Commit 0f78ff17 authored by Brian Gerst's avatar Brian Gerst Committed by Thomas Gleixner
Browse files

x86/entry: Drop asmlinkage from syscalls 



asmlinkage is no longer required since the syscall ABI is now fully under
x86 architecture control.  This makes the 32-bit native syscalls a bit more
effecient by passing in regs via EAX instead of on the stack.

Signed-off-by: default avatarBrian Gerst <brgerst@gmail.com>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Reviewed-by: default avatarDominik Brodowski <linux@dominikbrodowski.net>
Reviewed-by: default avatarAndy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200313195144.164260-18-brgerst@gmail.com
parent 25c619e5

arch/x86/entry/syscall_32.c

+1 −1
Original line number Diff line number Diff line
@@ -8,7 +8,7 @@ 
#include <asm/unistd.h>

#include <asm/syscall.h>



#define __SYSCALL_I386(nr, sym) extern asmlinkage long __ia32_##sym(const struct pt_regs *);

#define __SYSCALL_I386(nr, sym) extern long __ia32_##sym(const struct pt_regs *);



#include <asm/syscalls_32.h>

#undef __SYSCALL_I386

arch/x86/entry/syscall_64.c

+1 −1
Original line number Diff line number Diff line
@@ -11,7 +11,7 @@ 
#define __SYSCALL_X32(nr, sym)

#define __SYSCALL_COMMON(nr, sym) __SYSCALL_64(nr, sym)



#define __SYSCALL_64(nr, sym) extern asmlinkage long __x64_##sym(const struct pt_regs *);

#define __SYSCALL_64(nr, sym) extern long __x64_##sym(const struct pt_regs *);

#include <asm/syscalls_64.h>

#undef __SYSCALL_64

arch/x86/entry/syscall_x32.c

+2 −2
Original line number Diff line number Diff line
@@ -10,8 +10,8 @@ 


#define __SYSCALL_64(nr, sym)



#define __SYSCALL_X32(nr, sym) extern asmlinkage long __x32_##sym(const struct pt_regs *);

#define __SYSCALL_COMMON(nr, sym) extern asmlinkage long __x64_##sym(const struct pt_regs *);

#define __SYSCALL_X32(nr, sym) extern long __x32_##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

arch/x86/include/asm/syscall.h

+1 −1
Original line number Diff line number Diff line
@@ -16,7 +16,7 @@ 
#include <asm/thread_info.h>	/* for TS_COMPAT */

#include <asm/unistd.h>



typedef asmlinkage long (*sys_call_ptr_t)(const struct pt_regs *);

typedef long (*sys_call_ptr_t)(const struct pt_regs *);

extern const sys_call_ptr_t sys_call_table[];



#if defined(CONFIG_X86_32)

arch/x86/include/asm/syscall_wrapper.h

+14 −17
Original line number Diff line number Diff line
@@ -8,8 +8,8 @@ 


struct pt_regs;



extern asmlinkage long __x64_sys_ni_syscall(const struct pt_regs *regs);

extern asmlinkage long __ia32_sys_ni_syscall(const struct pt_regs *regs);

extern long __x64_sys_ni_syscall(const struct pt_regs *regs);

extern long __ia32_sys_ni_syscall(const struct pt_regs *regs);



/*

 * Instead of the generic __SYSCALL_DEFINEx() definition, the x86 version takes
@@ -66,22 +66,21 @@ extern asmlinkage long __ia32_sys_ni_syscall(const struct pt_regs *regs); 
	      ,,(unsigned int)regs->di,,(unsigned int)regs->bp)



#define __SYS_STUB0(abi, name)						\

	asmlinkage long __##abi##_##name(const struct pt_regs *regs);	\

	long __##abi##_##name(const struct pt_regs *regs);		\

	ALLOW_ERROR_INJECTION(__##abi##_##name, ERRNO);			\

	asmlinkage long __##abi##_##name(const struct pt_regs *regs)	\

	long __##abi##_##name(const struct pt_regs *regs)		\

		__alias(__do_##name);



#define __SYS_STUBx(abi, name, ...)					\

	asmlinkage long __##abi##_##name(const struct pt_regs *regs);	\

	long __##abi##_##name(const struct pt_regs *regs);		\

	ALLOW_ERROR_INJECTION(__##abi##_##name, ERRNO);			\

	asmlinkage long __##abi##_##name(const struct pt_regs *regs)	\

	long __##abi##_##name(const struct pt_regs *regs)		\

	{								\

		return __se_##name(__VA_ARGS__);			\

	}



#define __COND_SYSCALL(abi, name)					\

	asmlinkage __weak long						\

	__##abi##_##name(const struct pt_regs *__unused)		\

	__weak long __##abi##_##name(const struct pt_regs *__unused)	\

	{								\

		return sys_ni_syscall();				\

	}
@@ -192,11 +191,11 @@ extern asmlinkage long __ia32_sys_ni_syscall(const struct pt_regs *regs); 
 * of them.

 */

#define COMPAT_SYSCALL_DEFINE0(name)					\

	static asmlinkage long						\

	static long							\

	__do_compat_sys_##name(const struct pt_regs *__unused);		\

	__IA32_COMPAT_SYS_STUB0(name)					\

	__X32_COMPAT_SYS_STUB0(name)					\

	static asmlinkage long						\

	static long							\

	__do_compat_sys_##name(const struct pt_regs *__unused)



#define COMPAT_SYSCALL_DEFINEx(x, name, ...)					\
@@ -248,12 +247,10 @@ extern asmlinkage long __ia32_sys_ni_syscall(const struct pt_regs *regs); 
 */

#define SYSCALL_DEFINE0(sname)						\

	SYSCALL_METADATA(_##sname, 0);					\

	static asmlinkage long						\

	__do_sys_##sname(const struct pt_regs *__unused);		\

	static long __do_sys_##sname(const struct pt_regs *__unused);	\

	__X64_SYS_STUB0(sname)						\

	__IA32_SYS_STUB0(sname)						\

	static asmlinkage long						\

	__do_sys_##sname(const struct pt_regs *__unused)

	static long __do_sys_##sname(const struct pt_regs *__unused)



#define COND_SYSCALL(name)						\

	__X64_COND_SYSCALL(name)					\
@@ -268,8 +265,8 @@ extern asmlinkage long __ia32_sys_ni_syscall(const struct pt_regs *regs); 
 * For VSYSCALLS, we need to declare these three syscalls with the new

 * pt_regs-based calling convention for in-kernel use.

 */

asmlinkage long __x64_sys_getcpu(const struct pt_regs *regs);

asmlinkage long __x64_sys_gettimeofday(const struct pt_regs *regs);

asmlinkage long __x64_sys_time(const struct pt_regs *regs);

long __x64_sys_getcpu(const struct pt_regs *regs);

long __x64_sys_gettimeofday(const struct pt_regs *regs);

long __x64_sys_time(const struct pt_regs *regs);



#endif /* _ASM_X86_SYSCALL_WRAPPER_H */

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