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Commit f673c032 authored by Arnd Bergmann's avatar Arnd Bergmann
Browse files

score: add generic sys_call_table 



This adds back a sys_call_table to the score architecture, which
got lost in the conversion to the generic unistd.h file.
It's rather worrying that the code got submitted without a
system call table, which evidently means that it got zero
testing.

Since the system call table has a different layout from the old
one (which was modeled after the mips-o32 one), I also try to
fix the entry.S path to use it. In the modified calling conventions,
all system call arguments are passed as registers r4 through r9,
instead of r4 through r7 plus stack for the fifth and sixth argument.

This matches what other architectures to when they normally pass
arguments on the stack.

Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
parent 78229db4

arch/score/kernel/Makefile

+2 −1
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 
extra-y	:= head.o vmlinux.lds



obj-y += entry.o init_task.o irq.o process.o ptrace.o \

	setup.o signal.o sys_score.o time.o traps.o

	setup.o signal.o sys_score.o time.o traps.o \

	sys_call_table.o



obj-$(CONFIG_MODULES) += module.o

arch/score/kernel/entry.S

+3 −44
Original line number Diff line number Diff line
@@ -400,6 +400,8 @@ ENTRY(handle_sys) 
	sw	r4, [r0, PT_ORIG_R4]	#for restart syscall

	sw	r7, [r0, PT_ORIG_R7]	#for restart syscall

	sw	r27, [r0, PT_IS_SYSCALL] # it from syscall

	sw	r8, [r0, 16]		# argument 5 from user r8

	sw	r9, [r0, 20]		# argument 6 from user r9



	lw	r9, [r0, PT_EPC]	# skip syscall on return

	addi	r9, 4
@@ -408,19 +410,14 @@ ENTRY(handle_sys) 
	cmpi.c	r27, __NR_syscalls 	# check syscall number

	bgtu	illegal_syscall



	slli	r8, r27, 3		# get syscall routine

	slli	r8, r27, 2		# get syscall routine

	la	r11, sys_call_table

	add	r11, r11, r8

	lw	r10, [r11]		# get syscall entry

	lw	r11, [r11, 4]		# get number of args



	cmpz.c	r10

	beq	illegal_syscall



	cmpi.c	r11, 4			# more than 4 arguments?

	bgtu	stackargs



stack_done:

	lw	r8, [r28, TI_FLAGS]

	li	r9, _TIF_SYSCALL_TRACE

	and.c	r8, r8, r9
@@ -475,44 +472,6 @@ syscall_trace_entry: 
1:	sw	r4, [r0, PT_R2]		# result

	j	syscall_exit



stackargs:

	lw	r8, [r0, PT_R0]

	andri.c	r9, r8, 3		# test whether user sp is align a word

	bne	bad_stack

	subi	r11, 5

	slli	r9, r11, 2

	add.c	r9, r9, r8



	bmi	bad_stack

	la	r9, 3f			# calculate branch address

	slli	r11, r11, 3

	sub	r9, r9, r11

	br	r9



2:	lw	r9, [r8, 20]		# argument 6 from usp

	sw	r9, [r0, 20]



3:	lw	r9, [r8, 16]		# argument 5 from usp

	sw	r9, [r0, 16]

	j	stack_done



	.section __ex_table,"a"

	.word	2b, bad_stack

	.word	3b, bad_stack

	.previous



	/*

	 * The stackpointer for a call with more than 4 arguments is bad.

	 * We probably should handle this case a bit more drastic.

	 */

bad_stack:

	neg	r27, r27		# error

	sw	r27, [r0, PT_ORIG_R4]

	sw	r27, [r0, PT_R4]

	ldi	r8, 1			# set error flag

	sw	r8, [r0, PT_R7]

	j	syscall_return



illegal_syscall:

	ldi	r4, -ENOSYS		# error

	sw	r4, [r0, PT_ORIG_R4]

arch/score/kernel/sys_call_table.c

0 → 100644
+12 −0
Original line number Diff line number Diff line 
#include <linux/syscalls.h>

#include <linux/signal.h>

#include <linux/unistd.h>



#include <asm/syscalls.h>



#undef __SYSCALL

#define __SYSCALL(nr, call) [nr] = (call),



void *sys_call_table[__NR_syscalls] = {

#include <asm/unistd.h>

};

arch/score/kernel/sys_score.c

+1 −8
Original line number Diff line number Diff line
@@ -75,14 +75,7 @@ int score_clone(struct pt_regs *regs) 
	if (!newsp)

		newsp = regs->regs[0];

	parent_tidptr = (int __user *)regs->regs[6];



	child_tidptr = NULL;

	if (clone_flags & (CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID)) {

		int __user *__user *usp = (int __user *__user *)regs->regs[0];



		if (get_user(child_tidptr, &usp[4]))

			return -EFAULT;

	}

	child_tidptr = (int __user *)regs->regs[8];



	return do_fork(clone_flags, newsp, regs, 0,

			parent_tidptr, child_tidptr);