[PATCH -next] riscv: extable: add new extable type EX_TYPE_KACCESS_ERR_ZERO support

Tong Tiangen tongtiangen at huawei.com
Fri Aug 12 03:19:07 PDT 2022



在 2022/8/12 16:58, Conor.Dooley at microchip.com 写道:
> On 12/08/2022 09:52, Tong Tiangen wrote:
>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>>
>> Currently, The extable type EX_TYPE_UACCESS_ERR_ZERO is used by
>> __get/put_kernel_nofault(), but those helpers are not uaccess type, so we
>> add a new extable type EX_TYPE_KACCESS_ERR_ZERO which can be used by
>> __get/put_kernel_no_fault().
>>
>> Also change the name of __get/put_user_nocheck to __get/put_mem_nocheck
>> to make it conform to its use situation (not only used in uaccess).
> 
> Is there a reason why this should not be a different patch?
> Thanks,
> Conor.

Oh, my fault, this modification should be split.
Thanks,
Tong.

> 
>>
>> Signed-off-by: Tong Tiangen <tongtiangen at huawei.com>
>> ---
>>    arch/riscv/include/asm/asm-extable.h |  12 ++
>>    arch/riscv/include/asm/uaccess.h     | 160 +++++++++++++--------------
>>    2 files changed, 92 insertions(+), 80 deletions(-)
>>
>> diff --git a/arch/riscv/include/asm/asm-extable.h b/arch/riscv/include/asm/asm-extable.h
>> index 14be0673f5b5..73c70098a9c8 100644
>> --- a/arch/riscv/include/asm/asm-extable.h
>> +++ b/arch/riscv/include/asm/asm-extable.h
>> @@ -6,6 +6,7 @@
>>    #define EX_TYPE_FIXUP                  1
>>    #define EX_TYPE_BPF                    2
>>    #define EX_TYPE_UACCESS_ERR_ZERO       3
>> +#define EX_TYPE_KACCESS_ERR_ZERO       4
>>
>>    #ifdef __ASSEMBLY__
>>
>> @@ -57,9 +58,20 @@
>>                               EX_DATA_REG(ZERO, zero)                     \
>>                             ")")
>>
>> +#define _ASM_EXTABLE_KACCESS_ERR_ZERO(insn, fixup, err, zero)          \
>> +       __DEFINE_ASM_GPR_NUMS                                           \
>> +       __ASM_EXTABLE_RAW(#insn, #fixup,                                \
>> +                         __stringify(EX_TYPE_KACCESS_ERR_ZERO),        \
>> +                         "("                                           \
>> +                           EX_DATA_REG(ERR, err) " | "                 \
>> +                           EX_DATA_REG(ZERO, zero)                     \
>> +                         ")")
>> +
>>    #define _ASM_EXTABLE_UACCESS_ERR(insn, fixup, err)                     \
>>           _ASM_EXTABLE_UACCESS_ERR_ZERO(insn, fixup, err, zero)
>>
>> +#define _ASM_EXTABLE_KACCESS_ERR(insn, fixup, err)                     \
>> +       _ASM_EXTABLE_KACCESS_ERR_ZERO(insn, fixup, err, zero)
>>    #endif /* __ASSEMBLY__ */
>>
>>    #endif /* __ASM_ASM_EXTABLE_H */
>> diff --git a/arch/riscv/include/asm/uaccess.h b/arch/riscv/include/asm/uaccess.h
>> index 855450bed9f5..5372f3f1e3f6 100644
>> --- a/arch/riscv/include/asm/uaccess.h
>> +++ b/arch/riscv/include/asm/uaccess.h
>> @@ -50,62 +50,62 @@
>>     * call.
