[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <87zhklt9eg.fsf@concordia.ellerman.id.au>
Date: Wed, 07 Aug 2019 23:03:35 +1000
From: Michael Ellerman <mpe@...erman.id.au>
To: Jason Yan <yanaijie@...wei.com>, linuxppc-dev@...ts.ozlabs.org, diana.craciun@....com, christophe.leroy@....fr, benh@...nel.crashing.org, paulus@...ba.org, npiggin@...il.com, keescook@...omium.org, kernel-hardening@...ts.openwall.com
Cc: linux-kernel@...r.kernel.org, wangkefeng.wang@...wei.com, yebin10@...wei.com, thunder.leizhen@...wei.com, jingxiangfeng@...wei.com, fanchengyang@...wei.com, zhaohongjiang@...wei.com, Jason Yan <yanaijie@...wei.com>
Subject: Re: [PATCH v5 10/10] powerpc/fsl_booke/kaslr: dump out kernel offset information on panic
Jason Yan <yanaijie@...wei.com> writes:
> 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.
Some of this is taken from the arm64 version right? Please say so when
you copy other people's code.
> diff --git a/arch/powerpc/kernel/machine_kexec.c b/arch/powerpc/kernel/machine_kexec.c
> index c4ed328a7b96..078fe3d76feb 100644
> --- a/arch/powerpc/kernel/machine_kexec.c
> +++ b/arch/powerpc/kernel/machine_kexec.c
> @@ -86,6 +86,7 @@ void arch_crash_save_vmcoreinfo(void)
> VMCOREINFO_STRUCT_SIZE(mmu_psize_def);
> VMCOREINFO_OFFSET(mmu_psize_def, shift);
> #endif
> + vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
> }
There's no mention of that in the commit log.
Please split it into a separate patch and describe what you're doing and
why.
> diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c
> index 1f8db666468d..064075f02837 100644
> --- a/arch/powerpc/kernel/setup-common.c
> +++ b/arch/powerpc/kernel/setup-common.c
> @@ -715,12 +715,31 @@ 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)
> {
> /* PPC64 always does a hard irq disable in its panic handler */
> if (!IS_ENABLED(CONFIG_PPC64) && !ppc_md.panic)
> return;
> atomic_notifier_chain_register(&panic_notifier_list, &ppc_panic_block);
> + if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && kaslr_offset() > 0)
> + atomic_notifier_chain_register(&panic_notifier_list,
> + &kernel_offset_notifier);
Don't you want to do that before the return above?
> }
cheers
Powered by blists - more mailing lists
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
