From: Alex Shi <alex.shi@linaro.org>
To: Marc Zyngier <marc.zyngier@arm.com>,
Will Deacon <will.deacon@arm.com>,
Ard Biesheuvel <ard.biesheuvel@linaro.org>,
Catalin Marinas <catalin.marinas@arm.com>,
stable@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Cc: James Morse <james.morse@arm.com>,
Kees Cook <keescook@chromium.org>, Alex Shi <alex.shi@linaro.org>
Subject: [PATCH 06/45] arm64: Factor out PAN enabling/disabling into separate uaccess_* macros
Date: Thu, 1 Mar 2018 20:53:43 +0800 [thread overview]
Message-ID: <1519908862-11425-7-git-send-email-alex.shi@linaro.org> (raw)
In-Reply-To: <1519908862-11425-1-git-send-email-alex.shi@linaro.org>
From: Catalin Marinas <catalin.marinas@arm.com>
commit bd38967d406 upstream.
This patch moves the directly coded alternatives for turning PAN on/off
into separate uaccess_{enable,disable} macros or functions. The asm
macros take a few arguments which will be used in subsequent patches.
Note that any (unlikely) access that the compiler might generate between
uaccess_enable() and uaccess_disable(), other than those explicitly
specified by the user access code, will not be protected by PAN.
Cc: Will Deacon <will.deacon@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Alex Shi <alex.shi@linaro.org>
---
arch/arm64/include/asm/futex.h | 17 ++++----
arch/arm64/include/asm/uaccess.h | 79 +++++++++++++++++++++++++++++++-----
arch/arm64/kernel/armv8_deprecated.c | 11 +++--
arch/arm64/lib/clear_user.S | 11 ++---
arch/arm64/lib/copy_from_user.S | 11 ++---
arch/arm64/lib/copy_in_user.S | 11 ++---
arch/arm64/lib/copy_to_user.S | 11 ++---
7 files changed, 93 insertions(+), 58 deletions(-)
diff --git a/arch/arm64/include/asm/futex.h b/arch/arm64/include/asm/futex.h
index f2585cd..85c4a89 100644
--- a/arch/arm64/include/asm/futex.h
+++ b/arch/arm64/include/asm/futex.h
@@ -21,15 +21,12 @@
#include <linux/futex.h>
#include <linux/uaccess.h>
-#include <asm/alternative.h>
-#include <asm/cpufeature.h>
#include <asm/errno.h>
-#include <asm/sysreg.h>
#define __futex_atomic_op(insn, ret, oldval, uaddr, tmp, oparg) \
+do { \
+ uaccess_enable(); \
asm volatile( \
- ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_HAS_PAN, \
- CONFIG_ARM64_PAN) \
" prfm pstl1strm, %2\n" \
"1: ldxr %w1, %2\n" \
insn "\n" \
@@ -44,11 +41,11 @@
" .popsection\n" \
_ASM_EXTABLE(1b, 4b) \
_ASM_EXTABLE(2b, 4b) \
- ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_HAS_PAN, \
- CONFIG_ARM64_PAN) \
: "=&r" (ret), "=&r" (oldval), "+Q" (*uaddr), "=&r" (tmp) \
: "r" (oparg), "Ir" (-EFAULT) \
- : "memory")
+ : "memory"); \
+ uaccess_disable(); \
+} while (0)
static inline int
futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
@@ -118,8 +115,8 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
return -EFAULT;
+ uaccess_enable();
asm volatile("// futex_atomic_cmpxchg_inatomic\n"
-ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_HAS_PAN, CONFIG_ARM64_PAN)
" prfm pstl1strm, %2\n"
"1: ldxr %w1, %2\n"
" sub %w3, %w1, %w4\n"
@@ -134,10 +131,10 @@ ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_HAS_PAN, CONFIG_ARM64_PAN)
" .popsection\n"
_ASM_EXTABLE(1b, 4b)
_ASM_EXTABLE(2b, 4b)
-ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_HAS_PAN, CONFIG_ARM64_PAN)
: "+r" (ret), "=&r" (val), "+Q" (*uaddr), "=&r" (tmp)
: "r" (oldval), "r" (newval), "Ir" (-EFAULT)
: "memory");
+ uaccess_disable();
*uval = val;
return ret;
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 811cf16..94e1457 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -18,6 +18,11 @@
#ifndef __ASM_UACCESS_H
#define __ASM_UACCESS_H
+#include <asm/alternative.h>
+#include <asm/sysreg.h>
+
+#ifndef __ASSEMBLY__
+
/*
* User space memory access functions
*/
@@ -26,10 +31,8 @@
#include <linux/string.h>
#include <linux/thread_info.h>
-#include <asm/alternative.h>
#include <asm/cpufeature.h>
#include <asm/ptrace.h>
-#include <asm/sysreg.h>
#include <asm/errno.h>
#include <asm/memory.h>
#include <asm/compiler.h>
@@ -121,6 +124,44 @@ static inline void set_fs(mm_segment_t fs)
" .popsection\n"
/*
+ * User access enabling/disabling.
