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-rw-r--r--arch/tile/kernel/process.c171
1 files changed, 45 insertions, 126 deletions
diff --git a/arch/tile/kernel/process.c b/arch/tile/kernel/process.c
index 307d010..0e5661e 100644
--- a/arch/tile/kernel/process.c
+++ b/arch/tile/kernel/process.c
@@ -157,24 +157,43 @@ void arch_release_thread_info(struct thread_info *info)
static void save_arch_state(struct thread_struct *t);
int copy_thread(unsigned long clone_flags, unsigned long sp,
- unsigned long stack_size,
- struct task_struct *p, struct pt_regs *regs)
+ unsigned long arg, struct task_struct *p)
{
- struct pt_regs *childregs;
+ struct pt_regs *childregs = task_pt_regs(p), *regs = current_pt_regs();
unsigned long ksp;
+ unsigned long *callee_regs;
/*
- * When creating a new kernel thread we pass sp as zero.
- * Assign it to a reasonable value now that we have the stack.
+ * Set up the stack and stack pointer appropriately for the
+ * new child to find itself woken up in __switch_to().
+ * The callee-saved registers must be on the stack to be read;
+ * the new task will then jump to assembly support to handle
+ * calling schedule_tail(), etc., and (for userspace tasks)
+ * returning to the context set up in the pt_regs.
*/
- if (sp == 0 && regs->ex1 == PL_ICS_EX1(KERNEL_PL, 0))
- sp = KSTK_TOP(p);
+ ksp = (unsigned long) childregs;
+ ksp -= C_ABI_SAVE_AREA_SIZE; /* interrupt-entry save area */
+ ((long *)ksp)[0] = ((long *)ksp)[1] = 0;
+ ksp -= CALLEE_SAVED_REGS_COUNT * sizeof(unsigned long);
+ callee_regs = (unsigned long *)ksp;
+ ksp -= C_ABI_SAVE_AREA_SIZE; /* __switch_to() save area */
+ ((long *)ksp)[0] = ((long *)ksp)[1] = 0;
+ p->thread.ksp = ksp;
- /*
- * Do not clone step state from the parent; each thread
- * must make its own lazily.
- */
- task_thread_info(p)->step_state = NULL;
+ /* Record the pid of the task that created this one. */
+ p->thread.creator_pid = current->pid;
+
+ if (unlikely(p->flags & PF_KTHREAD)) {
+ /* kernel thread */
+ memset(childregs, 0, sizeof(struct pt_regs));
+ memset(&callee_regs[2], 0,
+ (CALLEE_SAVED_REGS_COUNT - 2) * sizeof(unsigned long));
+ callee_regs[0] = sp; /* r30 = function */
+ callee_regs[1] = arg; /* r31 = arg */
+ childregs->ex1 = PL_ICS_EX1(KERNEL_PL, 0);
+ p->thread.pc = (unsigned long) ret_from_kernel_thread;
+ return 0;
+ }
/*
* Start new thread in ret_from_fork so it schedules properly
@@ -182,46 +201,33 @@ int copy_thread(unsigned long clone_flags, unsigned long sp,
*/
p->thread.pc = (unsigned long) ret_from_fork;
- /* Save user stack top pointer so we can ID the stack vm area later. */
- p->thread.usp0 = sp;
-
- /* Record the pid of the process that created this one. */
- p->thread.creator_pid = current->pid;
+ /*
+ * Do not clone step state from the parent; each thread
+ * must make its own lazily.
+ */
+ task_thread_info(p)->step_state = NULL;
/*
* Copy the registers onto the kernel stack so the
* return-from-interrupt code will reload it into registers.
*/
- childregs = task_pt_regs(p);
- *childregs = *regs;
+ *childregs = *current_pt_regs();
childregs->regs[0] = 0; /* return value is zero */
- childregs->sp = sp; /* override with new user stack pointer */
+ if (sp)
+ childregs->sp = sp; /* override with new user stack pointer */
+ memcpy(callee_regs, &childregs->regs[CALLEE_SAVED_FIRST_REG],
+ CALLEE_SAVED_REGS_COUNT * sizeof(unsigned long));
+
+ /* Save user stack top pointer so we can ID the stack vm area later. */
+ p->thread.usp0 = childregs->sp;
/*
* If CLONE_SETTLS is set, set "tp" in the new task to "r4",
* which is passed in as arg #5 to sys_clone().
