[PATCH v5 6/6] arch: remove compat_alloc_user_space

From: Arnd Bergmann
Date: Tue Jul 27 2021 - 10:51:29 EST

From: Arnd Bergmann <arnd@xxxxxxxx>

All users of compat_alloc_user_space() and copy_in_user() have been
removed from the kernel, only a few functions in sparc remain that can
be changed to calling arch_copy_in_user() instead.

Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
---
arch/arm64/include/asm/compat.h | 5 --
arch/arm64/include/asm/uaccess.h | 11 ----
arch/arm64/lib/Makefile | 2 +-
arch/arm64/lib/copy_in_user.S | 77 -------------------------
arch/mips/cavium-octeon/octeon-memcpy.S | 2 -
arch/mips/include/asm/compat.h | 8 ---
arch/mips/include/asm/uaccess.h | 26 ---------
arch/mips/lib/memcpy.S | 11 ----
arch/parisc/include/asm/compat.h | 6 --
arch/parisc/include/asm/uaccess.h | 2 -
arch/parisc/lib/memcpy.c | 9 ---
arch/powerpc/include/asm/compat.h | 16 -----
arch/s390/include/asm/compat.h | 10 ----
arch/s390/include/asm/uaccess.h | 3 -
arch/s390/lib/uaccess.c | 63 --------------------
arch/sparc/include/asm/compat.h | 19 ------
arch/sparc/kernel/process_64.c | 2 +-
arch/sparc/kernel/signal32.c | 12 ++--
arch/sparc/kernel/signal_64.c | 8 +--
arch/x86/include/asm/compat.h | 13 -----
arch/x86/include/asm/uaccess_64.h | 7 ---
include/linux/compat.h | 2 -
include/linux/uaccess.h | 10 ----
kernel/compat.c | 21 -------
24 files changed, 12 insertions(+), 333 deletions(-)
delete mode 100644 arch/arm64/lib/copy_in_user.S

diff --git a/arch/arm64/include/asm/compat.h b/arch/arm64/include/asm/compat.h
index 79c1a750e357..eaa6ca062d89 100644
--- a/arch/arm64/include/asm/compat.h
+++ b/arch/arm64/include/asm/compat.h
@@ -107,11 +107,6 @@ struct compat_statfs {
#define compat_user_stack_pointer() (user_stack_pointer(task_pt_regs(current)))
#define COMPAT_MINSIGSTKSZ 2048

-static inline void __user *arch_compat_alloc_user_space(long len)
-{
- return (void __user *)compat_user_stack_pointer() - len;
-}
-
struct compat_ipc64_perm {
compat_key_t key;
__compat_uid32_t uid;
diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
index b5f08621fa29..190b494e22ab 100644
--- a/arch/arm64/include/asm/uaccess.h
+++ b/arch/arm64/include/asm/uaccess.h
@@ -430,17 +430,6 @@ extern unsigned long __must_check __arch_copy_to_user(void __user *to, const voi
__actu_ret; \
})

-extern unsigned long __must_check __arch_copy_in_user(void __user *to, const void __user *from, unsigned long n);
-#define raw_copy_in_user(to, from, n) \
-({ \
- unsigned long __aciu_ret; \
- uaccess_ttbr0_enable(); \
- __aciu_ret = __arch_copy_in_user(__uaccess_mask_ptr(to), \
- __uaccess_mask_ptr(from), (n)); \
- uaccess_ttbr0_disable(); \
- __aciu_ret; \
-})
-
#define INLINE_COPY_TO_USER
#define INLINE_COPY_FROM_USER

diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile
index 6dd56a49790a..0941180a86d3 100644
--- a/arch/arm64/lib/Makefile
+++ b/arch/arm64/lib/Makefile
@@ -1,6 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
lib-y := clear_user.o delay.o copy_from_user.o \
- copy_to_user.o copy_in_user.o copy_page.o \
+ copy_to_user.o copy_page.o \
clear_page.o csum.o insn.o memchr.o memcpy.o \
memset.o memcmp.o strcmp.o strncmp.o strlen.o \
strnlen.o strchr.o strrchr.o tishift.o
diff --git a/arch/arm64/lib/copy_in_user.S b/arch/arm64/lib/copy_in_user.S
deleted file mode 100644
index dbea3799c3ef..000000000000
--- a/arch/arm64/lib/copy_in_user.S
+++ /dev/null
@@ -1,77 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0-only */
-/*
- * Copy from user space to user space
- *
- * Copyright (C) 2012 ARM Ltd.
- */
-
-#include <linux/linkage.h>
-
-#include <asm/asm-uaccess.h>
-#include <asm/assembler.h>
-#include <asm/cache.h>
-
-/*
- * Copy from user space to user space (alignment handled by the hardware)
- *
- * Parameters:
- * x0 - to
- * x1 - from
- * x2 - n
- * Returns:
- * x0 - bytes not copied
- */
- .macro ldrb1 reg, ptr, val
- user_ldst 9998f, ldtrb, \reg, \ptr, \val
- .endm
-
- .macro strb1 reg, ptr, val
- user_ldst 9998f, sttrb, \reg, \ptr, \val
- .endm
-
- .macro ldrh1 reg, ptr, val
- user_ldst 9997f, ldtrh, \reg, \ptr, \val
- .endm
-
- .macro strh1 reg, ptr, val
- user_ldst 9997f, sttrh, \reg, \ptr, \val
- .endm
-
- .macro ldr1 reg, ptr, val
- user_ldst 9997f, ldtr, \reg, \ptr, \val
- .endm
-
- .macro str1 reg, ptr, val
- user_ldst 9997f, sttr, \reg, \ptr, \val
- .endm
-
- .macro ldp1 reg1, reg2, ptr, val
- user_ldp 9997f, \reg1, \reg2, \ptr, \val
- .endm
-
- .macro stp1 reg1, reg2, ptr, val
- user_stp 9997f, \reg1, \reg2, \ptr, \val
- .endm
-
-end .req x5
-srcin .req x15
-SYM_FUNC_START(__arch_copy_in_user)
- add end, x0, x2
- mov srcin, x1
-#include "copy_template.S"
- mov x0, #0
- ret
-SYM_FUNC_END(__arch_copy_in_user)
-EXPORT_SYMBOL(__arch_copy_in_user)
-
- .section .fixup,"ax"
- .align 2
-9997: cmp dst, dstin
- b.ne 9998f
- // Before being absolutely sure we couldn't copy anything, try harder
-USER(9998f, ldtrb tmp1w, [srcin])
-USER(9998f, sttrb tmp1w, [dst])
- add dst, dst, #1
-9998: sub x0, end, dst // bytes not copied
- ret
- .previous
diff --git a/arch/mips/cavium-octeon/octeon-memcpy.S b/arch/mips/cavium-octeon/octeon-memcpy.S
index 600d018cf354..0a515cde1c18 100644
--- a/arch/mips/cavium-octeon/octeon-memcpy.S
+++ b/arch/mips/cavium-octeon/octeon-memcpy.S
@@ -154,8 +154,6 @@ FEXPORT(__raw_copy_from_user)
EXPORT_SYMBOL(__raw_copy_from_user)
FEXPORT(__raw_copy_to_user)
EXPORT_SYMBOL(__raw_copy_to_user)
-FEXPORT(__raw_copy_in_user)
-EXPORT_SYMBOL(__raw_copy_in_user)
/*
* Note: dst & src may be unaligned, len may be 0
* Temps
diff --git a/arch/mips/include/asm/compat.h b/arch/mips/include/asm/compat.h
index 53f015a1b0a7..bbb3bc5a42fd 100644
--- a/arch/mips/include/asm/compat.h
+++ b/arch/mips/include/asm/compat.h
@@ -96,14 +96,6 @@ struct compat_statfs {

