[PATCH 21/26] printk: Register information into meminspect

Eugen Hristev
2025-11-19T15:45:58Z

Annotate vital static information into meminspect:
- prb_descs
- prb_infos
- prb
- prb_data
- printk_rb_static
- printk_rb_dynamic

Information on these variables is stored into inspection table.

Register dynamic information into meminspect:
- new_descs
- new_infos
- new_log_buf
This information is being allocated as a memblock, so call
memblock_mark_inspect to mark the block accordingly.

Signed-off-by: Eugen Hristev <eugen.hristev@linaro.org>
---
kernel/printk/printk.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 5aee9ffb16b9..8b5aba2527ac 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>
@@ -513,10 +514,16 @@ 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
@@ -1190,6 +1197,7 @@ void __init setup_log_buf(int early)
new_log_buf_len);
goto out;
}
+ memblock_mark_inspect(virt_to_phys(new_log_buf), new_log_buf_len);

new_descs_size = new_descs_count * sizeof(struct prb_desc);
new_descs = memblock_alloc(new_descs_size, LOG_ALIGN);
@@ -1198,6 +1206,7 @@ void __init setup_log_buf(int early)
new_descs_size);
goto err_free_log_buf;
}
+ memblock_mark_inspect(virt_to_phys(new_descs), new_descs_size);

new_infos_size = new_descs_count * sizeof(struct printk_info);
new_infos = memblock_alloc(new_infos_size, LOG_ALIGN);
@@ -1206,6 +1215,7 @@ void __init setup_log_buf(int early)
new_infos_size);
goto err_free_descs;
}
+ memblock_mark_inspect(virt_to_phys(new_infos), new_infos_size);

prb_rec_init_rd(&r, &info, &setup_text_buf[0], sizeof(setup_text_buf));

@@ -1258,8 +1268,10 @@ void __init setup_log_buf(int early)

err_free_descs:
memblock_free(new_descs, new_descs_size);
+ memblock_clear_inspect(virt_to_phys(new_descs), new_descs_size);
err_free_log_buf:
memblock_free(new_log_buf, new_log_buf_len);
+ memblock_clear_inspect(virt_to_phys(new_log_buf), new_log_buf_len);
out:
print_log_buf_usage_stats();
}
--
2.43.0