Re: [PATCH] MIPS Fixups for LTTng (Update)

Hi Manish, see annotations below,

* Manish Lachwani ([email protected]) wrote:
> Hi Mathieu,
> 
> I looked at the i386 stuff and made the necessary changes for MIPS (32-bit). Let me know your thoughts on this attached patch. 
> 
> Thanks,
> Manish Lachwani

> Source: MontaVista Software, Inc.
> Type: Defect Fix 
> Signed-off-by: Manish Lachwani <[email protected]>
> Description:
> 
> MIPS Fixups for LTTng:
> 
>  arch/mips/kernel/process.c     |    4 ----
>  arch/mips/kernel/scall32-o32.S |    9 ---------
>  arch/mips/kernel/traps.c       |   13 ++++++-------
>  arch/mips/mm/fault.c           |   12 ++++++------
>  4 files changed, 12 insertions(+), 26 deletions(-)
> 
> 
> Index: linux-2.6.18/arch/mips/kernel/process.c
> ===================================================================
> --- linux-2.6.18.orig/arch/mips/kernel/process.c
> +++ linux-2.6.18/arch/mips/kernel/process.c
> @@ -276,10 +276,6 @@ long kernel_thread(int (*fn)(void *), vo
>  	pid = do_fork(flags | CLONE_VM | CLONE_UNTRACED,
>  			0, &regs, 0, NULL, NULL);
>  	MARK(kernel_thread_create, "%ld %p", pid, fn);
> -#ifdef CONFIG_LTT
> -	if(pid >= 0)
> -		trace_process_kernel_thread(pid, fn);
> -#endif //CONFIG_LTT
>  	return pid;
>  }
>  

Missing MARKer for thread creation.

> Index: linux-2.6.18/arch/mips/kernel/traps.c
> ===================================================================
> --- linux-2.6.18.orig/arch/mips/kernel/traps.c
> +++ linux-2.6.18/arch/mips/kernel/traps.c
> @@ -591,7 +591,7 @@ asmlinkage void do_fpe(struct pt_regs *r
>  {
>  	die_if_kernel("FP exception in kernel code", regs);
>  
> -	trace_kernel_trap_entry(CAUSE_EXCCODE(regs->cp0_cause), (void*)regs->cp0_epc);
> +	MARK(kernel_trap_entry, "%d struct pt_regs %p", CAUSE_EXCCODE(regs->cp0_cause), regs);
>  	if (fcr31 & FPU_CSR_UNI_X) {
>  		int sig;
>  
> @@ -748,20 +748,19 @@ asmlinkage void do_cpu(struct pt_regs *r
>  
>  	die_if_kernel("do_cpu invoked from kernel context!", regs);
>  
> -	trace_kernel_trap_entry(CAUSE_EXCCODE(regs->cp0_cause), (void*)regs->cp0_epc);
> -
> +	MARK(kernel_trap_entry, "%d struct pt_regs %p", CAUSE_EXCCODE(regs->cp0_cause), regs);
>  	cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
>  
>  	switch (cpid) {
>  	case 0:
>  		if (!cpu_has_llsc)
>  			if (!simulate_llsc(regs)) {
> -				trace_kernel_trap_exit();
> +				MARK(kernel_trap_exit, MARK_NOARGS);
>  				return;
>  			}
>  
>  		if (!simulate_rdhwr(regs)) {
> -			trace_kernel_trap_exit();
> +			MARK(kernel_trap_exit, MARK_NOARGS);
>  			return;
>  		}
>  
> @@ -818,7 +817,7 @@ asmlinkage void do_cpu(struct pt_regs *r
>  			}
>  #endif /* CONFIG_MIPS_MT_FPAFF */
>  		}
> -		trace_kernel_trap_exit();
> +		MARK(kernel_trap_exit, MARK_NOARGS);
>  		return;
>  
>  	case 2:
> @@ -828,7 +827,7 @@ asmlinkage void do_cpu(struct pt_regs *r
>  	}
>  
>  	force_sig(SIGILL, current);
> -	trace_kernel_trap_exit();
> +	MARK(kernel_trap_exit, MARK_NOARGS);
>  }
>  
>  asmlinkage void do_mdmx(struct pt_regs *regs)
> Index: linux-2.6.18/arch/mips/kernel/scall32-o32.S
> ===================================================================
> --- linux-2.6.18.orig/arch/mips/kernel/scall32-o32.S
> +++ linux-2.6.18/arch/mips/kernel/scall32-o32.S
> @@ -69,7 +69,6 @@ stack_done:
>  #ifdef CONFIG_LTT
>  	sw  t2, PT_R1(sp)
>  	move  a0, sp
> -	jal     trace_real_syscall_entry
>  	lw  t2, PT_R1(sp)
>  
>  	lw  a0, PT_R4(sp)		# Restore argument registers
> @@ -94,10 +93,6 @@ stack_done:
>  					# restarting
>  1:	sw	v0, PT_R2(sp)		# result
>  
> -#ifdef CONFIG_LTT
> -	jal trace_real_syscall_exit
> -#endif // CONFIG_LTT
> -
>  o32_syscall_exit:
>  	raw_local_irq_disable	# make sure need_resched and
>  					# signals dont change between
> @@ -139,10 +134,6 @@ syscall_trace_entry:
>  					# restarting
>  1:	sw	v0, PT_R2(sp)		# result
>  
> -#ifdef CONFIG_LTT
> - jal trace_real_syscall_exit
> -#endif //CONFIG_LTT)
> -
>  	j	syscall_exit
>  
>  /* ------------------------------------------------------------------------ */

