2017-06-05 09:19:45

by Waldemar Brodkorb

[permalink] [raw]
Subject: sparc64 gcc 7.1 compile error

Hi,

I get a compile/linking error with gcc 7.1 when targeting qemu system
sparc64.

+ objects='arch/sparc/kernel/head_64.o init/built-in.o
--start-group usr/built-in.o arch/sparc/built-in.o
kernel/built-in.o certs/built-in.o mm/built-in.o fs/built-in.o
ipc/built-in.o security/built-in.o crypto/built-in.o
block/built-in.o lib/lib.a arch/sparc/prom/lib.a
arch/sparc/lib/lib.a lib/built-in.o arch/sparc/prom/built-in.o
arch/sparc/lib/built-in.o drivers/built-in.o sound/built-in.o
firmware/built-in.o net/built-in.o virt/built-in.o
--end-group '
+
/home/wbx/openadk/toolchain_qemu-sparc64_glibc_v9/usr/bin/sparc64-openadk-linux-gnu-ld
-m elf64_sparc --build-id -o vmlinux -T
./arch/sparc/kernel/vmlinux.lds arch/sparc/kernel/head_64.o
init/built-in.o --start-group usr/built-in.o arch/sparc/built-in.o
kernel/built-in.o certs/built-in.o mm/built-in.o fs/built-in.o
ipc/built-in.o security/built-in.o crypto/built-in.o
block/built-in.o lib/lib.a arch/sparc/prom/lib.a
arch/sparc/lib/lib.a lib/built-in.o arch/sparc/prom/built-in.o
arch/sparc/lib/built-in.o drivers/built-in.o sound/built-in.o
firmware/built-in.o net/built-in.o virt/built-in.o --end-group
ipc/built-in.o: In function `mq_attr_ok':
mqueue.c:(.text+0x6154): undefined reference to `__multi3'

I tried with Linux 4.11.3, Linus master and David Miller's SPARC
tree from today with the same result. The failing config is attached.

Any ideas?

best regards
Waldemar


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2017-06-05 15:59:37

by David Miller

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Subject: Re: sparc64 gcc 7.1 compile error

From: Waldemar Brodkorb <[email protected]>
Date: Mon, 5 Jun 2017 11:19:41 +0200

> I get a compile/linking error with gcc 7.1 when targeting qemu system
> sparc64.
>
> + objects='arch/sparc/kernel/head_64.o init/built-in.o
> --start-group usr/built-in.o arch/sparc/built-in.o
> kernel/built-in.o certs/built-in.o mm/built-in.o fs/built-in.o
> ipc/built-in.o security/built-in.o crypto/built-in.o
> block/built-in.o lib/lib.a arch/sparc/prom/lib.a
> arch/sparc/lib/lib.a lib/built-in.o arch/sparc/prom/built-in.o
> arch/sparc/lib/built-in.o drivers/built-in.o sound/built-in.o
> firmware/built-in.o net/built-in.o virt/built-in.o
> --end-group '
> +
> /home/wbx/openadk/toolchain_qemu-sparc64_glibc_v9/usr/bin/sparc64-openadk-linux-gnu-ld
> -m elf64_sparc --build-id -o vmlinux -T
> ./arch/sparc/kernel/vmlinux.lds arch/sparc/kernel/head_64.o
> init/built-in.o --start-group usr/built-in.o arch/sparc/built-in.o
> kernel/built-in.o certs/built-in.o mm/built-in.o fs/built-in.o
> ipc/built-in.o security/built-in.o crypto/built-in.o
> block/built-in.o lib/lib.a arch/sparc/prom/lib.a
> arch/sparc/lib/lib.a lib/built-in.o arch/sparc/prom/built-in.o
> arch/sparc/lib/built-in.o drivers/built-in.o sound/built-in.o
> firmware/built-in.o net/built-in.o virt/built-in.o --end-group
> ipc/built-in.o: In function `mq_attr_ok':
> mqueue.c:(.text+0x6154): undefined reference to `__multi3'
>
> I tried with Linux 4.11.3, Linus master and David Miller's SPARC
> tree from today with the same result. The failing config is attached.

GCC seems to be emitting a 128-bit multiply to work out this
expression in ipc/mqueue.c:

if (attr->mq_msgsize > (~0UL)/attr->mq_maxmsg)
return -92;

Seems like a bit of an extreme way to do this.

