Add elf_aux_info(3)

Designed to let userland peek at AT_HWCAP and AT_HWCAP2 using an already
existing interface coming from FreeBSD. Headers bits were snatched from
there.  Input & ok kettenis@

libc bump and sets sync will follow soon

3 files changed, 59 insertions, 1 deletions

diff --git a/src/regress/lib/libc/Makefile b/src/regress/lib/libc/Makefile
index 8b5e4d4503..3cd970e49d 100644
--- a/src/regress/lib/libc/Makefile
+++ b/src/regress/lib/libc/Makefile
@@ -1,10 +1,11 @@
-#       $OpenBSD: Makefile,v 1.58 2021/08/31 09:58:17 jasper Exp $
+#       $OpenBSD: Makefile,v 1.59 2024/07/14 09:48:48 jca Exp $
 
 SUBDIR+= _setjmp
 SUBDIR+= alloca arc4random-fork atexit
 SUBDIR+= basename
 SUBDIR+= cephes cxa-atexit
 SUBDIR+= db dirname
+SUBDIR+= elf_aux_info
 SUBDIR+= env explicit_bzero
 SUBDIR+= ffs fmemopen fnmatch fpclassify fread
 SUBDIR+= gcvt getaddrinfo getcap getopt getopt_long glob
diff --git a/src/regress/lib/libc/elf_aux_info/Makefile b/src/regress/lib/libc/elf_aux_info/Makefile
new file mode 100644
index 0000000000..2885fb1851
--- /dev/null
+++ b/src/regress/lib/libc/elf_aux_info/Makefile
@@ -0,0 +1,3 @@
+PROG=elf_aux_info
+
+.include <bsd.regress.mk>
diff --git a/src/regress/lib/libc/elf_aux_info/elf_aux_info.c b/src/regress/lib/libc/elf_aux_info/elf_aux_info.c
new file mode 100644
index 0000000000..481085d6d9
--- /dev/null
+++ b/src/regress/lib/libc/elf_aux_info/elf_aux_info.c
@@ -0,0 +1,54 @@
+#include <sys/auxv.h>
+
+#include <errno.h>
+#include <stdio.h>
+
+int
+main(void)
+{
+        int ret = 0;
+        int a;
+        unsigned long b;
+
+
+        /* Should always succeed */
+        if (elf_aux_info(AT_PAGESZ, &a, sizeof(a)))
+                ret |= 1;
+        else
+                fprintf(stderr, "AT_PAGESZ %d\n", a);
+
+        /* Wrong size */
+        if (elf_aux_info(AT_PAGESZ, &b, sizeof(b)) != EINVAL)
+                ret |= 2;
+
+        /* Invalid request */
+        if (elf_aux_info(-1, &a, sizeof(a)) != EINVAL)
+                ret |= 4;
+
+        /* Should either succeed or fail with ENOENT if not supported */
+        switch (elf_aux_info(AT_HWCAP, &b, sizeof(b))) {
+        case 0:
+                fprintf(stderr, "AT_HWCAP %lx\n", b);
+                break;
+        case ENOENT:
+                break;
+        default:
+                ret |= 8;
+        }
+
+        /* Should either succeed or fail with ENOENT if not supported */
+        switch (elf_aux_info(AT_HWCAP2, &b, sizeof(b))) {
+        case 0:
+                fprintf(stderr, "AT_HWCAP2 %lx\n", b);
+                break;
+        case ENOENT:
+                break;
+        default:
+                ret |= 16;
+        }
+
+        if (ret)
+                fprintf(stderr, "FAILED (status %x)\n", ret);
+
+        return ret;
+}