Annotate vital static, dynamic information into meminspect for debugging

Static:
 - prb_descs
 - prb_infos
 - prb
 - prb_data
 - printk_rb_static
 - printk_rb_dynamic

Dynamic:
 - new_descs
 - new_infos
 - new_log_buf

meminspect uses a different API to annotate variables for inspection,
and information about these variables is stored in the inspection table.

Reviewed-by: Petr Mladek <pmladek@suse.com>
Co-developed-by: Eugen Hristev <eugen.hristev@linaro.org>
Signed-off-by: Eugen Hristev <eugen.hristev@linaro.org>
Signed-off-by: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>
---
 kernel/printk/printk.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 0323149548f6..03216e7ef807 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -49,6 +49,7 @@
 #include <linux/sched/debug.h>
 #include <linux/sched/task_stack.h>
 #include <linux/panic.h>
+#include <linux/meminspect.h>
 
 #include <linux/uaccess.h>
 #include <asm/sections.h>
@@ -518,10 +519,16 @@ static u32 log_buf_len = __LOG_BUF_LEN;
 #endif
 _DEFINE_PRINTKRB(printk_rb_static, CONFIG_LOG_BUF_SHIFT - PRB_AVGBITS,
 		 PRB_AVGBITS, &__log_buf[0]);
+MEMINSPECT_NAMED_ENTRY(prb_descs, _printk_rb_static_descs);
+MEMINSPECT_NAMED_ENTRY(prb_infos, _printk_rb_static_infos);
+MEMINSPECT_NAMED_ENTRY(prb_data, __log_buf);
+MEMINSPECT_SIMPLE_ENTRY(printk_rb_static);
 
 static struct printk_ringbuffer printk_rb_dynamic;
+MEMINSPECT_SIMPLE_ENTRY(printk_rb_dynamic);
 
 struct printk_ringbuffer *prb = &printk_rb_static;
+MEMINSPECT_SIMPLE_ENTRY(prb);
 
 /*
  * We cannot access per-CPU data (e.g. per-CPU flush irq_work) before
@@ -1238,6 +1245,10 @@ void __init setup_log_buf(int early)
 
 	local_irq_restore(flags);
 
+	meminspect_register_va(new_log_buf, new_log_buf_len);
+	meminspect_register_va(new_descs, new_descs_size);
+	meminspect_register_va(new_infos, new_infos_size);
+
 	/*
 	 * Copy any remaining messages that might have appeared from
 	 * NMI context after copying but before switching to the

-- 
2.50.1

On 2026-03-11, Mukesh Ojha <mukesh.ojha@oss.qualcomm.com> wrote:
> Annotate vital static, dynamic information into meminspect for debugging
>
> Static:
>  - prb_descs
>  - prb_infos
>  - prb
>  - prb_data
>  - printk_rb_static
>  - printk_rb_dynamic

FYI: vmcore also exports the symbol "clear_seq". It is not required if
you are interested in reading _everything_ in the buffer. But it may be
interesting if you want to mirror vmcore tool features.

> Dynamic:
>  - new_descs
>  - new_infos
>  - new_log_buf
>
> meminspect uses a different API to annotate variables for inspection,
> and information about these variables is stored in the inspection table.
>
> Reviewed-by: Petr Mladek <pmladek@suse.com>
> Co-developed-by: Eugen Hristev <eugen.hristev@linaro.org>
> Signed-off-by: Eugen Hristev <eugen.hristev@linaro.org>
> Signed-off-by: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>

Reviewed-by: John Ogness <john.ogness@linutronix.de>

On 3/16/26 11:39, John Ogness wrote:
> On 2026-03-11, Mukesh Ojha <mukesh.ojha@oss.qualcomm.com> wrote:
>> Annotate vital static, dynamic information into meminspect for debugging
>>
>> Static:
>>  - prb_descs
>>  - prb_infos
>>  - prb
>>  - prb_data
>>  - printk_rb_static
>>  - printk_rb_dynamic
> 
> FYI: vmcore also exports the symbol "clear_seq". It is not required if
> you are interested in reading _everything_ in the buffer. But it may be
> interesting if you want to mirror vmcore tool features.

Thank you for your review and suggestion. One of the key points of
meminspect is to be easy to use by the kernel developer. E.g. to be easy
to add another symbol, like `clear_seq` for a particular use case.
So, someone wanting to make use of it, can easily add it.
The purpose of the initial submission would be to have a basic use case
working, and show it as an example for everyone.
If you would like to detail about the features you mention, it could be
interesting to try them and see if it would work with a meminspect dump.

Eugen
> 
>> Dynamic:
>>  - new_descs
>>  - new_infos
>>  - new_log_buf
>>
>> meminspect uses a different API to annotate variables for inspection,
>> and information about these variables is stored in the inspection table.
>>
>> Reviewed-by: Petr Mladek <pmladek@suse.com>
>> Co-developed-by: Eugen Hristev <eugen.hristev@linaro.org>
>> Signed-off-by: Eugen Hristev <eugen.hristev@linaro.org>
>> Signed-off-by: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>
> 
> Reviewed-by: John Ogness <john.ogness@linutronix.de>