From: Amal Raj T <amalrajt@xxxxxxxx>
Add a new query `linux.vmcoreinfo` to kgdb that returns
vmcoreinfo to the client using the mem2ebin encoding.
Maximum size of output buffer is set to 3X the maximum
size of VMCOREINFO_BYTES (kgdb_mem2ebin() requires 1x
for the temporary copy plus up to 2x for the escaped
data).
Signed-off-by: Amal Raj T <amalrajt@xxxxxxxx>
---
kernel/debug/gdbstub.c | 10 +++++++++-
lib/Kconfig.kgdb | 1 +
2 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/kernel/debug/gdbstub.c b/kernel/debug/gdbstub.c
index 6198d2eb49c4..5bec444fc6d3 100644
--- a/kernel/debug/gdbstub.c
+++ b/kernel/debug/gdbstub.c
@@ -34,13 +34,14 @@
#include <linux/uaccess.h>
#include <asm/cacheflush.h>
#include <linux/unaligned.h>
+#include <linux/vmcore_info.h>
#include "debug_core.h"
#define KGDB_MAX_THREAD_QUERY 17
/* Our I/O buffers. */
static char remcom_in_buffer[BUFMAX];
-static char remcom_out_buffer[BUFMAX];
+static char remcom_out_buffer[MAX(VMCOREINFO_BYTES*3, BUFMAX)];
static int gdbstub_use_prev_in_buf;
static int gdbstub_prev_in_buf_pos;
@@ -768,6 +769,13 @@ static void gdb_cmd_query(struct kgdb_state *ks)
*(--ptr) = '\0';
break;
+ case 'l':
+ if (memcmp(remcom_in_buffer + 1, "linux.vmcoreinfo", 16) == 0) {
+ remcom_out_buffer[0] = 'Q';
+ kgdb_mem2ebin(vmcoreinfo_data, remcom_out_buffer + 1, vmcoreinfo_size);
+ }
+ break;
+
case 'C':
/* Current thread id */
strcpy(remcom_out_buffer, "QC");
diff --git a/lib/Kconfig.kgdb b/lib/Kconfig.kgdb
index 537e1b3f5734..012529eee79e 100644
--- a/lib/Kconfig.kgdb
+++ b/lib/Kconfig.kgdb
@@ -12,6 +12,7 @@ menuconfig KGDB
bool "KGDB: kernel debugger"
depends on HAVE_ARCH_KGDB
depends on DEBUG_KERNEL
+ select VMCORE_INFO
help
If you say Y here, it will be possible to remotely debug the
kernel using gdb. It is recommended but not required, that
--
2.43.5
