Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal

Pull generic execve() changes from Al Viro:
 "This introduces the generic kernel_thread() and kernel_execve()
  functions, and switches x86, arm, alpha, um and s390 over to them."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: (26 commits)
  s390: convert to generic kernel_execve()
  s390: switch to generic kernel_thread()
  s390: fold kernel_thread_helper() into ret_from_fork()
  s390: fold execve_tail() into start_thread(), convert to generic sys_execve()
  um: switch to generic kernel_thread()
  x86, um/x86: switch to generic sys_execve and kernel_execve
  x86: split ret_from_fork
  alpha: introduce ret_from_kernel_execve(), switch to generic kernel_execve()
  alpha: switch to generic kernel_thread()
  alpha: switch to generic sys_execve()
  arm: get rid of execve wrapper, switch to generic execve() implementation
  arm: optimized current_pt_regs()
  arm: introduce ret_from_kernel_execve(), switch to generic kernel_execve()
  arm: split ret_from_fork, simplify kernel_thread() [based on patch by rmk]
  generic sys_execve()
  generic kernel_execve()
  new helper: current_pt_regs()
  preparation for generic kernel_thread()
  um: kill thread->forking
  um: let signal_delivered() do SIGTRAP on singlestepping into handler
  ...
This commit is contained in:
Linus Torvalds
2012-10-10 12:02:25 +09:00
96 changed files with 389 additions and 898 deletions
+19 -58
View File
@@ -263,33 +263,35 @@ alpha_vfork(struct pt_regs *regs)
/*
* Copy an alpha thread..
*
* Note the "stack_offset" stuff: when returning to kernel mode, we need
* to have some extra stack-space for the kernel stack that still exists
* after the "ret_from_fork". When returning to user mode, we only want
* the space needed by the syscall stack frame (ie "struct pt_regs").
* Use the passed "regs" pointer to determine how much space we need
* for a kernel fork().
*/
int
copy_thread(unsigned long clone_flags, unsigned long usp,
unsigned long unused,
unsigned long arg,
struct task_struct * p, struct pt_regs * regs)
{
extern void ret_from_fork(void);
extern void ret_from_kernel_thread(void);
struct thread_info *childti = task_thread_info(p);
struct pt_regs * childregs;
struct switch_stack * childstack, *stack;
unsigned long stack_offset, settls;
struct pt_regs *childregs = task_pt_regs(p);
struct switch_stack *childstack, *stack;
unsigned long settls;
stack_offset = PAGE_SIZE - sizeof(struct pt_regs);
if (!(regs->ps & 8))
stack_offset = (PAGE_SIZE-1) & (unsigned long) regs;
childregs = (struct pt_regs *)
(stack_offset + PAGE_SIZE + task_stack_page(p));
childstack = ((struct switch_stack *) childregs) - 1;
if (unlikely(!regs)) {
/* kernel thread */
memset(childstack, 0,
sizeof(struct switch_stack) + sizeof(struct pt_regs));
childstack->r26 = (unsigned long) ret_from_kernel_thread;
childstack->r9 = usp; /* function */
childstack->r10 = arg;
childregs->hae = alpha_mv.hae_cache,
childti->pcb.usp = 0;
childti->pcb.ksp = (unsigned long) childstack;
childti->pcb.flags = 1; /* set FEN, clear everything else */
return 0;
}
*childregs = *regs;
settls = regs->r20;
childregs->r0 = 0;
@@ -297,7 +299,6 @@ copy_thread(unsigned long clone_flags, unsigned long usp,
childregs->r20 = 1; /* OSF/1 has some strange fork() semantics. */
regs->r20 = 0;
stack = ((struct switch_stack *) regs) - 1;
childstack = ((struct switch_stack *) childregs) - 1;
*childstack = *stack;
childstack->r26 = (unsigned long) ret_from_fork;
childti->pcb.usp = usp;
@@ -385,27 +386,6 @@ dump_elf_task_fp(elf_fpreg_t *dest, struct task_struct *task)
}
EXPORT_SYMBOL(dump_elf_task_fp);
/*
* sys_execve() executes a new program.
*/
asmlinkage int
do_sys_execve(const char __user *ufilename,
const char __user *const __user *argv,
const char __user *const __user *envp, struct pt_regs *regs)
{
int error;
char *filename;
filename = getname(ufilename);
error = PTR_ERR(filename);
if (IS_ERR(filename))
goto out;
error = do_execve(filename, argv, envp, regs);
putname(filename);
out:
return error;
}
/*
* Return saved PC of a blocked thread. This assumes the frame
* pointer is the 6th saved long on the kernel stack and that the
@@ -459,22 +439,3 @@ get_wchan(struct task_struct *p)
}
return pc;
}
int kernel_execve(const char *path, const char *const argv[], const char *const envp[])
{
/* Avoid the HAE being gratuitously wrong, which would cause us
to do the whole turn off interrupts thing and restore it. */
struct pt_regs regs = {.hae = alpha_mv.hae_cache};
int err = do_execve(path, argv, envp, &regs);
if (!err) {
struct pt_regs *p = current_pt_regs();
/* copy regs to normal position and off to userland we go... */
*p = regs;
__asm__ __volatile__ (
"mov %0, $sp;"
"br $31, ret_from_sys_call"
: : "r"(p));
}
return err;
}
EXPORT_SYMBOL(kernel_execve);