Re: [PATCH] arm:traps: Don't print stack or raw PC/LR values in backtraces

[Xiaoming Ni]

On 2020/10/9 16:18, Sebastian Andrzej Siewior wrote:
> On 2020-10-09 09:08:50 [+0100], Russell King - ARM Linux admin wrote:
> > I am really not happy about this - it hurts at least my ability to
> > debug the kernel when people post oopses to the mailing list. If

In the reset scenario, dump_mem is retained:

@@ -125,6 +118,9 @@ static void dump_mem(const char *lvl, const char 
*str, unsigned long bottom,
        mm_segment_t fs;
        int i;

+ /* Do not print virtual addresses in non-reset scenarios */
+ if (!panic_on_oops)
+         return;


> > people wish to make the kernel harder to debug, and are prepared
> > to be told "your kernel is undebuggable" then this patch is fine.
>
> I haven't look at the patch but don't they keep/add the representation:
>    PC: symbol+offset/size
>    LR: symbol+offset/size
>
> ? This is needed at very least as a replacement for the missing address.

Yes, only %08lx was deleted, but %ps is still retained.

-	printk("%s[<%08lx>] (%ps) from [<%08lx>] (%pS)\n",
-		loglvl, where, (void *)where, from, (void *)from);
+	printk("%s (%ps) from (%pS)\n",
+		loglvl, (void *)where, (void *)from);

Thanks
Xiaoming Ni