boringssl/crypto/crypto.c
Adam Langley b18cb6a5d0 Make the POWER hardware capability value a global in crypto.c.
(Thanks to Sam Panzer for the patch.)

At least some linkers will drop constructor functions if no symbols from
that translation unit are used elsewhere in the program. On POWER, since
the cached capability value isn't a global in crypto.o (like other
platforms), the constructor function is getting discarded.

The C++11 spec says (3.6.2, paragraph 4):

    It is implementation-defined whether the dynamic initialization of a
    non-local variable with static storage duration is done before the
    first statement of main. If the initialization is deferred to some
    point in time after the first statement of main, it shall occur
    before the first odr-use (3.2) of any function or variable defined
    in the same translation unit as the variable to be initialized.

Compilers appear to interpret that to mean they are allowed to drop
(i.e. indefinitely defer) constructors that occur in translation units
that are never used, so they can avoid initializing some part of a
library if it's dropped on the floor.

This change makes the hardware capability value for POWER a global in
crypto.c, which should prevent the constructor function from being
ignored.

Change-Id: I43ebe492d0ac1491f6f6c2097971a277f923dd3e
Reviewed-on: https://boringssl-review.googlesource.com/14664
Commit-Queue: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
2017-04-04 18:19:19 +00:00

171 lines
4.8 KiB
C

/* Copyright (c) 2014, Google Inc.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
#include <openssl/crypto.h>
#include <openssl/cpu.h>
#include "internal.h"
#if !defined(OPENSSL_NO_ASM) && !defined(OPENSSL_STATIC_ARMCAP) && \
(defined(OPENSSL_X86) || defined(OPENSSL_X86_64) || \
defined(OPENSSL_ARM) || defined(OPENSSL_AARCH64) || \
defined(OPENSSL_PPC64LE))
/* x86, x86_64, the ARMs and ppc64le need to record the result of a
* cpuid/getauxval call for the asm to work correctly, unless compiled without
* asm code. */
#define NEED_CPUID
#else
/* Otherwise, don't emit a static initialiser. */
#if !defined(BORINGSSL_NO_STATIC_INITIALIZER)
#define BORINGSSL_NO_STATIC_INITIALIZER
#endif
#endif /* !OPENSSL_NO_ASM && (OPENSSL_X86 || OPENSSL_X86_64 ||
OPENSSL_ARM || OPENSSL_AARCH64) */
/* The capability variables are defined in this file in order to work around a
* linker bug. When linking with a .a, if no symbols in a .o are referenced
* then the .o is discarded, even if it has constructor functions.
*
* This still means that any binaries that don't include some functionality
* that tests the capability values will still skip the constructor but, so
* far, the init constructor function only sets the capability variables. */
#if defined(OPENSSL_X86) || defined(OPENSSL_X86_64)
/* This value must be explicitly initialised to zero in order to work around a
* bug in libtool or the linker on OS X.
*
* If not initialised then it becomes a "common symbol". When put into an
* archive, linking on OS X will fail to resolve common symbols. By
* initialising it to zero, it becomes a "data symbol", which isn't so
* affected. */
uint32_t OPENSSL_ia32cap_P[4] = {0};
#elif defined(OPENSSL_PPC64LE)
unsigned long OPENSSL_ppc64le_hwcap2 = 0;
#elif defined(OPENSSL_ARM) || defined(OPENSSL_AARCH64)
#include <openssl/arm_arch.h>
#if defined(OPENSSL_STATIC_ARMCAP)
uint32_t OPENSSL_armcap_P =
#if defined(OPENSSL_STATIC_ARMCAP_NEON) || defined(__ARM_NEON__)
ARMV7_NEON |
#endif
#if defined(OPENSSL_STATIC_ARMCAP_AES)
ARMV8_AES |
#endif
#if defined(OPENSSL_STATIC_ARMCAP_SHA1)
ARMV8_SHA1 |
#endif
#if defined(OPENSSL_STATIC_ARMCAP_SHA256)
ARMV8_SHA256 |
#endif
#if defined(OPENSSL_STATIC_ARMCAP_PMULL)
ARMV8_PMULL |
#endif
0;
#else
uint32_t OPENSSL_armcap_P = 0;
#endif
#endif
#if defined(OPENSSL_WINDOWS) && !defined(BORINGSSL_NO_STATIC_INITIALIZER)
#define OPENSSL_CDECL __cdecl
#else
#define OPENSSL_CDECL
#endif
#if defined(BORINGSSL_NO_STATIC_INITIALIZER)
static CRYPTO_once_t once = CRYPTO_ONCE_INIT;
#elif defined(OPENSSL_WINDOWS)
#pragma section(".CRT$XCU", read)
static void __cdecl do_library_init(void);
__declspec(allocate(".CRT$XCU")) void(*library_init_constructor)(void) =
do_library_init;
#else
static void do_library_init(void) __attribute__ ((constructor));
#endif
/* do_library_init is the actual initialization function. If
* BORINGSSL_NO_STATIC_INITIALIZER isn't defined, this is set as a static
* initializer. Otherwise, it is called by CRYPTO_library_init. */
static void OPENSSL_CDECL do_library_init(void) {
/* WARNING: this function may only configure the capability variables. See the
* note above about the linker bug. */
#if defined(NEED_CPUID)
OPENSSL_cpuid_setup();
#endif
}
void CRYPTO_library_init(void) {
/* TODO(davidben): It would be tidier if this build knob could be replaced
* with an internal lazy-init mechanism that would handle things correctly
* in-library. https://crbug.com/542879 */
#if defined(BORINGSSL_NO_STATIC_INITIALIZER)
CRYPTO_once(&once, do_library_init);
#endif
}
int CRYPTO_is_confidential_build(void) {
#if defined(BORINGSSL_CONFIDENTIAL)
return 1;
#else
return 0;
#endif
}
int CRYPTO_has_asm(void) {
#if defined(OPENSSL_NO_ASM)
return 0;
#else
return 1;
#endif
}
const char *SSLeay_version(int unused) {
return "BoringSSL";
}
unsigned long SSLeay(void) {
return OPENSSL_VERSION_NUMBER;
}
int CRYPTO_malloc_init(void) {
return 1;
}
void ENGINE_load_builtin_engines(void) {}
int ENGINE_register_all_complete(void) {
return 1;
}
void OPENSSL_load_builtin_modules(void) {}
int FIPS_mode(void) { return 0; }