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Commit d878d6da authored by Al Viro's avatar Al Viro
Browse files

m68k: switch to generic sys_execve()/kernel_execve() 



The tricky part here is that task_pt_regs() on m68k works *only* for
process inside do_signal().  However, we need something much simpler -
pt_regs of a process inside do_signal() may be at different offsets
from the stack bottom, depending on the way we'd entered the kernel,
but for a task inside sys_execve() it *is* at constant offset.
Moreover, for a kernel thread about to become a userland process the
same location is also fine - setting sp to that will leave the kernel
stack pointer at the very bottom of the kernel stack when we finally
switch to userland.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 533e6903

arch/m68k/include/asm/ptrace.h

+2 −0
Original line number Diff line number Diff line
@@ -85,6 +85,8 @@ struct switch_stack { 
#define user_mode(regs) (!((regs)->sr & PS_S))

#define instruction_pointer(regs) ((regs)->pc)

#define profile_pc(regs) instruction_pointer(regs)

#define current_pt_regs() \

	(struct pt_regs *)((char *)current_thread_info() + THREAD_SIZE) - 1



#define arch_has_single_step()	(1)

arch/m68k/include/asm/unistd.h

+2 −0
Original line number Diff line number Diff line
@@ -382,6 +382,8 @@ 
#define __ARCH_WANT_SYS_SIGPROCMASK

#define __ARCH_WANT_SYS_RT_SIGACTION

#define __ARCH_WANT_SYS_RT_SIGSUSPEND

#define __ARCH_WANT_SYS_EXECVE

#define __ARCH_WANT_KERNEL_EXECVE



/*

 * "Conditional" syscalls

arch/m68k/kernel/entry.S

+5 −0
Original line number Diff line number Diff line
@@ -122,6 +122,11 @@ ENTRY(ret_from_kernel_thread) 
	movel	%d0,(%sp)

	jra	sys_exit



ENTRY(ret_from_kernel_execve)

	movel	4(%sp), %sp

	GET_CURRENT(%d0)

	jra	ret_from_exception



#if defined(CONFIG_COLDFIRE) || !defined(CONFIG_MMU)



#ifdef TRAP_DBG_INTERRUPT

arch/m68k/kernel/process.c

+0 −20
Original line number Diff line number Diff line
@@ -298,26 +298,6 @@ int dump_fpu (struct pt_regs *regs, struct user_m68kfp_struct *fpu) 
EXPORT_SYMBOL(dump_fpu);

#endif /* CONFIG_FPU */



/*

 * sys_execve() executes a new program.

 */

asmlinkage int sys_execve(const char __user *name,

			  const char __user *const __user *argv,

			  const char __user *const __user *envp)

{

	int error;

	char * filename;

	struct pt_regs *regs = (struct pt_regs *) &name;



	filename = getname(name);

	error = PTR_ERR(filename);

	if (IS_ERR(filename))

		return error;

	error = do_execve(filename, argv, envp, regs);

	putname(filename);

	return error;

}



unsigned long get_wchan(struct task_struct *p)

{

	unsigned long fp, pc;

arch/m68k/kernel/sys_m68k.c

+0 −17
Original line number Diff line number Diff line
@@ -549,23 +549,6 @@ 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;