+ */
+#define __uaccess_disable(alt) \
+do { \
+ asm(ALTERNATIVE("nop", SET_PSTATE_PAN(1), alt, \
+ CONFIG_ARM64_PAN)); \
+} while (0)
+
+#define __uaccess_enable(alt) \
+do { \
+ asm(ALTERNATIVE("nop", SET_PSTATE_PAN(0), alt, \
+ CONFIG_ARM64_PAN)); \
+} while (0)
+
+static inline void uaccess_disable(void)
+{
+ __uaccess_disable(ARM64_HAS_PAN);
+}
+
+static inline void uaccess_enable(void)
+{
+ __uaccess_enable(ARM64_HAS_PAN);
+}
+
+/*
+ * These functions are no-ops when UAO is present.
+ */
+static inline void uaccess_disable_not_uao(void)
+{
+ __uaccess_disable(ARM64_ALT_PAN_NOT_UAO);
+}
+
+static inline void uaccess_enable_not_uao(void)
+{
+ __uaccess_enable(ARM64_ALT_PAN_NOT_UAO);
+}
+
+/*
* The "__xxx" versions of the user access functions do not verify the address
* space - it must have been done previously with a separate "access_ok()"
* call.
@@ -147,8 +188,7 @@ static inline void set_fs(mm_segment_t fs)
do { \
unsigned long __gu_val; \
__chk_user_ptr(ptr); \
- asm(ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_ALT_PAN_NOT_UAO,\
- CONFIG_ARM64_PAN)); \
+ uaccess_enable_not_uao(); \
switch (sizeof(*(ptr))) { \
case 1: \
__get_user_asm("ldrb", "ldtrb", "%w", __gu_val, (ptr), \
@@ -169,9 +209,8 @@ do { \
default: \
BUILD_BUG(); \
} \
+ uaccess_disable_not_uao(); \
(x) = (__force __typeof__(*(ptr)))__gu_val; \
- asm(ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_ALT_PAN_NOT_UAO,\
- CONFIG_ARM64_PAN)); \
} while (0)
#define __get_user(x, ptr) \
@@ -216,8 +255,7 @@ do { \
do { \
__typeof__(*(ptr)) __pu_val = (x); \
__chk_user_ptr(ptr); \
- asm(ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_ALT_PAN_NOT_UAO,\
- CONFIG_ARM64_PAN)); \
+ uaccess_enable_not_uao(); \
switch (sizeof(*(ptr))) { \
case 1: \
__put_user_asm("strb", "sttrb", "%w", __pu_val, (ptr), \
@@ -238,8 +276,7 @@ do { \
default: \
BUILD_BUG(); \
} \
- asm(ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_ALT_PAN_NOT_UAO,\
- CONFIG_ARM64_PAN)); \
+ uaccess_disable_not_uao(); \
} while (0)
#define __put_user(x, ptr) \
@@ -332,4 +369,26 @@ extern long strncpy_from_user(char *dest, const char __user *src, long count);
extern __must_check long strlen_user(const char __user *str);
extern __must_check long strnlen_user(const char __user *str, long n);
+#else /* __ASSEMBLY__ */
+
+#include <asm/assembler.h>
+
+/*
+ * User access enabling/disabling macros. These are no-ops when UAO is
+ * present.
+ */
+ .macro uaccess_disable_not_uao, tmp1
+alternative_if ARM64_ALT_PAN_NOT_UAO
+ SET_PSTATE_PAN(1)
+alternative_else_nop_endif
+ .endm
+
+ .macro uaccess_enable_not_uao, tmp1, tmp2
+alternative_if ARM64_ALT_PAN_NOT_UAO
+ SET_PSTATE_PAN(0)
+alternative_else_nop_endif
+ .endm
+
+#endif /* __ASSEMBLY__ */
+
#endif /* __ASM_UACCESS_H */
diff --git a/arch/arm64/kernel/armv8_deprecated.c b/arch/arm64/kernel/armv8_deprecated.c
index c0ede23..29d2ad8 100644
--- a/arch/arm64/kernel/armv8_deprecated.c
+++ b/arch/arm64/kernel/armv8_deprecated.c
@@ -14,7 +14,6 @@
#include <linux/slab.h>
#include <linux/sysctl.h>
-#include <asm/alternative.h>
#include <asm/cpufeature.h>
#include <asm/insn.h>
#include <asm/opcodes.h>
@@ -285,10 +284,10 @@ static void __init register_insn_emulation_sysctl(struct ctl_table *table)
#define __SWP_LL_SC_LOOPS 4
#define __user_swpX_asm(data, addr, res, temp, temp2, B) \
+do { \
+ uaccess_enable(); \
__asm__ __volatile__( \
" mov %w3, %w7\n" \
- ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_HAS_PAN, \
- CONFIG_ARM64_PAN) \
"0: ldxr"B" %w2, [%4]\n" \
"1: stxr"B" %w0, %w1, [%4]\n" \
" cbz %w0, 2f\n" \
@@ -306,13 +305,13 @@ static void __init register_insn_emulation_sysctl(struct ctl_table *table)
" .popsection" \
_ASM_EXTABLE(0b, 4b) \
_ASM_EXTABLE(1b, 4b) \
- ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_HAS_PAN, \
- CONFIG_ARM64_PAN) \
: "=&r" (res), "+r" (data), "=&r" (temp), "=&r" (temp2) \
: "r" ((unsigned long)addr), "i" (-EAGAIN), \
"i" (-EFAULT), \
"i" (__SWP_LL_SC_LOOPS) \
- : "memory")
+ : "memory"); \
+ uaccess_disable(); \
+} while (0)
#define __user_swp_asm(data, addr, res, temp, temp2) \
__user_swpX_asm(data, addr, res, temp, temp2, "")
diff --git a/arch/arm64/lib/clear_user.S b/arch/arm64/lib/clear_user.S
index 5d1cad3..d7150e3 100644
--- a/arch/arm64/lib/clear_user.S
+++ b/arch/arm64/lib/clear_user.S
@@ -17,10 +17,7 @@
*/
#include <linux/linkage.h>
-#include <asm/alternative.h>
-#include <asm/assembler.h>
-#include <asm/cpufeature.h>
-#include <asm/sysreg.h>
+#include <asm/uaccess.h>
.text
@@ -33,8 +30,7 @@
* Alignment fixed up by hardware.
