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| Started by | Stephen Rothwell <sfr@canb.auug.org.au> |
|---|---|
| First post | 2016-02-26 06:50 +0100 |
| Last post | 2016-02-26 23:50 +0100 |
| Articles | 5 — 3 participants |
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linux-next: build failure after merge of the akpm-current tree Stephen Rothwell <sfr@canb.auug.org.au> - 2016-02-26 06:50 +0100
Re: linux-next: build failure after merge of the akpm-current tree Dave Hansen <dave.hansen@linux.intel.com> - 2016-02-26 17:20 +0100
Re: linux-next: build failure after merge of the akpm-current tree Dave Hansen <dave.hansen@linux.intel.com> - 2016-02-26 21:20 +0100
Re: linux-next: build failure after merge of the akpm-current tree Andrew Morton <akpm@linux-foundation.org> - 2016-02-26 22:40 +0100
Re: linux-next: build failure after merge of the akpm-current tree Stephen Rothwell <sfr@canb.auug.org.au> - 2016-02-26 23:50 +0100
| From | Stephen Rothwell <sfr@canb.auug.org.au> |
|---|---|
| Date | 2016-02-26 06:50 +0100 |
| Subject | linux-next: build failure after merge of the akpm-current tree |
| Message-ID | <r6jrP-6ZV-1@gated-at.bofh.it> |
Hi all,
After merging the akpm-current tree, today's linux-next build (arm
multi_v7_defconfig) failed like this:
In file included from /home/sfr/next/next/include/linux/linkage.h:4:0,
from /home/sfr/next/next/arch/arm/include/asm/bug.h:4,
from /home/sfr/next/next/include/linux/bug.h:4,
from /home/sfr/next/next/include/linux/mmdebug.h:4,
from /home/sfr/next/next/include/linux/gfp.h:4,
from /home/sfr/next/next/include/linux/slab.h:14,
from /home/sfr/next/next/kernel/signal.c:13:
/home/sfr/next/next/kernel/signal.c: In function 'signals_init':
/home/sfr/next/next/include/linux/compiler.h:506:38: error: call to '__compiletime_assert_3610' declared with attribute error: BUILD_BUG_ON failed: __ARCH_SI_PREAMBLE_SIZE != offsetof(struct siginfo, _sifields._pad)
Caused by commit
21c0826ab237 ("kernel/signal.c: add compile-time check for __ARCH_SI_PREAMBLE_SIZE")
interacting with commit
cd0ea35ff551 ("signals, pkeys: Notify userspace about protection key faults")
from the tip tree.
The addition of the "u64 _pkey" has presumably changed the alignment of
the enclosing union on (some) 32 bit platforms and so added padding
after the si_code field. This is a user API issue. :-(
[As an aside, I am pretty sure that we should not be using "u64" in a
uapi header in any case.]
I have added the following patch for today (and will add it to the tip
tree merge from Monday unless some other fix comes along).
From: Stephen Rothwell <sfr@canb.auug.org.au>
Date: Fri, 26 Feb 2016 16:31:36 +1100
Subject: [PATCH] signals, pkeys: make si_pkey 32 bits for now
to prevent a change of alignment in the siginfo structure
Fixes: cd0ea35ff551 ("signals, pkeys: Notify userspace about protection key faults")
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
---
arch/ia64/include/uapi/asm/siginfo.h | 2 +-
arch/mips/include/uapi/asm/siginfo.h | 2 +-
include/uapi/asm-generic/siginfo.h | 2 +-
3 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/ia64/include/uapi/asm/siginfo.h b/arch/ia64/include/uapi/asm/siginfo.h
index 0151cfab929d..0c660bbccd3f 100644
--- a/arch/ia64/include/uapi/asm/siginfo.h
+++ b/arch/ia64/include/uapi/asm/siginfo.h
@@ -70,7 +70,7 @@ typedef struct siginfo {
void __user *_upper;
} _addr_bnd;
/* used when si_code=SEGV_PKUERR */
- u64 _pkey;
+ int _pkey;
};
} _sigfault;
diff --git a/arch/mips/include/uapi/asm/siginfo.h b/arch/mips/include/uapi/asm/siginfo.h
index 6f4edf0d794c..d2adebc0023d 100644
--- a/arch/mips/include/uapi/asm/siginfo.h
+++ b/arch/mips/include/uapi/asm/siginfo.h
@@ -93,7 +93,7 @@ typedef struct siginfo {
void __user *_upper;
} _addr_bnd;
/* used when si_code=SEGV_PKUERR */
- u64 _pkey;
+ int _pkey;
};
} _sigfault;
diff --git a/include/uapi/asm-generic/siginfo.h b/include/uapi/asm-generic/siginfo.h
index 90384d55225b..0f23ec63c291 100644
--- a/include/uapi/asm-generic/siginfo.h
+++ b/include/uapi/asm-generic/siginfo.h
@@ -98,7 +98,7 @@ typedef struct siginfo {
void __user *_upper;
} _addr_bnd;
/* used when si_code=SEGV_PKUERR */
- u64 _pkey;
+ int _pkey;
};
} _sigfault;
--
2.7.0
--
Cheers,
Stephen Rothwell
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| From | Dave Hansen <dave.hansen@linux.intel.com> |
|---|---|
| Date | 2016-02-26 17:20 +0100 |
| Message-ID | <r6thw-5Uo-7@gated-at.bofh.it> |
| In reply to | #1343790 |
On 02/25/2016 09:44 PM, Stephen Rothwell wrote:
> The addition of the "u64 _pkey" has presumably changed the alignment of
> the enclosing union on (some) 32 bit platforms and so added padding
> after the si_code field. This is a user API issue. :-(
>
> [As an aside, I am pretty sure that we should not be using "u64" in a
> uapi header in any case.]
