Re: linux-next: build failure after merge of most trees

[David Miller]

From: Nicholas Piggin <npiggin@xxxxxxxxx>
Date: Fri, 23 Jun 2017 00:33:39 +1000

> On Thu, 22 Jun 2017 10:13:06 -0400 (EDT)
> David Miller <davem@xxxxxxxxxxxxx> wrote:
> 
>> From: Nicholas Piggin <npiggin@xxxxxxxxx>
>> Date: Thu, 22 Jun 2017 18:41:16 +1000
>> 
>> > Is there any way for the linker to place the inputs to avoid unresolvable
>> > relocations where possible?  
>> 
>> I don't think so.
>> 
>> > A way to work around this is to make arch/sparc/lib/hweight.o an obj-y
>> > rather than lib-y. That's a hack because it just serves to move the
>> > input location, but not really any more of a hack than the current code
>> > that also only works because of input locations...  
>> 
>> I could adjust those branches in the sparc code into indirect calls
>> but it's going to perform a bit poorly on older cpus.
> 
> The build succeeds with your patch. That should solve it properly
> so it won't come back to bite again.
> 
> If you can tolerate the slowdown on old CPUs I'd be grateful if
> we could merge it for linux-next to get this thin archives tree
> unblocked.

Feel free to merge it into your series:

====================
sparc64: Use indirect calls in hamming weight stubs.

Otherwise, depending upon link order, the branch relocation
limits could be exceeded.

Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>

diff --git a/arch/sparc/lib/hweight.S b/arch/sparc/lib/hweight.S
index f9985f1..d21cf20 100644
--- a/arch/sparc/lib/hweight.S
+++ b/arch/sparc/lib/hweight.S
@@ -4,9 +4,9 @@
 	.text
 	.align	32
 ENTRY(__arch_hweight8)
-	ba,pt	%xcc, __sw_hweight8
+	sethi	%hi(__sw_hweight8), %g1
+	jmpl	%g1 + %lo(__sw_hweight8), %g0
 	 nop
-	nop
 ENDPROC(__arch_hweight8)
 EXPORT_SYMBOL(__arch_hweight8)
 	.section	.popc_3insn_patch, "ax"
@@ -17,9 +17,9 @@ EXPORT_SYMBOL(__arch_hweight8)
 	.previous
 
 ENTRY(__arch_hweight16)
-	ba,pt	%xcc, __sw_hweight16
+	sethi	%hi(__sw_hweight16), %g1
+	jmpl	%g1 + %lo(__sw_hweight16), %g0
 	 nop
-	nop
 ENDPROC(__arch_hweight16)
 EXPORT_SYMBOL(__arch_hweight16)
 	.section	.popc_3insn_patch, "ax"
@@ -30,9 +30,9 @@ EXPORT_SYMBOL(__arch_hweight16)
 	.previous
 
 ENTRY(__arch_hweight32)
-	ba,pt	%xcc, __sw_hweight32
+	sethi	%hi(__sw_hweight32), %g1
+	jmpl	%g1 + %lo(__sw_hweight32), %g0
 	 nop
-	nop
 ENDPROC(__arch_hweight32)
 EXPORT_SYMBOL(__arch_hweight32)
 	.section	.popc_3insn_patch, "ax"
@@ -43,9 +43,9 @@ EXPORT_SYMBOL(__arch_hweight32)
 	.previous
 
 ENTRY(__arch_hweight64)
-	ba,pt	%xcc, __sw_hweight64
+	sethi	%hi(__sw_hweight16), %g1
+	jmpl	%g1 + %lo(__sw_hweight16), %g0
 	 nop
-	nop
 ENDPROC(__arch_hweight64)
 EXPORT_SYMBOL(__arch_hweight64)
 	.section	.popc_3insn_patch, "ax"