Re: Linux 4.10-rc1

From: Hanjun Guo
Date: Mon Dec 26 2016 - 04:47:51 EST


On 2016/12/26 17:18, Al Viro wrote:
> On Mon, Dec 26, 2016 at 05:05:37PM +0800, Kefeng Wang wrote:
>> It looks like we need revert the changes from assembly files.

I tested Kefeng's patch and works. more comments below.

> Better yet, split the damn thing in two and include the asm-only part.

split will cause other places for building errors, because there is no

-#ifndef __ASSEMBLY__

in the file.

>
>> diff --git a/arch/arm64/mm/cache.S b/arch/arm64/mm/cache.S
>> diff --git a/arch/arm64/xen/hypercall.S b/arch/arm64/xen/hypercall.S
> Missed those two... OK, how about this?
>
> arm64: don't pull uaccess.h into *.S
>
> Split asm-only parts of arm64 uaccess.h into a new header and use that
> from *.S.
>
> Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
>
> diff --git a/arch/arm64/include/asm/asm-uaccess.h b/arch/arm64/include/asm/asm-uaccess.h
> new file mode 100644
> index 000000000000..df411f3e083c
> --- /dev/null
> +++ b/arch/arm64/include/asm/asm-uaccess.h
> @@ -0,0 +1,65 @@
> +#ifndef __ASM_ASM_UACCESS_H
> +#define __ASM_ASM_UACCESS_H
> +
> +#include <asm/alternative.h>
> +#include <asm/kernel-pgtable.h>
> +#include <asm/sysreg.h>
> +#include <asm/assembler.h>
> +
> +/*
> + * User access enabling/disabling macros.
> + */
> +#ifdef CONFIG_ARM64_SW_TTBR0_PAN
> + .macro __uaccess_ttbr0_disable, tmp1
> + mrs \tmp1, ttbr1_el1 // swapper_pg_dir
> + add \tmp1, \tmp1, #SWAPPER_DIR_SIZE // reserved_ttbr0 at the end of swapper_pg_dir
> + msr ttbr0_el1, \tmp1 // set reserved TTBR0_EL1
> + isb
> + .endm
> +
> + .macro __uaccess_ttbr0_enable, tmp1
> + get_thread_info \tmp1
> + ldr \tmp1, [\tmp1, #TSK_TI_TTBR0] // load saved TTBR0_EL1
> + msr ttbr0_el1, \tmp1 // set the non-PAN TTBR0_EL1
> + isb
> + .endm
> +
> + .macro uaccess_ttbr0_disable, tmp1
> +alternative_if_not ARM64_HAS_PAN
> + __uaccess_ttbr0_disable \tmp1
> +alternative_else_nop_endif
> + .endm
> +
> + .macro uaccess_ttbr0_enable, tmp1, tmp2
> +alternative_if_not ARM64_HAS_PAN
> + save_and_disable_irq \tmp2 // avoid preemption
> + __uaccess_ttbr0_enable \tmp1
> + restore_irq \tmp2
> +alternative_else_nop_endif
> + .endm
> +#else
> + .macro uaccess_ttbr0_disable, tmp1
> + .endm
> +
> + .macro uaccess_ttbr0_enable, tmp1, tmp2
> + .endm
> +#endif
> +
> +/*
> + * These macros are no-ops when UAO is present.
> + */
> + .macro uaccess_disable_not_uao, tmp1
> + uaccess_ttbr0_disable \tmp1
> +alternative_if ARM64_ALT_PAN_NOT_UAO
> + SET_PSTATE_PAN(1)
> +alternative_else_nop_endif
> + .endm
> +
> + .macro uaccess_enable_not_uao, tmp1, tmp2
> + uaccess_ttbr0_enable \tmp1, \tmp2
> +alternative_if ARM64_ALT_PAN_NOT_UAO
> + SET_PSTATE_PAN(0)
> +alternative_else_nop_endif
> + .endm
> +
> +#endif
> diff --git a/arch/arm64/include/asm/uaccess.h b/arch/arm64/include/asm/uaccess.h
> index d26750ca6e06..46da3ea638bb 100644
> --- a/arch/arm64/include/asm/uaccess.h
> +++ b/arch/arm64/include/asm/uaccess.h
> @@ -22,8 +22,6 @@
> #include <asm/kernel-pgtable.h>
> #include <asm/sysreg.h>
>
> -#ifndef __ASSEMBLY__
> -
> /*
> * User space memory access functions
> */
> @@ -424,66 +422,4 @@ extern long strncpy_from_user(char *dest, 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);
>
> -#else /* __ASSEMBLY__ */
> -
> -#include <asm/assembler.h>
> -
> -/*
> - * User access enabling/disabling macros.
> - */
> -#ifdef CONFIG_ARM64_SW_TTBR0_PAN
> - .macro __uaccess_ttbr0_disable, tmp1
> - mrs \tmp1, ttbr1_el1 // swapper_pg_dir
> - add \tmp1, \tmp1, #SWAPPER_DIR_SIZE // reserved_ttbr0 at the end of swapper_pg_dir
> - msr ttbr0_el1, \tmp1 // set reserved TTBR0_EL1
> - isb
> - .endm
> -
> - .macro __uaccess_ttbr0_enable, tmp1
> - get_thread_info \tmp1
> - ldr \tmp1, [\tmp1, #TSK_TI_TTBR0] // load saved TTBR0_EL1
> - msr ttbr0_el1, \tmp1 // set the non-PAN TTBR0_EL1
> - isb
> - .endm
> -
> - .macro uaccess_ttbr0_disable, tmp1
> -alternative_if_not ARM64_HAS_PAN
> - __uaccess_ttbr0_disable \tmp1
> -alternative_else_nop_endif
> - .endm
> -
> - .macro uaccess_ttbr0_enable, tmp1, tmp2
> -alternative_if_not ARM64_HAS_PAN
> - save_and_disable_irq \tmp2 // avoid preemption
> - __uaccess_ttbr0_enable \tmp1
> - restore_irq \tmp2
> -alternative_else_nop_endif
> - .endm
> -#else
> - .macro uaccess_ttbr0_disable, tmp1
> - .endm
> -
> - .macro uaccess_ttbr0_enable, tmp1, tmp2
> - .endm
> -#endif
> -
> -/*
> - * These macros are no-ops when UAO is present.
> - */
> - .macro uaccess_disable_not_uao, tmp1
> - uaccess_ttbr0_disable \tmp1
> -alternative_if ARM64_ALT_PAN_NOT_UAO
> - SET_PSTATE_PAN(1)
> -alternative_else_nop_endif
> - .endm
> -
> - .macro uaccess_enable_not_uao, tmp1, tmp2
> - uaccess_ttbr0_enable \tmp1, \tmp2
> -alternative_if ARM64_ALT_PAN_NOT_UAO
> - SET_PSTATE_PAN(0)
> -alternative_else_nop_endif
> - .endm
> -
> -#endif /* __ASSEMBLY__ */
> -
> #endif /* __ASM_UACCESS_H */