#define COMPAT_OFF_T_MAX 0x7fffffff

-static inline void __user *arch_compat_alloc_user_space(long len)
-{
- struct pt_regs *regs = (struct pt_regs *)
- ((unsigned long) current_thread_info() + THREAD_SIZE - 32) - 1;
-
- return (void __user *) (regs->regs[29] - len);
-}
-
struct compat_ipc64_perm {
compat_key_t key;
__compat_uid32_t uid;
diff --git a/arch/mips/include/asm/uaccess.h b/arch/mips/include/asm/uaccess.h
index 783fecce65c8..f8f74f9f5883 100644
--- a/arch/mips/include/asm/uaccess.h
+++ b/arch/mips/include/asm/uaccess.h
@@ -428,7 +428,6 @@ do { \

extern size_t __raw_copy_from_user(void *__to, const void *__from, size_t __n);
extern size_t __raw_copy_to_user(void *__to, const void *__from, size_t __n);
-extern size_t __raw_copy_in_user(void *__to, const void *__from, size_t __n);

static inline unsigned long
raw_copy_from_user(void *to, const void __user *from, unsigned long n)
@@ -480,31 +479,6 @@ raw_copy_to_user(void __user *to, const void *from, unsigned long n)
#define INLINE_COPY_FROM_USER
#define INLINE_COPY_TO_USER

-static inline unsigned long
-raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)
-{
- register void __user *__cu_to_r __asm__("$4");
- register const void __user *__cu_from_r __asm__("$5");
- register long __cu_len_r __asm__("$6");
-
- __cu_to_r = to;
- __cu_from_r = from;
- __cu_len_r = n;
-
- __asm__ __volatile__(
- ".set\tnoreorder\n\t"
- __MODULE_JAL(__raw_copy_in_user)
- ".set\tnoat\n\t"
- __UA_ADDU "\t$1, %1, %2\n\t"
- ".set\tat\n\t"
- ".set\treorder"
- : "+r" (__cu_to_r), "+r" (__cu_from_r), "+r" (__cu_len_r)
- :
- : "$8", "$9", "$10", "$11", "$12", "$14", "$15", "$24", "$31",
- DADDI_SCRATCH, "memory");
- return __cu_len_r;
-}
-
extern __kernel_size_t __bzero(void __user *addr, __kernel_size_t size);

/*
diff --git a/arch/mips/lib/memcpy.S b/arch/mips/lib/memcpy.S
index e19fb98b5d38..277c32296636 100644
--- a/arch/mips/lib/memcpy.S
+++ b/arch/mips/lib/memcpy.S
@@ -666,8 +666,6 @@ FEXPORT(__raw_copy_from_user)
EXPORT_SYMBOL(__raw_copy_from_user)
FEXPORT(__raw_copy_to_user)
EXPORT_SYMBOL(__raw_copy_to_user)
-FEXPORT(__raw_copy_in_user)
-EXPORT_SYMBOL(__raw_copy_in_user)
#endif
/* Legacy Mode, user <-> user */
__BUILD_COPY_USER LEGACY_MODE USEROP USEROP
@@ -703,13 +701,4 @@ EXPORT_SYMBOL(__raw_copy_to_user)
__BUILD_COPY_USER EVA_MODE KERNELOP USEROP
END(__raw_copy_to_user)

-/*
- * __copy_in_user (EVA)
- */
-
-LEAF(__raw_copy_in_user)
-EXPORT_SYMBOL(__raw_copy_in_user)
-__BUILD_COPY_USER EVA_MODE USEROP USEROP
-END(__raw_copy_in_user)
-
#endif
diff --git a/arch/parisc/include/asm/compat.h b/arch/parisc/include/asm/compat.h
index b5d90e82b65d..c04f5a637c39 100644
--- a/arch/parisc/include/asm/compat.h
+++ b/arch/parisc/include/asm/compat.h
@@ -163,12 +163,6 @@ struct compat_shmid64_ds {
#define COMPAT_ELF_NGREG 80
typedef compat_ulong_t compat_elf_gregset_t[COMPAT_ELF_NGREG];

