| Message ID | 20220216131332.1489939-8-arnd@kernel.org (mailing list archive) |
|---|---|
| State | Handled Elsewhere |
| Headers | show |
| Series | clean up asm/uaccess.h, kill set_fs for good | expand |
On Wed, Feb 16, 2022 at 02:13:21PM +0100, Arnd Bergmann wrote: > 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() Looks good: Reviewed-by: Christoph Hellwig <hch@lst.de>
On 2/16/22 07:13, Arnd Bergmann wrote: > 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 */ Acked-by: Dinh Nguyen <dinguyen@kernel.org>
On Thu, Feb 24, 2022 at 12:30 AM Dinh Nguyen <dinguyen@kernel.org> wrote: > On 2/16/22 07:13, Arnd Bergmann wrote: 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> > > Acked-by: Dinh Nguyen <dinguyen@kernel.org> Thanks! Could you also have a look at patch 2 (uaccess: fix nios2 and microblaze get_user_8)? That one is actually more critical, and should be backported to stable kernels. Arnd
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 */