linux/arch/m68knommu/kernel/sys_m68k.c
David Howells d7627467b7 Make do_execve() take a const filename pointer
Make do_execve() take a const filename pointer so that kernel_execve() compiles
correctly on ARM:

arch/arm/kernel/sys_arm.c:88: warning: passing argument 1 of 'do_execve' discards qualifiers from pointer target type

This also requires the argv and envp arguments to be consted twice, once for
the pointer array and once for the strings the array points to.  This is
because do_execve() passes a pointer to the filename (now const) to
copy_strings_kernel().  A simpler alternative would be to cast the filename
pointer in do_execve() when it's passed to copy_strings_kernel().

do_execve() may not change any of the strings it is passed as part of the argv
or envp lists as they are some of them in .rodata, so marking these strings as
const should be fine.

Further kernel_execve() and sys_execve() need to be changed to match.

This has been test built on x86_64, frv, arm and mips.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-17 18:07:43 -07:00

95 lines
2.1 KiB
C

/*
* linux/arch/m68knommu/kernel/sys_m68k.c
*
* This file contains various random system calls that
* have a non-standard calling sequence on the Linux/m68k
* platform.
*/
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/sem.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/stat.h>
#include <linux/syscalls.h>
#include <linux/mman.h>
#include <linux/file.h>
#include <linux/ipc.h>
#include <linux/fs.h>
#include <asm/setup.h>
#include <asm/uaccess.h>
#include <asm/cachectl.h>
#include <asm/traps.h>
#include <asm/cacheflush.h>
#include <asm/unistd.h>
/* sys_cacheflush -- flush (part of) the processor cache. */
asmlinkage int
sys_cacheflush (unsigned long addr, int scope, int cache, unsigned long len)
{
flush_cache_all();
return(0);
}
asmlinkage int sys_getpagesize(void)
{
return PAGE_SIZE;
}
/*
* Do a system call from kernel instead of calling sys_execve so we
* end up with proper pt_regs.
*/
int kernel_execve(const char *filename,
const char *const argv[],
const char *const envp[])
{
register long __res asm ("%d0") = __NR_execve;
register long __a asm ("%d1") = (long)(filename);
register long __b asm ("%d2") = (long)(argv);
register long __c asm ("%d3") = (long)(envp);
asm volatile ("trap #0" : "+d" (__res)
: "d" (__a), "d" (__b), "d" (__c));
return __res;
}
asmlinkage unsigned long sys_get_thread_area(void)
{
return current_thread_info()->tp_value;
}
asmlinkage int sys_set_thread_area(unsigned long tp)
{
current_thread_info()->tp_value = tp;
return 0;
}
/* This syscall gets its arguments in A0 (mem), D2 (oldval) and
D1 (newval). */
asmlinkage int
sys_atomic_cmpxchg_32(unsigned long newval, int oldval, int d3, int d4, int d5,
unsigned long __user * mem)
{
struct mm_struct *mm = current->mm;
unsigned long mem_value;
down_read(&mm->mmap_sem);
mem_value = *mem;
if (mem_value == oldval)
*mem = newval;
up_read(&mm->mmap_sem);
return mem_value;
}
asmlinkage int sys_atomic_barrier(void)
{
/* no code needed for uniprocs */
return 0;
}