[RFC PATCH 6/6] arch: add untagged_addr definition for other arches

Sat Mar 10 01:16:40 AEDT 2018

On 09/03/18 14:02, Andrey Konovalov wrote:
> To allow arm64 syscalls accept tagged pointers from userspace, we must
> untag them when they are passed to the kernel. Since untagging is done in
> generic parts of the kernel (like the mm subsystem), the untagged_addr
> macro should be defined for all architectures.

Would it not suffice to have an "#ifndef untagged_addr..." fallback in 
linux/uaccess.h?

Robin.

> Define it as a noop for all other architectures besides arm64.
> 
> Signed-off-by: Andrey Konovalov <andreyknvl at google.com>
> ---
>   arch/alpha/include/asm/uaccess.h      | 2 ++
>   arch/arc/include/asm/uaccess.h        | 1 +
>   arch/arm/include/asm/uaccess.h        | 2 ++
>   arch/blackfin/include/asm/uaccess.h   | 2 ++
>   arch/c6x/include/asm/uaccess.h        | 2 ++
>   arch/cris/include/asm/uaccess.h       | 2 ++
>   arch/frv/include/asm/uaccess.h        | 2 ++
>   arch/ia64/include/asm/uaccess.h       | 2 ++
>   arch/m32r/include/asm/uaccess.h       | 2 ++
>   arch/m68k/include/asm/uaccess.h       | 2 ++
>   arch/metag/include/asm/uaccess.h      | 2 ++
>   arch/microblaze/include/asm/uaccess.h | 2 ++
>   arch/mips/include/asm/uaccess.h       | 2 ++
>   arch/mn10300/include/asm/uaccess.h    | 2 ++
>   arch/nios2/include/asm/uaccess.h      | 2 ++
>   arch/openrisc/include/asm/uaccess.h   | 2 ++
>   arch/parisc/include/asm/uaccess.h     | 2 ++
>   arch/powerpc/include/asm/uaccess.h    | 2 ++
>   arch/riscv/include/asm/uaccess.h      | 2 ++
>   arch/score/include/asm/uaccess.h      | 2 ++
>   arch/sh/include/asm/uaccess.h         | 2 ++
>   arch/sparc/include/asm/uaccess.h      | 2 ++
>   arch/tile/include/asm/uaccess.h       | 2 ++
>   arch/x86/include/asm/uaccess.h        | 2 ++
>   arch/xtensa/include/asm/uaccess.h     | 2 ++
>   include/asm-generic/uaccess.h         | 2 ++
>   26 files changed, 51 insertions(+)
> 
> diff --git a/arch/alpha/include/asm/uaccess.h b/arch/alpha/include/asm/uaccess.h
> index 87d8c4f0307d..09d136bb4ff5 100644
> --- a/arch/alpha/include/asm/uaccess.h
> +++ b/arch/alpha/include/asm/uaccess.h
> @@ -2,6 +2,8 @@
>   #ifndef __ALPHA_UACCESS_H
>   #define __ALPHA_UACCESS_H
>   
> +#define untagged_addr(addr)	addr
> +
>   /*
>    * The fs value determines whether argument validity checking should be
>    * performed or not.  If get_fs() == USER_DS, checking is performed, with
> diff --git a/arch/arc/include/asm/uaccess.h b/arch/arc/include/asm/uaccess.h
> index c9173c02081c..2a04b7a4aada 100644
> --- a/arch/arc/include/asm/uaccess.h
> +++ b/arch/arc/include/asm/uaccess.h
> @@ -26,6 +26,7 @@
>   
>   #include <linux/string.h>	/* for generic string functions */
>   
> +#define untagged_addr(addr)	addr
>   
>   #define __kernel_ok		(uaccess_kernel())
>   
> diff --git a/arch/arm/include/asm/uaccess.h b/arch/arm/include/asm/uaccess.h
> index 0bf2347495f1..7d4f4e4021f2 100644
> --- a/arch/arm/include/asm/uaccess.h
> +++ b/arch/arm/include/asm/uaccess.h
> @@ -19,6 +19,8 @@
>   
>   #include <asm/extable.h>
>   
> +#define untagged_addr(addr)	addr
> +
>   /*
>    * These two functions allow hooking accesses to userspace to increase
>    * system integrity by ensuring that the kernel can not inadvertantly