>>     */
>>
>> -#define __get_user_asm(insn, x, ptr, err)                      \
>> -do {                                                           \
>> -       __typeof__(x) __x;                                      \
>> -       __asm__ __volatile__ (                                  \
>> -               "1:\n"                                          \
>> -               "       " insn " %1, %2\n"                      \
>> -               "2:\n"                                          \
>> -               _ASM_EXTABLE_UACCESS_ERR_ZERO(1b, 2b, %0, %1)   \
>> -               : "+r" (err), "=&r" (__x)                       \
>> -               : "m" (*(ptr)));                                \
>> -       (x) = __x;                                              \
>> +#define __get_mem_asm(insn, x, ptr, err, type)                         \
>> +do {                                                                   \
>> +       __typeof__(x) __x;                                              \
>> +       __asm__ __volatile__ (                                          \
>> +               "1:\n"                                                  \
>> +               "       " insn " %1, %2\n"                              \
>> +               "2:\n"                                                  \
>> +               _ASM_EXTABLE_##type##ACCESS_ERR_ZERO(1b, 2b, %0, %1)    \
>> +               : "+r" (err), "=&r" (__x)                               \
>> +               : "m" (*(ptr)));                                        \
>> +       (x) = __x;                                                      \
>>    } while (0)
>>
>>    #ifdef CONFIG_64BIT
>> -#define __get_user_8(x, ptr, err) \
>> -       __get_user_asm("ld", x, ptr, err)
>> +#define __get_mem_8(x, ptr, err, type) \
>> +       __get_mem_asm("ld", x, ptr, err, type)
>>    #else /* !CONFIG_64BIT */
>> -#define __get_user_8(x, ptr, err)                              \
>> -do {                                                           \
>> -       u32 __user *__ptr = (u32 __user *)(ptr);                \
>> -       u32 __lo, __hi;                                         \
>> -       __asm__ __volatile__ (                                  \
>> -               "1:\n"                                          \
>> -               "       lw %1, %3\n"                            \
>> -               "2:\n"                                          \
>> -               "       lw %2, %4\n"                            \
>> -               "3:\n"                                          \
>> -               _ASM_EXTABLE_UACCESS_ERR_ZERO(1b, 3b, %0, %1)   \
>> -               _ASM_EXTABLE_UACCESS_ERR_ZERO(2b, 3b, %0, %1)   \
>> -               : "+r" (err), "=&r" (__lo), "=r" (__hi)         \
>> -               : "m" (__ptr[__LSW]), "m" (__ptr[__MSW]));      \
>> -       if (err)                                                \
>> -               __hi = 0;                                       \
>> -       (x) = (__typeof__(x))((__typeof__((x)-(x)))(            \
>> -               (((u64)__hi << 32) | __lo)));                   \
>> +#define __get_mem_8(x, ptr, err, type)                                 \
>> +do {                                                                   \
>> +       u32 __user *__ptr = (u32 __user *)(ptr);                        \
>> +       u32 __lo, __hi;                                                 \
>> +       __asm__ __volatile__ (                                          \
>> +               "1:\n"                                                  \
>> +               "       lw %1, %3\n"                                    \
>> +               "2:\n"                                                  \
>> +               "       lw %2, %4\n"                                    \
>> +               "3:\n"                                                  \
>> +               _ASM_EXTABLE_##type##ACCESS_ERR_ZERO(1b, 3b, %0, %1)    \
>> +               _ASM_EXTABLE_##type##ACCESS_ERR_ZERO(2b, 3b, %0, %1)    \
>> +               : "+r" (err), "=&r" (__lo), "=r" (__hi)                 \
>> +               : "m" (__ptr[__LSW]), "m" (__ptr[__MSW]));              \
>> +       if (err)                                                        \
>> +               __hi = 0;                                               \
>> +       (x) = (__typeof__(x))((__typeof__((x)-(x)))(                    \
>> +               (((u64)__hi << 32) | __lo)));                           \
>>    } while (0)
>>    #endif /* CONFIG_64BIT */
>>
>> -#define __get_user_nocheck(x, __gu_ptr, __gu_err)              \
>> -do {                                                           \
>> -       switch (sizeof(*__gu_ptr)) {                            \
>> -       case 1:                                                 \
>> -               __get_user_asm("lb", (x), __gu_ptr, __gu_err);  \
>> -               break;                                          \
>> -       case 2:                                                 \
>> -               __get_user_asm("lh", (x), __gu_ptr, __gu_err);  \
>> -               break;                                          \
>> -       case 4:                                                 \
>> -               __get_user_asm("lw", (x), __gu_ptr, __gu_err);  \
>> -               break;                                          \
