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

From: Joe Perches
Date: Sat Oct 12 2013 - 17:35:43 EST


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.


> 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.

> 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);


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