build: fix x86 out-of-tree build without EFI

We can't have a source file with the same name that exist in both the
common code and in the arch specific code for efi/. This can lead to
confusion in make and it can pick up the wrong source file. This issue
lead to a failure to build a pv-shim for x86 out-of-tree, as this is
one example of an x86 build using the efi/stub.c.

The issue is that in out-of-tree, make might find x86/efi/stub.c via
VPATH, but as the target needs to be rebuilt due to FORCE, make
actually avoid changing the source tree and rebuilt the target with
VPATH ignored, so $@ lead to the build tree where "stub.c" doesn't
exist yet so a link is made to "common/stub.c".

Rework the new common/stub.c file to have a different name than the
already existing one, by renaming the existing one. We can hide the
compat aliases that x86 uses behind CONFIG_COMPAT so a Arm build will
not have them.

Also revert the change to the rule that creates symbolic links it's
better to just recreate the link in cases where an existing file exist
or the link goes to the wrong file.

Avoid using $(EFIOBJ-y) as an alias for $(clean-files), add
"stub.c" directly to $(clean-files).

Also update .gitignore as this was also missing from the original
patch.

Fixes: 7f96859b0d00 ("xen: reuse x86 EFI stub functions for Arm")
Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
Signed-off-by: Anthony PERARD <anthony.perard@citrix.com>

diff --git a/.gitignore b/.gitignore
index af9bf749c4345d5e8711114725f4b7869eb80974..418bdfaebf365be98c83709bd6886b4681f5a16d 100644 (file)
--- a/.gitignore
+++ b/.gitignore
@@ -275,6 +275,7 @@ xen/arch/x86/efi/mkreloc
 xen/arch/x86/include/asm/asm-macros.h
 xen/arch/*/xen.lds
 xen/arch/*/efi/boot.c
+xen/arch/*/efi/common-stub.c
 xen/arch/*/efi/compat.c
 xen/arch/*/efi/ebmalloc.c
 xen/arch/*/efi/efi.h

diff --git a/xen/arch/arm/efi/Makefile b/xen/arch/arm/efi/Makefile
index bd954a3b2d004a6e8855b7d2f46490d6605c3ad6..2459cbae3aef1196b1ef8e21a731241fdefe28a9 100644 (file)
--- a/xen/arch/arm/efi/Makefile
+++ b/xen/arch/arm/efi/Makefile
@@ -4,11 +4,7 @@ ifeq ($(CONFIG_ARM_EFI),y)
 obj-y += $(EFIOBJ-y)
 obj-$(CONFIG_ACPI) +=  efi-dom0.init.o
 else
-# Add stub.o to EFIOBJ-y to re-use the clean-files in
-# efi-common.mk. Otherwise the link of stub.c in arm/efi
-# will not be cleaned in "make clean".
-EFIOBJ-y += stub.o
-obj-y += stub.o
+obj-y += common-stub.o
 
 $(obj)/stub.o: CFLAGS-y += -fno-short-wchar
 

diff --git a/xen/arch/x86/efi/Makefile b/xen/arch/x86/efi/Makefile
index 034ec87895df7d95a312771bc6322a4fb7e28e45..24dfecfad184e5ada8d8872ff6334347da04fed5 100644 (file)
--- a/xen/arch/x86/efi/Makefile
+++ b/xen/arch/x86/efi/Makefile
@@ -11,7 +11,7 @@ $(obj)/boot.init.o: $(obj)/buildid.o
 $(call cc-option-add,cflags-stack-boundary,CC,-mpreferred-stack-boundary=4)
 $(addprefix $(obj)/,$(EFIOBJ-y)): CFLAGS_stack_boundary := $(cflags-stack-boundary)
 
-obj-y := stub.o
+obj-y := common-stub.o stub.o
 obj-$(XEN_BUILD_EFI) := $(filter-out %.init.o,$(EFIOBJ-y))
 obj-bin-$(XEN_BUILD_EFI) := $(filter %.init.o,$(EFIOBJ-y))
 extra-$(XEN_BUILD_EFI) += buildid.o relocs-dummy.o

diff --git a/xen/arch/x86/efi/stub.c b/xen/arch/x86/efi/stub.c
index f2365bc041d6af5de0a3903f0be60c3992d54dc9..2cd5c8d4dca9e144212997b631440f330acd522c 100644 (file)
--- a/xen/arch/x86/efi/stub.c
+++ b/xen/arch/x86/efi/stub.c
@@ -8,7 +8,6 @@
 #include <efi/eficon.h>
 #include <efi/efidevp.h>
 #include <efi/efiapi.h>
-#include "../../../common/efi/stub.c"
 
