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linux/arch/um/kernel/skas/syscall.c
Jeff Dike f87ea91d98 uml: redo the calculation of NR_syscalls
Redo the calculation of NR_syscalls since that disappeared from i386 and
use a similar mechanism on x86_64.

We now figure out the size of the system call table in arch code and stick
that in syscall_table_size.  arch/um/kernel/skas/syscall.c defines
NR_syscalls in terms of that since its the only thing that needs to know
how many system calls there are.

The old mechananism that was used on x86_64 is gone.

arch/um/include/sysdep-i386/syscalls.h got some formatting since I was
looking at it.

Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 09:44:32 -08:00

41 lines
1.1 KiB
C

/*
* Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
* Licensed under the GPL
*/
#include "linux/kernel.h"
#include "linux/ptrace.h"
#include "kern_util.h"
#include "sysdep/ptrace.h"
#include "sysdep/syscalls.h"
extern int syscall_table_size;
#define NR_syscalls (syscall_table_size / sizeof(void *))
void handle_syscall(struct uml_pt_regs *r)
{
struct pt_regs *regs = container_of(r, struct pt_regs, regs);
long result;
int syscall;
syscall_trace(r, 0);
/*
* This should go in the declaration of syscall, but when I do that,
* strace -f -c bash -c 'ls ; ls' breaks, sometimes not tracing
* children at all, sometimes hanging when bash doesn't see the first
* ls exit.
* The assembly looks functionally the same to me. This is
* gcc version 4.0.1 20050727 (Red Hat 4.0.1-5)
* in case it's a compiler bug.
*/
syscall = UPT_SYSCALL_NR(r);
if ((syscall >= NR_syscalls) || (syscall < 0))
result = -ENOSYS;
else result = EXECUTE_SYSCALL(syscall, regs);
REGS_SET_SYSCALL_RETURN(r->gp, result);
syscall_trace(r, 1);
}