[RFC][PATCH 1/7] futex: arch_futex_atomic_op_inuser() calling conventions change

Al Viro
2020-03-23T18:51:39Z

From: Al Viro <viro@zeniv.linux.org.uk>

Move access_ok() in and pagefault_enable()/pagefault_disable() out.
Mechanical conversion only - some instances don't really need
a separate access_ok() at all (e.g. the ones only using
get_user()/put_user(), or architectures where access_ok()
is always true); we'll deal with that in followups.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
arch/alpha/include/asm/futex.h | 5 ++---
arch/arc/include/asm/futex.h | 5 +++--
arch/arm/include/asm/futex.h | 5 +++--
arch/arm64/include/asm/futex.h | 5 ++---
arch/hexagon/include/asm/futex.h | 5 ++---
arch/ia64/include/asm/futex.h | 5 ++---
arch/microblaze/include/asm/futex.h | 5 ++---
arch/mips/include/asm/futex.h | 5 ++---
arch/nds32/include/asm/futex.h | 6 ++----
arch/openrisc/include/asm/futex.h | 5 ++---
arch/parisc/include/asm/futex.h | 5 +++--
arch/powerpc/include/asm/futex.h | 5 ++---
arch/riscv/include/asm/futex.h | 5 ++---
arch/s390/include/asm/futex.h | 4 ++--
arch/sh/include/asm/futex.h | 5 ++---
arch/sparc/include/asm/futex_64.h | 6 ++----
arch/x86/include/asm/futex.h | 5 ++---
arch/xtensa/include/asm/futex.h | 5 ++---
include/asm-generic/futex.h | 4 ++--
kernel/futex.c | 5 ++---
20 files changed, 43 insertions(+), 57 deletions(-)

diff --git a/arch/alpha/include/asm/futex.h b/arch/alpha/include/asm/futex.h
index bfd3c01038f8..da67afd578fd 100644
--- a/arch/alpha/include/asm/futex.h
+++ b/arch/alpha/include/asm/futex.h
@@ -31,7 +31,8 @@ static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
{
int oldval = 0, ret;

- pagefault_disable();
+ if (!access_ok(uaddr, sizeof(u32)))
+ return -EFAULT;

switch (op) {
case FUTEX_OP_SET:
@@ -53,8 +54,6 @@ static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
ret = -ENOSYS;
}

- pagefault_enable();
-
if (!ret)
*oval = oldval;

diff --git a/arch/arc/include/asm/futex.h b/arch/arc/include/asm/futex.h
index 9d0d070e6c22..607d1c16d4dd 100644
--- a/arch/arc/include/asm/futex.h
+++ b/arch/arc/include/asm/futex.h
@@ -75,10 +75,12 @@ static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
{
int oldval = 0, ret;

+ if (!access_ok(uaddr, sizeof(u32)))
+ return -EFAULT;
+
#ifndef CONFIG_ARC_HAS_LLSC
preempt_disable(); /* to guarantee atomic r-m-w of futex op */
#endif
- pagefault_disable();

switch (op) {
case FUTEX_OP_SET:
@@ -101,7 +103,6 @@ static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
ret = -ENOSYS;
}

- pagefault_enable();
#ifndef CONFIG_ARC_HAS_LLSC
preempt_enable();
#endif
diff --git a/arch/arm/include/asm/futex.h b/arch/arm/include/asm/futex.h
index 83c391b597d4..e133da303a98 100644
--- a/arch/arm/include/asm/futex.h
+++ b/arch/arm/include/asm/futex.h
@@ -134,10 +134,12 @@ arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
{
int oldval = 0, ret, tmp;

+ if (!access_ok(uaddr, sizeof(u32)))
+ return -EFAULT;
+
#ifndef CONFIG_SMP
preempt_disable();
#endif
- pagefault_disable();

switch (op) {
case FUTEX_OP_SET:
@@ -159,7 +161,6 @@ arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
ret = -ENOSYS;
}

- pagefault_enable();
#ifndef CONFIG_SMP
preempt_enable();
#endif
diff --git a/arch/arm64/include/asm/futex.h b/arch/arm64/include/asm/futex.h
index 6cc26a127819..97f6a63810ec 100644
--- a/arch/arm64/include/asm/futex.h
+++ b/arch/arm64/include/asm/futex.h
@@ -48,7 +48,8 @@ arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *_uaddr)
int oldval = 0, ret, tmp;
u32 __user *uaddr = __uaccess_mask_ptr(_uaddr);