-static __inline__ void __user *arch_compat_alloc_user_space(long len)
-{
- struct pt_regs *regs = &current->thread.regs;
- return (void __user *)regs->gr[30];
-}
-
static inline int __is_compat_task(struct task_struct *t)
{
return test_tsk_thread_flag(t, TIF_32BIT);
diff --git a/arch/parisc/include/asm/uaccess.h b/arch/parisc/include/asm/uaccess.h
index ed2cd4fb479b..7c13314aae4a 100644
--- a/arch/parisc/include/asm/uaccess.h
+++ b/arch/parisc/include/asm/uaccess.h
@@ -215,8 +215,6 @@ unsigned long __must_check raw_copy_to_user(void __user *dst, const void *src,
unsigned long len);
unsigned long __must_check raw_copy_from_user(void *dst, const void __user *src,
unsigned long len);
-unsigned long __must_check raw_copy_in_user(void __user *dst, const void __user *src,
- unsigned long len);
#define INLINE_COPY_TO_USER
#define INLINE_COPY_FROM_USER

diff --git a/arch/parisc/lib/memcpy.c b/arch/parisc/lib/memcpy.c
index 4b75388190b4..ea70a0e08321 100644
--- a/arch/parisc/lib/memcpy.c
+++ b/arch/parisc/lib/memcpy.c
@@ -38,14 +38,6 @@ unsigned long raw_copy_from_user(void *dst, const void __user *src,
}
EXPORT_SYMBOL(raw_copy_from_user);

-unsigned long raw_copy_in_user(void __user *dst, const void __user *src, unsigned long len)
-{
- mtsp(get_user_space(), 1);
- mtsp(get_user_space(), 2);
- return pa_memcpy((void __force *)dst, (void __force *)src, len);
-}
-
-
void * memcpy(void * dst,const void *src, size_t count)
{
mtsp(get_kernel_space(), 1);
@@ -54,7 +46,6 @@ void * memcpy(void * dst,const void *src, size_t count)
return dst;
}

-EXPORT_SYMBOL(raw_copy_in_user);
EXPORT_SYMBOL(memcpy);

bool copy_from_kernel_nofault_allowed(const void *unsafe_src, size_t size)
diff --git a/arch/powerpc/include/asm/compat.h b/arch/powerpc/include/asm/compat.h
index e33dcf134cdd..7afc96fb6524 100644
--- a/arch/powerpc/include/asm/compat.h
+++ b/arch/powerpc/include/asm/compat.h
@@ -83,22 +83,6 @@ struct compat_statfs {

#define COMPAT_OFF_T_MAX 0x7fffffff

-static inline void __user *arch_compat_alloc_user_space(long len)
-{
- struct pt_regs *regs = current->thread.regs;
- unsigned long usp = regs->gpr[1];
-
- /*
- * We can't access below the stack pointer in the 32bit ABI and
- * can access 288 bytes in the 64bit big-endian ABI,
- * or 512 bytes with the new ELFv2 little-endian ABI.
- */
- if (!is_32bit_task())
- usp -= USER_REDZONE_SIZE;
-
- return (void __user *) (usp - len);
-}
-
/*
* ipc64_perm is actually 32/64bit clean but since the compat layer refers to
* it we may as well define it.
diff --git a/arch/s390/include/asm/compat.h b/arch/s390/include/asm/compat.h
index 8d49505b4a43..cdc7ae72529d 100644
--- a/arch/s390/include/asm/compat.h
+++ b/arch/s390/include/asm/compat.h
@@ -176,16 +176,6 @@ static inline int is_compat_task(void)
return test_thread_flag(TIF_31BIT);
}