>> -       case 8:                                                 \
>> -               __get_user_8((x), __gu_ptr, __gu_err);  \
>> -               break;                                          \
>> -       default:                                                \
>> -               BUILD_BUG();                                    \
>> -       }                                                       \
>> +#define __get_mem_nocheck(x, __gu_ptr, __gu_err, type)                 \
>> +do {                                                                   \
>> +       switch (sizeof(*__gu_ptr)) {                                    \
>> +       case 1:                                                         \
>> +               __get_mem_asm("lb", (x), __gu_ptr, __gu_err, type);     \
>> +               break;                                                  \
>> +       case 2:                                                         \
>> +               __get_mem_asm("lh", (x), __gu_ptr, __gu_err, type);     \
>> +               break;                                                  \
>> +       case 4:                                                         \
>> +               __get_mem_asm("lw", (x), __gu_ptr, __gu_err, type);     \
>> +               break;                                                  \
>> +       case 8:                                                         \
>> +               __get_mem_8((x), __gu_ptr, __gu_err, type);             \
>> +               break;                                                  \
>> +       default:                                                        \
>> +               BUILD_BUG();                                            \
>> +       }                                                               \
>>    } while (0)
>>
>>    /**
>> @@ -136,7 +136,7 @@ do {                                                                \
>>           __chk_user_ptr(__gu_ptr);                               \
>>                                                                   \
>>           __enable_user_access();                                 \
>> -       __get_user_nocheck(x, __gu_ptr, __gu_err);              \
>> +       __get_mem_nocheck(x, __gu_ptr, __gu_err, U);            \
>>           __disable_user_access();                                \
>>                                                                   \
>>           __gu_err;                                               \
>> @@ -163,28 +163,28 @@ do {                                                              \
>>    ({                                                             \
>>           const __typeof__(*(ptr)) __user *__p = (ptr);           \
>>           might_fault();                                          \
>> -       access_ok(__p, sizeof(*__p)) ?          \
>> +       access_ok(__p, sizeof(*__p)) ?                          \
>>                   __get_user((x), __p) :                          \
>>                   ((x) = 0, -EFAULT);                             \
>>    })
>>
>> -#define __put_user_asm(insn, x, ptr, err)                      \
>> +#define __put_mem_asm(insn, x, ptr, err, type)                 \
>>    do {                                                           \
>>           __typeof__(*(ptr)) __x = x;                             \
>>           __asm__ __volatile__ (                                  \
>>                   "1:\n"                                          \
>>                   "       " insn " %z2, %1\n"                     \
>>                   "2:\n"                                          \
>> -               _ASM_EXTABLE_UACCESS_ERR(1b, 2b, %0)            \
>> +               _ASM_EXTABLE_##type##ACCESS_ERR(1b, 2b, %0)     \
>>                   : "+r" (err), "=m" (*(ptr))                     \
>>                   : "rJ" (__x));                                  \
>>    } while (0)
>>
>>    #ifdef CONFIG_64BIT
>> -#define __put_user_8(x, ptr, err) \
>> -       __put_user_asm("sd", x, ptr, err)
>> +#define __put_mem_8(x, ptr, err, type) \
>> +       __put_mem_asm("sd", x, ptr, err, type)
>>    #else /* !CONFIG_64BIT */
>> -#define __put_user_8(x, ptr, err)                              \
>> +#define __put_mem_8(x, ptr, err, type)                         \
>>    do {                                                           \
>>           u32 __user *__ptr = (u32 __user *)(ptr);                \
>>           u64 __x = (__typeof__((x)-(x)))(x);                     \
>> @@ -194,8 +194,8 @@ do {                                                                \
>>                   "2:\n"                                          \
>>                   "       sw %z4, %2\n"                           \
>>                   "3:\n"                                          \
>> -               _ASM_EXTABLE_UACCESS_ERR(1b, 3b, %0)            \
>> -               _ASM_EXTABLE_UACCESS_ERR(2b, 3b, %0)            \
>> +               _ASM_EXTABLE_##type##ACCESS_ERR(1b, 3b, %0)     \
>> +               _ASM_EXTABLE_##type##ACCESS_ERR(2b, 3b, %0)     \
>>                   : "+r" (err),                                   \
>>                           "=m" (__ptr[__LSW]),                    \
>>                           "=m" (__ptr[__MSW])                     \
>> @@ -203,24 +203,24 @@ do {                                                              \
>>    } while (0)
