kernel_debugger_core: Add sysrq command.

sysrq <c> will run the sysrq command <c> and dump what
was added to the kernel log while the command ran.

Signed-off-by: Brian Swetland <swetland@google.com>
Signed-off-by: Arve Hjønnevåg <arve@android.com>

diff --git a/drivers/misc/kernel_debugger.c b/drivers/misc/kernel_debugger.c
index 4c479d8..f10eaa4 100644 (file)
--- a/drivers/misc/kernel_debugger.c
+++ b/drivers/misc/kernel_debugger.c
@@ -20,6 +20,7 @@
 #include <linux/device.h>
 #include <linux/sched.h>
 #include <linux/spinlock.h>
+#include <linux/sysrq.h>
 #include <linux/kernel_debugger.h>
 
 #define dprintf(fmt...) (ctxt->printf(ctxt->cookie, fmt))
@@ -45,10 +46,33 @@ static void do_ps(struct kdbg_ctxt *ctxt)
        read_unlock(&tasklist_lock);
 }
 
+int log_buf_copy(char *dest, int idx, int len);
+extern int do_syslog(int type, char __user *bug, int count);
+static void do_sysrq(struct kdbg_ctxt *ctxt, char rq)
+{
+       char buf[128];
+       int ret;
+       int idx = 0;
+       do_syslog(5 /* clear */, NULL, 0);
+       __handle_sysrq(rq, NULL, 0);
+       while (1) {
+               ret = log_buf_copy(buf, idx, sizeof(buf) - 1);
+               if (ret <= 0)
+                       break;
+               buf[ret] = 0;
+               dprintf("%s", buf);
+               idx += ret;
+       }
+}
+
 int kernel_debugger(struct kdbg_ctxt *ctxt, char *cmd)
 {
        if (!strcmp(cmd, "ps"))
                do_ps(ctxt);
+       if (!strcmp(cmd, "sysrq"))
+               do_sysrq(ctxt, 'h');
+       if (!strncmp(cmd, "sysrq ", 6))
+               do_sysrq(ctxt, cmd[6]);
 
        return 0;
 }