-static inline void __user *arch_compat_alloc_user_space(long len)
-{
- unsigned long stack;
-
- stack = KSTK_ESP(current);
- if (is_compat_task())
- stack &= 0x7fffffffUL;
- return (void __user *) (stack - len);
-}
-
#endif

struct compat_ipc64_perm {
diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h
index 2316f2440881..98a1fce2ce67 100644
--- a/arch/s390/include/asm/uaccess.h
+++ b/arch/s390/include/asm/uaccess.h
@@ -227,9 +227,6 @@ static inline int __get_user_fn(void *x, const void __user *ptr, unsigned long s
__get_user(x, ptr); \
})

-unsigned long __must_check
-raw_copy_in_user(void __user *to, const void __user *from, unsigned long n);
-
/*
* Copy a null terminated string from userspace.
*/
diff --git a/arch/s390/lib/uaccess.c b/arch/s390/lib/uaccess.c
index 7ec8b1fa0f08..0df833cedd2c 100644
--- a/arch/s390/lib/uaccess.c
+++ b/arch/s390/lib/uaccess.c
@@ -204,69 +204,6 @@ unsigned long raw_copy_to_user(void __user *to, const void *from, unsigned long
}
EXPORT_SYMBOL(raw_copy_to_user);

-static inline unsigned long copy_in_user_mvcos(void __user *to, const void __user *from,
- unsigned long size)
-{
- unsigned long tmp1, tmp2;
-
- tmp1 = -4096UL;
- /* FIXME: copy with reduced length. */
- asm volatile(
- " lgr 0,%[spec]\n"
- "0: .insn ss,0xc80000000000,0(%0,%1),0(%2),0\n"
- " jz 2f\n"
- "1: algr %0,%3\n"
- " slgr %1,%3\n"
- " slgr %2,%3\n"
- " j 0b\n"
- "2:slgr %0,%0\n"
- "3: \n"
- EX_TABLE(0b,3b)
- : "+a" (size), "+a" (to), "+a" (from), "+a" (tmp1), "=a" (tmp2)
- : [spec] "d" (0x810081UL)
- : "cc", "memory", "0");
- return size;
-}
-
-static inline unsigned long copy_in_user_mvc(void __user *to, const void __user *from,
- unsigned long size)
-{
- unsigned long tmp1;
-
- asm volatile(
- " sacf 256\n"
- " aghi %0,-1\n"
- " jo 5f\n"
- " bras %3,3f\n"
- "0: aghi %0,257\n"
- "1: mvc 0(1,%1),0(%2)\n"
- " la %1,1(%1)\n"
- " la %2,1(%2)\n"
- " aghi %0,-1\n"
- " jnz 1b\n"
- " j 5f\n"
- "2: mvc 0(256,%1),0(%2)\n"
- " la %1,256(%1)\n"
- " la %2,256(%2)\n"
- "3: aghi %0,-256\n"
- " jnm 2b\n"
- "4: ex %0,1b-0b(%3)\n"
- "5: slgr %0,%0\n"
- "6: sacf 768\n"
- EX_TABLE(1b,6b) EX_TABLE(2b,0b) EX_TABLE(4b,0b)
- : "+a" (size), "+a" (to), "+a" (from), "=a" (tmp1)
- : : "cc", "memory");
- return size;
-}
-
-unsigned long raw_copy_in_user(void __user *to, const void __user *from, unsigned long n)
-{
- if (copy_with_mvcos())
- return copy_in_user_mvcos(to, from, n);
- return copy_in_user_mvc(to, from, n);
-}
-EXPORT_SYMBOL(raw_copy_in_user);
-
static inline unsigned long clear_user_mvcos(void __user *to, unsigned long size)
{
unsigned long tmp1, tmp2;
diff --git a/arch/sparc/include/asm/compat.h b/arch/sparc/include/asm/compat.h
index 8b63410e830f..bd949fcf9d63 100644
--- a/arch/sparc/include/asm/compat.h
+++ b/arch/sparc/include/asm/compat.h
@@ -116,25 +116,6 @@ struct compat_statfs {

