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-rw-r--r--arch/x86/include/asm/alternative-asm.h9
-rw-r--r--arch/x86/include/asm/alternative.h32
-rw-r--r--arch/x86/include/asm/fpu-internal.h42
-rw-r--r--arch/x86/include/asm/futex.h19
-rw-r--r--arch/x86/include/asm/processor-flags.h1
-rw-r--r--arch/x86/include/asm/smap.h91
-rw-r--r--arch/x86/include/asm/uaccess.h28
-rw-r--r--arch/x86/include/asm/uaccess_32.h3
-rw-r--r--arch/x86/include/asm/uaccess_64.h3
-rw-r--r--arch/x86/include/asm/xsave.h10
10 files changed, 190 insertions, 48 deletions
diff --git a/arch/x86/include/asm/alternative-asm.h b/arch/x86/include/asm/alternative-asm.h
index 952bd0100c5c..372231c22a47 100644
--- a/arch/x86/include/asm/alternative-asm.h
+++ b/arch/x86/include/asm/alternative-asm.h
@@ -1,3 +1,6 @@
+#ifndef _ASM_X86_ALTERNATIVE_ASM_H
+#define _ASM_X86_ALTERNATIVE_ASM_H
+
#ifdef __ASSEMBLY__
#include <asm/asm.h>
@@ -5,10 +8,10 @@
#ifdef CONFIG_SMP
.macro LOCK_PREFIX
672: lock
- .section .smp_locks,"a"
+ .pushsection .smp_locks,"a"
.balign 4
.long 672b - .
- .previous
+ .popsection
.endm
#else
.macro LOCK_PREFIX
@@ -24,3 +27,5 @@
.endm
#endif /* __ASSEMBLY__ */
+
+#endif /* _ASM_X86_ALTERNATIVE_ASM_H */
diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
index 444704c8e186..58ed6d96a6ac 100644
--- a/arch/x86/include/asm/alternative.h
+++ b/arch/x86/include/asm/alternative.h
@@ -29,10 +29,10 @@
#ifdef CONFIG_SMP
#define LOCK_PREFIX_HERE \
- ".section .smp_locks,\"a\"\n" \
- ".balign 4\n" \
- ".long 671f - .\n" /* offset */ \
- ".previous\n" \
+ ".pushsection .smp_locks,\"a\"\n" \
+ ".balign 4\n" \
+ ".long 671f - .\n" /* offset */ \
+ ".popsection\n" \
"671:"
#define LOCK_PREFIX LOCK_PREFIX_HERE "\n\tlock; "
@@ -99,30 +99,30 @@ static inline int alternatives_text_reserved(void *start, void *end)
/* alternative assembly primitive: */
#define ALTERNATIVE(oldinstr, newinstr, feature) \
OLDINSTR(oldinstr) \
- ".section .altinstructions,\"a\"\n" \
+ ".pushsection .altinstructions,\"a\"\n" \
ALTINSTR_ENTRY(feature, 1) \
- ".previous\n" \
- ".section .discard,\"aw\",@progbits\n" \
+ ".popsection\n" \
+ ".pushsection .discard,\"aw\",@progbits\n" \
DISCARD_ENTRY(1) \
- ".previous\n" \
- ".section .altinstr_replacement, \"ax\"\n" \
+ ".popsection\n" \
+ ".pushsection .altinstr_replacement, \"ax\"\n" \
ALTINSTR_REPLACEMENT(newinstr, feature, 1) \
- ".previous"
+ ".popsection"
#define ALTERNATIVE_2(oldinstr, newinstr1, feature1, newinstr2, feature2)\
OLDINSTR(oldinstr) \
- ".section .altinstructions,\"a\"\n" \
+ ".pushsection .altinstructions,\"a\"\n" \
ALTINSTR_ENTRY(feature1, 1) \
ALTINSTR_ENTRY(feature2, 2) \
- ".previous\n" \
- ".section .discard,\"aw\",@progbits\n" \
+ ".popsection\n" \