>>    #endif /* CONFIG_64BIT */
>>
>> -#define __put_user_nocheck(x, __gu_ptr, __pu_err)                                      \
>> -do {                                                           \
>> -       switch (sizeof(*__gu_ptr)) {                            \
>> -       case 1:                                                 \
>> -               __put_user_asm("sb", (x), __gu_ptr, __pu_err);  \
>> -               break;                                          \
>> -       case 2:                                                 \
>> -               __put_user_asm("sh", (x), __gu_ptr, __pu_err);  \
>> -               break;                                          \
>> -       case 4:                                                 \
>> -               __put_user_asm("sw", (x), __gu_ptr, __pu_err);  \
>> -               break;                                          \
>> -       case 8:                                                 \
>> -               __put_user_8((x), __gu_ptr, __pu_err);  \
>> -               break;                                          \
>> -       default:                                                \
>> -               BUILD_BUG();                                    \
>> -       }                                                       \
>> +#define __put_mem_nocheck(x, __gu_ptr, __pu_err, type)                 \
>> +do {                                                                   \
>> +       switch (sizeof(*__gu_ptr)) {                                    \
>> +       case 1:                                                         \
>> +               __put_mem_asm("sb", (x), __gu_ptr, __pu_err, type);     \
>> +               break;                                                  \
>> +       case 2:                                                         \
>> +               __put_mem_asm("sh", (x), __gu_ptr, __pu_err, type);     \
>> +               break;                                                  \
>> +       case 4:                                                         \
>> +               __put_mem_asm("sw", (x), __gu_ptr, __pu_err, type);     \
>> +               break;                                                  \
>> +       case 8:                                                         \
>> +               __put_mem_8((x), __gu_ptr, __pu_err, type);             \
>> +               break;                                                  \
>> +       default:                                                        \
>> +               BUILD_BUG();                                            \
>> +       }                                                               \
>>    } while (0)
>>
>>    /**
>> @@ -253,7 +253,7 @@ do {                                                                \
>>           __chk_user_ptr(__gu_ptr);                               \
>>                                                                   \
>>           __enable_user_access();                                 \
>> -       __put_user_nocheck(__val, __gu_ptr, __pu_err);          \
>> +       __put_mem_nocheck(__val, __gu_ptr, __pu_err, U);        \
>>           __disable_user_access();                                \
>>                                                                   \
>>           __pu_err;                                               \
>> @@ -279,7 +279,7 @@ do {                                                                \
>>    ({                                                             \
>>           __typeof__(*(ptr)) __user *__p = (ptr);                 \
>>           might_fault();                                          \
>> -       access_ok(__p, sizeof(*__p)) ?          \
>> +       access_ok(__p, sizeof(*__p)) ?                          \
>>                   __put_user((x), __p) :                          \
>>                   -EFAULT;                                        \
>>    })
>> @@ -321,7 +321,7 @@ unsigned long __must_check clear_user(void __user *to, unsigned long n)
>>    do {                                                                   \
>>           long __kr_err;                                                  \
>>                                                                           \
>> -       __get_user_nocheck(*((type *)(dst)), (type *)(src), __kr_err);  \
>> +       __get_mem_nocheck(*((type *)(dst)), (type *)(src), __kr_err, K);\
>>           if (unlikely(__kr_err))                                         \
>>                   goto err_label;                                         \
>>    } while (0)
>> @@ -330,7 +330,7 @@ do {                                                                        \
>>    do {                                                                   \
>>           long __kr_err;                                                  \
>>                                                                           \
>> -       __put_user_nocheck(*((type *)(src)), (type *)(dst), __kr_err);  \
>> +       __put_mem_nocheck(*((type *)(src)), (type *)(dst), __kr_err, K);\
>>           if (unlikely(__kr_err))                                         \
>>                   goto err_label;                                         \
>>    } while (0)
>> --
>> 2.25.1
>>
>>
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> 



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