*/
ENTRY(__clear_user)
-ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_ALT_PAN_NOT_UAO, \
- CONFIG_ARM64_PAN)
+ uaccess_enable_not_uao x2, x3
mov x2, x1 // save the size for fixup return
subs x1, x1, #8
b.mi 2f
@@ -54,8 +50,7 @@ uao_user_alternative 9f, strh, sttrh, wzr, x0, 2
b.mi 5f
uao_user_alternative 9f, strb, sttrb, wzr, x0, 0
5: mov x0, #0
-ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(1)), ARM64_ALT_PAN_NOT_UAO, \
- CONFIG_ARM64_PAN)
+ uaccess_disable_not_uao x2
ret
ENDPROC(__clear_user)
diff --git a/arch/arm64/lib/copy_from_user.S b/arch/arm64/lib/copy_from_user.S
index 4fd67ea..cfe1339 100644
--- a/arch/arm64/lib/copy_from_user.S
+++ b/arch/arm64/lib/copy_from_user.S
@@ -16,11 +16,8 @@
#include <linux/linkage.h>
-#include <asm/alternative.h>
-#include <asm/assembler.h>
#include <asm/cache.h>
-#include <asm/cpufeature.h>
-#include <asm/sysreg.h>
+#include <asm/uaccess.h>
/*
* Copy from user space to a kernel buffer (alignment handled by the hardware)
@@ -67,12 +64,10 @@
end .req x5
ENTRY(__arch_copy_from_user)
-ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_ALT_PAN_NOT_UAO, \
- CONFIG_ARM64_PAN)
+ uaccess_enable_not_uao x3, x4
add end, x0, x2
#include "copy_template.S"
-ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(1)), ARM64_ALT_PAN_NOT_UAO, \
- CONFIG_ARM64_PAN)
+ uaccess_disable_not_uao x3
mov x0, #0 // Nothing to copy
ret
ENDPROC(__arch_copy_from_user)
diff --git a/arch/arm64/lib/copy_in_user.S b/arch/arm64/lib/copy_in_user.S
index f7292dd0..718b1c4 100644
--- a/arch/arm64/lib/copy_in_user.S
+++ b/arch/arm64/lib/copy_in_user.S
@@ -18,11 +18,8 @@
#include <linux/linkage.h>
-#include <asm/alternative.h>
-#include <asm/assembler.h>
#include <asm/cache.h>
-#include <asm/cpufeature.h>
-#include <asm/sysreg.h>
+#include <asm/uaccess.h>
/*
* Copy from user space to user space (alignment handled by the hardware)
@@ -68,12 +65,10 @@
end .req x5
ENTRY(__copy_in_user)
-ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_ALT_PAN_NOT_UAO, \
- CONFIG_ARM64_PAN)
+ uaccess_enable_not_uao x3, x4
add end, x0, x2
#include "copy_template.S"
-ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(1)), ARM64_ALT_PAN_NOT_UAO, \
- CONFIG_ARM64_PAN)
+ uaccess_disable_not_uao x3
mov x0, #0
ret
ENDPROC(__copy_in_user)
diff --git a/arch/arm64/lib/copy_to_user.S b/arch/arm64/lib/copy_to_user.S
index 7a7efe2..e99e31c 100644
--- a/arch/arm64/lib/copy_to_user.S
+++ b/arch/arm64/lib/copy_to_user.S
@@ -16,11 +16,8 @@
#include <linux/linkage.h>
-#include <asm/alternative.h>
-#include <asm/assembler.h>
#include <asm/cache.h>
-#include <asm/cpufeature.h>
-#include <asm/sysreg.h>
+#include <asm/uaccess.h>
/*
* Copy to user space from a kernel buffer (alignment handled by the hardware)
@@ -66,12 +63,10 @@
end .req x5
ENTRY(__arch_copy_to_user)
-ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_ALT_PAN_NOT_UAO, \
- CONFIG_ARM64_PAN)
+ uaccess_enable_not_uao x3, x4
add end, x0, x2
#include "copy_template.S"
-ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(1)), ARM64_ALT_PAN_NOT_UAO, \
- CONFIG_ARM64_PAN)
+ uaccess_disable_not_uao x3
mov x0, #0
ret
ENDPROC(__arch_copy_to_user)
--
2.7.4
WARNING: multiple messages have this Message-ID (diff)
From: alex.shi@linaro.org (Alex Shi)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 06/45] arm64: Factor out PAN enabling/disabling into separate uaccess_* macros
Date: Thu, 1 Mar 2018 20:53:43 +0800 [thread overview]
Message-ID: <1519908862-11425-7-git-send-email-alex.shi@linaro.org> (raw)
In-Reply-To: <1519908862-11425-1-git-send-email-alex.shi@linaro.org>
From: Catalin Marinas <catalin.marinas@arm.com>
commit bd38967d406 upstream.
