svn commit: r352255 - head/lib/csu/powerpc64

[Leandro Lupori]

Author: luporl
Date: Thu Sep 12 16:45:07 2019
New Revision: 352255
URL: https://svnweb.freebsd.org/changeset/base/352255

Log:
  [PPC64] Add ifunc support in libcsu
  
  When ifuncs are used in statically linked binaries, the C runtime
  must perform the needed dynamic relocations, to make calls to ifuncs
  work correctly.
  
  Reviewed by:	jhibbits
  Differential Revision:	https://reviews.freebsd.org/D21070

Added:
  head/lib/csu/powerpc64/reloc.c   (contents, props changed)
Modified:
  head/lib/csu/powerpc64/Makefile
  head/lib/csu/powerpc64/crt1.c

Modified: head/lib/csu/powerpc64/Makefile
==============================================================================
--- head/lib/csu/powerpc64/Makefile	Thu Sep 12 16:28:30 2019	(r352254)
+++ head/lib/csu/powerpc64/Makefile	Thu Sep 12 16:45:07 2019	(r352255)
@@ -5,9 +5,9 @@
 SRCS=		crt1.c crti.S crtn.S
 OBJS=		${SRCS:N*.h:R:S/$/.o/g}
 OBJS+=		crtsavres.o Scrt1.o gcrt1.o
-CFLAGS+=	-I${.CURDIR:H}/common \
+CFLAGS+=	-I${.CURDIR} -I${.CURDIR:H}/common \
 		-I${SRCTOP}/lib/libc/include \
-		-mlongcall -DCRT_IRELOC_SUPPRESS
+		-mlongcall -DCRT_IRELOC_RELA
 
 FILES=		${OBJS}
 FILESMODE=	${LIBMODE}

Modified: head/lib/csu/powerpc64/crt1.c
==============================================================================
--- head/lib/csu/powerpc64/crt1.c	Thu Sep 12 16:28:30 2019	(r352254)
+++ head/lib/csu/powerpc64/crt1.c	Thu Sep 12 16:45:07 2019	(r352255)
@@ -45,7 +45,12 @@
 __FBSDID("$FreeBSD$");
 
 #include <stdlib.h>
+#include <stdint.h>
+#include <sys/elf.h>
 
+static uint32_t cpu_features;
+static uint32_t cpu_features2;
+
 #include "libc_private.h"
 #include "crtbrand.c"
 #include "ignore_init.c"
@@ -65,6 +70,30 @@ extern int etext;
 
 struct ps_strings *__ps_strings;
 
+static void
+init_cpu_features(char **env)
+{
+	const Elf_Auxinfo *aux;
+
+	/* Find the auxiliary vector on the stack. */
+	while (*env++ != 0)	/* Skip over environment, and NULL terminator */
+		;
+	aux = (const Elf_Auxinfo *)env;
+
+	/* Digest the auxiliary vector. */
+	for (;  aux->a_type != AT_NULL; aux++) {
+		switch (aux->a_type) {
+		case AT_HWCAP:
+			cpu_features = (uint32_t)aux->a_un.a_val;
+			break;
+		case AT_HWCAP2:
+			cpu_features2 = (uint32_t)aux->a_un.a_val;
+			break;
+		}
+	}
+}
+
+
 /* The entry function. */
 /*
  * First 5 arguments are specified by the PowerPC SVR4 ABI.
@@ -84,8 +113,11 @@ _start(int argc, char **argv, char **env,
 
 	if (&_DYNAMIC != NULL)
 		atexit(cleanup);
-	else
+	else {
+		init_cpu_features(env);
+		process_irelocs();
 		_init_tls();
+	}
 
 #ifdef GCRT
 	atexit(_mcleanup);

Added: head/lib/csu/powerpc64/reloc.c
==============================================================================
--- /dev/null	00:00:00 1970	(empty, because file is newly added)
+++ head/lib/csu/powerpc64/reloc.c	Thu Sep 12 16:45:07 2019	(r352255)
@@ -0,0 +1,43 @@
+/*-
+ * Copyright (c) 2019 Leandro Lupori
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+static void
+crt1_handle_rela(const Elf_Rela *r)
+{
+	typedef Elf_Addr (*ifunc_resolver_t)(
+	    uint32_t, uint32_t, uint64_t, uint64_t,
+	    uint64_t, uint64_t, uint64_t, uint64_t);
+	Elf_Addr *ptr, *where, target;
+
+	switch (ELF_R_TYPE(r->r_info)) {
+	case R_PPC_IRELATIVE:
+		ptr = (Elf_Addr *)r->r_addend;
+		where = (Elf_Addr *)r->r_offset;
+		target = ((ifunc_resolver_t)ptr)(cpu_features, cpu_features2,
+		    0, 0, 0, 0, 0, 0);
+		*where = target;
+		break;
+	}
+}