#define COMPAT_OFF_T_MAX 0x7fffffff

-#ifdef CONFIG_COMPAT
-static inline void __user *arch_compat_alloc_user_space(long len)
-{
- struct pt_regs *regs = current_thread_info()->kregs;
- unsigned long usp = regs->u_regs[UREG_I6];
-
- if (test_thread_64bit_stack(usp))
- usp += STACK_BIAS;
-
- if (test_thread_flag(TIF_32BIT))
- usp &= 0xffffffffUL;
-
- usp -= len;
- usp &= ~0x7UL;
-
- return (void __user *) usp;
-}
-#endif
-
struct compat_ipc64_perm {
compat_key_t key;
__compat_uid32_t uid;
diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c
index d33c58a58d4f..4f5967ebf4e5 100644
--- a/arch/sparc/kernel/process_64.c
+++ b/arch/sparc/kernel/process_64.c
@@ -458,7 +458,7 @@ static unsigned long clone_stackframe(unsigned long csp, unsigned long psp)

distance = fp - psp;
rval = (csp - distance);
- if (copy_in_user((void __user *) rval, (void __user *) psp, distance))
+ if (raw_copy_in_user((void __user *)rval, (void __user *)psp, distance))
rval = 0;
else if (!stack_64bit) {
if (put_user(((u32)csp),
diff --git a/arch/sparc/kernel/signal32.c b/arch/sparc/kernel/signal32.c
index e9695a06492f..afd8455ea05f 100644
--- a/arch/sparc/kernel/signal32.c
+++ b/arch/sparc/kernel/signal32.c
@@ -435,9 +435,9 @@ static int setup_frame32(struct ksignal *ksig, struct pt_regs *regs,
(_COMPAT_NSIG_WORDS - 1) * sizeof(unsigned int));

if (!wsaved) {
- err |= copy_in_user((u32 __user *)sf,
- (u32 __user *)(regs->u_regs[UREG_FP]),
- sizeof(struct reg_window32));
+ err |= raw_copy_in_user((u32 __user *)sf,
+ (u32 __user *)(regs->u_regs[UREG_FP]),
+ sizeof(struct reg_window32));
} else {
struct reg_window *rp;

@@ -567,9 +567,9 @@ static int setup_rt_frame32(struct ksignal *ksig, struct pt_regs *regs,
err |= put_compat_sigset(&sf->mask, oldset, sizeof(compat_sigset_t));

if (!wsaved) {
- err |= copy_in_user((u32 __user *)sf,
- (u32 __user *)(regs->u_regs[UREG_FP]),
- sizeof(struct reg_window32));
+ err |= raw_copy_in_user((u32 __user *)sf,
+ (u32 __user *)(regs->u_regs[UREG_FP]),
+ sizeof(struct reg_window32));
} else {
struct reg_window *rp;

diff --git a/arch/sparc/kernel/signal_64.c b/arch/sparc/kernel/signal_64.c
index a0eec62c825d..3bc4a25f7c25 100644
--- a/arch/sparc/kernel/signal_64.c
+++ b/arch/sparc/kernel/signal_64.c
@@ -406,10 +406,10 @@ setup_rt_frame(struct ksignal *ksig, struct pt_regs *regs)
err |= copy_to_user(&sf->mask, sigmask_to_save(), sizeof(sigset_t));

if (!wsaved) {
- err |= copy_in_user((u64 __user *)sf,
- (u64 __user *)(regs->u_regs[UREG_FP] +
- STACK_BIAS),
- sizeof(struct reg_window));
+ err |= raw_copy_in_user((u64 __user *)sf,
+ (u64 __user *)(regs->u_regs[UREG_FP] +
+ STACK_BIAS),
+ sizeof(struct reg_window));
} else {
struct reg_window *rp;

diff --git a/arch/x86/include/asm/compat.h b/arch/x86/include/asm/compat.h
index 4ae01cdb99de..7516e4199b3c 100644
--- a/arch/x86/include/asm/compat.h
+++ b/arch/x86/include/asm/compat.h
@@ -156,19 +156,6 @@ struct compat_shmid64_ds {
(!!(task_pt_regs(current)->orig_ax & __X32_SYSCALL_BIT))
#endif