This patch moves the directly coded alternatives for turning PAN on/off
into separate uaccess_{enable,disable} macros or functions. The asm
macros take a few arguments which will be used in subsequent patches.
Note that any (unlikely) access that the compiler might generate between
uaccess_enable() and uaccess_disable(), other than those explicitly
specified by the user access code, will not be protected by PAN.
Cc: Will Deacon <will.deacon@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Alex Shi <alex.shi@linaro.org>
---
arch/arm64/include/asm/futex.h | 17 ++++----
arch/arm64/include/asm/uaccess.h | 79 +++++++++++++++++++++++++++++++-----
arch/arm64/kernel/armv8_deprecated.c | 11 +++--
arch/arm64/lib/clear_user.S | 11 ++---
arch/arm64/lib/copy_from_user.S | 11 ++---
arch/arm64/lib/copy_in_user.S | 11 ++---
arch/arm64/lib/copy_to_user.S | 11 ++---
7 files changed, 93 insertions(+), 58 deletions(-)
diff --git a/arch/arm64/include/asm/futex.h b/arch/arm64/include/asm/futex.h
index f2585cd..85c4a89 100644
--- a/arch/arm64/include/asm/futex.h
+++ b/arch/arm64/include/asm/futex.h
@@ -21,15 +21,12 @@
#include <linux/futex.h>
#include <linux/uaccess.h>
-#include <asm/alternative.h>
-#include <asm/cpufeature.h>
#include <asm/errno.h>
-#include <asm/sysreg.h>
#define __futex_atomic_op(insn, ret, oldval, uaddr, tmp, oparg) \
+do { \
+ uaccess_enable(); \
asm volatile( \
- ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_HAS_PAN, \
- CONFIG_ARM64_PAN) \
" prfm pstl1strm, %2\n" \
"1: ldxr %w1, %2\n" \
insn "\n" \
@@ -44,11 +41,11 @@
" .popsection\n" \
_ASM_EXTABLE(1b, 4b) \
_ASM_EXTABLE(2b, 4b) \
- ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_HAS_PAN, \
- CONFIG_ARM64_PAN) \
: "=&r" (ret), "=&r" (oldval), "+Q" (*uaddr), "=&r" (tmp) \
: "r" (oparg), "Ir" (-EFAULT) \
- : "memory")
+ : "memory"); \
+ uaccess_disable(); \
+} while (0)
static inline int
futex_atomic_op_inuser (int encoded_op, u32 __user *uaddr)
@@ -118,8 +115,8 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
return -EFAULT;
+ uaccess_enable();
asm volatile("// futex_atomic_cmpxchg_inatomic\n"
-ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_HAS_PAN, CONFIG_ARM64_PAN)
" prfm pstl1strm, %2\n"
"1: ldxr %w1, %2\n"
" sub %w3, %w1, %w4\n"
@@ -134,10 +131,10 @@ ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_HAS_PAN, CONFIG_ARM64_PAN)
" .popsection\n"
_ASM_EXTABLE(1b, 4b)
_ASM_EXTABLE(2b, 4b)
-ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_HAS_PAN, CONFIG_ARM64_PAN)
: "+r" (ret), "=&r" (val), "+Q" (*uaddr), "=&r" (tmp)
: "r" (oldval), "r" (newval), "Ir" (-EFAULT)
: "memory");
+ uaccess_disable();
*uval = val;
return ret;
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index 811cf16..94e1457 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -18,6 +18,11 @@
#ifndef __ASM_UACCESS_H
#define __ASM_UACCESS_H
+#include <asm/alternative.h>
+#include <asm/sysreg.h>
+
+#ifndef __ASSEMBLY__
+
/*
* User space memory access functions
*/
@@ -26,10 +31,8 @@
#include <linux/string.h>
#include <linux/thread_info.h>
-#include <asm/alternative.h>
#include <asm/cpufeature.h>
#include <asm/ptrace.h>
-#include <asm/sysreg.h>
#include <asm/errno.h>
#include <asm/memory.h>
#include <asm/compiler.h>
@@ -121,6 +124,44 @@ static inline void set_fs(mm_segment_t fs)
" .popsection\n"
/*
+ * User access enabling/disabling.
