Build breakage due to latest ARM fixes

Build breakage due to latest ARM fixes

[Olof Johansson]

Russell,

Looks like you sent up some fixes to Linus that broke one of the atmel
configs (CONFIG_MMU=n):

commit 48be69a026b2c1 ARM: move signal handlers into a vdso-like page

seems to have caused it:

arch/arm/kernel/signal.c: In function 'setup_return':
arch/arm/kernel/signal.c:413:25: error: 'mm_context_t' has no member
named 'sigpage'

I see it with at91x40_defconfig.


-Olof

Build breakage due to latest ARM fixes

[Russell King - ARM Linux]

On Fri, Aug 02, 2013 at 04:41:11PM -0700, Olof Johansson wrote:
> Russell,
> 
> Looks like you sent up some fixes to Linus that broke one of the atmel
> configs (CONFIG_MMU=n):
> 
> commit 48be69a026b2c1 ARM: move signal handlers into a vdso-like page
> 
> seems to have caused it:
> 
> arch/arm/kernel/signal.c: In function 'setup_return':
> arch/arm/kernel/signal.c:413:25: error: 'mm_context_t' has no member
> named 'sigpage'
> 
> I see it with at91x40_defconfig.

I'll look into that.  Obviously, I never build nommu because it isn't
part of the build system and the nommu platform I do have - OKI67001 -
doesn't have mainline kernel support.  (And if it did, it would not be
DT, so I doubt it's submittable.)

Build breakage due to latest ARM fixes

[Olof Johansson]

On Fri, Aug 2, 2013 at 5:07 PM, Russell King - ARM Linux
<linux@arm.linux.org.uk> wrote:
> On Fri, Aug 02, 2013 at 04:41:11PM -0700, Olof Johansson wrote:
>> Russell,
>>
>> Looks like you sent up some fixes to Linus that broke one of the atmel
>> configs (CONFIG_MMU=n):
>>
>> commit 48be69a026b2c1 ARM: move signal handlers into a vdso-like page
>>
>> seems to have caused it:
>>
>> arch/arm/kernel/signal.c: In function 'setup_return':
>> arch/arm/kernel/signal.c:413:25: error: 'mm_context_t' has no member
>> named 'sigpage'
>>
>> I see it with at91x40_defconfig.
>
> I'll look into that.  Obviously, I never build nommu because it isn't
> part of the build system and the nommu platform I do have - OKI67001 -
> doesn't have mainline kernel support.  (And if it did, it would not be
> DT, so I doubt it's submittable.)

I just noticed a whole bunch of boot/runtime failures too across the board too.

tegra2 seaboard, exynos arndale, ux500 snowball all panicked. Panda,
cubox and sama5 were the only systems that stayed up. Note that I
don't do much with them per boot though, so with more runtime they
might have hit something too.

Some of the oopses below, they're probably not very useful though. Let
me know if I can help collect data in any way.

Maybe it's better to move this feature work to -next and iron out the
kinks there? :(


