[PATCH] arm64: LLVMLinux: Provide __aeabi_* symbols which are needed for clang

[PATCH] arm64: LLVMLinux: Provide __aeabi_* symbols which are needed for clang

[behanw at converseincode.com]

From: Behan Webster <behanw@converseincode.com>

These symbols are required when compiling the Linux kernel for arch ARM64 with
clang.

Author: Mark Charlebois <charlebm@gmail.com>
Signed-off-by: Mark Charlebois <charlebm@gmail.com>
Signed-off-by: Behan Webster <behanw@converseincode.com>
---
 arch/arm64/lib/Makefile |  4 ++++
 arch/arm64/lib/eabi.c   | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+)
 create mode 100644 arch/arm64/lib/eabi.c

diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile
index d98d3e3..0d3407c 100644
--- a/arch/arm64/lib/Makefile
+++ b/arch/arm64/lib/Makefile
@@ -3,3 +3,7 @@ lib-y		:= bitops.o clear_user.o delay.o copy_from_user.o	\
 		   clear_page.o memchr.o memcpy.o memmove.o memset.o	\
 		   memcmp.o strcmp.o strncmp.o strlen.o strnlen.o	\
 		   strchr.o strrchr.o
+
+ifeq ($(COMPILER),clang)
+lib-y += eabi.o
+endif
diff --git a/arch/arm64/lib/eabi.c b/arch/arm64/lib/eabi.c
new file mode 100644
index 0000000..41b27b2
--- /dev/null
+++ b/arch/arm64/lib/eabi.c
@@ -0,0 +1,32 @@
+/*
+ *  linux/lib/eabi.c
+ *
+ *  Copyright (C) 2012  Mark Charlebois
+ */
+
+/*
+ * EABI routines
+ */
+
+#include <linux/types.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+#include <linux/export.h>
+
+void __aeabi_memcpy(void *dest, const void *src, size_t n)
+{
+	(void)memcpy(dest, src, n);
+}
+EXPORT_SYMBOL(__aeabi_memcpy);
+
+void __aeabi_memmove(void *dest, const void *src, size_t n)
+{
+	(void)memmove(dest, src, n);
+}
+EXPORT_SYMBOL(__aeabi_memmove);
+
+void __aeabi_memset(void *s, size_t n, int c)
+{
+	(void)memset(s, c, n);
+}
+EXPORT_SYMBOL(__aeabi_memset);
-- 
1.9.1

[PATCH] arm64: LLVMLinux: Provide __aeabi_* symbols which are needed for clang

[Arnd Bergmann]

On Friday 05 September 2014 16:23:14 behanw at converseincode.com wrote:
> --- /dev/null
> +++ b/arch/arm64/lib/eabi.c
> @@ -0,0 +1,32 @@
> +/*
> + *  linux/lib/eabi.c

Please don't put the file names in the files themselves, it's redundant
and in this case actually wrong.

> + *  Copyright (C) 2012  Mark Charlebois
> + */
> +
> +/*
> + * EABI routines

Does EABI specify these function names? I would think that they are
just random libgcc (whatever that is called in clang) functions.

	Arnd

[PATCH] arm64: LLVMLinux: Provide __aeabi_* symbols which are needed for clang

[Behan Webster]

On 09/06/14 07:16, Arnd Bergmann wrote:
> On Friday 05 September 2014 16:23:14 behanw at converseincode.com wrote:
>> --- /dev/null
>> +++ b/arch/arm64/lib/eabi.c
>> @@ -0,0 +1,32 @@
>> +/*
>> + *  linux/lib/eabi.c
> Please don't put the file names in the files themselves, it's redundant
> and in this case actually wrong.
Will fix.

>> + *  Copyright (C) 2012  Mark Charlebois
>> + */
>> +
>> +/*
>> + * EABI routines
> Does EABI specify these function names? I would think that they are
> just random libgcc (whatever that is called in clang) functions.
These specialized functions are part of the ABI for the ARM architecture 
(AEABI). They aren't random.

Memcpy and memmove *could* might be satisfied with linker magic instead. 
But memset uses the reverse parameter list.

Behan

-- 
Behan Webster
behanw at converseincode.com

[PATCH] arm64: LLVMLinux: Provide __aeabi_* symbols which are needed for clang

[Mark Charlebois]

On Sat, Sep 6, 2014 at 7:16 AM, Arnd Bergmann <arnd@arndb.de> wrote:
>
> On Friday 05 September 2014 16:23:14 behanw at converseincode.com wrote:
> > --- /dev/null
> > +++ b/arch/arm64/lib/eabi.c
> > @@ -0,0 +1,32 @@
> > +/*
> > + *  linux/lib/eabi.c
>
> Please don't put the file names in the files themselves, it's redundant
> and in this case actually wrong.

Sorry, will fix.

