[PATCH v2 07/18] nios2: drop access_ok() check from __put_user()
From: Arnd Bergmann <arnd@kernel.org>
Date: 2022-02-16 13:17:22
Also in:
linux-api, linux-arch, linux-m68k, linux-mips, linux-mm, linux-riscv, linux-s390, linux-sh, linux-um, linuxppc-dev, lkml, sparclinux
Subsystem:
nios2 architecture, the rest · Maintainers:
Dinh Nguyen, Linus Torvalds
From: Arnd Bergmann <arnd@arndb.de> Unlike other architectures, the nios2 version of __put_user() has an extra check for access_ok(), preventing it from being used to implement __put_kernel_nofault(). Split up put_user() along the same lines as __get_user()/get_user() Signed-off-by: Arnd Bergmann <arnd@arndb.de> --- arch/nios2/include/asm/uaccess.h | 56 +++++++++++++++++++------------- 1 file changed, 33 insertions(+), 23 deletions(-)
diff --git a/arch/nios2/include/asm/uaccess.h b/arch/nios2/include/asm/uaccess.h
index ca9285a915ef..a5cbe07cf0da 100644
--- a/arch/nios2/include/asm/uaccess.h
+++ b/arch/nios2/include/asm/uaccess.h@@ -167,34 +167,44 @@ do { \ : "r" (val), "r" (ptr), "i" (-EFAULT)); \ } -#define put_user(x, ptr) \ +#define __put_user_common(__pu_val, __pu_ptr) \ ({ \ long __pu_err = -EFAULT; \ - __typeof__(*(ptr)) __user *__pu_ptr = (ptr); \ - __typeof__(*(ptr)) __pu_val = (__typeof(*ptr))(x); \ - if (access_ok(__pu_ptr, sizeof(*__pu_ptr))) { \ - switch (sizeof(*__pu_ptr)) { \ - case 1: \ - __put_user_asm(__pu_val, "stb", __pu_ptr, __pu_err); \ - break; \ - case 2: \ - __put_user_asm(__pu_val, "sth", __pu_ptr, __pu_err); \ - break; \ - case 4: \ - __put_user_asm(__pu_val, "stw", __pu_ptr, __pu_err); \ - break; \ - default: \ - /* XXX: This looks wrong... */ \ - __pu_err = 0; \ - if (copy_to_user(__pu_ptr, &(__pu_val), \ - sizeof(*__pu_ptr))) \ - __pu_err = -EFAULT; \ - break; \ - } \ + switch (sizeof(*__pu_ptr)) { \ + case 1: \ + __put_user_asm(__pu_val, "stb", __pu_ptr, __pu_err); \ + break; \ + case 2: \ + __put_user_asm(__pu_val, "sth", __pu_ptr, __pu_err); \ + break; \ + case 4: \ + __put_user_asm(__pu_val, "stw", __pu_ptr, __pu_err); \ + break; \ + default: \ + /* XXX: This looks wrong... */ \ + __pu_err = 0; \ + if (__copy_to_user(__pu_ptr, &(__pu_val), \ + sizeof(*__pu_ptr))) \ + __pu_err = -EFAULT; \ + break; \ } \ __pu_err; \ }) -#define __put_user(x, ptr) put_user(x, ptr) +#define __put_user(x, ptr) \ +({ \ + __auto_type __pu_ptr = (ptr); \ + typeof(*__pu_ptr) __pu_val = (typeof(*__pu_ptr))(x); \ + __put_user_common(__pu_val, __pu_ptr); \ +}) + +#define put_user(x, ptr) \ +({ \ + __auto_type __pu_ptr = (ptr); \ + typeof(*__pu_ptr) __pu_val = (typeof(*__pu_ptr))(x); \ + access_ok(__pu_ptr, sizeof(*__pu_ptr)) ? \ + __put_user_common(__pu_val, __pu_ptr) : \ + -EFAULT; \ +}) #endif /* _ASM_NIOS2_UACCESS_H */
--
2.29.2