[   13.193059] ------------[ cut here ]------------
[   13.197669] kernel BUG at /home/olof/work/batch/include/linux/mm.h:414!
[   13.204265] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM
[   13.210080] Modules linked in:
[   13.213129] CPU: 0 PID: 490 Comm: killall5 Not tainted
3.11.0-rc3-00288-gabe0308 #53
[   13.220852] task: e90acac0 ti: e9be8000 task.ti: e9be8000
[   13.226246] PC is at special_mapping_fault+0xa4/0xc4
[   13.231196] LR is at __do_fault+0x68/0x48c
[   13.235279] pc : [<c00b8d50>]    lr : [<c00b3280>]    psr: 60000013
[   13.235279] sp : e9be9e00  ip : 000b6f90  fp : 00000000
[   13.246729] r10: 00000000  r9 : e9232db8  r8 : 00000000
[   13.251937] r7 : b6f90000  r6 : e904e540  r5 : 00000008  r4 : c0769b80
[   13.258444] r3 : 00000000  r2 : 000b6f90  r1 : e9be9e28  r0 : e9be9e84
[   13.264954] Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
[   13.272069] Control: 10c5387d  Table: 2923004a  DAC: 00000015
[   13.277798] Process killall5 (pid: 490, stack limit = 0xe9be8238)
[   13.283872] Stack: (0xe9be9e00 to 0xe9bea000)
[   13.288216] 9e00: c0fb1540 00000000 e93d0a50 c00b3280 c07a9780
00000188 e916e000 00000000
[   13.296374] 9e20: e904e540 e916e620 00000008 000b6f90 b6f90000
00000000 000003c0 e93d0a50
[   13.304532] 9e40: 000b6f90 e904e540 e916e640 e93d0a50 00000008
00000000 c0728f54 c00b64f8
[   13.312689] 9e60: 000b6f90 00000008 00000000 c00a1bfc c00a12f8
00000171 e9be9f4c 00000052
[   13.320847] 9e80: c0fafe80 c0769b80 c0fafe80 00000000 c0fafe80
e9230000 000005b7 b6f90000
[   13.329005] 9ea0: e904e540 e93d0a50 00000008 e9232db8 c0728f54
c00b6c8c e9232db8 00000008
[   13.337162] 9ec0: 00000052 e93d0a50 e90acac0 b6f90000 e904e540
e9be9f6c 00000052 c00b6dec
[   13.345320] 9ee0: e9be8000 00000000 c07a9780 c072b984 c0733920
00000000 00000000 00000010
[   13.353477] 9f00: e9be8000 00000001 00000016 00000000 c0723da8
b6f90000 e93d0a50 e904e540
[   13.361634] 9f20: e9be9f6c 00000001 00000001 e904e570 00000001
c00b7d7c 00000052 00000000
[   13.369791] 9f40: 00000000 e9be9f6c e93d0a50 b6f91000 bf000000
b6f90000 e904e540 c00b8248
[   13.377949] 9f60: e9be8000 e9be8000 e904e574 00000001 e9be8000
00000000 e9be8000 e9be8000
[   13.386106] 9f80: 00000098 c000e644 e9be8000 00000000 00000006
c00b853c 00000000 00000001
[   13.394263] 9fa0: 000001d8 c000e4c0 00000000 00000001 00000003
00000016 b6e914c0 00000010
[   13.402420] 9fc0: 00000000 00000001 000001d8 00000098 00013134
00000006 be8eae24 00000006
[   13.410577] 9fe0: b6f1dcf0 be8eac9c 000090d3 b6f1dcfc 80000010
00000003 00003142 00003143
[   13.418736] Code: e8bd8010 e3a00002 e28dd008 e8bd8010 (e7f001f2)
[   13.424812] ---[ end trace d069f2c36c63aa68 ]---


[    2.856972] Unable to handle kernel paging request at virtual
address 000959a0
[    2.862641] pgd = ee944000
[    2.865271] [000959a0] *pgd=6e9c1831, *pte=00000000, *ppte=00000000
[    2.871423] Internal error: Oops: 17 [#1] PREEMPT SMP ARM
[    2.876715] Modules linked in:
[    2.879709] CPU: 0 PID: 1206 Comm: startpar Not tainted
3.11.0-rc3-00288-gabe0308 #52
[    2.887393] task: ef223740 ti: ef2a4000 task.ti: ef2a4000
[    2.892698] PC is at mark_page_accessed+0x8/0xfc
[    2.897217] LR is at follow_page_mask+0x188/0x2b0
[    2.901828] pc : [<c0082204>]    lr : [<c0095290>]    psr: 60000013
[    2.901828] sp : ef2a5eb8  ip : 0006f7f5  fp : 04acd59f
[    2.913101] r10: 00000694  r9 : 00000000  r8 : eea48fec
[    2.918226] r7 : 00000000  r6 : 000959a0  r5 : ee925210  r4 : 000959a0
[    2.924632] r3 : ef223740  r2 : 00000000  r1 : b6fa5000  r0 : 000959a0
[    2.931039] Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
[    2.938041] Control: 10c5387d  Table: 6e94406a  DAC: 00000015
[    2.943679] Process startpar (pid: 1206, stack limit = 0xef2a4238)
[    2.949742] Stack: (0xef2a5eb8 to 0xef2a6000)
[    2.954014] 5ea0:
    00000052 c0095290
[    2.962043] 5ec0: c04bc72c ee946db8 ee946db8 00000052 ee925210
ef223740 b6fa5000 eea48fc0
[    2.970072] 5ee0: ef2a5f6c c04c5378 c04bc72c c0096208 ef223740
c004447c 00100100 c0515580
[    2.978101] 5f00: 00000000 00000010 ef2a4000 00000001 60000013
00000000 eea49000 00040075
[    2.986129] 5f20: ef2a5f6c bf000000 b6fa5000 eea48fc0 00000001
eea48ffc 00000001 c009711c
[    2.994158] 5f40: 00000052 00000000 00000000 ef2a5f6c ee925a50
ee925210 b6fa6000 c0097584
[    3.002186] 5f60: eea48ffc c01af3ac eea49000 00000001 ef2a4000
00000000 ef2a4000 ef2a4000
[    3.010215] 5f80: 00000098 c000e408 ef2a4000 00000000 bea7bf45
c0097870 000161f4 0000ce14
[    3.018244] 5fa0: 0000ce08 c000e260 000161f4 0000ce14 00000003
bea79848 00000000 00000000
[    3.026272] 5fc0: 000161f4 0000ce14 0000ce08 00000098 000161f4
00000000 bea7bf40 bea7bf45
[    3.034301] 5fe0: 00000001 bea79978 0000adfd b6f3441c 80000010
00000003 2004e6a8 f44fe6a6
[    3.042332] Code: eaffffdd c04b1b14 e92d4010 e1a04000 (e5903000)
[    3.048333] ---[ end trace a090a6786a576447 ]---



