[PATCH v1 1/3] libelf: Preserve log callback after elf_init

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

The elf_init function uses the log callback to report
errors. But it also memsets the whole structure so the
log callback (if set) is wiped out!

This preserves the log callback function along with its
states.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
 xen/common/libelf/libelf-loader.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/xen/common/libelf/libelf-loader.c b/xen/common/libelf/libelf-loader.c
index 6f42bea..32a9724 100644
--- a/xen/common/libelf/libelf-loader.c
+++ b/xen/common/libelf/libelf-loader.c
@@ -27,14 +27,28 @@ elf_errorstatus elf_init(struct elf_binary *elf, const char *image_input, size_t
 {
     ELF_HANDLE_DECL(elf_shdr) shdr;
     uint64_t i, count, section, offset;
+#ifndef __XEN__
+    elf_log_callback *callback;
+    void *log_callback_data;
+#endif
+    int verbose;
 
     if ( !elf_is_elfbinary(image_input, size) )
     {
         elf_err(elf, "%s: not an ELF binary\n", __FUNCTION__);
         return -1;
     }
-
+#ifndef __XEN__
+    callback = elf->log_callback;
+    log_callback_data = elf->log_caller_data;
+#endif
+    verbose = elf->verbose;
     elf_memset_unchecked(elf, 0, sizeof(*elf));
+#ifndef __XEN__
+    elf->log_callback = callback;
+    elf->log_caller_data = log_callback_data;
+#endif
+    elf->verbose = verbose;
     elf->image_base = image_input;
     elf->size = size;
     elf->ehdr = ELF_MAKE_HANDLE(elf_ehdr, (elf_ptrval)image_input);
-- 
2.4.3