* [PATCH v2] powerpc/vmlinux.lds: Drop binutils < 2.18 workarounds
@ 2019-03-29 6:44 Joel Stanley
2019-03-29 9:53 ` Segher Boessenkool
0 siblings, 1 reply; 5+ messages in thread
From: Joel Stanley @ 2019-03-29 6:44 UTC (permalink / raw)
To: linuxppc-dev
Segher added some workarounds for binutils < 2.18 and GCC < 4.2. We
now set GCC 4.6 and binutils 2.20 as the minimum, so the workarounds
can be dropped.
This is mostly a revert of c69cccc95fe4 ("powerpc: Fix build bug with
binutils < 2.18 and GCC < 4.2"), except we keep the kernel PHDRS
statement as ppc64_defconfig would fail to link without it:
powerpc64-linux-ld: .tmp_vmlinux1: Not enough room for program headers, try linking with -N
powerpc64-linux-ld: final link failed: Bad value
See https://lore.kernel.org/linuxppc-dev/20190321003253.22100-1-joel@jms.id.au/
for the discussion.
Signed-off-by: Joel Stanley <joel@jms.id.au>
---
v2: Fix ppc64_defconfig by keeping kernel PHDRS
Segher, Christophe, I did my best but to summarise your conversation.
Please suggest corrections or additions to the commit message if you
have any.
---
arch/powerpc/kernel/vmlinux.lds.S | 25 +------------------------
1 file changed, 1 insertion(+), 24 deletions(-)
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 060a1acd7c6d..9ddc7c0dc672 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -19,21 +19,6 @@ ENTRY(_stext)
PHDRS {
kernel PT_LOAD FLAGS(7); /* RWX */
- notes PT_NOTE FLAGS(0);
- dummy PT_NOTE FLAGS(0);
-
- /* binutils < 2.18 has a bug that makes it misbehave when taking an
- ELF file with all segments at load address 0 as input. This
- happens when running "strip" on vmlinux, because of the AT() magic
- in this linker script. People using GCC >= 4.2 won't run into
- this problem, because the "build-id" support will put some data
- into the "notes" segment (at a non-zero load address).
-
- To work around this, we force some data into both the "dummy"
- segment and the kernel segment, so the dummy segment will get a
- non-zero load address. It's not enough to always create the
- "notes" segment, since if nothing gets assigned to it, its load
- address will be zero. */
}
#ifdef CONFIG_PPC64
@@ -177,15 +162,7 @@ SECTIONS
#endif
EXCEPTION_TABLE(0)
- NOTES :kernel :notes
-
- /* The dummy segment contents for the bug workaround mentioned above
- near PHDRS. */
- .dummy : AT(ADDR(.dummy) - LOAD_OFFSET) {
- LONG(0)
- LONG(0)
- LONG(0)
- } :kernel :dummy
+ NOTES
/*
* Init sections discarded at runtime
--
2.20.1
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v2] powerpc/vmlinux.lds: Drop binutils < 2.18 workarounds
2019-03-29 6:44 [PATCH v2] powerpc/vmlinux.lds: Drop binutils < 2.18 workarounds Joel Stanley
@ 2019-03-29 9:53 ` Segher Boessenkool
2019-04-04 12:17 ` Joel Stanley
0 siblings, 1 reply; 5+ messages in thread
From: Segher Boessenkool @ 2019-03-29 9:53 UTC (permalink / raw)
To: Joel Stanley; +Cc: linuxppc-dev
Hi!
On Fri, Mar 29, 2019 at 05:14:53PM +1030, Joel Stanley wrote:
> - NOTES :kernel :notes
> + NOTES
I think this still need to be
NOTES :kernel
or the linker will complain. Did you try to build ppc64_defconfig?
(And I do not know if there are any tools that expect the notes in a phdr,
or even specifically the second phdr).
Segher
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2] powerpc/vmlinux.lds: Drop binutils < 2.18 workarounds
2019-03-29 9:53 ` Segher Boessenkool
@ 2019-04-04 12:17 ` Joel Stanley
2019-04-04 14:53 ` Segher Boessenkool
0 siblings, 1 reply; 5+ messages in thread
From: Joel Stanley @ 2019-04-04 12:17 UTC (permalink / raw)
To: Segher Boessenkool; +Cc: linuxppc-dev
On Fri, 29 Mar 2019 at 09:53, Segher Boessenkool
<segher@kernel.crashing.org> wrote:
>
> Hi!