> diff --git a/arch/blackfin/include/asm/uaccess.h b/arch/blackfin/include/asm/uaccess.h
> index 45da4bcb050e..fb6bdc54e7bd 100644
> --- a/arch/blackfin/include/asm/uaccess.h
> +++ b/arch/blackfin/include/asm/uaccess.h
> @@ -18,6 +18,8 @@
>   #include <asm/segment.h>
>   #include <asm/sections.h>
>   
> +#define untagged_addr(addr)	addr
> +
>   #define get_ds()        (KERNEL_DS)
>   #define get_fs()        (current_thread_info()->addr_limit)
>   
> diff --git a/arch/c6x/include/asm/uaccess.h b/arch/c6x/include/asm/uaccess.h
> index ba6756879f00..f187696cf440 100644
> --- a/arch/c6x/include/asm/uaccess.h
> +++ b/arch/c6x/include/asm/uaccess.h
> @@ -9,6 +9,8 @@
>   #ifndef _ASM_C6X_UACCESS_H
>   #define _ASM_C6X_UACCESS_H
>   
> +#define untagged_addr(addr)	addr
> +
>   #include <linux/types.h>
>   #include <linux/compiler.h>
>   #include <linux/string.h>
> diff --git a/arch/cris/include/asm/uaccess.h b/arch/cris/include/asm/uaccess.h
> index 3b42ab0cae93..86d8fbd200c4 100644
> --- a/arch/cris/include/asm/uaccess.h
> +++ b/arch/cris/include/asm/uaccess.h
> @@ -19,6 +19,8 @@
>   #include <asm/processor.h>
>   #include <asm/page.h>
>   
> +#define untagged_addr(addr)	addr
> +
>   /*
>    * The fs value determines whether argument validity checking should be
>    * performed or not.  If get_fs() == USER_DS, checking is performed, with
> diff --git a/arch/frv/include/asm/uaccess.h b/arch/frv/include/asm/uaccess.h
> index ff9562dc6825..be21b42bde09 100644
> --- a/arch/frv/include/asm/uaccess.h
> +++ b/arch/frv/include/asm/uaccess.h
> @@ -12,6 +12,8 @@
>   #ifndef _ASM_UACCESS_H
>   #define _ASM_UACCESS_H
>   
> +#define untagged_addr(addr)	addr
> +
>   /*
>    * User space memory access functions
>    */
> diff --git a/arch/ia64/include/asm/uaccess.h b/arch/ia64/include/asm/uaccess.h
> index a74524f2d625..1c46bf1c4f73 100644
> --- a/arch/ia64/include/asm/uaccess.h
> +++ b/arch/ia64/include/asm/uaccess.h
> @@ -42,6 +42,8 @@
>   #include <asm/io.h>
>   #include <asm/extable.h>
>   
> +#define untagged_addr(addr)	addr
> +
>   /*
>    * For historical reasons, the following macros are grossly misnamed:
>    */
> diff --git a/arch/m32r/include/asm/uaccess.h b/arch/m32r/include/asm/uaccess.h
> index 9d89bc3d8181..6e0fe6b215be 100644
> --- a/arch/m32r/include/asm/uaccess.h
> +++ b/arch/m32r/include/asm/uaccess.h
> @@ -16,6 +16,8 @@
>   #include <asm/setup.h>
>   #include <linux/prefetch.h>
>   
> +#define untagged_addr(addr)	addr
> +
>   /*
>    * The fs value determines whether argument validity checking should be
>    * performed or not.  If get_fs() == USER_DS, checking is performed, with
> diff --git a/arch/m68k/include/asm/uaccess.h b/arch/m68k/include/asm/uaccess.h
> index e896466a41a4..02e0c5878ad5 100644
> --- a/arch/m68k/include/asm/uaccess.h
> +++ b/arch/m68k/include/asm/uaccess.h
> @@ -5,3 +5,5 @@
>   #include <asm/uaccess_mm.h>
>   #endif
>   #include <asm/extable.h>
> +
> +#define untagged_addr(addr)	addr
> diff --git a/arch/metag/include/asm/uaccess.h b/arch/metag/include/asm/uaccess.h
> index a5311eb36e32..1b2f0478868a 100644
> --- a/arch/metag/include/asm/uaccess.h
> +++ b/arch/metag/include/asm/uaccess.h
> @@ -14,6 +14,8 @@
>    * For historical reasons, these macros are grossly misnamed.
