Add support for AT_HWCAP2.

3 files changed, 31 insertions, 5 deletions

diff --git a/elf/dl-support.c b/elf/dl-support.c
index 7a55b82e34..a8cebc24f3 100644
--- a/elf/dl-support.c
+++ b/elf/dl-support.c
@@ -193,6 +193,10 @@ _dl_aux_init (ElfW(auxv_t) *av)
   uid_t uid = 0;
   gid_t gid = 0;
 
+  /* Don't rely on a specific order of AT_HWCAP and AT_HWCAP2.  Collate into a
+     zeroed temp and assign to _dl_hwcap after the auxv has been parsed.  */
+  uint64_t hwcap = 0;
+
   _dl_auxv = av;
   for (; av->a_type != AT_NULL; ++av)
     switch (av->a_type)
@@ -211,8 +215,12 @@ _dl_aux_init (ElfW(auxv_t) *av)
 	GL(dl_phnum) = av->a_un.a_val;
 	break;
       case AT_HWCAP:
-	GLRO(dl_hwcap) = (unsigned long int) av->a_un.a_val;
+	hwcap |= (unsigned long int) av->a_un.a_val;
+	break;
+      case AT_HWCAP2:
+	hwcap |= ((uint64_t) av->a_un.a_val) << 32;
 	break;
+
 #ifdef NEED_DL_SYSINFO
       case AT_SYSINFO:
 	GL(dl_sysinfo) = av->a_un.a_val;
@@ -251,6 +259,9 @@ _dl_aux_init (ElfW(auxv_t) *av)
       DL_PLATFORM_AUXV
 # endif
       }
+
+  GLRO(dl_hwcap) = hwcap;
+
   if (seen == 0xf)
     {
       __libc_enable_secure = uid != 0 || gid != 0;
diff --git a/elf/dl-sysdep.c b/elf/dl-sysdep.c
index d8f3dd2fb9..832a57b6d6 100644
--- a/elf/dl-sysdep.c
+++ b/elf/dl-sysdep.c
@@ -107,6 +107,10 @@ _dl_sysdep_start (void **start_argptr,
   uintptr_t new_sysinfo = 0;
 #endif
 
+  /* Don't rely on a specific order of AT_HWCAP and AT_HWCAP2.  Collate into a
+     zeroed temp and assign to _dl_hwcap after the auxv has been parsed.  */
+  uint64_t hwcap = 0;
+
   __libc_stack_end = DL_STACK_END (start_argptr);
   DL_FIND_ARG_COMPONENTS (start_argptr, _dl_argc, INTUSE(_dl_argv), _environ,
 			  GLRO(dl_auxv));
@@ -154,7 +158,10 @@ _dl_sysdep_start (void **start_argptr,
 	GLRO(dl_platform) = (void *) av->a_un.a_val;
 	break;
       case AT_HWCAP:
-	GLRO(dl_hwcap) = (unsigned long int) av->a_un.a_val;
+	hwcap |= (unsigned long int) av->a_un.a_val;
+	break;
+      case AT_HWCAP2:
+	hwcap |= ((uint64_t) av->a_un.a_val) << 32;
 	break;
       case AT_CLKTCK:
 	GLRO(dl_clktck) = av->a_un.a_val;
@@ -180,6 +187,8 @@ _dl_sysdep_start (void **start_argptr,
 #endif
       }
 
+  GLRO(dl_hwcap) = hwcap;
+
 #ifndef HAVE_AUX_SECURE
   if (seen != -1)
     {
@@ -298,6 +307,7 @@ _dl_show_auxv (void)
 	  [AT_SYSINFO - 2] =		{ "SYSINFO:      0x", hex },
 	  [AT_SYSINFO_EHDR - 2] =	{ "SYSINFO_EHDR: 0x", hex },
 	  [AT_RANDOM - 2] =		{ "RANDOM:       0x", hex },
+	  [AT_HWCAP2 - 2] =		{ "HWCAP2:       ", hex },
 	};
       unsigned int idx = (unsigned int) (av->a_type - 2);
 
@@ -309,10 +319,12 @@ _dl_show_auxv (void)
       assert (AT_NULL == 0);
       assert (AT_IGNORE == 1);
 
-      if (av->a_type == AT_HWCAP)
+      if (av->a_type == AT_HWCAP || av->a_type == AT_HWCAP2)
 	{
-	  /* This is handled special.  */
-	  if (_dl_procinfo (av->a_un.a_val) == 0)
+	  /* HWCAP bits are translated into representative strings, per
+	     platform.  */
+	  if (_dl_procinfo (av->a_type, av->a_un.a_val) == 0)
+
 	    continue;
 	}
 
diff --git a/elf/elf.h b/elf/elf.h
index 4ad4f39999..b473a0ebd5 100644
--- a/elf/elf.h
+++ b/elf/elf.h
@@ -1015,6 +1015,9 @@ typedef struct
 
 #define AT_RANDOM	25		/* Address of 16 random bytes.  */
 
+#define AT_HWCAP2	26		/* Extended machine dependent hints
+					   about processor capabilities.  */
+
 #define AT_EXECFN	31		/* Filename of executable.  */
 
 /* Pointer to the global system page used for system calls and other