[PATCH v2 2/2] kexec-tools: Make xc_dlhandle static

[Eric DeVolder]

Daniel, thanks for the review, inline responses below.
eric

On 01/23/2018 02:59 PM, Daniel Kiper wrote:
> On Tue, Jan 23, 2018 at 01:12:51PM -0600, Eric DeVolder wrote:
>> This patch is a follow-on to commit 43d3932e "kexec-tools: Perform
>> run-time linking of libxenctrl.so". This patch addresses feedback
>> from Daniel Kiper.
>>
>> This patch implements Daniel's suggestion to make the
>> xc_dlhandle variable static.
>>
>> Signed-off-by: Eric DeVolder <eric.devolder at oracle.com>
> 
> Just two nitpicks... Otherwise you can add
> 
> Reviewed-by: Daniel Kiper <daniel.kiper at oracle.com>
> 
>> ---
>> v1: 23jan2018
>>   - Implemented feedback from Daniel Kiper
>>
>> v2: 23jan2018
>>   - Implemented feedback from Daniel Kiper
>>   - Broke patch into two
>> ---
>>   kexec/kexec-xen.c | 9 ++++++++-
>>   kexec/kexec-xen.h | 9 ++++-----
>>   2 files changed, 12 insertions(+), 6 deletions(-)
>>
>> diff --git a/kexec/kexec-xen.c b/kexec/kexec-xen.c
>> index 75f8758..960fa16 100644
>> --- a/kexec/kexec-xen.c
>> +++ b/kexec/kexec-xen.c
>> @@ -15,8 +15,15 @@
>>   #include "crashdump.h"
>>
>>   #ifdef CONFIG_LIBXENCTRL_DL
>> -void *xc_dlhandle;
>> +/* The handle from dlopen(), needed by dlsym(), dlclose() */
>> +static void *xc_dlhandle;
>>   xc_hypercall_buffer_t XC__HYPERCALL_BUFFER_NAME(HYPERCALL_BUFFER_NULL);
>> +
>> +void *__xc_dlsym(const char *symbol)
>> +{
>> +	return dlsym(xc_dlhandle, symbol);
>> +}
>> +
>>   xc_interface *__xc_interface_open(xentoollog_logger *logger,
>>   				  xentoollog_logger *dombuild_logger,
>>   				  unsigned open_flags)
>> diff --git a/kexec/kexec-xen.h b/kexec/kexec-xen.h
>> index ffb8743..8955334 100644
>> --- a/kexec/kexec-xen.h
>> +++ b/kexec/kexec-xen.h
>> @@ -6,9 +6,8 @@
>>
>>   #ifdef CONFIG_LIBXENCTRL_DL
>>   #include <dlfcn.h>
> 
> I think that you can drop this include too.

I did check and this is the only place in kexec-tools that includes this 
header file (it has the prototypes for dlopen/close/sym()). Without this 
header file included, compilation fails. Thus I've left it in.

> 
>> -
>> -/* The handle from dlopen(), needed by dlsym(), dlclose() */
>> -extern void *xc_dlhandle;
>> +/* Lookup symbols in libxenctrl.so */
>> +void *__xc_dlsym(const char *symbol);
> 
> extern void *__xc_dlsym(const char *symbol);?

Done for this and the others.

> 
> But then, IMO, you should put extern for __xc_interface_open()
> and __xc_interface_close() below too. You can do it in separate
> patch with Reviewed-by: Daniel Kiper <daniel.kiper at oracle.com>
> 
> Daniel

Thanks, I've posted v3 of this patch, including your RB.