+ */
+#define __uaccess_disable(alt) \
+do { \
+ asm(ALTERNATIVE("nop", SET_PSTATE_PAN(1), alt, \
+ CONFIG_ARM64_PAN)); \
+} while (0)
+
+#define __uaccess_enable(alt) \
+do { \
+ asm(ALTERNATIVE("nop", SET_PSTATE_PAN(0), alt, \
+ CONFIG_ARM64_PAN)); \
+} while (0)
+
+static inline void uaccess_disable(void)
+{
+ __uaccess_disable(ARM64_HAS_PAN);
+}
+
+static inline void uaccess_enable(void)
+{
+ __uaccess_enable(ARM64_HAS_PAN);
+}
+
+/*
+ * These functions are no-ops when UAO is present.
+ */
+static inline void uaccess_disable_not_uao(void)
+{
+ __uaccess_disable(ARM64_ALT_PAN_NOT_UAO);
+}
+
+static inline void uaccess_enable_not_uao(void)
+{
+ __uaccess_enable(ARM64_ALT_PAN_NOT_UAO);
+}
+
+/*
* The "__xxx" versions of the user access functions do not verify the address
* space - it must have been done previously with a separate "access_ok()"
* call.
@@ -147,8 +188,7 @@ static inline void set_fs(mm_segment_t fs)
do { \
unsigned long __gu_val; \
__chk_user_ptr(ptr); \
- asm(ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_ALT_PAN_NOT_UAO,\
- CONFIG_ARM64_PAN)); \
+ uaccess_enable_not_uao(); \
switch (sizeof(*(ptr))) { \
case 1: \
__get_user_asm("ldrb", "ldtrb", "%w", __gu_val, (ptr), \
@@ -169,9 +209,8 @@ do { \
default: \
BUILD_BUG(); \
} \
+ uaccess_disable_not_uao(); \
(x) = (__force __typeof__(*(ptr)))__gu_val; \
- asm(ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_ALT_PAN_NOT_UAO,\
- CONFIG_ARM64_PAN)); \
} while (0)
#define __get_user(x, ptr) \
@@ -216,8 +255,7 @@ do { \
do { \
__typeof__(*(ptr)) __pu_val = (x); \
__chk_user_ptr(ptr); \
- asm(ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_ALT_PAN_NOT_UAO,\
- CONFIG_ARM64_PAN)); \
+ uaccess_enable_not_uao(); \
switch (sizeof(*(ptr))) { \
case 1: \
__put_user_asm("strb", "sttrb", "%w", __pu_val, (ptr), \
@@ -238,8 +276,7 @@ do { \
default: \
BUILD_BUG(); \
} \
- asm(ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_ALT_PAN_NOT_UAO,\
- CONFIG_ARM64_PAN)); \
+ uaccess_disable_not_uao(); \
} while (0)
#define __put_user(x, ptr) \
@@ -332,4 +369,26 @@ extern long strncpy_from_user(char *dest, const char __user *src, long count);
extern __must_check long strlen_user(const char __user *str);
extern __must_check long strnlen_user(const char __user *str, long n);
+#else /* __ASSEMBLY__ */
+
+#include <asm/assembler.h>
+
+/*
+ * User access enabling/disabling macros. These are no-ops when UAO is
+ * present.
+ */
+ .macro uaccess_disable_not_uao, tmp1
+alternative_if ARM64_ALT_PAN_NOT_UAO
+ SET_PSTATE_PAN(1)
+alternative_else_nop_endif
+ .endm
+
+ .macro uaccess_enable_not_uao, tmp1, tmp2
+alternative_if ARM64_ALT_PAN_NOT_UAO
+ SET_PSTATE_PAN(0)
+alternative_else_nop_endif
+ .endm
+
+#endif /* __ASSEMBLY__ */
+
#endif /* __ASM_UACCESS_H */
diff --git a/arch/arm64/kernel/armv8_deprecated.c b/arch/arm64/kernel/armv8_deprecated.c
index c0ede23..29d2ad8 100644
--- a/arch/arm64/kernel/armv8_deprecated.c
+++ b/arch/arm64/kernel/armv8_deprecated.c
@@ -14,7 +14,6 @@
#include <linux/slab.h>
#include <linux/sysctl.h>
-#include <asm/alternative.h>
#include <asm/cpufeature.h>
#include <asm/insn.h>
#include <asm/opcodes.h>
@@ -285,10 +284,10 @@ static void __init register_insn_emulation_sysctl(struct ctl_table *table)
#define __SWP_LL_SC_LOOPS 4
#define __user_swpX_asm(data, addr, res, temp, temp2, B) \
+do { \
+ uaccess_enable(); \
__asm__ __volatile__( \
" mov %w3, %w7\n" \
- ALTERNATIVE("nop", SET_PSTATE_PAN(0), ARM64_HAS_PAN, \
- CONFIG_ARM64_PAN) \
"0: ldxr"B" %w2, [%4]\n" \
"1: stxr"B" %w0, %w1, [%4]\n" \
" cbz %w0, 2f\n" \
@@ -306,13 +305,13 @@ static void __init register_insn_emulation_sysctl(struct ctl_table *table)
" .popsection" \
_ASM_EXTABLE(0b, 4b) \
_ASM_EXTABLE(1b, 4b) \
- ALTERNATIVE("nop", SET_PSTATE_PAN(1), ARM64_HAS_PAN, \
- CONFIG_ARM64_PAN) \
: "=&r" (res), "+r" (data), "=&r" (temp), "=&r" (temp2) \
: "r" ((unsigned long)addr), "i" (-EAGAIN), \
"i" (-EFAULT), \
"i" (__SWP_LL_SC_LOOPS) \
- : "memory")
+ : "memory"); \
+ uaccess_disable(); \
+} while (0)
#define __user_swp_asm(data, addr, res, temp, temp2) \
__user_swpX_asm(data, addr, res, temp, temp2, "")
diff --git a/arch/arm64/lib/clear_user.S b/arch/arm64/lib/clear_user.S
index 5d1cad3..d7150e3 100644
--- a/arch/arm64/lib/clear_user.S
+++ b/arch/arm64/lib/clear_user.S
@@ -17,10 +17,7 @@
*/
#include <linux/linkage.h>
-#include <asm/alternative.h>
-#include <asm/assembler.h>
-#include <asm/cpufeature.h>
-#include <asm/sysreg.h>
+#include <asm/uaccess.h>
.text
@@ -33,8 +30,7 @@
* Alignment fixed up by hardware.