 /*
  * Here we are in EFI stub. EFI calls are not supported due to lack
@@ -55,9 +54,3 @@ bool efi_boot_mem_unused(unsigned long *start, unsigned long *end)
 }
 
 void efi_update_l4_pgtable(unsigned int l4idx, l4_pgentry_t l4e) { }
-
-int efi_compat_get_info(uint32_t idx, union compat_pf_efi_info *)
-    __attribute__((__alias__("efi_get_info")));
-
-int efi_compat_runtime_call(struct compat_pf_efi_runtime_call *)
-    __attribute__((__alias__("efi_runtime_call")));

diff --git a/xen/common/efi/common-stub.c b/xen/common/efi/common-stub.c
new file mode 100644 (file)
index 0000000..5a91fe2
--- /dev/null
+++ b/xen/common/efi/common-stub.c
@@ -0,0 +1,42 @@
+#include <xen/efi.h>
+#include <xen/errno.h>
+#include <xen/lib.h>
+
+bool efi_enabled(unsigned int feature)
+{
+    return false;
+}
+
+bool efi_rs_using_pgtables(void)
+{
+    return false;
+}
+
+unsigned long efi_get_time(void)
+{
+    BUG();
+    return 0;
+}
+
+void efi_halt_system(void) { }
+void efi_reset_system(bool warm) { }
+
+int efi_get_info(uint32_t idx, union xenpf_efi_info *info)
+{
+    return -ENOSYS;
+}
+
+int efi_runtime_call(struct xenpf_efi_runtime_call *op)
+{
+    return -ENOSYS;
+}
+
+#ifdef CONFIG_COMPAT
+
+int efi_compat_get_info(uint32_t idx, union compat_pf_efi_info *)
+    __attribute__((__alias__("efi_get_info")));
+
+int efi_compat_runtime_call(struct compat_pf_efi_runtime_call *)
+    __attribute__((__alias__("efi_runtime_call")));
+
+#endif

diff --git a/xen/common/efi/efi-common.mk b/xen/common/efi/efi-common.mk
index ec2c34f19836e9f74cfa43f005d6b7b9340a063d..53fdb81583580a1a0fb4764e4a569f271f4bfa10 100644 (file)
--- a/xen/common/efi/efi-common.mk
+++ b/xen/common/efi/efi-common.mk
@@ -9,9 +9,9 @@ CFLAGS-y += -iquote $(srcdir)
 # e.g.: It transforms "dir/foo/bar" into successively
 #       "dir foo bar", ".. .. ..", "../../.."
 $(obj)/%.c: $(srctree)/common/efi/%.c FORCE
-       $(Q)test -f $@ || \
-           ln -nfs $(subst $(space),/,$(patsubst %,..,$(subst /, ,$(obj))))/source/common/efi/$(<F) $@
+       $(Q)ln -nfs $(subst $(space),/,$(patsubst %,..,$(subst /, ,$(obj))))/source/common/efi/$(<F) $@
 
 clean-files += $(patsubst %.o, %.c, $(EFIOBJ-y:.init.o=.o) $(EFIOBJ-))
+clean-files += common-stub.c
 
 .PRECIOUS: $(obj)/%.c

diff --git a/xen/common/efi/stub.c b/xen/common/efi/stub.c
deleted file mode 100644 (file)
index 1569463..0000000
--- a/xen/common/efi/stub.c
+++ /dev/null
@@ -1,32 +0,0 @@
-#include <xen/efi.h>
-#include <xen/errno.h>
-#include <xen/lib.h>
-
-bool efi_enabled(unsigned int feature)
-{
-    return false;
-}
-
-bool efi_rs_using_pgtables(void)
-{
-    return false;
-}
-
-unsigned long efi_get_time(void)
-{
-    BUG();
-    return 0;
-}
-
-void efi_halt_system(void) { }
-void efi_reset_system(bool warm) { }
-
-int efi_get_info(uint32_t idx, union xenpf_efi_info *info)
-{
-    return -ENOSYS;
-}
-
-int efi_runtime_call(struct xenpf_efi_runtime_call *op)
-{
-    return -ENOSYS;
-}