Unable to handle kernel NULL pointer dereference at virtual address 00000010
pgd = ee868000
[00000010] *pgd=2f25f831, *pte=00000000, *ppte=00000000
Internal error: Oops: 17 [#1] PREEMPT SMP ARM
Modules linked in:
CPU: 1 PID: 905 Comm: startpar Not tainted 3.11.0-rc3-00288-gabe0308 #51
task: ef0e0300 ti: ef26c000 task.ti: ef26c000
PC is at __get_page_tail+0x24/0xb4
LR is at special_mapping_fault+0xa4/0xb4
pc : [<c007ce1c>]    lr : [<c0092474>]    psr: a0000013
sp : ef26de28  ip : 000b6fab  fp : ee86adb8
r10: ef229478  r9 : 00000008  r8 : b6fab000
r7 : 00000000  r6 : 00000008  r5 : 00000000  r4 : ee86adb8
r3 : 2e86d831  r2 : 000b6fab  r1 : ef26de58  r0 : ee86adb8
Flags: NzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
Control: 10c5787d  Table: 2e86804a  DAC: 00000015
Process startpar (pid: 905, stack limit = 0xef26c238)
Stack: (0xef26de28 to 0xef26e000)
de20:                   2e86d831 ee86adb8 ef22f380 c0092474 c0d662a0 ef26de58
de40: 00000000 c008d2b4 c0d662a0 ef22f3ac 00000000 ee86d670 00000008 000b6fab
de60: b6fab000 00000000 00000300 00000000 ee86d6ac ef229478 000b6fab ef22f380
de80: 00000008 ee86adb8 c05126b4 c00900c0 000b6fab 00000008 00000000 c053d180
dea0: c0d69d00 ee868000 000005b7 b6fab000 ef22f380 ef229478 00000008 ee86adb8
dec0: c05126b4 c00904c4 ee86adb8 00000008 00000052 ef229478 ef0e0300 b6fab000
dee0: ef22f380 ef26df6c c0567780 c0090604 c053d861 00000000 c0514b44 c051d278
df00: 00000000 00000010 ef26c000 00000001 c007d904 00000000 c0d7e580 00040075
df20: ef26df6c bf000000 b6fab000 ef22f380 00000001 ef22f3b0 00000001 c0091510
df40: 00000052 00000000 00000000 ef26df6c ef229528 ef229478 b6fac000 c0091978
df60: ef26c000 ef26c000 ef22f3b4 00000001 ef26c000 00000000 ef26c000 ef26c000
df80: 00000098 c000e488 ef26c000 00000000 be89df45 c0091c64 000161f4 0000ce14
dfa0: 0000ce08 c000e2e0 000161f4 0000ce14 00000003 be89b848 00000000 00000000
dfc0: 000161f4 0000ce14 0000ce08 00000098 000161f4 00000000 be89df40 be89df45
dfe0: 00000001 be89b978 0000adfd b6f3a41c 80000010 00000003 00000000 00000000
Code: e8bd8038 e590501c e1500005 0afffffa (e5952010)
---[ end trace d3081553bdf3d87f ]---