*/
ENTRY(__clear_user)
-ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_ALT_PAN_NOT_UAO, \
- CONFIG_ARM64_PAN)
+ uaccess_enable_not_uao x2, x3
mov x2, x1 // save the size for fixup return
subs x1, x1, #8
b.mi 2f
@@ -54,8 +50,7 @@ uao_user_alternative 9f, strh, sttrh, wzr, x0, 2
b.mi 5f
uao_user_alternative 9f, strb, sttrb, wzr, x0, 0
5: mov x0, #0
-ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(1)), ARM64_ALT_PAN_NOT_UAO, \
- CONFIG_ARM64_PAN)
+ uaccess_disable_not_uao x2
ret
ENDPROC(__clear_user)
diff --git a/arch/arm64/lib/copy_from_user.S b/arch/arm64/lib/copy_from_user.S
index 4fd67ea..cfe1339 100644
--- a/arch/arm64/lib/copy_from_user.S
+++ b/arch/arm64/lib/copy_from_user.S
@@ -16,11 +16,8 @@
#include <linux/linkage.h>
-#include <asm/alternative.h>
-#include <asm/assembler.h>
#include <asm/cache.h>
-#include <asm/cpufeature.h>
-#include <asm/sysreg.h>
+#include <asm/uaccess.h>
/*
* Copy from user space to a kernel buffer (alignment handled by the hardware)
@@ -67,12 +64,10 @@
end .req x5
ENTRY(__arch_copy_from_user)
-ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_ALT_PAN_NOT_UAO, \
- CONFIG_ARM64_PAN)
+ uaccess_enable_not_uao x3, x4
add end, x0, x2
#include "copy_template.S"
-ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(1)), ARM64_ALT_PAN_NOT_UAO, \
- CONFIG_ARM64_PAN)
+ uaccess_disable_not_uao x3
mov x0, #0 // Nothing to copy
ret
ENDPROC(__arch_copy_from_user)
diff --git a/arch/arm64/lib/copy_in_user.S b/arch/arm64/lib/copy_in_user.S
index f7292dd0..718b1c4 100644
--- a/arch/arm64/lib/copy_in_user.S
+++ b/arch/arm64/lib/copy_in_user.S
@@ -18,11 +18,8 @@
#include <linux/linkage.h>
-#include <asm/alternative.h>
-#include <asm/assembler.h>
#include <asm/cache.h>
-#include <asm/cpufeature.h>
-#include <asm/sysreg.h>
+#include <asm/uaccess.h>
/*
* Copy from user space to user space (alignment handled by the hardware)
@@ -68,12 +65,10 @@
end .req x5
ENTRY(__copy_in_user)
-ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_ALT_PAN_NOT_UAO, \
- CONFIG_ARM64_PAN)
+ uaccess_enable_not_uao x3, x4
add end, x0, x2
#include "copy_template.S"
-ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(1)), ARM64_ALT_PAN_NOT_UAO, \
- CONFIG_ARM64_PAN)
+ uaccess_disable_not_uao x3
mov x0, #0
ret
ENDPROC(__copy_in_user)
diff --git a/arch/arm64/lib/copy_to_user.S b/arch/arm64/lib/copy_to_user.S
index 7a7efe2..e99e31c 100644
--- a/arch/arm64/lib/copy_to_user.S
+++ b/arch/arm64/lib/copy_to_user.S
@@ -16,11 +16,8 @@
#include <linux/linkage.h>
-#include <asm/alternative.h>
-#include <asm/assembler.h>
#include <asm/cache.h>
-#include <asm/cpufeature.h>
-#include <asm/sysreg.h>
+#include <asm/uaccess.h>
/*
* Copy to user space from a kernel buffer (alignment handled by the hardware)
@@ -66,12 +63,10 @@
end .req x5
ENTRY(__arch_copy_to_user)
-ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(0)), ARM64_ALT_PAN_NOT_UAO, \
- CONFIG_ARM64_PAN)
+ uaccess_enable_not_uao x3, x4
add end, x0, x2
#include "copy_template.S"
-ALTERNATIVE("nop", __stringify(SET_PSTATE_PAN(1)), ARM64_ALT_PAN_NOT_UAO, \
- CONFIG_ARM64_PAN)
+ uaccess_disable_not_uao x3
mov x0, #0
ret
ENDPROC(__arch_copy_to_user)
--
2.7.4
next prev parent reply other threads:[~2018-03-01 12:56 UTC|newest]
Thread overview: 119+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-01 12:53 [PATCH 00/45] arm Spectre fix backport review for LTS 4.9 Alex Shi