- pagefault_disable();
+ if (!access_ok(_uaddr, sizeof(u32)))
+ return -EFAULT;

switch (op) {
case FUTEX_OP_SET:
@@ -75,8 +76,6 @@ arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *_uaddr)
ret = -ENOSYS;
}

- pagefault_enable();
-
if (!ret)
*oval = oldval;

diff --git a/arch/hexagon/include/asm/futex.h b/arch/hexagon/include/asm/futex.h
index 0191f7c7193e..6b9c554aee78 100644
--- a/arch/hexagon/include/asm/futex.h
+++ b/arch/hexagon/include/asm/futex.h
@@ -36,7 +36,8 @@ arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
{
int oldval = 0, ret;

- pagefault_disable();
+ if (!access_ok(uaddr, sizeof(u32)))
+ return -EFAULT;

switch (op) {
case FUTEX_OP_SET:
@@ -62,8 +63,6 @@ arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
ret = -ENOSYS;
}

- pagefault_enable();
-
if (!ret)
*oval = oldval;

diff --git a/arch/ia64/include/asm/futex.h b/arch/ia64/include/asm/futex.h
index 2e106d462196..1db26b432d8c 100644
--- a/arch/ia64/include/asm/futex.h
+++ b/arch/ia64/include/asm/futex.h
@@ -50,7 +50,8 @@ arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
{
int oldval = 0, ret;

- pagefault_disable();
+ if (!access_ok(uaddr, sizeof(u32)))
+ return -EFAULT;

switch (op) {
case FUTEX_OP_SET:
@@ -74,8 +75,6 @@ arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
ret = -ENOSYS;
}

- pagefault_enable();
-
if (!ret)
*oval = oldval;

diff --git a/arch/microblaze/include/asm/futex.h b/arch/microblaze/include/asm/futex.h
index 8c90357e5983..86131ed84c9a 100644
--- a/arch/microblaze/include/asm/futex.h
+++ b/arch/microblaze/include/asm/futex.h
@@ -34,7 +34,8 @@ arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
{
int oldval = 0, ret;

- pagefault_disable();
+ if (!access_ok(uaddr, sizeof(u32)))
+ return -EFAULT;

switch (op) {
case FUTEX_OP_SET:
@@ -56,8 +57,6 @@ arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
ret = -ENOSYS;
}

- pagefault_enable();
-
if (!ret)
*oval = oldval;

diff --git a/arch/mips/include/asm/futex.h b/arch/mips/include/asm/futex.h
index 110220705e97..2bf8f6014579 100644
--- a/arch/mips/include/asm/futex.h
+++ b/arch/mips/include/asm/futex.h
@@ -89,7 +89,8 @@ arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
{
int oldval = 0, ret;

- pagefault_disable();
+ if (!access_ok(uaddr, sizeof(u32)))
+ return -EFAULT;

switch (op) {
case FUTEX_OP_SET:
@@ -116,8 +117,6 @@ arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
ret = -ENOSYS;
}

- pagefault_enable();
-
if (!ret)
*oval = oldval;

diff --git a/arch/nds32/include/asm/futex.h b/arch/nds32/include/asm/futex.h
index 5213c65c2e0b..4223f473bd36 100644
--- a/arch/nds32/include/asm/futex.h
+++ b/arch/nds32/include/asm/futex.h
@@ -66,8 +66,8 @@ arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
{
int oldval = 0, ret;

-
- pagefault_disable();
+ if (!access_ok(uaddr, sizeof(u32)))
+ return -EFAULT;
switch (op) {
case FUTEX_OP_SET:
__futex_atomic_op("move %0, %3", ret, oldval, tmp, uaddr,
@@ -93,8 +93,6 @@ arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
ret = -ENOSYS;
}

- pagefault_enable();
-
if (!ret)
*oval = oldval;

diff --git a/arch/openrisc/include/asm/futex.h b/arch/openrisc/include/asm/futex.h
index fe894e6331ae..865e9cd0d97b 100644
--- a/arch/openrisc/include/asm/futex.h
+++ b/arch/openrisc/include/asm/futex.h
@@ -35,7 +35,8 @@ arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
{
int oldval = 0, ret;