>
> > + *  Copyright (C) 2012  Mark Charlebois
> > + */
> > +
> > +/*
> > + * EABI routines
>
> Does EABI specify these function names? I would think that they are
> just random libgcc (whatever that is called in clang) functions.

http://infocenter.arm.com/help/topic/com.arm.doc.ihi0043d/IHI0043D_rtabi.pdf

See section 4.3.4 Memory copying, clearing, and setting

>
>         Arnd

[PATCH] arm64: LLVMLinux: Provide __aeabi_* symbols which are needed for clang

[Catalin Marinas]

On 7 Sep 2014, at 03:30, Mark Charlebois <charlebm@gmail.com> wrote:
> On Sat, Sep 6, 2014 at 7:16 AM, Arnd Bergmann <arnd@arndb.de> wrote:
>> 
>> On Friday 05 September 2014 16:23:14 behanw at converseincode.com wrote:
>>> + *  Copyright (C) 2012  Mark Charlebois
>>> + */
>>> +
>>> +/*
>>> + * EABI routines
>> 
>> Does EABI specify these function names? I would think that they are
>> just random libgcc (whatever that is called in clang) functions.
> 
> http://infocenter.arm.com/help/topic/com.arm.doc.ihi0043d/IHI0043D_rtabi.pdf
> 
> See section 4.3.4 Memory copying, clearing, and setting

What does this document have to do with arm64 (AArch64, A64)? We don?t
need such symbols on arm64. Also, the arm64 kernel links with libgcc (no
immediate need AFAICT but the compiler does not guarantee the intrinsics
would always be generated inline).

Catalin

[PATCH] arm64: LLVMLinux: Provide __aeabi_* symbols which are needed for clang

[Mark Charlebois]

On Sun, Sep 7, 2014 at 12:30 AM, Catalin Marinas
<catalin.marinas@arm.com> wrote:
> On 7 Sep 2014, at 03:30, Mark Charlebois <charlebm@gmail.com> wrote:
>> On Sat, Sep 6, 2014 at 7:16 AM, Arnd Bergmann <arnd@arndb.de> wrote:
>>>
>>> On Friday 05 September 2014 16:23:14 behanw at converseincode.com wrote:
>>>> + *  Copyright (C) 2012  Mark Charlebois
>>>> + */
>>>> +
>>>> +/*
>>>> + * EABI routines
>>>
>>> Does EABI specify these function names? I would think that they are
>>> just random libgcc (whatever that is called in clang) functions.
>>
>> http://infocenter.arm.com/help/topic/com.arm.doc.ihi0043d/IHI0043D_rtabi.pdf
>>
>> See section 4.3.4 Memory copying, clearing, and setting
>
> What does this document have to do with arm64 (AArch64, A64)? We don?t
> need such symbols on arm64. Also, the arm64 kernel links with libgcc (no
> immediate need AFAICT but the compiler does not guarantee the intrinsics
> would always be generated inline).

[reposting in plain text]

This patch was made early in the arm64 kernel support. I just retested
and you are correct, it is no longer needed.  My apologies to all.

-Mark

>
> Catalin

[PATCH] arm64: LLVMLinux: Provide __aeabi_* symbols which are needed for clang

[Behan Webster]

On 09/08/14 16:01, Mark Charlebois wrote:
> On Sun, Sep 7, 2014 at 12:30 AM, Catalin Marinas
> <catalin.marinas@arm.com> wrote:
>> On 7 Sep 2014, at 03:30, Mark Charlebois <charlebm@gmail.com> wrote:
>>> On Sat, Sep 6, 2014 at 7:16 AM, Arnd Bergmann <arnd@arndb.de> wrote:
>>>> On Friday 05 September 2014 16:23:14 behanw at converseincode.com wrote:
>>>>> + *  Copyright (C) 2012  Mark Charlebois
>>>>> + */
>>>>> +
>>>>> +/*
>>>>> + * EABI routines
>>>> Does EABI specify these function names? I would think that they are
>>>> just random libgcc (whatever that is called in clang) functions.
>>> http://infocenter.arm.com/help/topic/com.arm.doc.ihi0043d/IHI0043D_rtabi.pdf
>>>
>>> See section 4.3.4 Memory copying, clearing, and setting
>> What does this document have to do with arm64 (AArch64, A64)? We don?t
>> need such symbols on arm64. Also, the arm64 kernel links with libgcc (no
>> immediate need AFAICT but the compiler does not guarantee the intrinsics
>> would always be generated inline).
> [reposting in plain text]
>
> This patch was made early in the arm64 kernel support. I just retested
> and you are correct, it is no longer needed.  My apologies to all.

Whoops. I normally check whether a patch is still needed before posting 
them. I seem to have missed that step this time. My apologies as well.

That all being said, I prefer to see patches no longer required, than 
needing them to be upstreamed, so in that this is a win.

Behan

-- 
Behan Webster
behanw at converseincode.com