stubdom/vtpm: add extern to function declarations

Code compiled with gcc10 will not link properly due to multiple definition of the same function.

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Reviewed-by: Jason Andryuk <jandryuk@gmail.com>
Acked-by: Samuel Thibault <samuel.thibaut@ens-lyon.org>
Reviewed-by: Ian Jackson <ian.jackson@eu.citrix.com>
Release-acked-by: Paul Durrant <paul@xen.org>

stubdom/Makefile

@@ -231,6 +231,7 @@ tpm_emulator-$(XEN_TARGET_ARCH): tpm_emulator-$(TPMEMU_VERSION).tar.gz
 	patch -d $@ -p1 < vtpm-cmake-Wextra.patch
 	patch -d $@ -p1 < vtpm-implicit-fallthrough.patch
 	patch -d $@ -p1 < vtpm_TPM_ChangeAuthAsymFinish.patch
+	patch -d $@ -p1 < vtpm_extern.patch
 	mkdir $@/build
 	cd $@/build; CC=${CC} $(CMAKE) .. -DCMAKE_C_FLAGS:STRING="-std=c99 -DTPM_NO_EXTERN $(TARGET_CPPFLAGS) $(TARGET_CFLAGS) -Wno-declaration-after-statement"
 	touch $@

stubdom/vtpm_extern.patch

@@ -0,0 +1,48 @@
+ld: /home/abuild/rpmbuild/BUILD/xen-4.8.20191211T160002.8db85532cb/non-dbg/stubdom/vtpm/vtpm.a(vtpm_cmd.o):(.bss+0x28): multiple definition of `tpm_malloc'; /home/abuild/rpmbuild/BUILD/xen-4.8.20191211T160002.8db85532cb/non-dbg/stubdom/vtpm/vtpm.a(vtpm.o):(.bss+0x728): first defined here
+--- a/tpm/tpm_emulator_extern.h
++++ b/tpm/tpm_emulator_extern.h
+@@ -29,7 +29,7 @@ enum {
+   TPM_LOG_ERROR
+ };
+ 
+-void (*tpm_log)(int priority, const char *fmt, ...);
++extern void (*tpm_log)(int priority, const char *fmt, ...);
+ 
+ #if defined(_WIN32) || defined(_WIN64)
+ #define __BFILE__ ((strrchr(__FILE__, '\\') ? : __FILE__ - 1) + 1)
+@@ -44,27 +44,27 @@ void (*tpm_log)(int priority, const char
+ #define error(fmt, ...) tpm_log(TPM_LOG_ERROR, "%s:%d: Error: " fmt "\n", \
+                                 __BFILE__, __LINE__, ## __VA_ARGS__)
+ /* initialization */
+-int (*tpm_extern_init)(void);
+-void (*tpm_extern_release)(void);
++extern int (*tpm_extern_init)(void);
++extern void (*tpm_extern_release)(void);
+ 
+ /* memory allocation */
+ 
+-void* (*tpm_malloc)(size_t size);
++extern void* (*tpm_malloc)(size_t size);
+ 
+-void (*tpm_free)(/*const*/ void *ptr);
++extern void (*tpm_free)(/*const*/ void *ptr);
+ 
+ /* random numbers */
+ 
+-void (*tpm_get_extern_random_bytes)(void *buf, size_t nbytes);
++extern void (*tpm_get_extern_random_bytes)(void *buf, size_t nbytes);
+ 
+ /* usec since last call */
+ 
+-uint64_t (*tpm_get_ticks)(void);
++extern uint64_t (*tpm_get_ticks)(void);
+ 
+ /* file handling */
+ 
+-int (*tpm_write_to_storage)(uint8_t *data, size_t data_length);
+-int (*tpm_read_from_storage)(uint8_t **data, size_t *data_length);
++extern int (*tpm_write_to_storage)(uint8_t *data, size_t data_length);
++extern int (*tpm_read_from_storage)(uint8_t **data, size_t *data_length);
+ 
+ #endif /* _TPM_EMULATOR_EXTERN_H_ */
+