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    Subject[RESEND PATCH 1/6] x86/entry/x32: rename __x32_compat_sys_* to __x64_compat_sys_*
    Date
    In arch/x86/entry/syscall_x32.c, the macros are mapped to symbols
    as follows:

    __SYSCALL_COMMON(nr, sym) --> __x64_<sym>
    __SYSCALL_X32(nr, sym) --> __x32_<sym>

    Originally, the syscalls in the x32 special range (512-547) were all
    compat.

    This assumption is now broken after the following commits:

    55db9c0e8534 ("net: remove compat_sys_{get,set}sockopt")
    5f764d624a89 ("fs: remove the compat readv/writev syscalls")
    598b3cec831f ("fs: remove compat_sys_vmsplice")
    c3973b401ef2 ("mm: remove compat_process_vm_{readv,writev}")

    Those commits redefined __x32_sys_* to __x64_sys_* because there is
    no stub like __x32_sys_*.

    I think defining as follows is more sensible and cleaner.

    __SYSCALL_COMMON(nr, sym) --> __x64_<sym>
    __SYSCALL_X32(nr, sym) --> __x64_<sym>

    This works because both x86_64 and x32 use the same ABI
    (RDI, RSI, RDX, R10, R8, R9)

    The ugly #define __x32_sys_* will go away.

    Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
    ---

    arch/x86/entry/syscall_x32.c | 16 ++--------------
    arch/x86/include/asm/syscall_wrapper.h | 10 +++++-----
    2 files changed, 7 insertions(+), 19 deletions(-)

    diff --git a/arch/x86/entry/syscall_x32.c b/arch/x86/entry/syscall_x32.c
    index f2fe0a33bcfd..3fea8fb9cd6a 100644
    --- a/arch/x86/entry/syscall_x32.c
    +++ b/arch/x86/entry/syscall_x32.c
    @@ -8,27 +8,15 @@
    #include <asm/unistd.h>
    #include <asm/syscall.h>

    -/*
    - * Reuse the 64-bit entry points for the x32 versions that occupy different
    - * slots in the syscall table.
    - */
    -#define __x32_sys_readv __x64_sys_readv
    -#define __x32_sys_writev __x64_sys_writev
    -#define __x32_sys_getsockopt __x64_sys_getsockopt
    -#define __x32_sys_setsockopt __x64_sys_setsockopt
    -#define __x32_sys_vmsplice __x64_sys_vmsplice
    -#define __x32_sys_process_vm_readv __x64_sys_process_vm_readv
    -#define __x32_sys_process_vm_writev __x64_sys_process_vm_writev
    -
    #define __SYSCALL_64(nr, sym)

    -#define __SYSCALL_X32(nr, sym) extern long __x32_##sym(const struct pt_regs *);
    +#define __SYSCALL_X32(nr, sym) extern long __x64_##sym(const struct pt_regs *);
    #define __SYSCALL_COMMON(nr, sym) extern long __x64_##sym(const struct pt_regs *);
    #include <asm/syscalls_64.h>
    #undef __SYSCALL_X32
    #undef __SYSCALL_COMMON

    -#define __SYSCALL_X32(nr, sym) [nr] = __x32_##sym,
    +#define __SYSCALL_X32(nr, sym) [nr] = __x64_##sym,
    #define __SYSCALL_COMMON(nr, sym) [nr] = __x64_##sym,

    asmlinkage const sys_call_ptr_t x32_sys_call_table[__NR_x32_syscall_max+1] = {
    diff --git a/arch/x86/include/asm/syscall_wrapper.h b/arch/x86/include/asm/syscall_wrapper.h
    index 80c08c7d5e72..6a2827d0681f 100644
    --- a/arch/x86/include/asm/syscall_wrapper.h
    +++ b/arch/x86/include/asm/syscall_wrapper.h
    @@ -17,7 +17,7 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs);
    * __x64_sys_*() - 64-bit native syscall
    * __ia32_sys_*() - 32-bit native syscall or common compat syscall
    * __ia32_compat_sys_*() - 32-bit compat syscall
    - * __x32_compat_sys_*() - 64-bit X32 compat syscall
    + * __x64_compat_sys_*() - 64-bit X32 compat syscall
    *
    * The registers are decoded according to the ABI:
    * 64-bit: RDI, RSI, RDX, R10, R8, R9
    @@ -166,17 +166,17 @@ extern long __ia32_sys_ni_syscall(const struct pt_regs *regs);
    * with x86_64 obviously do not need such care.
    */
    #define __X32_COMPAT_SYS_STUB0(name) \
    - __SYS_STUB0(x32, compat_sys_##name)
    + __SYS_STUB0(x64, compat_sys_##name)

    #define __X32_COMPAT_SYS_STUBx(x, name, ...) \
    - __SYS_STUBx(x32, compat_sys##name, \
    + __SYS_STUBx(x64, compat_sys##name, \
    SC_X86_64_REGS_TO_ARGS(x, __VA_ARGS__))

    #define __X32_COMPAT_COND_SYSCALL(name) \
    - __COND_SYSCALL(x32, compat_sys_##name)
    + __COND_SYSCALL(x64, compat_sys_##name)

    #define __X32_COMPAT_SYS_NI(name) \
    - __SYS_NI(x32, compat_sys_##name)
    + __SYS_NI(x64, compat_sys_##name)
    #else /* CONFIG_X86_X32 */
    #define __X32_COMPAT_SYS_STUB0(name)
    #define __X32_COMPAT_SYS_STUBx(x, name, ...)
    --
    2.27.0
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