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: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/arch/m68k/include/asm/ptrace.h b/arch/m68k/include/asm/ptrace.h
index 65322b17..5e08b59 100644
--- a/arch/m68k/include/asm/ptrace.h
+++ b/arch/m68k/include/asm/ptrace.h
@@ -85,6 +85,8 @@
#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)
diff --git a/arch/m68k/include/asm/unistd.h b/arch/m68k/include/asm/unistd.h
index 045cfd6..c702ad7 100644
--- a/arch/m68k/include/asm/unistd.h
+++ b/arch/m68k/include/asm/unistd.h
@@ -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
diff --git a/arch/m68k/kernel/entry.S b/arch/m68k/kernel/entry.S
index 8a01f58..946cb01 100644
--- a/arch/m68k/kernel/entry.S
+++ b/arch/m68k/kernel/entry.S
@@ -122,6 +122,11 @@
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
diff --git a/arch/m68k/kernel/process.c b/arch/m68k/kernel/process.c
index b3d4760..4e54b4c 100644
--- a/arch/m68k/kernel/process.c
+++ b/arch/m68k/kernel/process.c
@@ -298,26 +298,6 @@
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;
diff --git a/arch/m68k/kernel/sys_m68k.c b/arch/m68k/kernel/sys_m68k.c
index 9a5932e..3a480b3 100644
--- a/arch/m68k/kernel/sys_m68k.c
+++ b/arch/m68k/kernel/sys_m68k.c
@@ -549,23 +549,6 @@
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;