Ahh, so if _addr_bnd wasn't 64-bit-aligned, the compiler is free to
align it and enlarge the structure. But, this only applied to
architectures where _addr_bnd wasn't 64-bit-aligned:
Would anybody object to _pkey being an 'unsigned long'? It would at
least keep existing 64-bit userspace (mostly my tests) from having to
change.
Here's the snippet of the struct in question:
> union {
> /* used when si_code=SEGV_BNDERR */
> struct {
> void __user *_lower;
> void __user *_upper;
> } _addr_bnd;
> /* used when si_code=SEGV_PKUERR */
> u64 _pkey;
> };
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| From | Dave Hansen <dave.hansen@linux.intel.com> |
|---|---|
| Date | 2016-02-26 21:20 +0100 |
| Message-ID | <r6x1M-6H-21@gated-at.bofh.it> |
| In reply to | #1343790 |
On 02/25/2016 09:44 PM, Stephen Rothwell wrote:
> Fixes: cd0ea35ff551 ("signals, pkeys: Notify userspace about protection key faults")
> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
> ---
> arch/ia64/include/uapi/asm/siginfo.h | 2 +-
> arch/mips/include/uapi/asm/siginfo.h | 2 +-
> include/uapi/asm-generic/siginfo.h | 2 +-
> 3 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/arch/ia64/include/uapi/asm/siginfo.h b/arch/ia64/include/uapi/asm/siginfo.h
> index 0151cfab929d..0c660bbccd3f 100644
> --- a/arch/ia64/include/uapi/asm/siginfo.h
> +++ b/arch/ia64/include/uapi/asm/siginfo.h
> @@ -70,7 +70,7 @@ typedef struct siginfo {
> void __user *_upper;
> } _addr_bnd;
> /* used when si_code=SEGV_PKUERR */
> - u64 _pkey;
> + int _pkey;
> };
> } _sigfault;
Considering Peter's feedback on my 'unsigned long' approach, I'm fine
with your patch, Stephen. Can it just be picked up in to the tip tree?
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
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| From | Andrew Morton <akpm@linux-foundation.org> |
|---|---|
| Date | 2016-02-26 22:40 +0100 |
| Message-ID | <r6yhc-RJ-37@gated-at.bofh.it> |
| In reply to | #1344650 |
On Fri, 26 Feb 2016 12:10:06 -0800 Dave Hansen <dave.hansen@linux.intel.com> wrote:
> On 02/25/2016 09:44 PM, Stephen Rothwell wrote:
> > Fixes: cd0ea35ff551 ("signals, pkeys: Notify userspace about protection key faults")
> > Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
> > ---
> > arch/ia64/include/uapi/asm/siginfo.h | 2 +-
> > arch/mips/include/uapi/asm/siginfo.h | 2 +-
> > include/uapi/asm-generic/siginfo.h | 2 +-
> > 3 files changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/arch/ia64/include/uapi/asm/siginfo.h b/arch/ia64/include/uapi/asm/siginfo.h
> > index 0151cfab929d..0c660bbccd3f 100644
> > --- a/arch/ia64/include/uapi/asm/siginfo.h
> > +++ b/arch/ia64/include/uapi/asm/siginfo.h
> > @@ -70,7 +70,7 @@ typedef struct siginfo {
> > void __user *_upper;
> > } _addr_bnd;
> > /* used when si_code=SEGV_PKUERR */
> > - u64 _pkey;
> > + int _pkey;
> > };
> > } _sigfault;
>
> Considering Peter's feedback on my 'unsigned long' approach, I'm fine
> with your patch, Stephen. Can it just be picked up in to the tip tree?
>
> Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
I've moved add-compile-time-check-for-__arch_si_preamble_size.patch to
be after linux-next and have added this patch (as
add-compile-time-check-for-__arch_si_preamble_size-fix.patch) to be
folded into add-compile-time-check-for-__arch_si_preamble_size.patch
later on.
So no -tip changes should be needed.
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| From | Stephen Rothwell <sfr@canb.auug.org.au> |
|---|---|
| Date | 2016-02-26 23:50 +0100 |
| Message-ID | <r6zmW-1EG-3@gated-at.bofh.it> |
| In reply to | #1344702 |
Hi Andrew, On Fri, 26 Feb 2016 13:33:50 -0800 Andrew Morton <akpm@linux-foundation.org> wrote: > > I've moved add-compile-time-check-for-__arch_si_preamble_size.patch to > be after linux-next and have added this patch (as > add-compile-time-check-for-__arch_si_preamble_size-fix.patch) to be > folded into add-compile-time-check-for-__arch_si_preamble_size.patch > later on. > > So no -tip changes should be needed. But the fix should go into the tip tree since the tip tree patch is not correct even without this new build time check. -- Cheers, Stephen Rothwell
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