-Olof

Build breakage due to latest ARM fixes

[Russell King - ARM Linux]

On Fri, Aug 02, 2013 at 05:24:21PM -0700, Olof Johansson wrote:
> On Fri, Aug 2, 2013 at 5:07 PM, Russell King - ARM Linux
> <linux@arm.linux.org.uk> wrote:
> > On Fri, Aug 02, 2013 at 04:41:11PM -0700, Olof Johansson wrote:
> >> Russell,
> >>
> >> Looks like you sent up some fixes to Linus that broke one of the atmel
> >> configs (CONFIG_MMU=n):
> >>
> >> commit 48be69a026b2c1 ARM: move signal handlers into a vdso-like page
> >>
> >> seems to have caused it:
> >>
> >> arch/arm/kernel/signal.c: In function 'setup_return':
> >> arch/arm/kernel/signal.c:413:25: error: 'mm_context_t' has no member
> >> named 'sigpage'
> >>
> >> I see it with at91x40_defconfig.
> >
> > I'll look into that.  Obviously, I never build nommu because it isn't
> > part of the build system and the nommu platform I do have - OKI67001 -
> > doesn't have mainline kernel support.  (And if it did, it would not be
> > DT, so I doubt it's submittable.)
> 
> I just noticed a whole bunch of boot/runtime failures too across the board too.
> 
> tegra2 seaboard, exynos arndale, ux500 snowball all panicked. Panda,
> cubox and sama5 were the only systems that stayed up. Note that I
> don't do much with them per boot though, so with more runtime they
> might have hit something too.
> 
> Some of the oopses below, they're probably not very useful though. Let
> me know if I can help collect data in any way.

Gah, it looks like I didn't commit an update to these patches.

> Maybe it's better to move this feature work to -next and iron out the
> kinks there? :(

Tell me how I can put this stuff into -next _and_ keep it secret because
it's security related.  The two things are totally incompatible with each
other.  Sorry.

Build breakage due to latest ARM fixes

[Russell King - ARM Linux]

On Sat, Aug 03, 2013 at 01:41:11AM +0100, Russell King - ARM Linux wrote:
> On Fri, Aug 02, 2013 at 05:24:21PM -0700, Olof Johansson wrote:
> > On Fri, Aug 2, 2013 at 5:07 PM, Russell King - ARM Linux
> > <linux@arm.linux.org.uk> wrote:
> > > On Fri, Aug 02, 2013 at 04:41:11PM -0700, Olof Johansson wrote:
> > >> Russell,
> > >>
> > >> Looks like you sent up some fixes to Linus that broke one of the atmel
> > >> configs (CONFIG_MMU=n):
> > >>
> > >> commit 48be69a026b2c1 ARM: move signal handlers into a vdso-like page
> > >>
> > >> seems to have caused it:
> > >>
> > >> arch/arm/kernel/signal.c: In function 'setup_return':
> > >> arch/arm/kernel/signal.c:413:25: error: 'mm_context_t' has no member
> > >> named 'sigpage'
> > >>
> > >> I see it with at91x40_defconfig.
> > >
> > > I'll look into that.  Obviously, I never build nommu because it isn't
> > > part of the build system and the nommu platform I do have - OKI67001 -
> > > doesn't have mainline kernel support.  (And if it did, it would not be
> > > DT, so I doubt it's submittable.)
> > 
> > I just noticed a whole bunch of boot/runtime failures too across the board too.
> > 
> > tegra2 seaboard, exynos arndale, ux500 snowball all panicked. Panda,
> > cubox and sama5 were the only systems that stayed up. Note that I
> > don't do much with them per boot though, so with more runtime they
> > might have hit something too.
> > 
> > Some of the oopses below, they're probably not very useful though. Let
> > me know if I can help collect data in any way.
> 
> Gah, it looks like I didn't commit an update to these patches.