+ ".pushsection .discard,\"aw\",@progbits\n" \
DISCARD_ENTRY(1) \
DISCARD_ENTRY(2) \
- ".previous\n" \
- ".section .altinstr_replacement, \"ax\"\n" \
+ ".popsection\n" \
+ ".pushsection .altinstr_replacement, \"ax\"\n" \
ALTINSTR_REPLACEMENT(newinstr1, feature1, 1) \
ALTINSTR_REPLACEMENT(newinstr2, feature2, 2) \
- ".previous"
+ ".popsection"
/*
* This must be included *after* the definition of ALTERNATIVE due to
diff --git a/arch/x86/include/asm/fpu-internal.h b/arch/x86/include/asm/fpu-internal.h
index 92f3c6ed817f..831dbb9c6c02 100644
--- a/arch/x86/include/asm/fpu-internal.h
+++ b/arch/x86/include/asm/fpu-internal.h
@@ -21,6 +21,7 @@
#include <asm/user.h>
#include <asm/uaccess.h>
#include <asm/xsave.h>
+#include <asm/smap.h>
#ifdef CONFIG_X86_64
# include <asm/sigcontext32.h>
@@ -121,6 +122,22 @@ static inline void sanitize_i387_state(struct task_struct *tsk)
__sanitize_i387_state(tsk);
}
+#define user_insn(insn, output, input...) \
+({ \
+ int err; \
+ asm volatile(ASM_STAC "\n" \
+ "1:" #insn "\n\t" \
+ "2: " ASM_CLAC "\n" \
+ ".section .fixup,\"ax\"\n" \
+ "3: movl $-1,%[err]\n" \
+ " jmp 2b\n" \
+ ".previous\n" \
+ _ASM_EXTABLE(1b, 3b) \
+ : [err] "=r" (err), output \
+ : "0"(0), input); \
+ err; \
+})
+
#define check_insn(insn, output, input...) \
({ \
int err; \
@@ -138,18 +155,18 @@ static inline void sanitize_i387_state(struct task_struct *tsk)
static inline int fsave_user(struct i387_fsave_struct __user *fx)
{
- return check_insn(fnsave %[fx]; fwait, [fx] "=m" (*fx), "m" (*fx));
+ return user_insn(fnsave %[fx]; fwait, [fx] "=m" (*fx), "m" (*fx));
}
static inline int fxsave_user(struct i387_fxsave_struct __user *fx)
{
if (config_enabled(CONFIG_X86_32))
- return check_insn(fxsave %[fx], [fx] "=m" (*fx), "m" (*fx));
+ return user_insn(fxsave %[fx], [fx] "=m" (*fx), "m" (*fx));
else if (config_enabled(CONFIG_AS_FXSAVEQ))
- return check_insn(fxsaveq %[fx], [fx] "=m" (*fx), "m" (*fx));
+ return user_insn(fxsaveq %[fx], [fx] "=m" (*fx), "m" (*fx));
/* See comment in fpu_fxsave() below. */
- return check_insn(rex64/fxsave (%[fx]), "=m" (*fx), [fx] "R" (fx));
+ return user_insn(rex64/fxsave (%[fx]), "=m" (*fx), [fx] "R" (fx));
}
static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
@@ -164,11 +181,28 @@ static inline int fxrstor_checking(struct i387_fxsave_struct *fx)
"m" (*fx));
}
+static inline int fxrstor_user(struct i387_fxsave_struct __user *fx)
+{
+ if (config_enabled(CONFIG_X86_32))
+ return user_insn(fxrstor %[fx], "=m" (*fx), [fx] "m" (*fx));
+ else if (config_enabled(CONFIG_AS_FXSAVEQ))
+ return user_insn(fxrstorq %[fx], "=m" (*fx), [fx] "m" (*fx));
+
+ /* See comment in fpu_fxsave() below. */
+ return user_insn(rex64/fxrstor (%[fx]), "=m" (*fx), [fx] "R" (fx),