2018-03-01 12:53 ` Alex Shi
2018-03-01 12:53 ` [PATCH 01/45] mm: Introduce lm_alias Alex Shi
2018-03-01 12:53 ` Alex Shi
2018-03-01 12:53 ` [PATCH 02/45] arm64: alternatives: apply boot time fixups via the linear mapping Alex Shi
2018-03-01 12:53 ` Alex Shi
2018-03-01 12:53 ` [PATCH 03/45] arm64: barrier: Add CSDB macros to control data-value prediction Alex Shi
2018-03-01 12:53 ` Alex Shi
2018-03-01 12:53 ` [PATCH 04/45] arm64: Implement array_index_mask_nospec() Alex Shi
2018-03-01 12:53 ` Alex Shi
2018-03-01 12:53 ` [PATCH 05/45] arm64: move TASK_* definitions to <asm/processor.h> Alex Shi
2018-03-01 12:53 ` Alex Shi
2018-03-01 12:53 ` Alex Shi [this message]
2018-03-01 12:53 ` [PATCH 06/45] arm64: Factor out PAN enabling/disabling into separate uaccess_* macros Alex Shi
2018-03-01 12:53 ` [PATCH 07/45] arm64: Factor out TTBR0_EL1 post-update workaround into a specific asm macro Alex Shi
2018-03-01 12:53 ` Alex Shi
2018-03-01 12:53 ` [PATCH 08/45] arm64: uaccess: consistently check object sizes Alex Shi
2018-03-01 12:53 ` Alex Shi
2018-03-01 12:53 ` [PATCH 09/45] arm64: Make USER_DS an inclusive limit Alex Shi
2018-03-01 12:53 ` Alex Shi
2018-03-01 12:53 ` [PATCH 10/45] arm64: Use pointer masking to limit uaccess speculation Alex Shi
2018-03-01 12:53 ` Alex Shi
2018-03-01 12:53 ` [PATCH 11/45] arm64: syscallno is secretly an int, make it official Alex Shi
2018-03-01 12:53 ` Alex Shi
2018-03-01 12:53 ` [PATCH 12/45] arm64: entry: Ensure branch through syscall table is bounded under speculation Alex Shi
2018-03-01 12:53 ` Alex Shi
2018-03-01 12:53 ` [PATCH 13/45] arm64: uaccess: Prevent speculative use of the current addr_limit Alex Shi
2018-03-01 12:53 ` Alex Shi
2018-03-01 12:53 ` [PATCH 14/45] arm64: uaccess: Don't bother eliding access_ok checks in __{get, put}_user Alex Shi
2018-03-01 12:53 ` Alex Shi
2018-03-01 12:53 ` [PATCH 15/45] arm64: uaccess: Mask __user pointers for __arch_{clear, copy_*}_user Alex Shi
2018-03-01 12:53 ` Alex Shi
2018-03-01 12:53 ` [PATCH 16/45] arm64: futex: Mask __user pointers prior to dereference Alex Shi
2018-03-01 12:53 ` Alex Shi
2018-03-01 12:53 ` [PATCH 17/45] drivers/firmware: Expose psci_get_version through psci_ops structure Alex Shi
2018-03-01 12:53 ` Alex Shi
2018-03-01 12:53 ` [PATCH 18/45] arm64: cpufeature: __this_cpu_has_cap() shouldn't stop early Alex Shi
2018-03-01 12:53 ` Alex Shi
2018-03-01 12:53 ` [PATCH 19/45] arm64: cpu_errata: Allow an erratum to be match for all revisions of a core Alex Shi
2018-03-01 12:53 ` Alex Shi
2018-03-01 12:53 ` [PATCH 20/45] arm64: Run enable method for errata work arounds on late CPUs Alex Shi
2018-03-01 12:53 ` Alex Shi
2018-03-01 12:53 ` [PATCH 21/45] arm64: cpufeature: Pass capability structure to ->enable callback Alex Shi
2018-03-01 12:53 ` Alex Shi
2018-03-01 12:53 ` [PATCH 22/45] arm64: Move post_ttbr_update_workaround to C code Alex Shi
2018-03-01 12:53 ` Alex Shi
2018-03-01 12:54 ` [PATCH 23/45] arm64: Add skeleton to harden the branch predictor against aliasing attacks Alex Shi
2018-03-01 12:54 ` Alex Shi
2018-03-01 12:54 ` [PATCH 24/45] arm64: Move BP hardening to check_and_switch_context Alex Shi
2018-03-01 12:54 ` Alex Shi
2018-03-01 12:54 ` [PATCH 25/45] arm64: KVM: Use per-CPU vector when BP hardening is enabled Alex Shi
2018-03-01 12:54 ` Alex Shi
