fold ret_from_kernel_thread into ret_from_fork
The only difference is former needs to call thread entry point which can
be detected inside ret_from_fork too.
Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
arch/arc/kernel/entry.S | 18 +++++++++++-------
arch/arc/kernel/process.c | 8 ++++----
2 files changed, 15 insertions(+), 11 deletions(-)
diff --git a/arch/arc/kernel/entry.S b/arch/arc/kernel/entry.S
index b2291fc..69a0c9f 100644
--- a/arch/arc/kernel/entry.S
+++ b/arch/arc/kernel/entry.S
@@ -575,16 +575,20 @@ ARC_ENTRY ret_from_fork
; when the forked child comes here from the __switch_to function
; r0 has the last task pointer.
; put last task in scheduler queue
- bl @schedule_tail
- b @ret_from_exception
-ARC_EXIT ret_from_fork
+ bl @schedule_tail
+
+ ; If kernel thread, jump to it's entry-point
+ ld r9, [sp, PT_status32]
+ brne r9, 0, 1f
-ARC_ENTRY ret_from_kernel_thread
- bl @schedule_tail
- jl.d [r14] ; kernel_thread "payload"
+ jl.d [r14]
mov r0, r13 ; arg to payload
+
+1:
+ ; special case of kernel_thread entry point returning back due to
+ ; kernel_execve() - pretend return from syscall to ret to userland
b ret_from_exception
-ARC_EXIT ret_from_kernel_thread
+ARC_EXIT ret_from_fork
;################### Special Sys Call Wrappers ##########################
diff --git a/arch/arc/kernel/process.c b/arch/arc/kernel/process.c
index 20d8b4d..403de7e 100644
--- a/arch/arc/kernel/process.c
+++ b/arch/arc/kernel/process.c
@@ -99,7 +99,6 @@ void cpu_idle(void)
}
asmlinkage void ret_from_fork(void);
-asmlinkage void ret_from_kernel_thread(void) __attribute__((noreturn));
/* Layout of Child kernel mode stack as setup at the end of this function is
*
@@ -155,15 +154,16 @@ int copy_thread(unsigned long clone_flags,
*/
p->thread.ksp = (unsigned long)c_callee; /* THREAD_KSP */
+ /* __switch_to expects FP(0), BLINK(return addr) at top */
+ childksp[0] = 0; /* fp */
+ childksp[1] = (unsigned long)ret_from_fork; /* blink */
+
if (unlikely(p->flags & PF_KTHREAD)) {
memset(c_regs, 0, sizeof(struct pt_regs));
c_callee->r13 = arg; /* argument to kernel thread */
c_callee->r14 = usp; /* function */
- /* __switch_to expects FP(0), BLINK(return addr) at top */
- childksp[0] = 0; /* fp */
- childksp[1] = (unsigned long)ret_from_kernel_thread; /* blink */
return 0;
}
--
1.7.4.1
--
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