Commit e4dace36 authored by Florian Fainelli's avatar Florian Fainelli Committed by Linus Torvalds

lib: add test module for CONFIG_DEBUG_VIRTUAL

Add a test module that allows testing that CONFIG_DEBUG_VIRTUAL works
correctly, at least that it can catch invalid calls to virt_to_phys()
against the non-linear kernel virtual address map.

Link: http://lkml.kernel.org/r/20170808164035.26725-1-f.fainelli@gmail.comSigned-off-by: 's avatarFlorian Fainelli <f.fainelli@gmail.com>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: 's avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: 's avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 9888a588
......@@ -1930,6 +1930,17 @@ config TEST_KMOD
If unsure, say N.
config TEST_DEBUG_VIRTUAL
tristate "Test CONFIG_DEBUG_VIRTUAL feature"
depends on DEBUG_VIRTUAL
help
Test the kernel's ability to detect incorrect calls to
virt_to_phys() done against the non-linear part of the
kernel's virtual address map.
If unsure, say N.
source "samples/Kconfig"
source "lib/Kconfig.kgdb"
......
......@@ -62,6 +62,7 @@ obj-$(CONFIG_TEST_BITMAP) += test_bitmap.o
obj-$(CONFIG_TEST_UUID) += test_uuid.o
obj-$(CONFIG_TEST_PARMAN) += test_parman.o
obj-$(CONFIG_TEST_KMOD) += test_kmod.o
obj-$(CONFIG_TEST_DEBUG_VIRTUAL) += test_debug_virtual.o
ifeq ($(CONFIG_DEBUG_KOBJECT),y)
CFLAGS_kobject.o += -DDEBUG
......
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/export.h>
#include <linux/mm.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/sizes.h>
#include <asm/page.h>
#ifdef CONFIG_MIPS
#include <asm/bootinfo.h>
#endif
struct foo {
unsigned int bar;
};
struct foo *foo;
static int __init test_debug_virtual_init(void)
{
phys_addr_t pa;
void *va;
va = (void *)VMALLOC_START;
pa = virt_to_phys(va);
pr_info("PA: %pa for VA: 0x%lx\n", &pa, (unsigned long)va);
foo = kzalloc(sizeof(*foo), GFP_KERNEL);
if (!foo)
return -ENOMEM;
pa = virt_to_phys(foo);
va = foo;
pr_info("PA: %pa for VA: 0x%lx\n", &pa, (unsigned long)va);
return 0;
}
module_init(test_debug_virtual_init);
static void __exit test_debug_virtual_exit(void)
{
kfree(foo);
}
module_exit(test_debug_virtual_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Test module for CONFIG_DEBUG_VIRTUAL");
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