[RFC PATCH 2/2] build: convert crash_debug to Kconfig

From: Doug Goldstein <cardoe@cardoe.com>
To: xen-devel@lists.xen.org
Cc: Keir Fraser <keir@xen.org>, Doug Goldstein <cardoe@cardoe.com>,
	Jan Beulich <jbeulich@suse.com>,
	Andrew Cooper <andrew.cooper3@citrix.com>
Subject: [RFC PATCH 2/2] build: convert crash_debug to Kconfig
Date: Thu, 24 Mar 2016 11:48:19 -0500	[thread overview]
Message-ID: <1458838099-12053-2-git-send-email-cardoe@cardoe.com> (raw)
In-Reply-To: <1458838099-12053-1-git-send-email-cardoe@cardoe.com>

Convert the crash_debug option to Kconfig as CONFIG_CRASH_DEBUG. This
was previously togglable on the command line so this adds a message for
users enabling it from the command line to tell them to enable it from
make menuconfig.

Signed-off-by: Doug Goldstein <cardoe@cardoe.com>
---
This is an example of using the debug menu.


CC: Keir Fraser <keir@xen.org>
CC: Jan Beulich <jbeulich@suse.com>
CC: Andrew Cooper <andrew.cooper3@citrix.com>
---
 docs/misc/crashdb.txt          |  4 ++--
 xen/Kconfig.debug              | 11 +++++++++++
 xen/Rules.mk                   |  5 +++--
 xen/arch/x86/Makefile          |  3 +--
 xen/arch/x86/x86_64/Makefile   |  2 +-
 xen/common/Makefile            |  2 +-
 xen/include/asm-x86/debugger.h |  2 +-
 xen/include/xen/gdbstub.h      |  2 +-
 8 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/docs/misc/crashdb.txt b/docs/misc/crashdb.txt
index b41a538..9733666 100644
--- a/docs/misc/crashdb.txt
+++ b/docs/misc/crashdb.txt
@@ -5,7 +5,7 @@ Xen has a simple gdb stub for doing post-mortem debugging i.e. once
 you've crashed it, you get to poke around and find out why.  There's
 also a special key handler for making it crash, which is handy.
 
-You need to have crash_debug=y set when compiling , and you also need
+You need to have CRASH_DEBUG=y set when compiling, and you also need
 to enable it on the Xen command line, eg by gdb=com1.
 
 If you need to have a serial port shared between gdb and the console,
@@ -19,7 +19,7 @@ if you have a simple null modem connection between the test box and
 the workstation, and aren't using a H/L split console:
 
   * Set debug=y in Config.mk
-  * Set crash_debug=y in xen/Rules.mk
+  * Set CRASH_DEBUG=y with `make -C xen menuconfig`
   * Make the changes in the attached patch, and build.
   * Arrange to pass gdb=com1 as a hypervisor command line argument
     (I already have com1=38400,8n1 console=com1,vga sync_console)
diff --git a/xen/Kconfig.debug b/xen/Kconfig.debug
index 36890bd..3336a64 100644
--- a/xen/Kconfig.debug
+++ b/xen/Kconfig.debug
@@ -4,3 +4,14 @@ menuconfig DEBUG
 	---help---
 	  If you want to debug Xen say Y and select any additional debugging
 	  support options.
+
+if DEBUG
+
+config CRASH_DEBUG
+	bool "Crash Debugging Support"
+	depends on X86
+	---help---
+	  If you want to be able to attach gdb to Xen to be able to debug
+	  Xen if it crashes then say Y.
+
+endif # DEBUG
diff --git a/xen/Rules.mk b/xen/Rules.mk
index f29491e..b5d8d33 100644
--- a/xen/Rules.mk
+++ b/xen/Rules.mk
@@ -7,7 +7,6 @@ verbose       ?= n
 perfc         ?= n
 perfc_arrays  ?= n
 lock_profile  ?= n
-crash_debug   ?= n
 frame_pointer ?= n
 lto           ?= n
 
@@ -30,6 +29,9 @@ endif
 ifneq ($(origin kexec),undefined)
 $(error "You must use 'make menuconfig' to enable/disable kexec now.")
 endif
+ifneq ($(origin crash_debug),undefined)
+$(error "You must use 'make menuconfig' to enable/disable crash_debug now.")
+endif
 
