Merge tag 'for_linus-3.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb

Pull KGDB/KDB updates from Jason Wessel:
 "Fixes:
   - Fix KDB keyboard repeat scan codes and leaked keyboard events
   - Fix kernel crash with kdb_printf() for users who compile new
     kdb_printf()'s in early code
   - Return all segment registers to gdb on x86_64

  Features:
   - KDB/KGDB hook the reboot notifier and end user can control if it
     stops, detaches or does nothing (updated docs as well)
   - Notify users who use CONFIG_DEBUG_RODATA to use hw breakpoints"

* tag 'for_linus-3.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/kgdb:
  kdb: Add message about CONFIG_DEBUG_RODATA on failure to install breakpoint
  kdb: Avoid using dbg_io_ops until it is initialized
  kgdb,debug_core: add the ability to control the reboot notifier
  KDB: Fix usability issues relating to the 'enter' key.
  kgdb,debug-core,gdbstub: Hook the reboot notifier for debugger detach
  kgdb: Respect that flush op is optional
  kgdb: x86: Return all segment registers also in 64-bit mode

1 files changed, 7 insertions, 0 deletions

diff --git a/kernel/debug/kdb/kdb_bp.c b/kernel/debug/kdb/kdb_bp.c
index 20059ef4459a..8418c2f8ec5d 100644
--- a/kernel/debug/kdb/kdb_bp.c
+++ b/kernel/debug/kdb/kdb_bp.c
@@ -153,6 +153,13 @@ static int _kdb_bp_install(struct pt_regs *regs, kdb_bp_t *bp)
         } else {
                 kdb_printf("%s: failed to set breakpoint at 0x%lx\n",
                            __func__, bp->bp_addr);
+#ifdef CONFIG_DEBUG_RODATA
+                if (!bp->bp_type) {
+                        kdb_printf("Software breakpoints are unavailable.\n"
+                                   "  Change the kernel CONFIG_DEBUG_RODATA=n\n"
+                                   "  OR use hw breaks: help bph\n");
+                }
+#endif
                 return 1;
         }
         return 0;