2018-03-01 12:54 ` [PATCH 26/45] arm64: entry: Apply BP hardening for high-priority synchronous exceptions Alex Shi
2018-03-01 12:54 ` Alex Shi
2018-03-01 12:54 ` [PATCH 27/45] arm64: entry: Apply BP hardening for suspicious interrupts from EL0 Alex Shi
2018-03-01 12:54 ` Alex Shi
2018-03-01 12:54 ` [PATCH 28/45] arm64: cputype: Add missing MIDR values for Cortex-A72 and Cortex-A75 Alex Shi
2018-03-01 12:54 ` Alex Shi
2018-03-01 12:54 ` [PATCH 29/45] arm64: Implement branch predictor hardening for affected Cortex-A CPUs Alex Shi
2018-03-01 12:54 ` Alex Shi
2018-03-01 12:54 ` [PATCH 30/45] arm64: KVM: Increment PC after handling an SMC trap Alex Shi
2018-03-01 12:54 ` Alex Shi
2018-03-01 12:54 ` [PATCH 31/45] arm/arm64: KVM: Consolidate the PSCI include files Alex Shi
2018-03-01 12:54 ` Alex Shi
2018-03-01 12:54 ` [PATCH 32/45] arm/arm64: KVM: Add PSCI_VERSION helper Alex Shi
2018-03-01 12:54 ` Alex Shi
2018-03-01 12:54 ` [PATCH 33/45] arm/arm64: KVM: Add smccc accessors to PSCI code Alex Shi
2018-03-01 12:54 ` Alex Shi
2018-03-01 12:54 ` [PATCH 34/45] arm/arm64: KVM: Implement PSCI 1.0 support Alex Shi
2018-03-01 12:54 ` Alex Shi
2018-03-01 12:54 ` [PATCH 35/45] arm/arm64: KVM: Advertise SMCCC v1.1 Alex Shi
2018-03-01 12:54 ` Alex Shi
2018-03-01 12:54 ` [PATCH 36/45] arm64: KVM: Make PSCI_VERSION a fast path Alex Shi
2018-03-01 12:54 ` Alex Shi
2018-03-01 12:54 ` [PATCH 37/45] arm/arm64: KVM: Turn kvm_psci_version into a static inline Alex Shi
2018-03-01 12:54 ` Alex Shi
2018-03-01 12:54 ` [PATCH 38/45] arm64: KVM: Report SMCCC_ARCH_WORKAROUND_1 BP hardening support Alex Shi
2018-03-01 12:54 ` Alex Shi
2018-03-01 12:54 ` [PATCH 39/45] arm64: KVM: Add SMCCC_ARCH_WORKAROUND_1 fast handling Alex Shi
2018-03-01 12:54 ` Alex Shi
2018-03-01 12:54 ` [PATCH 40/45] firmware/psci: Expose PSCI conduit Alex Shi
2018-03-01 12:54 ` Alex Shi
2018-03-01 12:54 ` [PATCH 41/45] firmware/psci: Expose SMCCC version through psci_ops Alex Shi
2018-03-01 12:54 ` Alex Shi
2018-03-01 12:54 ` [PATCH 42/45] arm/arm64: smccc: Make function identifiers an unsigned quantity Alex Shi
2018-03-01 12:54 ` Alex Shi
2018-03-01 12:54 ` [PATCH 43/45] arm/arm64: smccc: Implement SMCCC v1.1 inline primitive Alex Shi
2018-03-01 12:54 ` Alex Shi
2018-03-01 12:54 ` [PATCH 44/45] arm64: Add ARM_SMCCC_ARCH_WORKAROUND_1 BP hardening support Alex Shi
2018-03-01 12:54 ` Alex Shi
2018-03-01 12:54 ` [PATCH 45/45] arm64: Kill PSCI_GET_VERSION as a variant-2 workaround Alex Shi
2018-03-01 12:54 ` Alex Shi
2018-03-01 16:45 ` [PATCH 00/45] arm Spectre fix backport review for LTS 4.9 Greg KH
2018-03-01 16:45 ` Greg KH
2018-03-02 7:26 ` Alex Shi
2018-03-02 7:26 ` Alex Shi
2018-03-01 16:46 ` Greg KH
2018-03-01 16:46 ` Greg KH
2018-03-02 9:02 ` Alex Shi
2018-03-02 9:02 ` Alex Shi
2018-03-02 10:29 ` Marc Zyngier
2018-03-02 10:29 ` Marc Zyngier
2018-03-03 0:52 ` Alex Shi
2018-03-03 0:52 ` Alex Shi
2018-03-02 10:30 ` Will Deacon
2018-03-02 10:30 ` Will Deacon
2018-03-03 0:54 ` Alex Shi
2018-03-03 0:54 ` Alex Shi
2018-03-08 12:27 ` Pavel Machek
2018-03-08 12:27 ` Pavel Machek
2018-03-08 13:21 ` Pali Rohár
2018-03-08 13:21 ` Pali Rohár
2018-03-08 13:33 ` Ivaylo Dimitrov
2018-03-08 13:33 ` Ivaylo Dimitrov
2018-03-08 13:33 ` Ivaylo Dimitrov
2018-03-08 13:35 ` Marc Zyngier
2018-03-08 13:35 ` Marc Zyngier
2018-03-08 17:01 ` Pali Rohár
2018-03-08 17:01 ` Pali Rohár
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