From 5d00f46e1527235ecd28a14c5413355c3ea66dfc Mon Sep 17 00:00:00 2001
From: Patrick Steuer <patrick.steuer@de.ibm.com>
Date: Thu, 18 Jul 2019 11:42:58 +0200
Subject: [PATCH] s390x assembly pack: use getauxval to detect hw capabilities

if available.

Signed-off-by: Patrick Steuer <patrick.steuer@de.ibm.com>

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9410)
---
 crypto/s390xcap.c | 95 +++++++++++++++++++++++++++++++----------------
 1 file changed, 63 insertions(+), 32 deletions(-)

diff --git a/crypto/s390xcap.c b/crypto/s390xcap.c
index 7d06695949..5123e14fa6 100644
--- a/crypto/s390xcap.c
+++ b/crypto/s390xcap.c
@@ -16,6 +16,13 @@
 #include "internal/ctype.h"
 #include "s390x_arch.h"
 
+#if defined(__GLIBC__) && defined(__GLIBC_PREREQ)
+# if __GLIBC_PREREQ(2, 16)
+#  include <sys/auxv.h>
+#  define OSSL_IMPLEMENT_GETAUXVAL
+# endif
+#endif
+
 #define LEN     128
 #define STR_(S) #S
 #define STR(S)  STR_(S)
@@ -47,25 +54,26 @@
             memcpy(cap, &NAME, sizeof(*cap));                           \
     }
 
+#ifndef OSSL_IMPLEMENT_GETAUXVAL
 static sigjmp_buf ill_jmp;
 static void ill_handler(int sig)
 {
     siglongjmp(ill_jmp, sig);
 }
 
+void OPENSSL_vx_probe(void);
+#endif
+
 static const char *env;
 static int parse_env(struct OPENSSL_s390xcap_st *cap);
 
 void OPENSSL_s390x_facilities(void);
 void OPENSSL_s390x_functions(void);
-void OPENSSL_vx_probe(void);
 
 struct OPENSSL_s390xcap_st OPENSSL_s390xcap_P;
 
 void OPENSSL_cpuid_setup(void)
 {
-    sigset_t oset;
-    struct sigaction ill_act, oact_ill, oact_fpe;
     struct OPENSSL_s390xcap_st cap;
 
     if (OPENSSL_s390xcap_P.stfle[0])
@@ -74,47 +82,70 @@ void OPENSSL_cpuid_setup(void)
     /* set a bit that will not be tested later */
     OPENSSL_s390xcap_P.stfle[0] |= S390X_CAPBIT(0);
 
+#ifdef OSSL_IMPLEMENT_GETAUXVAL
+    {
+        const unsigned long hwcap = getauxval(AT_HWCAP);
+
+        /* protection against missing store-facility-list-extended */
+        if (hwcap & HWCAP_S390_STFLE)
+            OPENSSL_s390x_facilities();
+
+        /* protection against disabled vector facility */
+        if (!(hwcap & HWCAP_S390_VX)) {
+            OPENSSL_s390xcap_P.stfle[2] &= ~(S390X_CAPBIT(S390X_VX)
+                                             | S390X_CAPBIT(S390X_VXD)
+                                             | S390X_CAPBIT(S390X_VXE));
+        }
+    }
+#else
+    {
+        sigset_t oset;
+        struct sigaction ill_act, oact_ill, oact_fpe;
+
+        memset(&ill_act, 0, sizeof(ill_act));
+        ill_act.sa_handler = ill_handler;
+        sigfillset(&ill_act.sa_mask);
+        sigdelset(&ill_act.sa_mask, SIGILL);
+        sigdelset(&ill_act.sa_mask, SIGFPE);
+        sigdelset(&ill_act.sa_mask, SIGTRAP);
+
+        sigprocmask(SIG_SETMASK, &ill_act.sa_mask, &oset);
+        sigaction(SIGILL, &ill_act, &oact_ill);
+        sigaction(SIGFPE, &ill_act, &oact_fpe);
+
+        /* protection against missing store-facility-list-extended */
+        if (sigsetjmp(ill_jmp, 1) == 0)
+            OPENSSL_s390x_facilities();
+
+        /* protection against disabled vector facility */
+        if ((OPENSSL_s390xcap_P.stfle[2] & S390X_CAPBIT(S390X_VX))
+            && (sigsetjmp(ill_jmp, 1) == 0)) {
+            OPENSSL_vx_probe();
+        } else {
+            OPENSSL_s390xcap_P.stfle[2] &= ~(S390X_CAPBIT(S390X_VX)
+                                             | S390X_CAPBIT(S390X_VXD)
+                                             | S390X_CAPBIT(S390X_VXE));
+        }
+
+        sigaction(SIGFPE, &oact_fpe, NULL);
+        sigaction(SIGILL, &oact_ill, NULL);
+        sigprocmask(SIG_SETMASK, &oset, NULL);
+    }
+#endif
+
     env = getenv("OPENSSL_s390xcap");
     if (env != NULL) {
         if (!parse_env(&cap))
             env = NULL;
     }
 
-    memset(&ill_act, 0, sizeof(ill_act));
-    ill_act.sa_handler = ill_handler;
-    sigfillset(&ill_act.sa_mask);
-    sigdelset(&ill_act.sa_mask, SIGILL);
-    sigdelset(&ill_act.sa_mask, SIGFPE);
-    sigdelset(&ill_act.sa_mask, SIGTRAP);
-    sigprocmask(SIG_SETMASK, &ill_act.sa_mask, &oset);
-    sigaction(SIGILL, &ill_act, &oact_ill);
-    sigaction(SIGFPE, &ill_act, &oact_fpe);
-
-    /* protection against missing store-facility-list-extended */
-    if (sigsetjmp(ill_jmp, 1) == 0)
-        OPENSSL_s390x_facilities();
-
     if (env != NULL) {
         OPENSSL_s390xcap_P.stfle[0] &= cap.stfle[0];
         OPENSSL_s390xcap_P.stfle[1] &= cap.stfle[1];
         OPENSSL_s390xcap_P.stfle[2] &= cap.stfle[2];
     }
 
-    /* protection against disabled vector facility */
-    if ((OPENSSL_s390xcap_P.stfle[2] & S390X_CAPBIT(S390X_VX))
-        && (sigsetjmp(ill_jmp, 1) == 0)) {
-        OPENSSL_vx_probe();
-    } else {
-        OPENSSL_s390xcap_P.stfle[2] &= ~(S390X_CAPBIT(S390X_VX)
-                                         | S390X_CAPBIT(S390X_VXD)
-                                         | S390X_CAPBIT(S390X_VXE));
-    }
-
-    sigaction(SIGFPE, &oact_fpe, NULL);
-    sigaction(SIGILL, &oact_ill, NULL);
-    sigprocmask(SIG_SETMASK, &oset, NULL);
-
-    OPENSSL_s390x_functions();
+    OPENSSL_s390x_functions(); /* check OPENSSL_s390xcap_P.stfle */
 
     if (env != NULL) {
         OPENSSL_s390xcap_P.kimd[0] &= cap.kimd[0];
-- 
2.25.1