Commit 3a790cc1 authored by Sven Schnelle's avatar Sven Schnelle Committed by Vasily Gorbik
Browse files

s390: pass struct pt_regs instead of registers to syscalls 



Instead of fetching all registers from struct pt_regs and passing
them to the syscall wrappers, let the system call wrappers only
fetch the values really required.

Signed-off-by: default avatarSven Schnelle <svens@linux.ibm.com>
Reviewed-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent 39589ada

arch/s390/include/asm/processor.h

+1 −3
Original line number Diff line number Diff line
@@ -40,9 +40,7 @@ 
#include <asm/fpu/internal.h>

#include <asm/irqflags.h>



typedef long (*sys_call_ptr_t)(unsigned long, unsigned long,

			       unsigned long, unsigned long,

			       unsigned long, unsigned long);

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



static inline void set_cpu_flag(int flag)

{

arch/s390/include/asm/syscall_wrapper.h

+72 −42
Original line number Diff line number Diff line
@@ -7,6 +7,33 @@ 
#ifndef _ASM_S390_SYSCALL_WRAPPER_H

#define _ASM_S390_SYSCALL_WRAPPER_H



#define __SC_TYPE(t, a) t



#define SYSCALL_PT_ARG6(regs, m, t1, t2, t3, t4, t5, t6)\

	SYSCALL_PT_ARG5(regs, m, t1, t2, t3, t4, t5),	\

		m(t6, (regs->gprs[7]))



#define SYSCALL_PT_ARG5(regs, m, t1, t2, t3, t4, t5)	\

	SYSCALL_PT_ARG4(regs, m, t1, t2, t3, t4),	\

		m(t5, (regs->gprs[6]))



#define SYSCALL_PT_ARG4(regs, m, t1, t2, t3, t4)	\

	SYSCALL_PT_ARG3(regs, m, t1, t2, t3),		\

		m(t4, (regs->gprs[5]))



#define SYSCALL_PT_ARG3(regs, m, t1, t2, t3)		\

	SYSCALL_PT_ARG2(regs, m, t1, t2),		\

		m(t3, (regs->gprs[4]))



#define SYSCALL_PT_ARG2(regs, m, t1, t2)		\

	SYSCALL_PT_ARG1(regs, m, t1),			\

		m(t2, (regs->gprs[3]))



#define SYSCALL_PT_ARG1(regs, m, t1)			\

		m(t1, (regs->orig_gpr2))



#define SYSCALL_PT_ARGS(x, ...) SYSCALL_PT_ARG##x(__VA_ARGS__)



#ifdef CONFIG_COMPAT

#define __SC_COMPAT_TYPE(t, a) \

	__typeof(__builtin_choose_expr(sizeof(t) > 4, 0L, (t)0)) a
@@ -30,11 +57,12 @@ 
})



#define __S390_SYS_STUBx(x, name, ...)						\

	long __s390_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__));		\

	long __s390_sys##name(struct pt_regs *regs);				\

	ALLOW_ERROR_INJECTION(__s390_sys##name, ERRNO);				\

	long __s390_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__))		\

	long __s390_sys##name(struct pt_regs *regs)				\

	{									\

		long ret = __s390x_sys##name(__MAP(x,__SC_COMPAT_CAST,__VA_ARGS__));\

		long ret = __do_sys##name(SYSCALL_PT_ARGS(x, regs,		\

			__SC_COMPAT_CAST, __MAP(x, __SC_TYPE, __VA_ARGS__)));	\

		__MAP(x,__SC_TEST,__VA_ARGS__);					\

		return ret;							\

	}
@@ -69,15 +97,16 @@ 
	__diag_push();									\

	__diag_ignore(GCC, 8, "-Wattribute-alias",					\

		      "Type aliasing is used to sanitize syscall arguments");		\

	long __s390_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));		\

	long __s390_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))		\

	long __s390_compat_sys##name(struct pt_regs *regs);				\

	long __s390_compat_sys##name(struct pt_regs *regs)				\

		__attribute__((alias(__stringify(__se_compat_sys##name))));		\

	ALLOW_ERROR_INJECTION(__s390_compat_sys##name, ERRNO);				\

	static inline long __do_compat_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));	\

	long __se_compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__));		\

	long __se_compat_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__))		\

	long __se_compat_sys##name(struct pt_regs *regs);				\

	long __se_compat_sys##name(struct pt_regs *regs)				\

	{										\

		long ret = __do_compat_sys##name(__MAP(x,__SC_DELOUSE,__VA_ARGS__));\

		long ret = __do_compat_sys##name(SYSCALL_PT_ARGS(x, regs, __SC_DELOUSE,	\

						 __MAP(x, __SC_TYPE, __VA_ARGS__)));	\

		__MAP(x,__SC_TEST,__VA_ARGS__);						\

		return ret;								\

	}										\
@@ -117,15 +146,16 @@ 
	__diag_push();									\

	__diag_ignore(GCC, 8, "-Wattribute-alias",					\

		      "Type aliasing is used to sanitize syscall arguments");		\

	long __s390x_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))			\

	long __s390x_sys##name(struct pt_regs *regs)					\

		__attribute__((alias(__stringify(__se_sys##name))));			\

	ALLOW_ERROR_INJECTION(__s390x_sys##name, ERRNO);				\

	long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__));			\

	static inline long __do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));		\

	long __se_sys##name(struct pt_regs *regs);					\

	__S390_SYS_STUBx(x, name, __VA_ARGS__)						\

	long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__))			\

	long __se_sys##name(struct pt_regs *regs)					\

	{										\

		long ret = __do_sys##name(__MAP(x,__SC_CAST,__VA_ARGS__));	\

		long ret = __do_sys##name(SYSCALL_PT_ARGS(x, regs,			\

				    __SC_CAST, __MAP(x, __SC_TYPE, __VA_ARGS__)));	\

		__MAP(x,__SC_TEST,__VA_ARGS__);						\

		return ret;								\

	}										\

arch/s390/kernel/syscall.c

+2 −6
Original line number Diff line number Diff line
@@ -132,12 +132,8 @@ void do_syscall(struct pt_regs *regs) 
	 */

	if (!test_pt_regs_flag(regs, PIF_SYSCALL_RET_SET)) {

		regs->gprs[2] = -ENOSYS;

		if (likely(nr < NR_syscalls)) {

			regs->gprs[2] = current->thread.sys_call_table[nr](

					regs->orig_gpr2, regs->gprs[3],

					regs->gprs[4], regs->gprs[5],

					regs->gprs[6], regs->gprs[7]);

		}

		if (likely(nr < NR_syscalls))

			regs->gprs[2] = current->thread.sys_call_table[nr](regs);

	} else {

		clear_pt_regs_flag(regs, PIF_SYSCALL_RET_SET);

	}