Re: [PATCH] m68k: Use generic strncpy_from_user(), strlen_user(), and strnlen_user()

Greg Ungerer
2012-05-30T03:08:15Z

Hi Geert,

On 30/05/12 07:33, Geert Uytterhoeven wrote:
> Signed-off-by: Geert Uytterhoeven<geert@linux-m68k.org>

Looks good:

Acked-by: Greg Ungerer <gerg@uclinux.org>

> ---
> Do we also want
>
> select HAVE_EFFICIENT_UNALIGNED_ACCESS if (!COLDFIRE&& !M68000)

Maybe yes.

Regards
Greg

> arch/m68k/Kconfig | 2 +
> arch/m68k/include/asm/Kbuild | 2 +
> arch/m68k/include/asm/uaccess_mm.h | 11 +++--
> arch/m68k/lib/uaccess.c | 74 ------------------------------------
> 4 files changed, 11 insertions(+), 78 deletions(-)
>
> diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
> index cac5b6b..1471201 100644
> --- a/arch/m68k/Kconfig
> +++ b/arch/m68k/Kconfig
> @@ -7,6 +7,8 @@ config M68K
> select GENERIC_IRQ_SHOW
> select ARCH_HAVE_NMI_SAFE_CMPXCHG if RMW_INSNS
> select GENERIC_CPU_DEVICES
> + select GENERIC_STRNCPY_FROM_USER if MMU
> + select GENERIC_STRNLEN_USER if MMU
> select FPU if MMU
> select ARCH_USES_GETTIMEOFFSET if MMU&& !COLDFIRE
>
> diff --git a/arch/m68k/include/asm/Kbuild b/arch/m68k/include/asm/Kbuild
> index 1a922fa..eafa253 100644
> --- a/arch/m68k/include/asm/Kbuild
> +++ b/arch/m68k/include/asm/Kbuild
> @@ -1,2 +1,4 @@
> include include/asm-generic/Kbuild.asm
> header-y += cachectl.h
> +
> +generic-y += word-at-a-time.h
> diff --git a/arch/m68k/include/asm/uaccess_mm.h b/arch/m68k/include/asm/uaccess_mm.h
> index 9c80cd5..472c891 100644
> --- a/arch/m68k/include/asm/uaccess_mm.h
> +++ b/arch/m68k/include/asm/uaccess_mm.h
> @@ -379,12 +379,15 @@ __constant_copy_to_user(void __user *to, const void *from, unsigned long n)
> #define copy_from_user(to, from, n) __copy_from_user(to, from, n)
> #define copy_to_user(to, from, n) __copy_to_user(to, from, n)
>
> -long strncpy_from_user(char *dst, const char __user *src, long count);
> -long strnlen_user(const char __user *src, long n);
> +#define user_addr_max() \
> + (segment_eq(get_fs(), USER_DS) ? TASK_SIZE : ~0UL)
> +
> +extern long 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 __clear_user(void __user *to, unsigned long n);
>
> #define clear_user __clear_user
>
> -#define strlen_user(str) strnlen_user(str, 32767)
> -
> #endif /* _M68K_UACCESS_H */
> diff --git a/arch/m68k/lib/uaccess.c b/arch/m68k/lib/uaccess.c
> index 5664386..5e97f2e 100644
> --- a/arch/m68k/lib/uaccess.c
> +++ b/arch/m68k/lib/uaccess.c
> @@ -104,80 +104,6 @@ unsigned long __generic_copy_to_user(void __user *to, const void *from,
> EXPORT_SYMBOL(__generic_copy_to_user);
>
> /*
> - * Copy a null terminated string from userspace.
> - */
> -long strncpy_from_user(char *dst, const char __user *src, long count)
> -{
> - long res;
> - char c;
> -
> - if (count<= 0)
> - return count;
> -
> - asm volatile ("\n"
> - "1: "MOVES".b (%2)+,%4\n"
> - " move.b %4,(%1)+\n"
> - " jeq 2f\n"
> - " subq.l #1,%3\n"
> - " jne 1b\n"
> - "2: sub.l %3,%0\n"
> - "3:\n"
> - " .section .fixup,\"ax\"\n"
> - " .even\n"
> - "10: move.l %5,%0\n"
> - " jra 3b\n"
> - " .previous\n"
> - "\n"
> - " .section __ex_table,\"a\"\n"
> - " .align 4\n"
> - " .long 1b,10b\n"
> - " .previous"
> - : "=d" (res), "+a" (dst), "+a" (src), "+r" (count), "=&d" (c)
> - : "i" (-EFAULT), "0" (count));
> -
> - return res;
> -}
> -EXPORT_SYMBOL(strncpy_from_user);
> -
> -/*
> - * Return the size of a string (including the ending 0)
> - *
> - * Return 0 on exception, a value greater than N if too long
> - */
> -long strnlen_user(const char __user *src, long n)
> -{
> - char c;
> - long res;
> -
> - asm volatile ("\n"
> - "1: subq.l #1,%1\n"
> - " jmi 3f\n"
> - "2: "MOVES".b (%0)+,%2\n"
> - " tst.b %2\n"
> - " jne 1b\n"
> - " jra 4f\n"
> - "\n"
> - "3: addq.l #1,%0\n"
> - "4: sub.l %4,%0\n"
> - "5:\n"
> - " .section .fixup,\"ax\"\n"
> - " .even\n"
> - "20: sub.l %0,%0\n"
> - " jra 5b\n"
> - " .previous\n"
> - "\n"
> - " .section __ex_table,\"a\"\n"
> - " .align 4\n"
> - " .long 2b,20b\n"
> - " .previous\n"
> - : "=&a" (res), "+d" (n), "=&d" (c)
> - : "0" (src), "r" (src));
> -
> - return res;
> -}
> -EXPORT_SYMBOL(strnlen_user);
> -
> -/*
> * Zero Userspace
> */
>

--
------------------------------------------------------------------------
Greg Ungerer -- Principal Engineer EMAIL: gerg@snapgear.com
SnapGear Group, McAfee PHONE: +61 7 3435 2888
8 Gardner Close FAX: +61 7 3217 5323
Milton, QLD, 4064, Australia WEB: http://www.SnapGear.com