Okay, this should fix it - *untested* though because of the fscking time
it is here again.  The problem is that install_special_mapping() assumes
that the pointer to the pages will be persistent, and it wasn't.  I found
that during testing and thought I'd merged the patches in, but I seem to
have totally destroyed the original fixes for this.

 arch/arm/kernel/process.c |    9 +++++----
 arch/arm/kernel/signal.c  |   41 +++++++++++++++++++----------------------
 2 files changed, 24 insertions(+), 26 deletions(-)

diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index 16ed3f7..536c85f 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -474,17 +474,18 @@ const char *arch_vma_name(struct vm_area_struct *vma)
 		 "[sigpage]" : NULL;
 }
 
+static struct page *signal_page;
 extern struct page *get_signal_page(void);
 
 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 {
 	struct mm_struct *mm = current->mm;
-	struct page *page;
 	unsigned long addr;
 	int ret;
 
-	page = get_signal_page();
-	if (!page)
+	if (!signal_page)
+		signal_page = get_signal_page();
+	if (!signal_page)
 		return -ENOMEM;
 
 	down_write(&mm->mmap_sem);
@@ -496,7 +497,7 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
 
 	ret = install_special_mapping(mm, addr, PAGE_SIZE,
 		VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
-		&page);
+		&signal_page);
 
 	if (ret == 0)
 		mm->context.sigpage = addr;
diff --git a/arch/arm/kernel/signal.c b/arch/arm/kernel/signal.c
index 0f17e06..39e7105 100644
--- a/arch/arm/kernel/signal.c
+++ b/arch/arm/kernel/signal.c
@@ -614,35 +614,32 @@ do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall)
 	return 0;
 }
 
-static struct page *signal_page;
-
 struct page *get_signal_page(void)
 {
-	if (!signal_page) {
-		unsigned long ptr;
-		unsigned offset;
-		void *addr;
+	unsigned long ptr;
+	unsigned offset;
+	struct page *page;
+	void *addr;
 
-		signal_page = alloc_pages(GFP_KERNEL, 0);
+	page = alloc_pages(GFP_KERNEL, 0);
 
-		if (!signal_page)
-			return NULL;
+	if (!page)
+		return NULL;
 
-		addr = page_address(signal_page);
+	addr = page_address(page);
 
-		/* Give the signal return code some randomness */
-		offset = 0x200 + (get_random_int() & 0x7fc);
-		signal_return_offset = offset;
+	/* Give the signal return code some randomness */
+	offset = 0x200 + (get_random_int() & 0x7fc);
+	signal_return_offset = offset;
 
-		/*
-		 * Copy signal return handlers into the vector page, and
-		 * set sigreturn to be a pointer to these.
-		 */
-		memcpy(addr + offset, sigreturn_codes, sizeof(sigreturn_codes));
+	/*
+	 * Copy signal return handlers into the vector page, and
+	 * set sigreturn to be a pointer to these.
+	 */
+	memcpy(addr + offset, sigreturn_codes, sizeof(sigreturn_codes));
 
-		ptr = (unsigned long)addr + offset;
-		flush_icache_range(ptr, ptr + sizeof(sigreturn_codes));
-	}
+	ptr = (unsigned long)addr + offset;
+	flush_icache_range(ptr, ptr + sizeof(sigreturn_codes));
 
-	return signal_page;
+	return page;
 }

Build breakage due to latest ARM fixes

[Olof Johansson]

On Fri, Aug 2, 2013 at 5:48 PM, Russell King - ARM Linux
<linux@arm.linux.org.uk> wrote:

> Okay, this should fix it - *untested* though because of the fscking time
> it is here again.  The problem is that install_special_mapping() assumes
> that the pointer to the pages will be persistent, and it wasn't.  I found
> that during testing and thought I'd merged the patches in, but I seem to
> have totally destroyed the original fixes for this.

Ran it through my autobuilder/booter here, didn't fall over like without it.

Tested-by: Olof Johansson <olof@lixom.net>


-Olof

Build breakage due to latest ARM fixes

[Russell King - ARM Linux]

On Fri, Aug 02, 2013 at 05:24:21PM -0700, Olof Johansson wrote:
> Maybe it's better to move this feature work to -next and iron out the
> kinks there? :(

And to correct that statement still further, it is *NOT* feature work.