>    */
>   
> +#define untagged_addr(addr)	addr
> +
>   #define MAKE_MM_SEG(s)  ((mm_segment_t) { (s) })
>   
>   #define KERNEL_DS       MAKE_MM_SEG(0xFFFFFFFF)
> diff --git a/arch/microblaze/include/asm/uaccess.h b/arch/microblaze/include/asm/uaccess.h
> index 81f16aadbf9e..a66bc26660c3 100644
> --- a/arch/microblaze/include/asm/uaccess.h
> +++ b/arch/microblaze/include/asm/uaccess.h
> @@ -20,6 +20,8 @@
>   #include <asm/extable.h>
>   #include <linux/string.h>
>   
> +#define untagged_addr(addr)	addr
> +
>   /*
>    * On Microblaze the fs value is actually the top of the corresponding
>    * address space.
> diff --git a/arch/mips/include/asm/uaccess.h b/arch/mips/include/asm/uaccess.h
> index b71306947290..2db7606c388b 100644
> --- a/arch/mips/include/asm/uaccess.h
> +++ b/arch/mips/include/asm/uaccess.h
> @@ -16,6 +16,8 @@
>   #include <asm/asm-eva.h>
>   #include <asm/extable.h>
>   
> +#define untagged_addr(addr)	addr
> +
>   /*
>    * The fs value determines whether argument validity checking should be
>    * performed or not.  If get_fs() == USER_DS, checking is performed, with
> diff --git a/arch/mn10300/include/asm/uaccess.h b/arch/mn10300/include/asm/uaccess.h
> index 5af468fd1359..6604699b34b6 100644
> --- a/arch/mn10300/include/asm/uaccess.h
> +++ b/arch/mn10300/include/asm/uaccess.h
> @@ -17,6 +17,8 @@
>   #include <linux/kernel.h>
>   #include <asm/page.h>
>   
> +#define untagged_addr(addr)	addr
> +
>   /*
>    * The fs value determines whether argument validity checking should be
>    * performed or not.  If get_fs() == USER_DS, checking is performed, with
> diff --git a/arch/nios2/include/asm/uaccess.h b/arch/nios2/include/asm/uaccess.h
> index dfa3c7cb30b4..36152a7302a8 100644
> --- a/arch/nios2/include/asm/uaccess.h
> +++ b/arch/nios2/include/asm/uaccess.h
> @@ -19,6 +19,8 @@
>   
>   #include <asm/extable.h>
>   
> +#define untagged_addr(addr)	addr
> +
>   /*
>    * Segment stuff
>    */
> diff --git a/arch/openrisc/include/asm/uaccess.h b/arch/openrisc/include/asm/uaccess.h
> index bbf5c79cce7a..5b43d13ab363 100644
> --- a/arch/openrisc/include/asm/uaccess.h
> +++ b/arch/openrisc/include/asm/uaccess.h
> @@ -27,6 +27,8 @@
>   #include <asm/page.h>
>   #include <asm/extable.h>
>   
> +#define untagged_addr(addr)	addr
> +
>   /*
>    * The fs value determines whether argument validity checking should be
>    * performed or not.  If get_fs() == USER_DS, checking is performed, with
> diff --git a/arch/parisc/include/asm/uaccess.h b/arch/parisc/include/asm/uaccess.h
> index ea70e36ce6af..b0f3cd529c8d 100644
> --- a/arch/parisc/include/asm/uaccess.h
> +++ b/arch/parisc/include/asm/uaccess.h
> @@ -11,6 +11,8 @@
>   #include <linux/bug.h>
>   #include <linux/string.h>
>   
> +#define untagged_addr(addr)	addr
> +
>   #define KERNEL_DS	((mm_segment_t){0})
>   #define USER_DS 	((mm_segment_t){1})
>   
> diff --git a/arch/powerpc/include/asm/uaccess.h b/arch/powerpc/include/asm/uaccess.h
> index 51bfeb8777f0..07ae1c318166 100644
> --- a/arch/powerpc/include/asm/uaccess.h
> +++ b/arch/powerpc/include/asm/uaccess.h
> @@ -8,6 +8,8 @@
>   #include <asm/page.h>
>   #include <asm/extable.h>
>   
> +#define untagged_addr(addr)	addr
> +
>   /*
>    * The fs value determines whether argument validity checking should be
>    * performed or not.  If get_fs() == USER_DS, checking is performed, with
> diff --git a/arch/riscv/include/asm/uaccess.h b/arch/riscv/include/asm/uaccess.h
> index 14b0b22fb578..e774239aac24 100644
> --- a/arch/riscv/include/asm/uaccess.h
