Van: Michal Meloun <meloun.mic...@gmail.com>
Datum: vrijdag, 3 september 2021 12:02
Aan: Dimitry Andric <d...@freebsd.org>, Ronald Klop <ronald-li...@klop.ws>
CC: FreeBSD Ports <freebsd-po...@freebsd.org>, Ed Maste <ema...@freebsd.org>
Onderwerp: Re: (solved) Re: undefined symbol: __aarch64_ldadd8_acq_rel since
llvm12 (mongodb44)
On 03.09.2021 11:08, Dimitry Andric wrote:
> On 3 Sep 2021, at 10:31, Ronald Klop <ronald-li...@klop.ws> wrote:
>>
>> Van: Ronald Klop <ronald-li...@klop.ws>
>> Datum: zondag, 25 juli 2021 08:10
>> Aan: FreeBSD Ports <freebsd-po...@freebsd.org>, Michal Meloun <m...@freebsd.org>,
Dimitry Andric <d...@freebsd.org>
>> Onderwerp: (solved) Re: undefined symbol: __aarch64_ldadd8_acq_rel since
llvm12 (mongodb44)
>>
>> Van: Dimitry Andric <d...@freebsd.org>
>> Datum: 19 juli 2021 11:01
>> Aan: Ronald Klop <ronald-li...@klop.ws>
>> CC: FreeBSD Ports <freebsd-po...@freebsd.org>, Michal Meloun
<m...@freebsd.org>
>> Onderwerp: Re: undefined symbol: __aarch64_ldadd8_acq_rel since llvm12
(mongodb44)
>>
>>>
>>>
>>> On 19 Jul 2021, at 09:29, Ronald Klop <ronald-li...@klop.ws> wrote:
>>>>>> Does anybody have a clue why I get this error since clang 12 on
aarch64/arm64?
>>>> Do other ports have the same issue?
>>>>>> Regards,
>>>> Ronald.
>>>>>> Van: Ronald Klop <ronald-li...@klop.ws>
>>>> Datum: vrijdag, 16 juli 2021 09:43
>>>> Aan: freebsd-...@freebsd.org
>>>> Onderwerp: undefined symbol: __aarch64_ldadd8_acq_rel since llvm12
(mongodb44)
>>>>> Hi,
>>>>> I'm also maintaining databases/mongodb44 and this gives undefined symbols
since llvm12 (I think).
>>>>> See:
http://www.ipv6proxy.net/go.php?u=http://ampere2.nyi.freebsd.org/data/main-arm64-default/pf44e1c1de734_s63ca9ea4f3/logs/errors/mongodb44-4.4.6.log
>>>>> And look for:
>>>>> ld.lld: error: undefined symbol: __aarch64_ldadd8_acq_rel
>>>>> There are a bunch of similar symbols not found while linking.
>>>>> This compiles fine using llvm11 or on amd64.
>>>
>>> It turns out clang 12 now enables -moutline-atomics by default, but we
>>> don't yet expose the necessary functions from compiler-rt. As a
>>> temporary workaround, compile with -mno-outline-atomics. Meanwhile,
>>> adding these functions to the compiler-rt lib is on my TODO list.
> ...
>> Hi Dimitry,
>>
>> I upgraded my poudriere and tried building mongodb50 with -moutline-atomics
enabled.
>> [00:00:56] Host OSVERSION: 1400032
>> [00:00:56] Jail OSVERSION: 1400032
>> ...
>>
>> [09:33:20] ld.lld: error: undefined hidden symbol: __aarch64_have_lse_atomics
>> [09:33:20] >>> referenced by outline_atomic_cas1_1.S:121
>> [09:33:20] >>> outline_atomic_cas1_1.o:(__aarch64_cas1_relax)
in archive /usr/lib/libgcc.a
>> [09:33:20] >>> referenced by outline_atomic_cas1_1.S:121
>> [09:33:20] >>> outline_atomic_cas1_1.o:(__aarch64_cas1_relax)
in archive /usr/lib/libgcc.a
>> [09:33:20] >>> referenced by outline_atomic_cas1_2.S:121
>> [09:33:20] >>> outline_atomic_cas1_2.o:(__aarch64_cas1_acq) in
archive /usr/lib/libgcc.a
>> [09:33:20] >>> referenced 57 more times
>> [09:33:20] c++: error: linker command failed with exit code 1 (use -v to see
invocation)
>> [09:33:22] scons: *** [build/opt/mongo/shell/mongo] Error 1
>> [09:33:58] ld.lld: error: undefined hidden symbol: __aarch64_have_lse_atomics
>> [09:33:58] >>> referenced by outline_atomic_cas1_1.S:121
>> [09:33:58] >>> outline_atomic_cas1_1.o:(__aarch64_cas1_relax)
in archive /usr/lib/libgcc.a
>> [09:33:58] >>> referenced by outline_atomic_cas1_1.S:121
>> [09:33:58] >>> outline_atomic_cas1_1.o:(__aarch64_cas1_relax)
in archive /usr/lib/libgcc.a
>> [09:33:58] >>> referenced by outline_atomic_cas1_2.S:121
>> [09:33:58] >>> outline_atomic_cas1_2.o:(__aarch64_cas1_acq) in
archive /usr/lib/libgcc.a
>> [09:33:58] >>> referenced 57 more times
>> [09:33:59] c++: error: linker command failed with exit code 1 (use -v to see
invocation)
>> [09:33:59] scons: *** [build/opt/mongo/db/mongod] Error 1
>
> It turns out that this function is defined in
> contrib/llvm-project/compiler-rt/lib/builtins/cpu_model.c, which we have
> compiled only for x86 until now. But upstream added the
> __aarch64_have_lse_atomics symbol and an initialization function for it.
