leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

powerpc/fsl_booke/kaslr: dump out kernel offset information on panic

Browse Source 
When kaslr is enabled, the kernel offset is different for every boot.
This brings some difficult to debug the kernel. Dump out the kernel
offset when panic so that we can easily debug the kernel.

This code is derived from x86/arm64 which has similar functionality.

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Diana Craciun <diana.craciun@nxp.com>
Tested-by: Diana Craciun <diana.craciun@nxp.com>
Signed-off-by: Scott Wood <oss@buserror.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Jason Yan 2019-09-20 17:45:44 +08:00 committed by Michael Ellerman
parent 8c2ae87be5
commit 921a79b780
2 changed files with 25 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
arch/powerpc/include/asm/page.h
View File

@ -327,6 +327,11 @@ struct vm_area_struct;
extern unsigned long kernstart_virt_addr;
static inline unsigned long kaslr_offset(void)
{
return kernstart_virt_addr - KERNELBASE;
}
#include <asm-generic/memory_model.h>
#endif /* __ASSEMBLY__ */
#include <asm/slice.h>

20
arch/powerpc/kernel/setup-common.c
View File

@ -715,8 +715,28 @@ static struct notifier_block ppc_panic_block = {
.priority = INT_MIN /* may not return; must be done last */
};
/*
* Dump out kernel offset information on panic.
*/
static int dump_kernel_offset(struct notifier_block *self, unsigned long v,
void *p)
{
pr_emerg("Kernel Offset: 0x%lx from 0x%lx\n",
kaslr_offset(), KERNELBASE);
return 0;
}
static struct notifier_block kernel_offset_notifier = {
.notifier_call = dump_kernel_offset
};
void __init setup_panic(void)
{
if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && kaslr_offset() > 0)
atomic_notifier_chain_register(&panic_notifier_list,
&kernel_offset_notifier);
/* PPC64 always does a hard irq disable in its panic handler */
if (!IS_ENABLED(CONFIG_PPC64) && !ppc_md.panic)
return;