-static inline void __user *arch_compat_alloc_user_space(long len)
-{
- compat_uptr_t sp = task_pt_regs(current)->sp;
-
- /*
- * -128 for the x32 ABI redzone. For IA32, it is not strictly
- * necessary, but not harmful.
- */
- sp -= 128;
-
- return (void __user *)round_down(sp - len, 16);
-}
-
static inline bool in_x32_syscall(void)
{
#ifdef CONFIG_X86_X32_ABI
diff --git a/arch/x86/include/asm/uaccess_64.h b/arch/x86/include/asm/uaccess_64.h
index e7265a552f4f..45697e04d771 100644
--- a/arch/x86/include/asm/uaccess_64.h
+++ b/arch/x86/include/asm/uaccess_64.h
@@ -58,13 +58,6 @@ raw_copy_to_user(void __user *dst, const void *src, unsigned long size)
return copy_user_generic((__force void *)dst, src, size);
}

-static __always_inline __must_check
-unsigned long raw_copy_in_user(void __user *dst, const void __user *src, unsigned long size)
-{
- return copy_user_generic((__force void *)dst,
- (__force void *)src, size);
-}
-
extern long __copy_user_nocache(void *dst, const void __user *src,
unsigned size, int zerorest);

diff --git a/include/linux/compat.h b/include/linux/compat.h
index 2d42cebd1fb8..1c758b0e0359 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -511,8 +511,6 @@ extern long compat_arch_ptrace(struct task_struct *child, compat_long_t request,

struct epoll_event; /* fortunately, this one is fixed-layout */

-extern void __user *compat_alloc_user_space(unsigned long len);
-
int compat_restore_altstack(const compat_stack_t __user *uss);
int __compat_save_altstack(compat_stack_t __user *, unsigned long);
#define unsafe_compat_save_altstack(uss, sp, label) do { \
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index c05e903cef02..ac0394087f7d 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -200,16 +200,6 @@ copy_to_user(void __user *to, const void *from, unsigned long n)
n = _copy_to_user(to, from, n);
return n;
}
-#ifdef CONFIG_COMPAT
-static __always_inline unsigned long __must_check
-copy_in_user(void __user *to, const void __user *from, unsigned long n)
-{
- might_fault();
- if (access_ok(to, n) && access_ok(from, n))
- n = raw_copy_in_user(to, from, n);
- return n;
-}
-#endif

#ifndef copy_mc_to_kernel
/*
diff --git a/kernel/compat.c b/kernel/compat.c
index 05adfd6fa8bf..55551989d9da 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -269,24 +269,3 @@ get_compat_sigset(sigset_t *set, const compat_sigset_t __user *compat)
return 0;
}
EXPORT_SYMBOL_GPL(get_compat_sigset);
-
-/*
- * Allocate user-space memory for the duration of a single system call,
- * in order to marshall parameters inside a compat thunk.
- */
-void __user *compat_alloc_user_space(unsigned long len)
-{
- void __user *ptr;
-
- /* If len would occupy more than half of the entire compat space... */
- if (unlikely(len > (((compat_uptr_t)~0) >> 1)))
- return NULL;
-
- ptr = arch_compat_alloc_user_space(len);
-
- if (unlikely(!access_ok(ptr, len)))
- return NULL;
-
- return ptr;
-}
-EXPORT_SYMBOL_GPL(compat_alloc_user_space);
--
2.29.2