- pagefault_disable();
+ if (!access_ok(uaddr, sizeof(u32)))
+ return -EFAULT;

switch (op) {
case FUTEX_OP_SET:
@@ -57,8 +58,6 @@ arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
ret = -ENOSYS;
}

- pagefault_enable();
-
if (!ret)
*oval = oldval;

diff --git a/arch/parisc/include/asm/futex.h b/arch/parisc/include/asm/futex.h
index d2c3e4106851..c10cc9010cc1 100644
--- a/arch/parisc/include/asm/futex.h
+++ b/arch/parisc/include/asm/futex.h
@@ -39,8 +39,10 @@ arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
int oldval, ret;
u32 tmp;

+ if (!access_ok(uaddr, sizeof(u32)))
+ return -EFAULT;
+
_futex_spin_lock_irqsave(uaddr, &flags);
- pagefault_disable();

ret = -EFAULT;
if (unlikely(get_user(oldval, uaddr) != 0))
@@ -73,7 +75,6 @@ arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
ret = -EFAULT;

out_pagefault_enable:
- pagefault_enable();
_futex_spin_unlock_irqrestore(uaddr, &flags);

if (!ret)
diff --git a/arch/powerpc/include/asm/futex.h b/arch/powerpc/include/asm/futex.h
index bc7d9d06a6d9..f187bb5e524e 100644
--- a/arch/powerpc/include/asm/futex.h
+++ b/arch/powerpc/include/asm/futex.h
@@ -35,8 +35,9 @@ static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
{
int oldval = 0, ret;

+ if (!access_ok(uaddr, sizeof(u32)))
+ return -EFAULT;
allow_read_write_user(uaddr, uaddr, sizeof(*uaddr));
- pagefault_disable();

switch (op) {
case FUTEX_OP_SET:
@@ -58,8 +59,6 @@ static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
ret = -ENOSYS;
}

- pagefault_enable();
-
*oval = oldval;

prevent_read_write_user(uaddr, uaddr, sizeof(*uaddr));
diff --git a/arch/riscv/include/asm/futex.h b/arch/riscv/include/asm/futex.h
index fdfaf7f3df7c..1b00badb9f87 100644
--- a/arch/riscv/include/asm/futex.h
+++ b/arch/riscv/include/asm/futex.h
@@ -46,7 +46,8 @@ arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
{
int oldval = 0, ret = 0;

- pagefault_disable();
+ if (!access_ok(uaddr, sizeof(u32)))
+ return -EFAULT;

switch (op) {
case FUTEX_OP_SET:
@@ -73,8 +74,6 @@ arch_futex_atomic_op_inuser(int op, int oparg, int *oval, u32 __user *uaddr)
ret = -ENOSYS;
}

- pagefault_enable();
-
if (!ret)
*oval = oldval;

diff --git a/arch/s390/include/asm/futex.h b/arch/s390/include/asm/futex.h
index 5e97a4353147..ed965c3ecd5b 100644
--- a/arch/s390/include/asm/futex.h
+++ b/arch/s390/include/asm/futex.h
@@ -28,8 +28,9 @@ static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
int oldval = 0, newval, ret;
mm_segment_t old_fs;

+ if (!access_ok(uaddr, sizeof(u32)))
+ return -EFAULT;
old_fs = enable_sacf_uaccess();
- pagefault_disable();
switch (op) {
case FUTEX_OP_SET:
__futex_atomic_op("lr %2,%5\n",
@@ -54,7 +55,6 @@ static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
default:
ret = -ENOSYS;
}
- pagefault_enable();
disable_sacf_uaccess(old_fs);

if (!ret)
diff --git a/arch/sh/include/asm/futex.h b/arch/sh/include/asm/futex.h
index 3190ec89df81..324fa680b13d 100644
--- a/arch/sh/include/asm/futex.h
+++ b/arch/sh/include/asm/futex.h
@@ -34,7 +34,8 @@ static inline int arch_futex_atomic_op_inuser(int op, u32 oparg, int *oval,
u32 oldval, newval, prev;
int ret;

