[PATCH] kdump: add dmesg gdbmacro into document

Add gdb macro which print the kernel ring buffer into kdump docs

Signed-off-by: Akinobu Mita <mita@miraclelinux.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 22 insertions, 0 deletions

diff --git a/Documentation/kdump/gdbmacros.txt b/Documentation/kdump/gdbmacros.txt
index bc1b9eb92ae1..dcf5580380ab 100644
--- a/Documentation/kdump/gdbmacros.txt
+++ b/Documentation/kdump/gdbmacros.txt
@@ -177,3 +177,25 @@ document trapinfo
         'trapinfo <pid>' will tell you by which trap & possibly
         addresthe kernel paniced.
 end
+
+
+define dmesg
+        set $i = 0
+        set $end_idx = (log_end - 1) & (log_buf_len - 1)
+
+        while ($i < logged_chars)
+                set $idx = (log_end - 1 - logged_chars + $i) & (log_buf_len - 1)
+
+                if ($idx + 100 <= $end_idx) || \
+                   ($end_idx <= $idx && $idx + 100 < log_buf_len)
+                        printf "%.100s", &log_buf[$idx]
+                        set $i = $i + 100
+                else
+                        printf "%c", log_buf[$idx]
+                        set $i = $i + 1
+                end
+        end
+end
+document dmesg
+        print the kernel ring buffer
+end