Messages in this thread | | | Subject | Re: [PATCH v7 0/2] ARM: Implement MODULE_PLT support in FTRACE | From | Alexander Sverdlin <> | Date | Tue, 2 Mar 2021 11:00:51 +0100 |
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Hello Linus,
On 02/03/2021 09:29, Linus Walleij wrote: >>>> FTRACE's function tracer currently doesn't always work on ARM with >>>> MODULE_PLT option enabled. If the module is loaded too far, FTRACE's
First of all:
config ARM_MODULE_PLTS bool "Use PLTs to allow module memory to spill over into vmalloc area"
[...]
> Any suggestions on a quick use case that illustrates how the problem > manifest and how to test it is gone? The errors in patch 2, what do > I need to configure in to get them? Does it manifest at modprobe?
And then I use this module to test for the problem:
/********************************************************************** * Author: Alexander Sverdlin <alexander.sverdlin@nokia.com> * * Copyright (c) 2018 Nokia * * SPDX-License-Identifier: GPL-2.0 * * This module is intended to test ARM MODULE_PLT functionality **********************************************************************/
#include <linux/types.h> #include <linux/kernel.h> #include <linux/module.h>
static int fatmod_init(void) { asm volatile (".rept (6 * 1024 * 1024 / 2)\n\t" "nop\n\t" ".endr"); return 0; } module_init(fatmod_init);
static void __exit fatmod_exit(void) { } module_exit(fatmod_exit);
MODULE_AUTHOR("Alexander Sverdlin <alexander.sverdlin@nokia.com>"); MODULE_DESCRIPTION("ARM MODULE_PLT test module"); MODULE_LICENSE("GPL");
-- Best regards, Alexander Sverdlin.
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