+ "m" (*fx));
+}
+
static inline int frstor_checking(struct i387_fsave_struct *fx)
{
return check_insn(frstor %[fx], "=m" (*fx), [fx] "m" (*fx));
}
+static inline int frstor_user(struct i387_fsave_struct __user *fx)
+{
+ return user_insn(frstor %[fx], "=m" (*fx), [fx] "m" (*fx));
+}
+
static inline void fpu_fxsave(struct fpu *fpu)
{
if (config_enabled(CONFIG_X86_32))
diff --git a/arch/x86/include/asm/futex.h b/arch/x86/include/asm/futex.h
index 71ecbcba1a4e..f373046e63ec 100644
--- a/arch/x86/include/asm/futex.h
+++ b/arch/x86/include/asm/futex.h
@@ -9,10 +9,13 @@
#include <asm/asm.h>
#include <asm/errno.h>
#include <asm/processor.h>
+#include <asm/smap.h>
#define __futex_atomic_op1(insn, ret, oldval, uaddr, oparg) \
- asm volatile("1:\t" insn "\n" \
- "2:\t.section .fixup,\"ax\"\n" \
+ asm volatile("\t" ASM_STAC "\n" \
+ "1:\t" insn "\n" \
+ "2:\t" ASM_CLAC "\n" \
+ "\t.section .fixup,\"ax\"\n" \
"3:\tmov\t%3, %1\n" \
"\tjmp\t2b\n" \
"\t.previous\n" \
@@ -21,12 +24,14 @@
: "i" (-EFAULT), "0" (oparg), "1" (0))
#define __futex_atomic_op2(insn, ret, oldval, uaddr, oparg) \
- asm volatile("1:\tmovl %2, %0\n" \
+ asm volatile("\t" ASM_STAC "\n" \
+ "1:\tmovl %2, %0\n" \
"\tmovl\t%0, %3\n" \
"\t" insn "\n" \
"2:\t" LOCK_PREFIX "cmpxchgl %3, %2\n" \
"\tjnz\t1b\n" \
- "3:\t.section .fixup,\"ax\"\n" \
+ "3:\t" ASM_CLAC "\n" \
+ "\t.section .fixup,\"ax\"\n" \
"4:\tmov\t%5, %1\n" \
"\tjmp\t3b\n" \
"\t.previous\n" \
@@ -122,8 +127,10 @@ static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
return -EFAULT;
- asm volatile("1:\t" LOCK_PREFIX "cmpxchgl %4, %2\n"
- "2:\t.section .fixup, \"ax\"\n"
+ asm volatile("\t" ASM_STAC "\n"
+ "1:\t" LOCK_PREFIX "cmpxchgl %4, %2\n"
+ "2:\t" ASM_CLAC "\n"
+ "\t.section .fixup, \"ax\"\n"
"3:\tmov %3, %0\n"
"\tjmp 2b\n"
"\t.previous\n"
diff --git a/arch/x86/include/asm/processor-flags.h b/arch/x86/include/asm/processor-flags.h
index aea1d1d848c7..680cf09ed100 100644
--- a/arch/x86/include/asm/processor-flags.h
+++ b/arch/x86/include/asm/processor-flags.h
@@ -65,6 +65,7 @@
#define X86_CR4_PCIDE 0x00020000 /* enable PCID support */
#define X86_CR4_OSXSAVE 0x00040000 /* enable xsave and xrestore */
#define X86_CR4_SMEP 0x00100000 /* enable SMEP support */
+#define X86_CR4_SMAP 0x00200000 /* enable SMAP support */
/*
* x86-64 Task Priority Register, CR8
diff --git a/arch/x86/include/asm/smap.h b/arch/x86/include/asm/smap.h
new file mode 100644
index 000000000000..8d3120f4e270
--- /dev/null
+++ b/arch/x86/include/asm/smap.h
@@ -0,0 +1,91 @@
+/*
+ * Supervisor Mode Access Prevention support
+ *
+ * Copyright (C) 2012 Intel Corporation
+ * Author: H. Peter Anvin <hpa@linux.intel.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; version 2
+ * of the License.