> +++ b/arch/riscv/include/asm/uaccess.h
> @@ -25,6 +25,8 @@
>   #include <asm/byteorder.h>
>   #include <asm/asm.h>
>   
> +#define untagged_addr(addr)	addr
> +
>   #define __enable_user_access()							\
>   	__asm__ __volatile__ ("csrs sstatus, %0" : : "r" (SR_SUM) : "memory")
>   #define __disable_user_access()							\
> diff --git a/arch/score/include/asm/uaccess.h b/arch/score/include/asm/uaccess.h
> index a233f3236846..fd16c2a71091 100644
> --- a/arch/score/include/asm/uaccess.h
> +++ b/arch/score/include/asm/uaccess.h
> @@ -5,6 +5,8 @@
>   #include <linux/kernel.h>
>   #include <asm/extable.h>
>   
> +#define untagged_addr(addr)	addr
> +
>   #define get_ds()		(KERNEL_DS)
>   #define get_fs()		(current_thread_info()->addr_limit)
>   #define segment_eq(a, b)	((a).seg == (b).seg)
> diff --git a/arch/sh/include/asm/uaccess.h b/arch/sh/include/asm/uaccess.h
> index 32eb56e00c11..31f3ea075190 100644
> --- a/arch/sh/include/asm/uaccess.h
> +++ b/arch/sh/include/asm/uaccess.h
> @@ -5,6 +5,8 @@
>   #include <asm/segment.h>
>   #include <asm/extable.h>
>   
> +#define untagged_addr(addr)	addr
> +
>   #define __addr_ok(addr) \
>   	((unsigned long __force)(addr) < current_thread_info()->addr_limit.seg)
>   
> diff --git a/arch/sparc/include/asm/uaccess.h b/arch/sparc/include/asm/uaccess.h
> index dd85bc2c2cad..70c2f5ea09ce 100644
> --- a/arch/sparc/include/asm/uaccess.h
> +++ b/arch/sparc/include/asm/uaccess.h
> @@ -7,6 +7,8 @@
>   #include <asm/uaccess_32.h>
>   #endif
>   
> +#define untagged_addr(addr)	addr
> +
>   #define user_addr_max() \
>   	(uaccess_kernel() ? ~0UL : TASK_SIZE)
>   
> diff --git a/arch/tile/include/asm/uaccess.h b/arch/tile/include/asm/uaccess.h
> index cb4fbe7e4f88..7d365b087dcb 100644
> --- a/arch/tile/include/asm/uaccess.h
> +++ b/arch/tile/include/asm/uaccess.h
> @@ -22,6 +22,8 @@
>   #include <asm/processor.h>
>   #include <asm/page.h>
>   
> +#define untagged_addr(addr)	addr
> +
>   /*
>    * The fs value determines whether argument validity checking should be
>    * performed or not.  If get_fs() == USER_DS, checking is performed, with
> diff --git a/arch/x86/include/asm/uaccess.h b/arch/x86/include/asm/uaccess.h
> index aae77eb8491c..3c233fbdd32b 100644
> --- a/arch/x86/include/asm/uaccess.h
> +++ b/arch/x86/include/asm/uaccess.h
> @@ -12,6 +12,8 @@
>   #include <asm/smap.h>
>   #include <asm/extable.h>
>   
> +#define untagged_addr(addr)	addr
> +
>   /*
>    * The fs value determines whether argument validity checking should be
>    * performed or not.  If get_fs() == USER_DS, checking is performed, with
> diff --git a/arch/xtensa/include/asm/uaccess.h b/arch/xtensa/include/asm/uaccess.h
> index f1158b4c629c..130e419c4d6e 100644
> --- a/arch/xtensa/include/asm/uaccess.h
> +++ b/arch/xtensa/include/asm/uaccess.h
> @@ -20,6 +20,8 @@
>   #include <asm/types.h>
>   #include <asm/extable.h>
>   
> +#define untagged_addr(addr)	addr
> +
>   /*
>    * The fs value determines whether argument validity checking should
>    * be performed or not.  If get_fs() == USER_DS, checking is
> diff --git a/include/asm-generic/uaccess.h b/include/asm-generic/uaccess.h
> index 6b2e63df2739..2c46d2253dba 100644
> --- a/include/asm-generic/uaccess.h
> +++ b/include/asm-generic/uaccess.h
> @@ -35,6 +35,8 @@ static inline void set_fs(mm_segment_t fs)
>   #define segment_eq(a, b) ((a).seg == (b).seg)
>   #endif
>   
> +#define untagged_addr(addr) addr
> +
>   #define access_ok(type, addr, size) __access_ok((unsigned long)(addr),(size))
>   
>   /*
> 