RE: [PATCH] vsprintf: Do not break early boot with probing addresses

From: christophe leroy

Sent: 10 May 2019 18:35
Le 10/05/2019 à 18:24, Steven Rostedt a écrit :

quoted

On Fri, 10 May 2019 10:42:13 +0200
Petr Mladek [off-list ref] wrote:

quoted

  static const char *check_pointer_msg(const void *ptr)
  {
-	char byte;
-
  	if (!ptr)
  		return "(null)";

-	if (probe_kernel_address(ptr, byte))
+	if ((unsigned long)ptr < PAGE_SIZE || IS_ERR_VALUE(ptr))
  		return "(efault)";

"efault" looks a bit like a spellling mistake for "default".

quoted

	< PAGE_SIZE ?

do you mean: < TASK_SIZE ?

I guess not.

Usually, < PAGE_SIZE means NULL pointer dereference (via the member of a
struct)

Maybe the caller should pass in a short buffer so that you can return
"(err-%d)" or "(null+%#x)" ?

	David

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