From 9860e1f7cc0f5e63d5e2bfb487ef4533d5b8516b Mon Sep 17 00:00:00 2001
From: "Richard W.M. Jones" <rjones@redhat.com>
Date: Thu, 1 Jan 1970 00:00:00 +0000
Subject: [PATCH] virt-dmesg working.
---
dmesg/virt_dmesg.ml | 35 ++++++++++++++++++++++++++++++++---
1 file changed, 32 insertions(+), 3 deletions(-)
diff --git a/dmesg/virt_dmesg.ml b/dmesg/virt_dmesg.ml
index 2435bbc..10d231f 100644
--- a/dmesg/virt_dmesg.ml
+++ b/dmesg/virt_dmesg.ml
@@ -45,13 +45,42 @@ let () =
* It's possible we can fall back to memory scanning. XXX
*)
let log_buf = lookup_ksym "log_buf" in
+ let log_buf = follow_pointer mem log_buf in
let log_buf_len = lookup_ksym "log_buf_len" in
- let log_start = lookup_ksym "log_start" in
+ let log_buf_len = Int64.of_int32 (get_C_int mem log_buf_len) in
+(* let log_start = lookup_ksym "log_start" in
+ let log_start = get_C_long mem log_start in *)
let log_end = lookup_ksym "log_end" in
- let con_start = lookup_ksym "con_start" in
+ let log_end = get_C_long mem log_end in
+(* let con_start = lookup_ksym "con_start" in
+ let con_start = get_C_long mem con_start in *)
+ let logged_chars = lookup_ksym "logged_chars" in
+ let logged_chars = get_C_long mem logged_chars in
- ()
+ (* This is basically the same algorithm from printk.c:do_syslog
+ * type=3, translated into OCaml. Unlike the kernel version
+ * however we don't copy the buffer backwards.
+ *)
+ let get_log_buf idx =
+ let addr = log_buf +^ (idx &^ (log_buf_len -^ 1L)) in
+ Char.chr (get_byte mem addr)
+ in
+
+ let count = log_buf_len in
+ let count = if count > logged_chars then logged_chars else count in
+ let limit = log_end in
+ let rec loop i =
+ if i >= 0L then (
+ let j = limit-^1L-^i in
+ if j +^ log_buf_len >= log_end then (
+ let c = get_log_buf j in
+ printf "%c" c;
+ loop (i-^1L)
+ )
+ )
+ in
+ loop (count-^1L)
with
Not_found ->
eprintf (f_"%s: could not find kernel log buffer in kernel image\n")
--
1.8.3.1