_KUEP */
-#if defined(CONFIG_PPC_KUEP) && defined(CONFIG_PPC_BOOK3S_32)
-void kuep_lock(void);
-void kuep_unlock(void);
-#else
+#ifndef CONFIG_PPC_BOOK3S_32
static inline void kuep_lock(void) { }
static inline void kuep_unlock(void) { }
#endif
diff --git a/arch/powerpc/mm/book3s32/kuep.c b/arch/powerpc/mm/book3s32/kuep.c
index 6eafe7b2b031..919595f47e25 100644
--- a/arch/powerpc/mm/book3s32/kuep.c
+++ b/arch/powerpc/mm/book3s32/kuep.c
@@ -1,43 +1,6 @@
// SPDX-License-Identifier: GPL-2.0-or-later
#include <asm/kup.h>
-#include <asm/reg.h>
-#include <asm/task_size_32.h>
-#include <asm/mmu.h>
-
-#define KUEP_UPDATE_TWO_USER_SEGMENTS(n) do { \
- if (TASK_SIZE > ((n) << 28)) \
- mtsr(val1, (n) << 28); \
- if (TASK_SIZE > (((n) + 1) << 28)) \
- mtsr(val2, ((n) + 1) << 28); \
- val1 = (val1 + 0x222) & 0xf0ffffff; \
- val2 = (val2 + 0x222) & 0xf0ffffff; \
-} while (0)
-
-static __always_inline void kuep_update(u32 val)
-{
- int val1 = val;
- int val2 = (val + 0x111) & 0xf0ffffff;
-
- KUEP_UPDATE_TWO_USER_SEGMENTS(0);
- KUEP_UPDATE_TWO_USER_SEGMENTS(2);
- KUEP_UPDATE_TWO_USER_SEGMENTS(4);
- KUEP_UPDATE_TWO_USER_SEGMENTS(6);
- KUEP_UPDATE_TWO_USER_SEGMENTS(8);
- KUEP_UPDATE_TWO_USER_SEGMENTS(10);
- KUEP_UPDATE_TWO_USER_SEGMENTS(12);
- KUEP_UPDATE_TWO_USER_SEGMENTS(14);
-}
-
-void kuep_lock(void)
-{
- kuep_update(mfsr(0) | SR_NX);
-}
-
-void kuep_unlock(void)
-{
- kuep_update(mfsr(0) & ~SR_NX);
-}
void __init setup_kuep(bool disabled)
{
--
2.25.0
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