Hi Ley Foon, On Apr 18, Ley Foon Tan wrote: > + > + /* Get thread info pointer */ > + movi r11, %lo(0xfffff000) > + and r11, sp, r11 > + ldw r11, TI_FLAGS(r11) > + > + /* If someone is ptrace:ing us, take the long way. */ > + BTBNZ r11, r11, TIF_SYSCALL_TRACE, traced_system_call > + Are you sure this is correct? Have you tested this works correctly? Last time I tested this, it caused the traced_system_call to be taken for every system call. I already reported and provided a patch a few months ago: http://lists.rocketboards.org/pipermail/nios2-dev/2014-January/006968.html Here's my proposed fix: diff --git a/arch/nios2/kernel/entry.S b/arch/nios2/kernel/entry.S index 9cf2bac..3798008 100644 --- a/arch/nios2/kernel/entry.S +++ b/arch/nios2/kernel/entry.S @@ -204,13 +204,10 @@ ENTRY(handle_system_call) ldw r1, %lo(sys_call_table)(r1) beq r1, r0, ret_invsyscall - /* Get thread info pointer */ - movi r11, %lo(0xfffff000) - and r11, sp, r11 - ldw r11, TI_FLAGS(r11) - - /* If someone is ptrace:ing us, take the long way. */ - BTBNZ r11, r11, TIF_SYSCALL_TRACE, traced_system_call + /* Check if we are being traced */ + GET_THREAD_INFO r11 + ldw r11,TI_FLAGS(r11) + BTBNZ r11,r11,TIF_SYSCALL_TRACE,traced_system_call /* Execute the system call */ callr r1 -- 1.9.1 -- Ezequiel García, Free Electrons Embedded Linux, Kernel and Android Engineering http://free-electrons.com -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html