[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH v5 11/16] livepatch: tests: Make them compile under ARM64



Hi Konrad,

On 21/09/16 18:32, Konrad Rzeszutek Wilk wrote:
We need to two things:
1) Wrap the platform-specific objcopy parameters in defines
   The input and output parameters for $(OBJCOPY) are different
   based on the platforms. As such provide them in the
   OBJCOPY_MAGIC define and use that.

2) The alternative is a bit different (exists only under ARM64
   and x86), while and there are no exceptions under ARM at all.
   We use the LIVEPATCH_FEATURE CPU id feature for ARM similar to
   how it is done on x86.

We are not yet attempting to build them under ARM32 so
that is still ifdefed out.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>

---
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Cc: George Dunlap <George.Dunlap@xxxxxxxxxxxxx>
Cc: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
Cc: Jan Beulich <jbeulich@xxxxxxxx>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Cc: Tim Deegan <tim@xxxxxxx>
Cc: Wei Liu <wei.liu2@xxxxxxxxxx>

v1: First submission
v2: Corrected description by Julien
    Add #ifeq instead of #else for ARM case.
v3: Moved 'asm(alter..)' by one space to the left.
v4: Rebase on top of "livepatch/tests: Make .livepatch.depends be read-only"
    Rewrote the commit description 2) a bit.
---
 xen/test/Makefile                         |  2 +-
 xen/test/livepatch/Makefile               | 12 ++++++++++--
 xen/test/livepatch/xen_hello_world_func.c |  7 +++++++
 3 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/xen/test/Makefile b/xen/test/Makefile
index 8c53040..95c1755 100644
--- a/xen/test/Makefile
+++ b/xen/test/Makefile
@@ -1,6 +1,6 @@
 .PHONY: tests
 tests:
I am wondering if there is any way to use the
-ifeq ($(XEN_TARGET_ARCH),x86_64)
+ifneq $(XEN_TARGET_ARCH),arm32)

NIT: I am wondering if you could instead use CONFIG_LIVEPATCH here, so the tests would only be built when livepatch is enabled.

        $(MAKE) -f $(BASEDIR)/Rules.mk -C livepatch livepatch
 endif

diff --git a/xen/test/livepatch/Makefile b/xen/test/livepatch/Makefile
index 48ff843..5db4d9c 100644
--- a/xen/test/livepatch/Makefile
+++ b/xen/test/livepatch/Makefile
@@ -1,5 +1,12 @@
 include $(XEN_ROOT)/Config.mk

+ifeq ($(XEN_TARGET_ARCH),x86_64)
+OBJCOPY_MAGIC := -I binary -O elf64-x86-64 -B i386:x86-64
+endif
+ifeq ($(XEN_TARGET_ARCH),arm64)
+OBJCOPY_MAGIC := -I binary -O elf64-littleaarch64 -B aarch64
+endif
+
 CODE_ADDR=$(shell nm --defined $(1) | grep $(2) | awk '{print "0x"$$1}')
 CODE_SZ=$(shell nm --defined -S $(1) | grep $(2) | awk '{ print "0x"$$2}')

@@ -54,8 +61,9 @@ $(LIVEPATCH): xen_hello_world_func.o xen_hello_world.o note.o
 .PHONY: note.o
 note.o:
        $(OBJCOPY) -O binary --only-section=.note.gnu.build-id 
$(BASEDIR)/xen-syms $@.bin
-       $(OBJCOPY) -I binary -O elf64-x86-64 -B i386:x86-64 \
+       $(OBJCOPY) $(OBJCOPY_MAGIC) \
                   
--rename-section=.data=.livepatch.depends,alloc,load,readonly,data,contents -S 
$@.bin $@
+                  --rename-section=.data=.livepatch.depends -S $@.bin $@

I am not sure why you added this line. Did you intend to replace the previous one?

        rm -f $@.bin

 #
@@ -65,7 +73,7 @@ note.o:
 .PHONY: hello_world_note.o
 hello_world_note.o: $(LIVEPATCH)
        $(OBJCOPY) -O binary --only-section=.note.gnu.build-id $(LIVEPATCH) 
$@.bin
-       $(OBJCOPY)  -I binary -O elf64-x86-64 -B i386:x86-64 \
+       $(OBJCOPY) $(OBJCOPY_MAGIC) \
                   
--rename-section=.data=.livepatch.depends,alloc,load,readonly,data,contents -S 
$@.bin $@
        rm -f $@.bin

diff --git a/xen/test/livepatch/xen_hello_world_func.c 
b/xen/test/livepatch/xen_hello_world_func.c
index 0321f3e..c5c0da1 100644
--- a/xen/test/livepatch/xen_hello_world_func.c
+++ b/xen/test/livepatch/xen_hello_world_func.c
@@ -7,14 +7,17 @@

 #include <asm/alternative.h>
 #include <asm/livepatch.h>
+#ifdef CONFIG_X86
 #include <asm/nops.h>
 #include <asm/uaccess.h>

 static unsigned long *non_canonical_addr = (unsigned long 
*)0xdead000000000000ULL;
+#endif

 /* Our replacement function for xen_extra_version. */
 const char *xen_hello_world(void)
 {
+#ifdef CONFIG_X86
     unsigned long tmp;
     int rc;

@@ -25,6 +28,10 @@ const char *xen_hello_world(void)
      */
     rc = __get_user(tmp, non_canonical_addr);
     BUG_ON(rc != -EFAULT);
+#endif
+#ifdef CONFIG_ARM_64

NIT: I would use:

#if defined(CONFIG_ARM) && defined(CONFIG_HAS_ALTERNATIVE)

in order to handle alternative if we decide to add support for ARM32.

+    asm(ALTERNATIVE("nop", "nop", LIVEPATCH_FEATURE));
+#endif

     return "Hello World";
 }


Regards,

--
Julien Grall

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel

 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.