For the following one, I changed the way page fauls are instrumented. Look
closely at the i386 implementation (I removed most of the markers from fault.c
to put an instrumentation in handle_mm_fault.

> Index: linux-2.6.18/arch/mips/mm/fault.c
> ===================================================================
> --- linux-2.6.18.orig/arch/mips/mm/fault.c
> +++ linux-2.6.18/arch/mips/mm/fault.c
> @@ -115,7 +115,7 @@ survive:
>  	}
>  
>  	up_read(&mm->mmap_sem);
> -	trace_kernel_trap_exit();
> +	MARK(kernel_trap_exit, MARK_NOARGS);
>  	return;
>  
>  /*
> @@ -144,7 +144,7 @@ bad_area_nosemaphore:
>  		/* info.si_code has been set above */
>  		info.si_addr = (void __user *) address;
>  		force_sig_info(SIGSEGV, &info, tsk);
> -		trace_kernel_trap_exit();
> +		MARK(kernel_trap_exit, MARK_NOARGS);
>  		return;
>  	}
>  
> @@ -210,7 +210,7 @@ do_sigbus:
>  	info.si_addr = (void __user *) address;
>  	force_sig_info(SIGBUS, &info, tsk);
>  
> -	trace_kernel_trap_exit();
> +	MARK(kernel_trap_exit, MARK_NOARGS);
>  	return;
>  vmalloc_fault:
>  	{
> @@ -248,9 +248,9 @@ vmalloc_fault:
>  		pte_k = pte_offset_kernel(pmd_k, address);
>  		if (!pte_present(*pte_k))
>  			goto no_context;
> -		trace_kernel_trap_entry(CAUSE_EXCCODE(regs->cp0_cause), (void*)regs->cp0_epc);
> -		trace_kernel_trap_exit();
> +		MARK(kernel_trap_entry, "%d struct pt_regs %p", CAUSE_EXCCODE(regs->cp0_cause), regs);
> +		MARK(kernel_trap_exit, MARK_NOARGS);
>  		return;
>  	}
> -	trace_kernel_trap_exit();
> +	MARK(kernel_trap_exit, MARK_NOARGS);
>  }

Mathieu

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