Re: [PATCH 1/1] dumpstack: fix printk_address for direct addresses

From: Jiri Slaby
Date: Wed Oct 16 2013 - 05:52:34 EST


On 10/12/2013 11:35 PM, Joe Perches wrote:
> On Sat, 2013-10-12 at 22:13 +0200, Jiri Slaby wrote:
> []
>> To fix that, we use %pS only for stack addresses printouts (via newly
>> added printk_stack_address) and %pB for regs->ip (via printk_address).
>> I.e. we revert to the old behaviour for all except call stacks. And
>> since from all those reliable is 1, we remove that parameter from
>> printk_address.
>
> I'm still waiting for you to apply this:
>
> https://lkml.org/lkml/2013/7/22/701
> https://lkml.org/lkml/2013/7/22/700
>
> Oh wait, wrong Jiri... ;-)
>
> Anyway, I'd rather your specific changes be done inline
> so it's less possible to have interleaved messages.

Why you are putting this here?

>> diff --git a/arch/x86/include/asm/kdebug.h b/arch/x86/include/asm/kdebug.h
> []
>> @@ -21,7 +21,7 @@ enum die_val {
>> DIE_NMIUNKNOWN,
>> };
>>
>> -extern void printk_address(unsigned long address, int reliable);
>> +extern void printk_address(unsigned long address);
>
> I think this can be removed.

I'm waiting for an x86's guys input as to what do they prefer to be done?

>> diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
> []
>> @@ -25,12 +25,17 @@ unsigned int code_bytes = 64;
>> int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE;
>> static int die_counter;
>>
>> -void printk_address(unsigned long address, int reliable)
>> +static void printk_stack_address(unsigned long address, int reliable)
>> {
>> pr_cont(" [<%p>] %s%pB\n",
>> (void *)address, reliable ? "" : "? ", (void *)address);
>> }
>
> This is now used only once and could/should be done
> at the single use site.
>
>> +void printk_address(unsigned long address)
>> +{
>> + pr_cont(" [<%p>] %pS\n", (void *)address, (void *)address);
>> +}
>> +
>
> And this could/should be done inline in the few
> places it's used.
>
>> #ifdef CONFIG_FUNCTION_GRAPH_TRACER
>> static void
>> print_ftrace_graph_addr(unsigned long addr, void *data,
>> @@ -151,7 +156,7 @@ static void print_trace_address(void *data, unsigned long addr, int reliable)
>> {
>> touch_nmi_watchdog();
>> printk(data);
>> - printk_address(addr, reliable);
>> + printk_stack_address(addr, reliable);
>
> printk("%s [<%p>] %s%pB\n",
> data, (void *)addr, reliable ? "" : "? ", (void *)addr);
>
>> @@ -281,7 +286,7 @@ int __kprobes __die(const char *str, struct pt_regs *regs, long err)
>> #else
>> /* Executive summary in case the oops scrolled away */
>> printk(KERN_ALERT "RIP ");
>> - printk_address(regs->ip, 1);
>> + printk_address(regs->ip);
>
> printk(KERN_ALERT "RIP [<%p>] %pS\n",
> (void *)regs->ip, (void *)regs->ip);
>
>> diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
> []
>> @@ -63,7 +63,7 @@ void __show_regs(struct pt_regs *regs, int all)
>> unsigned int ds, cs, es;
>>
>> printk(KERN_DEFAULT "RIP: %04lx:[<%016lx>] ", regs->cs & 0xffff, regs->ip);
>> - printk_address(regs->ip, 1);
>> + printk_address(regs->ip);
>
> printk(KERN_DEFAULT "RIP: %04lx:[<%016lx>] [<%p>] %pS\n",
> regs->cs & 0xffff, regs->ip,
> (void *)regs->ip, (void *)regs->ip);
>
> This one looks ugly to me.
> It emits the address twice.
>
>> printk(KERN_DEFAULT "RSP: %04lx:%016lx EFLAGS: %08lx\n", regs->ss,
>> regs->sp, regs->flags);
>> printk(KERN_DEFAULT "RAX: %016lx RBX: %016lx RCX: %016lx\n",
>> diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
>> index 3aaeffc..18feeb3 100644
>> --- a/arch/x86/mm/fault.c
>> +++ b/arch/x86/mm/fault.c
>> @@ -596,7 +596,7 @@ show_fault_oops(struct pt_regs *regs, unsigned long error_code,
>>
>> printk(KERN_CONT " at %p\n", (void *) address);
>> printk(KERN_ALERT "IP:");
>> - printk_address(regs->ip, 1);
>> + printk_address(regs->ip);
>
> printk(KERN_ALERT "IP: [<%p>] %pS\n",
> (void *)regs->ip, (void *)regs->ip);
>
>> dump_pagetable(address);
>> }
>> diff --git a/arch/x86/platform/uv/uv_nmi.c b/arch/x86/platform/uv/uv_nmi.c
>> index 9126dfb..019b6ec 100644
>> --- a/arch/x86/platform/uv/uv_nmi.c
>> +++ b/arch/x86/platform/uv/uv_nmi.c
>> @@ -402,7 +402,7 @@ static void uv_nmi_dump_cpu_ip(int cpu, struct pt_regs *regs)
>> printk(KERN_DEFAULT "UV: %4d %6d %-32.32s ",
>> cpu, current->pid, current->comm);
>>
>> - printk_address(regs->ip, 1);
>> + printk_address(regs->ip);
>
> printk(KERN_DEFAULT "UV: %4d %6d %-32.32s [<%p>] %pS\n",
> cpu, current->pid, current->comm,
> (void *)regs->ip, (void *)regs->ip);
>
>


--
js
suse labs
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