*/
if (clone_flags & CLONE_SETTLS)
- childregs->tp = regs->regs[4];
+ childregs->tp = childregs->regs[4];
- /*
- * Copy the callee-saved registers from the passed pt_regs struct
- * into the context-switch callee-saved registers area.
- * This way when we start the interrupt-return sequence, the
- * callee-save registers will be correctly in registers, which
- * is how we assume the compiler leaves them as we start doing
- * the normal return-from-interrupt path after calling C code.
- * Zero out the C ABI save area to mark the top of the stack.
- */
- ksp = (unsigned long) childregs;
- ksp -= C_ABI_SAVE_AREA_SIZE; /* interrupt-entry save area */
- ((long *)ksp)[0] = ((long *)ksp)[1] = 0;
- ksp -= CALLEE_SAVED_REGS_COUNT * sizeof(unsigned long);
- memcpy((void *)ksp, &regs->regs[CALLEE_SAVED_FIRST_REG],
- CALLEE_SAVED_REGS_COUNT * sizeof(unsigned long));
- ksp -= C_ABI_SAVE_AREA_SIZE; /* __switch_to() save area */
- ((long *)ksp)[0] = ((long *)ksp)[1] = 0;
- p->thread.ksp = ksp;
#if CHIP_HAS_TILE_DMA()
/*
@@ -577,62 +583,6 @@ int do_work_pending(struct pt_regs *regs, u32 thread_info_flags)
panic("work_pending: bad flags %#x\n", thread_info_flags);
}
-/* Note there is an implicit fifth argument if (clone_flags & CLONE_SETTLS). */
-SYSCALL_DEFINE5(clone, unsigned long, clone_flags, unsigned long, newsp,
- void __user *, parent_tidptr, void __user *, child_tidptr,
- struct pt_regs *, regs)
-{
- if (!newsp)
- newsp = regs->sp;
- return do_fork(clone_flags, newsp, regs, 0,
- parent_tidptr, child_tidptr);
-}
-
-/*
- * sys_execve() executes a new program.
- */
-SYSCALL_DEFINE4(execve, const char __user *, path,
- const char __user *const __user *, argv,
- const char __user *const __user *, envp,
- struct pt_regs *, regs)
-{
- long error;
- struct filename *filename;
-
- filename = getname(path);
- error = PTR_ERR(filename);
- if (IS_ERR(filename))
- goto out;
- error = do_execve(filename->name, argv, envp, regs);
- putname(filename);
- if (error == 0)
- single_step_execve();
-out:
- return error;
-}
-
-#ifdef CONFIG_COMPAT
-long compat_sys_execve(const char __user *path,
- compat_uptr_t __user *argv,
- compat_uptr_t __user *envp,
- struct pt_regs *regs)
-{
- long error;
- struct filename *filename;
-
- filename = getname(path);
- error = PTR_ERR(filename);
- if (IS_ERR(filename))
- goto out;
- error = compat_do_execve(filename->name, argv, envp, regs);
- putname(filename);
- if (error == 0)
- single_step_execve();
-out:
- return error;
-}
-#endif
-
unsigned long get_wchan(struct task_struct *p)
{
struct KBacktraceIterator kbt;
@@ -650,37 +600,6 @@ unsigned long get_wchan(struct task_struct *p)
return 0;
}
-/*
- * We pass in lr as zero (cleared in kernel_thread) and the caller
- * part of the backtrace ABI on the stack also zeroed (in copy_thread)
- * so that backtraces will stop with this function.
- * Note that we don't use r0, since copy_thread() clears it.
- */
-static void start_kernel_thread(int dummy, int (*fn)(int), int arg)
-{
- do_exit(fn(arg));
-}
-
-/*
- * Create a kernel thread
- */
-int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
-{
- struct pt_regs regs;
-
- memset(&regs, 0, sizeof(regs));
- regs.ex1 = PL_ICS_EX1(KERNEL_PL, 0); /* run at kernel PL, no ICS */
- regs.pc = (long) start_kernel_thread;
- regs.flags = PT_FLAGS_CALLER_SAVES; /* need to restore r1 and r2 */
- regs.regs[1] = (long) fn; /* function pointer */
- regs.regs[2] = (long) arg; /* parameter register */
-
- /* Ok, create the new process.. */
- return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs,
- 0, NULL, NULL);
-}
-EXPORT_SYMBOL(kernel_thread);
-
/* Flush thread state. */
void flush_thread(void)
{