- pagefault_disable();
+ if (!access_ok(uaddr, sizeof(u32)))
+ return -EFAULT;

do {
ret = get_user(oldval, uaddr);
@@ -67,8 +68,6 @@ static inline int arch_futex_atomic_op_inuser(int op, u32 oparg, int *oval,
ret = futex_atomic_cmpxchg_inatomic(&prev, uaddr, oldval, newval);
} while (!ret && prev != oldval);

- pagefault_enable();
-
if (!ret)
*oval = oldval;

diff --git a/arch/sparc/include/asm/futex_64.h b/arch/sparc/include/asm/futex_64.h
index 0865ce77ec00..84fffaaf59d3 100644
--- a/arch/sparc/include/asm/futex_64.h
+++ b/arch/sparc/include/asm/futex_64.h
@@ -35,11 +35,11 @@ static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
{
int oldval = 0, ret, tem;

+ if (!access_ok(uaddr, sizeof(u32)))
+ return -EFAULT;
if (unlikely((((unsigned long) uaddr) & 0x3UL)))
return -EINVAL;

- pagefault_disable();
-
switch (op) {
case FUTEX_OP_SET:
__futex_cas_op("mov\t%4, %1", ret, oldval, uaddr, oparg);
@@ -60,8 +60,6 @@ static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
ret = -ENOSYS;
}

- pagefault_enable();
-
if (!ret)
*oval = oldval;

diff --git a/arch/x86/include/asm/futex.h b/arch/x86/include/asm/futex.h
index 13c83fe97988..6bcd1c1486d9 100644
--- a/arch/x86/include/asm/futex.h
+++ b/arch/x86/include/asm/futex.h
@@ -47,7 +47,8 @@ static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
{
int oldval = 0, ret, tem;

- pagefault_disable();
+ if (!access_ok(uaddr, sizeof(u32)))
+ return -EFAULT;

switch (op) {
case FUTEX_OP_SET:
@@ -70,8 +71,6 @@ static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
ret = -ENOSYS;
}

- pagefault_enable();
-
if (!ret)
*oval = oldval;

diff --git a/arch/xtensa/include/asm/futex.h b/arch/xtensa/include/asm/futex.h
index 964611083224..a1a27b2ea460 100644
--- a/arch/xtensa/include/asm/futex.h
+++ b/arch/xtensa/include/asm/futex.h
@@ -72,7 +72,8 @@ static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
#if XCHAL_HAVE_S32C1I || XCHAL_HAVE_EXCLUSIVE
int oldval = 0, ret;

- pagefault_disable();
+ if (!access_ok(uaddr, sizeof(u32)))
+ return -EFAULT;

switch (op) {
case FUTEX_OP_SET:
@@ -99,8 +100,6 @@ static inline int arch_futex_atomic_op_inuser(int op, int oparg, int *oval,
ret = -ENOSYS;
}

- pagefault_enable();
-
if (!ret)
*oval = oldval;

diff --git a/include/asm-generic/futex.h b/include/asm-generic/futex.h
index 02970b11f71f..3eab7ba912fc 100644
--- a/include/asm-generic/futex.h
+++ b/include/asm-generic/futex.h
@@ -33,8 +33,9 @@ arch_futex_atomic_op_inuser(int op, u32 oparg, int *oval, u32 __user *uaddr)
int oldval, ret;
u32 tmp;

+ if (!access_ok(uaddr, sizeof(u32)))
+ return -EFAULT;
preempt_disable();
- pagefault_disable();

ret = -EFAULT;
if (unlikely(get_user(oldval, uaddr) != 0))
@@ -67,7 +68,6 @@ arch_futex_atomic_op_inuser(int op, u32 oparg, int *oval, u32 __user *uaddr)
ret = -EFAULT;

out_pagefault_enable:
- pagefault_enable();
preempt_enable();

if (ret == 0)
diff --git a/kernel/futex.c b/kernel/futex.c
index 0cf84c8664f2..7fdd2c949487 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -1723,10 +1723,9 @@ static int futex_atomic_op_inuser(unsigned int encoded_op, u32 __user *uaddr)
oparg = 1 << oparg;
}

- if (!access_ok(uaddr, sizeof(u32)))
- return -EFAULT;
-
+ pagefault_disable();
ret = arch_futex_atomic_op_inuser(op, oparg, &oldval, uaddr);
+ pagefault_enable();
if (ret)
return ret;

--
2.11.0