Commit 2e958a8a authored by Masahiro Yamada's avatar Masahiro Yamada Committed by Thomas Gleixner
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x86/entry/x32: Rename __x32_compat_sys_* to __x64_compat_sys_* 



The SYSCALL 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:

  55db9c0e ("net: remove compat_sys_{get,set}sockopt")
  5f764d62 ("fs: remove the compat readv/writev syscalls")
  598b3cec ("fs: remove compat_sys_vmsplice")
  c3973b40 ("mm: remove compat_process_vm_{readv,writev}")

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

Defining them 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: default avatarMasahiro Yamada <masahiroy@kernel.org>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/20210517073815.97426-2-masahiroy@kernel.org
parent 41f45fb0

arch/x86/entry/syscall_x32.c

+2 −14
Original line number Diff line number Diff line
@@ -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] = {

arch/x86/include/asm/syscall_wrapper.h

+5 −5
Original line number Diff line number Diff line
@@ -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, ...)