 # Set ARCH/SUBARCH appropriately.
 override TARGET_SUBARCH  := $(XEN_TARGET_ARCH)
@@ -53,7 +55,6 @@ CFLAGS += -pipe -g -D__XEN__ -include $(BASEDIR)/include/xen/config.h
 CFLAGS += '-D__OBJECT_FILE__="$@"'
 
 CFLAGS-$(verbose)       += -DVERBOSE
-CFLAGS-$(crash_debug)   += -DCRASH_DEBUG
 CFLAGS-$(perfc)         += -DPERF_COUNTERS
 CFLAGS-$(perfc_arrays)  += -DPERF_ARRAYS
 CFLAGS-$(lock_profile)  += -DLOCK_PROFILE
diff --git a/xen/arch/x86/Makefile b/xen/arch/x86/Makefile
index 1bcb08b..21d7e5f 100644
--- a/xen/arch/x86/Makefile
+++ b/xen/arch/x86/Makefile
@@ -24,6 +24,7 @@ obj-y += domain_page.o
 obj-y += e820.o
 obj-y += extable.o
 obj-y += flushtlb.o
+obj-$(CONFIG_CRASH_DEBUG) += gdbstub.o
 obj-y += i387.o
 obj-y += i8259.o
 obj-y += io_apic.o
@@ -62,8 +63,6 @@ obj-y += hpet.o
 obj-y += vm_event.o
 obj-y += xstate.o
 
-obj-$(crash_debug) += gdbstub.o
-
 x86_emulate.o: x86_emulate/x86_emulate.c x86_emulate/x86_emulate.h
 
 efi-y := $(shell if [ ! -r $(BASEDIR)/include/xen/compile.h -o \
diff --git a/xen/arch/x86/x86_64/Makefile b/xen/arch/x86/x86_64/Makefile
index 5b54c16..d8815e7 100644
--- a/xen/arch/x86/x86_64/Makefile
+++ b/xen/arch/x86/x86_64/Makefile
@@ -14,4 +14,4 @@ obj-y += cpu_idle.o
 obj-y += cpufreq.o
 obj-bin-$(CONFIG_KEXEC) += kexec_reloc.o
 
-obj-$(crash_debug)   += gdbstub.o
+obj-$(CONFIG_CRASH_DEBUG)   += gdbstub.o
diff --git a/xen/common/Makefile b/xen/common/Makefile
index 77de27e..39a83fc 100644
--- a/xen/common/Makefile
+++ b/xen/common/Makefile
@@ -8,6 +8,7 @@ obj-y += domain.o
 obj-y += event_2l.o
 obj-y += event_channel.o
 obj-y += event_fifo.o
+obj-$(CONFIG_CRASH_DEBUG) += gdbstub.o
 obj-y += grant_table.o
 obj-y += guestcopy.o
 obj-bin-y += gunzip.init.o
@@ -61,7 +62,6 @@ obj-y += xmalloc_tlsf.o
 obj-bin-$(CONFIG_X86) += $(foreach n,decompress bunzip2 unxz unlzma unlzo unlz4 earlycpio,$(n).init.o)
 
 obj-$(perfc)       += perfc.o
-obj-$(crash_debug) += gdbstub.o
 
 obj-$(CONFIG_COMPAT) += $(addprefix compat/,domain.o kernel.o memory.o multicall.o xlat.o)
 
diff --git a/xen/include/asm-x86/debugger.h b/xen/include/asm-x86/debugger.h
index 33f4700..fb92ee4 100644
--- a/xen/include/asm-x86/debugger.h
+++ b/xen/include/asm-x86/debugger.h
@@ -39,7 +39,7 @@
 #define DEBUGGER_trap_fatal(_v, _r) \
     if ( debugger_trap_fatal(_v, _r) ) return;
 
-#if defined(CRASH_DEBUG)
+#if defined(CONFIG_CRASH_DEBUG)
 
 #include <xen/gdbstub.h>
 
diff --git a/xen/include/xen/gdbstub.h b/xen/include/xen/gdbstub.h
index ab710da..a5e6714 100644
--- a/xen/include/xen/gdbstub.h
+++ b/xen/include/xen/gdbstub.h
@@ -23,7 +23,7 @@
 #include <asm/atomic.h>
 #include <asm/page.h>
 
-#ifdef CRASH_DEBUG
+#ifdef CONFIG_CRASH_DEBUG
 
 struct gdb_context {
     int                 serhnd;           /* handle on our serial line */
-- 
2.7.3


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