[PATCH v2] xen: add support for crash dump analysis with xen.efi

[Juergen Gross <jgross@xxxxxxxx>]

Today it is not possible to analyse crash dumps of a system in
hypervisor mode when it had been booted via EFI, as the crash utility
doesn't understand the file format of xen.efi.

This can easily be solved by creating an ELF file from xen.efi via
objcopy. Using that file as name list for crash enables the user to
analyse the dump in hypervisor mode. Note that crash isn't happy with
a file containing no text and data, so using --only-keep-debug is not
an option.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
V2:
- drop Kconfig help text changes (Jan Beulich)
- apply some Makefile changes (Jan Beulich)
- add xen.efi.elf removal to _clean target
---
 xen/Makefile          | 11 +++++++----
 xen/arch/x86/Makefile |  3 +++
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/xen/Makefile b/xen/Makefile
index 2710d7327e..5166403cff 100644
--- a/xen/Makefile
+++ b/xen/Makefile
@@ -502,9 +502,11 @@ _install: $(TARGET)$(CONFIG_XEN_INSTALL_SUFFIX)
        if [ -r $(TARGET).efi -a -n '$(EFI_DIR)' ]; then \
                [ -d $(D)$(EFI_DIR) ] || $(INSTALL_DIR) $(D)$(EFI_DIR); \
                $(INSTALL_DATA) $(TARGET).efi 
$(D)$(EFI_DIR)/$(T)-$(XEN_FULLVERSION).efi; \
-               if [ -e $(TARGET).efi.map ]; then \
-                       $(INSTALL_DATA) $(TARGET).efi.map 
$(D)$(DEBUG_DIR)/$(T)-$(XEN_FULLVERSION).efi.map; \
-               fi; \
+               for x in map elf; do \
+                       if [ -e $(TARGET).efi.$$x ]; then \
+                               $(INSTALL_DATA) $(TARGET).efi.$$x 
$(D)$(DEBUG_DIR)/$(T)-$(XEN_FULLVERSION).efi.$$x; \
+                       fi; \
+               done; \
                ln -sf $(T)-$(XEN_FULLVERSION).efi 
$(D)$(EFI_DIR)/$(T)-$(XEN_VERSION).$(XEN_SUBVERSION).efi; \
                ln -sf $(T)-$(XEN_FULLVERSION).efi 
$(D)$(EFI_DIR)/$(T)-$(XEN_VERSION).efi; \
                ln -sf $(T)-$(XEN_FULLVERSION).efi $(D)$(EFI_DIR)/$(T).efi; \
@@ -539,6 +541,7 @@ _uninstall:
        rm -f $(D)$(DEBUG_DIR)/$(T)-syms-$(XEN_FULLVERSION).map
        rm -f $(D)$(EFI_DIR)/$(T)-$(XEN_FULLVERSION).efi
        rm -f $(D)$(EFI_DIR)/$(T)-$(XEN_VERSION).$(XEN_SUBVERSION).efi
+       rm -f $(D)$(DEBUG_DIR)/$(T)-$(XEN_FULLVERSION).efi.elf
        rm -f $(D)$(DEBUG_DIR)/$(T)-$(XEN_FULLVERSION).efi.map
        rm -f $(D)$(EFI_DIR)/$(T)-$(XEN_VERSION).efi
        rm -f $(D)$(EFI_DIR)/$(T).efi
@@ -569,7 +572,7 @@ _clean:
                -o -name '*.lex.c' -o -name '*.tab.[ch]' -o -name "*.gcno" \
                -o -name ".*.cmd" -o -name "lib.a" \) -exec rm -f {} \;
        rm -f include/asm $(TARGET) $(TARGET).gz $(TARGET)-syms 
$(TARGET)-syms.map
-       rm -f $(TARGET).efi $(TARGET).efi.map $(TARGET).efi.stripped
+       rm -f $(TARGET).efi $(TARGET).efi.map $(TARGET).efi.elf 
$(TARGET).efi.stripped
        rm -f asm-offsets.s arch/*/include/asm/asm-offsets.h
        rm -f .banner .allconfig.tmp include/xen/compile.h
 
diff --git a/xen/arch/x86/Makefile b/xen/arch/x86/Makefile
index fc9487aa40..0c66ba9086 100644
--- a/xen/arch/x86/Makefile
+++ b/xen/arch/x86/Makefile
@@ -226,6 +226,9 @@ endif
              $(@D)/.$(@F).1r.o $(@D)/.$(@F).1s.o $(orphan-handling-y) 
$(note_file_option) -o $@
        $(NM) -pa --format=sysv $(@D)/$(@F) \
                | $(objtree)/tools/symbols --all-symbols --xensyms --sysv 
--sort >$(@D)/$(@F).map
+ifeq ($(CONFIG_DEBUG_INFO),y)
+       $(if $(filter --strip-debug,$(EFI_LDFLAGS)),:,$(OBJCOPY) -O 
elf64-x86-64 $@ $@.elf)
+endif
        rm -f $(@D)/.$(@F).[0-9]* $(@D)/..$(@F).[0-9]*
 ifeq ($(CONFIG_XEN_IBT),y)
        $(SHELL) $(srctree)/tools/check-endbr.sh $@
-- 
2.35.3