>
> On Fri, Mar 29, 2019 at 05:14:53PM +1030, Joel Stanley wrote:
> > - NOTES :kernel :notes
> > + NOTES
>
> I think this still need to be
>
> NOTES :kernel
>
> or the linker will complain. Did you try to build ppc64_defconfig?
Yeah, I did build (and boot, in qemu) the ppc64_defconfig. I tried
leaving in/removing the :kernel annotation in a bunch of places and as
long as I had it in the first spot, the kernel linked.
Shall I respin with this added?
> (And I do not know if there are any tools that expect the notes in a phdr,
> or even specifically the second phdr).
>
>
> Segher
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2] powerpc/vmlinux.lds: Drop binutils < 2.18 workarounds
2019-04-04 12:17 ` Joel Stanley
@ 2019-04-04 14:53 ` Segher Boessenkool
2019-04-04 14:58 ` Christophe Leroy
0 siblings, 1 reply; 5+ messages in thread
From: Segher Boessenkool @ 2019-04-04 14:53 UTC (permalink / raw)
To: Joel Stanley; +Cc: linuxppc-dev
Hi Joel,
On Thu, Apr 04, 2019 at 12:17:40PM +0000, Joel Stanley wrote:
> On Fri, 29 Mar 2019 at 09:53, Segher Boessenkool
> <segher@kernel.crashing.org> wrote:
> > On Fri, Mar 29, 2019 at 05:14:53PM +1030, Joel Stanley wrote:
> > > - NOTES :kernel :notes
> > > + NOTES
> >
> > I think this still need to be
> >
> > NOTES :kernel
> >
> > or the linker will complain. Did you try to build ppc64_defconfig?
>
> Yeah, I did build (and boot, in qemu) the ppc64_defconfig. I tried
> leaving in/removing the :kernel annotation in a bunch of places and as
> long as I had it in the first spot, the kernel linked.
>
> Shall I respin with this added?
Yes please, if only so we are testing the exact same thing :-)
There may be a binutils version difference here.
> > (And I do not know if there are any tools that expect the notes in a phdr,
> > or even specifically the second phdr).
^^^ This question remains?
Segher
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2] powerpc/vmlinux.lds: Drop binutils < 2.18 workarounds
2019-04-04 14:53 ` Segher Boessenkool
@ 2019-04-04 14:58 ` Christophe Leroy
0 siblings, 0 replies; 5+ messages in thread
From: Christophe Leroy @ 2019-04-04 14:58 UTC (permalink / raw)
To: Segher Boessenkool, Joel Stanley; +Cc: linuxppc-dev
Le 04/04/2019 à 16:53, Segher Boessenkool a écrit :
> Hi Joel,
>
> On Thu, Apr 04, 2019 at 12:17:40PM +0000, Joel Stanley wrote:
>> On Fri, 29 Mar 2019 at 09:53, Segher Boessenkool
>> <segher@kernel.crashing.org> wrote:
>>> On Fri, Mar 29, 2019 at 05:14:53PM +1030, Joel Stanley wrote:
>>>> - NOTES :kernel :notes
>>>> + NOTES
>>>
>>> I think this still need to be
>>>
>>> NOTES :kernel
>>>
>>> or the linker will complain. Did you try to build ppc64_defconfig?
>>
>> Yeah, I did build (and boot, in qemu) the ppc64_defconfig. I tried
>> leaving in/removing the :kernel annotation in a bunch of places and as
>> long as I had it in the first spot, the kernel linked.
>>
>> Shall I respin with this added?
>
> Yes please, if only so we are testing the exact same thing :-)
>
> There may be a binutils version difference here.
>
>>> (And I do not know if there are any tools that expect the notes in a phdr,
>>> or even specifically the second phdr).
>
> ^^^ This question remains?
A few days ago while I was investigating
https://github.com/linuxppc/issues/issues/208 , I had the feeling that
QEMU expects some sort of NOTES section.
I didn't investigate further though.
Christophe
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2019-04-04 14:59 UTC | newest]
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2019-03-29 6:44 [PATCH v2] powerpc/vmlinux.lds: Drop binutils < 2.18 workarounds Joel Stanley
2019-03-29 9:53 ` Segher Boessenkool
2019-04-04 12:17 ` Joel Stanley
2019-04-04 14:53 ` Segher Boessenkool
2019-04-04 14:58 ` Christophe Leroy
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