But worst case we'll have to add __multi3 to the kernel libraries.

2017-06-05 18:31:05

by David Miller

[permalink] [raw]
Subject: Re: sparc64 gcc 7.1 compile error

From: Waldemar Brodkorb <[email protected]>
Date: Mon, 5 Jun 2017 11:19:41 +0200

> I get a compile/linking error with gcc 7.1 when targeting qemu system
> sparc64.

This should fix the problem, please let me know if it works for you:

====================
>From 1b4af13ff2cc6897557bb0b8d9e2fad4fa4d67aa Mon Sep 17 00:00:00 2001
From: "David S. Miller" <[email protected]>
Date: Mon, 5 Jun 2017 11:28:57 -0700
Subject: [PATCH] sparc64: Add __multi3 for gcc 7.x and later.

Reported-by: Waldemar Brodkorb <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
---
arch/sparc/lib/Makefile | 1 +
arch/sparc/lib/multi3.S | 35 +++++++++++++++++++++++++++++++++++
2 files changed, 36 insertions(+)
create mode 100644 arch/sparc/lib/multi3.S

diff --git a/arch/sparc/lib/Makefile b/arch/sparc/lib/Makefile
index 69912d2..07c03e7 100644
--- a/arch/sparc/lib/Makefile
+++ b/arch/sparc/lib/Makefile
@@ -15,6 +15,7 @@ lib-$(CONFIG_SPARC32) += copy_user.o locks.o
lib-$(CONFIG_SPARC64) += atomic_64.o
lib-$(CONFIG_SPARC32) += lshrdi3.o ashldi3.o
lib-$(CONFIG_SPARC32) += muldi3.o bitext.o cmpdi2.o
+lib-$(CONFIG_SPARC64) += multi3.o

lib-$(CONFIG_SPARC64) += copy_page.o clear_page.o bzero.o
lib-$(CONFIG_SPARC64) += csum_copy.o csum_copy_from_user.o csum_copy_to_user.o
diff --git a/arch/sparc/lib/multi3.S b/arch/sparc/lib/multi3.S
new file mode 100644
index 0000000..d6b6c97
--- /dev/null
+++ b/arch/sparc/lib/multi3.S
@@ -0,0 +1,35 @@
+#include <linux/linkage.h>
+#include <asm/export.h>
+
+ .text
+ .align 4
+ENTRY(__multi3) /* %o0 = u, %o1 = v */
+ mov %o1, %g1
+ srl %o3, 0, %g4
+ mulx %g4, %g1, %o1
+ srlx %g1, 0x20, %g3
+ mulx %g3, %g4, %g5
+ sllx %g5, 0x20, %o5
+ srl %g1, 0, %g4
+ sub %o1, %o5, %o5
+ srlx %o5, 0x20, %o5
+ addcc %g5, %o5, %g5
+ srlx %o3, 0x20, %o5
+ mulx %g4, %o5, %g4
+ mulx %g3, %o5, %o5
+ sethi %hi(0x80000000), %g3
+ addcc %g5, %g4, %g5
+ srlx %g5, 0x20, %g5
+ add %g3, %g3, %g3
+ movcc %xcc, %g0, %g3
+ addcc %o5, %g5, %o5
+ sllx %g4, 0x20, %g4
+ add %o1, %g4, %o1
+ add %o5, %g3, %g2
+ mulx %g1, %o2, %g1
+ add %g1, %g2, %g1
+ mulx %o0, %o3, %o0
+ retl
+ add %g1, %o0, %o0
+ENDPROC(__multi3)
+EXPORT_SYMBOL(__multi3)
--
2.1.2.532.g19b5d50

2017-06-06 00:06:14

by Waldemar Brodkorb

[permalink] [raw]
Subject: Re: sparc64 gcc 7.1 compile error

Hi David,
David Miller wrote,

> From: Waldemar Brodkorb <[email protected]>
> Date: Mon, 5 Jun 2017 11:19:41 +0200
>
> > I get a compile/linking error with gcc 7.1 when targeting qemu system
> > sparc64.
>
> This should fix the problem, please let me know if it works for you:

Yes, that works fine for me. Thanks again for the fast help,

best regards
Waldemar