Commit e78acf67 authored Feb 27, 2013 by Tiejun Chen Committed by Jason Wessel Mar 02, 2013

kgdb/kgdbts: support ppc64



We can't look up the address of the entry point of the function simply
via that function symbol for all architectures.

For PPC64 ABI, actually there is a function descriptors structure.

A function descriptor is a three doubleword data structure that contains
the following values:
	* The first doubleword contains the address of the entry point of
		the function.
	* The second doubleword contains the TOC base address for
		the function.
	* The third doubleword contains the environment pointer for
		languages such as Pascal and PL/1.

So we should call a wapperred dereference_function_descriptor() to get
the address of the entry point of the function.

Note this is also safe for other architecture after refer to
"include/asm-generic/sections.h" since:

dereference_function_descriptor(p) always is (p) if without arched definition.

Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>

parent f7c82d5a

drivers/misc/kgdbts.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -103,6 +103,7 @@
		#include <linux/delay.h>
		#include <linux/kthread.h>
		#include <linux/module.h>
		#include <asm/sections.h>

		#define v1printk(a...) do { \
		if (verbose) \
		@@ -222,6 +223,7 @@ static unsigned long lookup_addr(char *arg)
		addr = (unsigned long)do_fork;
		else if (!strcmp(arg, "hw_break_val"))
		addr = (unsigned long)&hw_break_val;
		addr = (unsigned long) dereference_function_descriptor((void *)addr);
		return addr;
		}