2023-07-22 13:57:18

by Alexandre Ghiti

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Subject: [PATCH v6 2/5] riscv: Dump out kernel offset information on panic

Dump out the KASLR virtual kernel offset when panic to help debug kernel.

Signed-off-by: Zong Li <[email protected]>
Signed-off-by: Alexandre Ghiti <[email protected]>
---
arch/riscv/kernel/setup.c | 25 +++++++++++++++++++++++++
1 file changed, 25 insertions(+)

diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index 971fe776e2f8..0fb5a26ca4cc 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -21,6 +21,7 @@
#include <linux/smp.h>
#include <linux/efi.h>
#include <linux/crash_dump.h>
+#include <linux/panic_notifier.h>

#include <asm/acpi.h>
#include <asm/alternative.h>
@@ -341,3 +342,27 @@ void free_initmem(void)

free_initmem_default(POISON_FREE_INITMEM);
}
+
+static int dump_kernel_offset(struct notifier_block *self,
+ unsigned long v, void *p)
+{
+ pr_emerg("Kernel Offset: 0x%lx from 0x%lx\n",
+ kernel_map.virt_offset,
+ KERNEL_LINK_ADDR);
+
+ return 0;
+}
+
+static struct notifier_block kernel_offset_notifier = {
+ .notifier_call = dump_kernel_offset
+};
+
+static int __init register_kernel_offset_dumper(void)
+{
+ if (IS_ENABLED(CONFIG_RANDOMIZE_BASE))
+ atomic_notifier_chain_register(&panic_notifier_list,
+ &kernel_offset_notifier);
+
+ return 0;
+}
+device_initcall(register_kernel_offset_dumper);
--
2.39.2



2023-07-24 14:39:50

by Conor Dooley

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Subject: Re: [PATCH v6 2/5] riscv: Dump out kernel offset information on panic

Hey Alex,

On Sat, Jul 22, 2023 at 02:38:47PM +0200, Alexandre Ghiti wrote:
> Dump out the KASLR virtual kernel offset when panic to help debug kernel.
>
> Signed-off-by: Zong Li <[email protected]>

Either you're missing a Co-developed-by: or the author of this patch is
incorrect.

> Signed-off-by: Alexandre Ghiti <[email protected]>


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2023-07-25 07:17:29

by Alexandre Ghiti

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Subject: Re: [PATCH v6 2/5] riscv: Dump out kernel offset information on panic

Hi Conor,

On Mon, Jul 24, 2023 at 4:20 PM Conor Dooley <[email protected]> wrote:
>
> Hey Alex,
>
> On Sat, Jul 22, 2023 at 02:38:47PM +0200, Alexandre Ghiti wrote:
> > Dump out the KASLR virtual kernel offset when panic to help debug kernel.
> >
> > Signed-off-by: Zong Li <[email protected]>
>
> Either you're missing a Co-developed-by: or the author of this patch is
> incorrect.

Ok, I thought it would work this way, Zong first did something similar
a few years ago, so we need his name here. @Palmer Dabbelt if no other
changes are needed, do you mind replacing the SoB with a
Co-developed-by?

Thanks,

Alex

>
> > Signed-off-by: Alexandre Ghiti <[email protected]>

2023-07-25 07:30:20

by Conor Dooley

[permalink] [raw]
Subject: Re: [PATCH v6 2/5] riscv: Dump out kernel offset information on panic

On Tue, Jul 25, 2023 at 09:05:37AM +0200, Alexandre Ghiti wrote:
> Hi Conor,
>
> On Mon, Jul 24, 2023 at 4:20 PM Conor Dooley <[email protected]> wrote:
> >
> > Hey Alex,
> >
> > On Sat, Jul 22, 2023 at 02:38:47PM +0200, Alexandre Ghiti wrote:
> > > Dump out the KASLR virtual kernel offset when panic to help debug kernel.
> > >
> > > Signed-off-by: Zong Li <[email protected]>
> >
> > Either you're missing a Co-developed-by: or the author of this patch is
> > incorrect.
>
> Ok, I thought it would work this way, Zong first did something similar
> a few years ago, so we need his name here. @Palmer Dabbelt if no other
> changes are needed, do you mind replacing the SoB with a
> Co-developed-by?

You can't have a Co-developed-by without a SoB, so both are needed :)


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