Re: [PATCH] ld.so: Add architecture specific fields

["H.J. Lu" <hjl dot tools at gmail dot com>]

On Wed, Nov 8, 2017 at 3:03 PM, H.J. Lu <hjl.tools@gmail.com> wrote:
> On Tue, Oct 31, 2017 at 9:37 AM, H.J. Lu <hongjiu.lu@intel.com> wrote:
>> To support Intel Control-flow Enforcement Technology (CET) run-time
>> control:
>>
>> 1. An architecture specific field in the writable ld.so namespace is
>> needed to indicate if CET features are enabled at run-time.
>> 2. An architecture specific field in struct link_map is needed if
>> CET features are enabled in an ELF module.
>>
>> This patch adds dl-procruntime.c to the writable ld.so namespace and
>> link_map.h to struct link_map.
>>
>> Tested on x86-64.
>>
>> Any comments?
>>
>> H.J.
>> --
>>         * elf/dl-support.c: Include <dl-procruntime.c>.
>>         * include/link.h: Include <link_map.h>.
>>         * sysdeps/generic/dl-procruntime.c: New file.
>>         * sysdeps/generic/link_map.h: Likewise.
>>         * sysdeps/generic/ldsodefs.h: Include <dl-procruntime.c> in
>>         the writable ld.so namespace.
>> ---
>>  elf/dl-support.c                 |  1 +
>>  include/link.h                   |  2 ++
>>  sysdeps/generic/dl-procruntime.c |  1 +
>>  sysdeps/generic/ldsodefs.h       | 11 +++++++----
>>  sysdeps/generic/link_map.h       |  1 +
>>  5 files changed, 12 insertions(+), 4 deletions(-)
>>  create mode 100644 sysdeps/generic/dl-procruntime.c
>>  create mode 100644 sysdeps/generic/link_map.h
>>
>> diff --git a/elf/dl-support.c b/elf/dl-support.c
>> index 5e3de90598..235d3a7f46 100644
>> --- a/elf/dl-support.c
>> +++ b/elf/dl-support.c
>> @@ -126,6 +126,7 @@ int _dl_starting_up = 1;
>>  void *_dl_random;
>>
>>  /* Get architecture specific initializer.  */
>> +#include <dl-procruntime.c>
>>  #include <dl-procinfo.c>
>>
>>  /* Initial value of the CPU clock.  */
>> diff --git a/include/link.h b/include/link.h
>> index 3e1b2aefb7..82b77a6b41 100644
>> --- a/include/link.h
>> +++ b/include/link.h
>> @@ -203,6 +203,8 @@ struct link_map
>>                                        freed, ie. not allocated with
>>                                        the dummy malloc in ld.so.  */
>>
>> +#include <link_map.h>
>> +
>>      /* Collected information about own RPATH directories.  */
>>      struct r_search_path_struct l_rpath_dirs;
>>
>> diff --git a/sysdeps/generic/dl-procruntime.c b/sysdeps/generic/dl-procruntime.c
>> new file mode 100644
>> index 0000000000..a056184690
>> --- /dev/null
>> +++ b/sysdeps/generic/dl-procruntime.c
>> @@ -0,0 +1 @@
>> +/* No architecture specific definitions.  */
>> diff --git a/sysdeps/generic/ldsodefs.h b/sysdeps/generic/ldsodefs.h
>> index 5efae2d96d..52a792a597 100644
>> --- a/sysdeps/generic/ldsodefs.h
>> +++ b/sysdeps/generic/ldsodefs.h
>> @@ -373,6 +373,13 @@ struct rtld_global
>>    EXTERN void (*_dl_rtld_unlock_recursive) (void *);
>>  #endif
>>
>> +  /* Get architecture specific definitions.  */
>> +#define PROCINFO_DECL
>> +#ifndef PROCINFO_CLASS
>> +# define PROCINFO_CLASS EXTERN
>> +#endif
>> +#include <dl-procruntime.c>
>> +
>>    /* If loading a shared object requires that we make the stack executable
>>       when it was not, we do it by calling this function.
>>       It returns an errno code or zero on success.  */
>> @@ -529,10 +536,6 @@ struct rtld_global_ro
>>  #endif
>>
>>    /* Get architecture specific definitions.  */
>> -#define PROCINFO_DECL
>> -#ifndef PROCINFO_CLASS
>> -# define PROCINFO_CLASS EXTERN
>> -#endif
>>  #include <dl-procinfo.c>
>>
>>    /* Names of shared object for which the RPATH should be ignored.  */
>> diff --git a/sysdeps/generic/link_map.h b/sysdeps/generic/link_map.h
>> new file mode 100644
>> index 0000000000..a056184690
>> --- /dev/null
>> +++ b/sysdeps/generic/link_map.h
>> @@ -0,0 +1 @@
>> +/* No architecture specific definitions.  */
>> --
>> 2.13.6
>>
>
> I tested it with build-many-glibcs.py.  If there are no objections, I will
> check it next week.
>
>

I am checking it in.

-- 
H.J.