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[PPC64] Add ifunc support in libcsu

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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
This commit is contained in:
luporl 2019-09-12 16:45:07 +00:00
parent 5d30abe359
commit 9d5f53729c
3 changed files with 78 additions and 3 deletions
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4
lib/csu/powerpc64/Makefile
View File

@ -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}

34
lib/csu/powerpc64/crt1.c
View File

@ -45,6 +45,11 @@
__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"
@ -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);

43
lib/csu/powerpc64/reloc.c Normal file
View File

@ -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;
}
}