+ */
+
+#ifndef _ASM_X86_SMAP_H
+#define _ASM_X86_SMAP_H
+
+#include <linux/stringify.h>
+#include <asm/nops.h>
+#include <asm/cpufeature.h>
+
+/* "Raw" instruction opcodes */
+#define __ASM_CLAC .byte 0x0f,0x01,0xca
+#define __ASM_STAC .byte 0x0f,0x01,0xcb
+
+#ifdef __ASSEMBLY__
+
+#include <asm/alternative-asm.h>
+
+#ifdef CONFIG_X86_SMAP
+
+#define ASM_CLAC \
+ 661: ASM_NOP3 ; \
+ .pushsection .altinstr_replacement, "ax" ; \
+ 662: __ASM_CLAC ; \
+ .popsection ; \
+ .pushsection .altinstructions, "a" ; \
+ altinstruction_entry 661b, 662b, X86_FEATURE_SMAP, 3, 3 ; \
+ .popsection
+
+#define ASM_STAC \
+ 661: ASM_NOP3 ; \
+ .pushsection .altinstr_replacement, "ax" ; \
+ 662: __ASM_STAC ; \
+ .popsection ; \
+ .pushsection .altinstructions, "a" ; \
+ altinstruction_entry 661b, 662b, X86_FEATURE_SMAP, 3, 3 ; \
+ .popsection
+
+#else /* CONFIG_X86_SMAP */
+
+#define ASM_CLAC
+#define ASM_STAC
+
+#endif /* CONFIG_X86_SMAP */
+
+#else /* __ASSEMBLY__ */
+
+#include <asm/alternative.h>
+
+#ifdef CONFIG_X86_SMAP
+
+static __always_inline void clac(void)
+{
+ /* Note: a barrier is implicit in alternative() */
+ alternative(ASM_NOP3, __stringify(__ASM_CLAC), X86_FEATURE_SMAP);
+}
+
+static __always_inline void stac(void)
+{
+ /* Note: a barrier is implicit in alternative() */
+ alternative(ASM_NOP3, __stringify(__ASM_STAC), X86_FEATURE_SMAP);
+}
+
+/* These macros can be used in asm() statements */
+#define ASM_CLAC \
+ ALTERNATIVE(ASM_NOP3, __stringify(__ASM_CLAC), X86_FEATURE_SMAP)
+#define ASM_STAC \
+ ALTERNATIVE(ASM_NOP3, __stringify(__ASM_STAC), X86_FEATURE_SMAP)
+
+#else /* CONFIG_X86_SMAP */
+
+static inline void clac(void) { }
+static inline void stac(void) { }
+
+#define ASM_CLAC
+#define ASM_STAC
+
+#endif /* CONFIG_X86_SMAP */
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* _ASM_X86_SMAP_H */
diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
index e1f3a17034fc..a91acfbb1a98 100644
--- a/arch/x86/include/asm/uaccess.h
+++ b/arch/x86/include/asm/uaccess.h
@@ -9,6 +9,7 @@
#include <linux/string.h>
#include <asm/asm.h>
#include <asm/page.h>
+#include <asm/smap.h>
#define VERIFY_READ 0
#define VERIFY_WRITE 1
@@ -192,9 +193,10 @@ extern int __get_user_bad(void);
#ifdef CONFIG_X86_32
#define __put_user_asm_u64(x, addr, err, errret) \
- asm volatile("1: movl %%eax,0(%2)\n" \
+ asm volatile(ASM_STAC "\n" \
+ "1: movl %%eax,0(%2)\n" \
"2: movl %%edx,4(%2)\n" \
- "3:\n" \
+ "3: " ASM_CLAC "\n" \
".section .fixup,\"ax\"\n" \
"4: movl %3,%0\n" \
" jmp 3b\n" \
@@ -205,9 +207,10 @@ extern int __get_user_bad(void);
: "A" (x), "r" (addr), "i" (errret), "0" (err))
#define __put_user_asm_ex_u64(x, addr) \
- asm volatile("1: movl %%eax,0(%1)\n" \
+ asm volatile(ASM_STAC "\n" \
+ "1: movl %%eax,0(%1)\n" \
"2: movl %%edx,4(%1)\n" \
- "3:\n" \
+ "3: " ASM_CLAC "\n" \
_ASM_EXTABLE_EX(1b, 2b) \
_ASM_EXTABLE_EX(2b, 3b) \
: : "A" (x), "r" (addr))
@@ -379,8 +382,9 @@ do { \
} while (0)
#define __get_user_asm(x, addr, err, itype, rtype, ltype, errret) \
- asm volatile("1: mov"itype" %2,%"rtype"1\n" \
- "2:\n" \
+ asm volatile(ASM_STAC "\n" \
+ "1: mov"itype" %2,%"rtype"1\n" \
+ "2: " ASM_CLAC "\n" \
".section .fixup,\"ax\"\n" \
"3: mov %3,%0\n" \
" xor"itype" %"rtype"1,%"rtype"1\n" \
@@ -443,8 +447,9 @@ struct __large_struct { unsigned long buf[100]; };
* aliasing issues.