>
> I tried simply enabling this file for the libcompiler-rt build on
> aarch64, but it turns out that the implementation is rather Linuxy, and
> does not compile on FreeBSD:
>
> contrib/llvm-project/compiler-rt/lib/builtins/cpu_model.c:778:25: error:
implicit declaration of function 'getauxval' is invalid in C99
[-Werror,-Wimplicit-function-declaration]
> unsigned long hwcap = getauxval(AT_HWCAP);
> ^
> 1 error generated.
>
> The implementation looks like:
>
> // LSE support detection for out-of-line atomics
> // using HWCAP and Auxiliary vector
> _Bool __aarch64_have_lse_atomics
> __attribute__((visibility("hidden"), nocommon));
> #if defined(__has_include)
> #if __has_include(<sys/auxv.h>)
> #include <sys/auxv.h>
> #ifndef AT_HWCAP
> #define AT_HWCAP 16
> #endif
> #ifndef HWCAP_ATOMICS
> #define HWCAP_ATOMICS (1 << 8)
> #endif
> static void CONSTRUCTOR_ATTRIBUTE init_have_lse_atomics(void) {
> unsigned long hwcap = getauxval(AT_HWCAP);
> __aarch64_have_lse_atomics = (hwcap & HWCAP_ATOMICS) != 0;
> }
>
> but in FreeBSD we don't have getauxval(), and I'm unsure if AT_HWCAP
> works on aarch64.
>
> As this is all outside my domain of knowledge I'd appreciate if somebody
> knows how to retrieve this information on our AArch64 implementation. :)
>
> -Dimitry
>
We already have elf_aux_info(3) as counterpart to getauxval() and AT_HWCAP and
AT_HWCAP2 are supported on arm64 as well, so the fix is trivial.
I'll try do it over the weekend, but I'm having some weird HW issues on my
build box so, I'm not sure if it will be possible...
Michal
Hi,
Dusted off my rusty C skills and came up with a patch.
I hope the attachment comes through.
It is currently building mongodb again to see if poudriere becomes happy. Will
report back in a couple of hours.
Regards,
Ronald.
diff --git a/contrib/llvm-project/compiler-rt/lib/builtins/cpu_model.c b/contrib/llvm-project/compiler-rt/lib/builtins/cpu_model.c
index 51bedd98c3..4691a4dc98 100644
--- a/contrib/llvm-project/compiler-rt/lib/builtins/cpu_model.c
+++ b/contrib/llvm-project/compiler-rt/lib/builtins/cpu_model.c
@@ -761,6 +761,7 @@ int CONSTRUCTOR_ATTRIBUTE __cpu_indicator_init(void) {
return 0;
}
#elif defined(__aarch64__)
+#include <err.h>
// LSE support detection for out-of-line atomics
// using HWCAP and Auxiliary vector
_Bool __aarch64_have_lse_atomics
@@ -775,7 +776,15 @@ _Bool __aarch64_have_lse_atomics
#define HWCAP_ATOMICS (1 << 8)
#endif
static void CONSTRUCTOR_ATTRIBUTE init_have_lse_atomics(void) {
- unsigned long hwcap = getauxval(AT_HWCAP);
+ u_long hwcap;
+ int error;
+
+ error = elf_aux_info(AT_HWCAP, &hwcap, sizeof(hwcap));
+ if (error != 0) {
+ warnc(error, "%s:%u: elf_aux_info failed", __FILE__, __LINE__);
+ return;
+ }
+
__aarch64_have_lse_atomics = (hwcap & HWCAP_ATOMICS) != 0;
}
#endif // defined(__has_include)
diff --git a/lib/libcompiler_rt/Makefile.inc b/lib/libcompiler_rt/Makefile.inc
index aa0a6a6c9e..4e5e1323d3 100644
--- a/lib/libcompiler_rt/Makefile.inc
+++ b/lib/libcompiler_rt/Makefile.inc
@@ -147,7 +147,7 @@ SRCF+= floatundixf
.endif
# __cpu_model support, only used on x86
-.if ${MACHINE_CPUARCH} == "amd64" || ${MACHINE_CPUARCH} == "i386"
+.if ${MACHINE_CPUARCH} == "amd64" || ${MACHINE_CPUARCH} == "i386" || ${MACHINE_CPUARCH} == "aarch64"
SRCF+= cpu_model
.endif