I think we need to remove the split and keep it unchanged, just
add the change below.

Thanks
Hanjun

> diff --git a/arch/arm64/lib/clear_user.S b/arch/arm64/lib/clear_user.S
> index add4a1334085..e88fb99c1561 100644
> --- a/arch/arm64/lib/clear_user.S
> +++ b/arch/arm64/lib/clear_user.S
> @@ -17,7 +17,7 @@
> */
> #include <linux/linkage.h>
>
> -#include <linux/uaccess.h>
> +#include <asm/asm-uaccess.h>
>
> .text
>
> diff --git a/arch/arm64/lib/copy_from_user.S b/arch/arm64/lib/copy_from_user.S
> index fd6cd05593f9..4b5d826895ff 100644
> --- a/arch/arm64/lib/copy_from_user.S
> +++ b/arch/arm64/lib/copy_from_user.S
> @@ -17,7 +17,7 @@
> #include <linux/linkage.h>
>
> #include <asm/cache.h>
> -#include <linux/uaccess.h>
> +#include <asm/asm-uaccess.h>
>
> /*
> * Copy from user space to a kernel buffer (alignment handled by the hardware)
> diff --git a/arch/arm64/lib/copy_in_user.S b/arch/arm64/lib/copy_in_user.S
> index d828540ded6f..47184c3a97da 100644
> --- a/arch/arm64/lib/copy_in_user.S
> +++ b/arch/arm64/lib/copy_in_user.S
> @@ -19,7 +19,7 @@
> #include <linux/linkage.h>
>
> #include <asm/cache.h>
> -#include <linux/uaccess.h>
> +#include <asm/asm-uaccess.h>
>
> /*
> * Copy from user space to user space (alignment handled by the hardware)
> diff --git a/arch/arm64/lib/copy_to_user.S b/arch/arm64/lib/copy_to_user.S
> index 3e6ae2663b82..351f0766f7a6 100644
> --- a/arch/arm64/lib/copy_to_user.S
> +++ b/arch/arm64/lib/copy_to_user.S
> @@ -17,7 +17,7 @@
> #include <linux/linkage.h>
>
> #include <asm/cache.h>
> -#include <linux/uaccess.h>
> +#include <asm/asm-uaccess.h>
>
> /*
> * Copy to user space from a kernel buffer (alignment handled by the hardware)
> diff --git a/arch/arm64/mm/cache.S b/arch/arm64/mm/cache.S
> index 17f422a4dc55..83c27b6e6dca 100644
> --- a/arch/arm64/mm/cache.S
> +++ b/arch/arm64/mm/cache.S
> @@ -23,7 +23,7 @@
> #include <asm/assembler.h>
> #include <asm/cpufeature.h>
> #include <asm/alternative.h>
> -#include <linux/uaccess.h>
> +#include <asm/asm-uaccess.h>
>
> /*
> * flush_icache_range(start,end)
> diff --git a/arch/arm64/xen/hypercall.S b/arch/arm64/xen/hypercall.S
> index 47cf3f9d89ff..947830a459d2 100644
> --- a/arch/arm64/xen/hypercall.S
> +++ b/arch/arm64/xen/hypercall.S
> @@ -49,7 +49,7 @@
>
> #include <linux/linkage.h>
> #include <asm/assembler.h>
> -#include <linux/uaccess.h>
> +#include <asm/asm-uaccess.h>
> #include <xen/interface/xen.h>
>
>
>
> .
>