*/
#define __put_user_asm(x, addr, err, itype, rtype, ltype, errret) \
- asm volatile("1: mov"itype" %"rtype"1,%2\n" \
- "2:\n" \
+ asm volatile(ASM_STAC "\n" \
+ "1: mov"itype" %"rtype"1,%2\n" \
+ "2: " ASM_CLAC "\n" \
".section .fixup,\"ax\"\n" \
"3: mov %3,%0\n" \
" jmp 2b\n" \
@@ -463,13 +468,13 @@ struct __large_struct { unsigned long buf[100]; };
* uaccess_try and catch
*/
#define uaccess_try do { \
- int prev_err = current_thread_info()->uaccess_err; \
current_thread_info()->uaccess_err = 0; \
+ stac(); \
barrier();
#define uaccess_catch(err) \
+ clac(); \
(err) |= (current_thread_info()->uaccess_err ? -EFAULT : 0); \
- current_thread_info()->uaccess_err = prev_err; \
} while (0)
/**
@@ -569,6 +574,9 @@ strncpy_from_user(char *dst, 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);
+unsigned long __must_check clear_user(void __user *mem, unsigned long len);
+unsigned long __must_check __clear_user(void __user *mem, unsigned long len);
+
/*
* movsl can be slow when source and dest are not both 8-byte aligned
*/
diff --git a/arch/x86/include/asm/uaccess_32.h b/arch/x86/include/asm/uaccess_32.h
index 576e39bca6ad..7f760a9f1f61 100644
--- a/arch/x86/include/asm/uaccess_32.h
+++ b/arch/x86/include/asm/uaccess_32.h
@@ -213,7 +213,4 @@ static inline unsigned long __must_check copy_from_user(void *to,
return n;
}
-unsigned long __must_check clear_user(void __user *mem, unsigned long len);
-unsigned long __must_check __clear_user(void __user *mem, unsigned long len);
-
#endif /* _ASM_X86_UACCESS_32_H */
diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h
index d8def8b3dba0..142810c457dc 100644
--- a/arch/x86/include/asm/uaccess_64.h
+++ b/arch/x86/include/asm/uaccess_64.h
@@ -217,9 +217,6 @@ int __copy_in_user(void __user *dst, const void __user *src, unsigned size)
}
}
-__must_check unsigned long clear_user(void __user *mem, unsigned long len);
-__must_check unsigned long __clear_user(void __user *mem, unsigned long len);
-
static __must_check __always_inline int
__copy_from_user_inatomic(void *dst, const void __user *src, unsigned size)
{
diff --git a/arch/x86/include/asm/xsave.h b/arch/x86/include/asm/xsave.h
index 2ddee1b87793..0415cdabb5a6 100644
--- a/arch/x86/include/asm/xsave.h
+++ b/arch/x86/include/asm/xsave.h
@@ -70,8 +70,9 @@ static inline int xsave_user(struct xsave_struct __user *buf)
if (unlikely(err))
return -EFAULT;
- __asm__ __volatile__("1: .byte " REX_PREFIX "0x0f,0xae,0x27\n"
- "2:\n"
+ __asm__ __volatile__(ASM_STAC "\n"
+ "1: .byte " REX_PREFIX "0x0f,0xae,0x27\n"
+ "2: " ASM_CLAC "\n"
".section .fixup,\"ax\"\n"
"3: movl $-1,%[err]\n"
" jmp 2b\n"
@@ -90,8 +91,9 @@ static inline int xrestore_user(struct xsave_struct __user *buf, u64 mask)
u32 lmask = mask;
u32 hmask = mask >> 32;
- __asm__ __volatile__("1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n"
- "2:\n"
+ __asm__ __volatile__(ASM_STAC "\n"
+ "1: .byte " REX_PREFIX "0x0f,0xae,0x2f\n"
+ "2: " ASM_CLAC "\n"
".section .fixup,\"ax\"\n"
"3: movl $-1,%[err]\n"
" jmp 2b\n"
generated by cgit v1.2.3 (git 2.39.0) at 2025-03-01 01:48:15 +0300