Build breakage due to latest ARM fixes

[Russell King - ARM Linux]

On Sat, Aug 03, 2013 at 01:07:31AM +0100, Russell King - ARM Linux wrote:
> I'll look into that.  Obviously, I never build nommu because it isn't
> part of the build system and the nommu platform I do have - OKI67001 -
> doesn't have mainline kernel support.  (And if it did, it would not be
> DT, so I doubt it's submittable.)

Okay, what I'm going to do is push the OKI67001 stuff into mainline
irrespective of DT or not, so that I can then add noMMU build _and_
boot tests to my build system, which should ensure that problems
like that get detected before they're pushed upstream.

If people want me to care about noMMU, that's what has to happen
because I have no other noMMU platform - if not, people can put up with
noMMU breaking from time to time.

Build breakage due to latest ARM fixes

[Olof Johansson]

On Sun, Aug 4, 2013 at 5:53 AM, Russell King - ARM Linux
<linux@arm.linux.org.uk> wrote:
> On Sat, Aug 03, 2013 at 01:07:31AM +0100, Russell King - ARM Linux wrote:
>> I'll look into that.  Obviously, I never build nommu because it isn't
>> part of the build system and the nommu platform I do have - OKI67001 -
>> doesn't have mainline kernel support.  (And if it did, it would not be
>> DT, so I doubt it's submittable.)
>
> Okay, what I'm going to do is push the OKI67001 stuff into mainline
> irrespective of DT or not, so that I can then add noMMU build _and_
> boot tests to my build system, which should ensure that problems
> like that get detected before they're pushed upstream.

That seems like a step backwards. How have !MMU changes been handled
until now? Someone external has been relied on for testing?

> If people want me to care about noMMU, that's what has to happen
> because I have no other noMMU platform - if not, people can put up with
> noMMU breaking from time to time.

It seems that qemu has a couple of the stellaris platforms supported,
but as usual I suspect they can't be relied on to actually work.


-Olof

Build breakage due to latest ARM fixes

[Russell King - ARM Linux]

On Sun, Aug 04, 2013 at 11:20:21AM -0700, Olof Johansson wrote:
> On Sun, Aug 4, 2013 at 5:53 AM, Russell King - ARM Linux
> <linux@arm.linux.org.uk> wrote:
> > On Sat, Aug 03, 2013 at 01:07:31AM +0100, Russell King - ARM Linux wrote:
> >> I'll look into that.  Obviously, I never build nommu because it isn't
> >> part of the build system and the nommu platform I do have - OKI67001 -
> >> doesn't have mainline kernel support.  (And if it did, it would not be
> >> DT, so I doubt it's submittable.)
> >
> > Okay, what I'm going to do is push the OKI67001 stuff into mainline
> > irrespective of DT or not, so that I can then add noMMU build _and_
> > boot tests to my build system, which should ensure that problems
> > like that get detected before they're pushed upstream.
> 
> That seems like a step backwards. How have !MMU changes been handled
> until now? Someone external has been relied on for testing?

No, they've had no testing as far as I'm aware.  noMMU never got to the
stage when it was merged that it had any platforms before Hiyok went
silent.

The only real testing I'm aware of is when I recreated the OKI67001
support a while back and got my board to boot.

As for qemu, software emulations while nice and convenient don't
accurately reflect real hardware.

Build breakage due to latest ARM fixes

[Olof Johansson]

On Sun, Aug 4, 2013 at 11:37 AM, Russell King - ARM Linux
<linux@arm.linux.org.uk> wrote:
> On Sun, Aug 04, 2013 at 11:20:21AM -0700, Olof Johansson wrote:
>> On Sun, Aug 4, 2013 at 5:53 AM, Russell King - ARM Linux
>> <linux@arm.linux.org.uk> wrote:
>> > On Sat, Aug 03, 2013 at 01:07:31AM +0100, Russell King - ARM Linux wrote:
>> >> I'll look into that.  Obviously, I never build nommu because it isn't
>> >> part of the build system and the nommu platform I do have - OKI67001 -
>> >> doesn't have mainline kernel support.  (And if it did, it would not be
>> >> DT, so I doubt it's submittable.)
>> >
>> > Okay, what I'm going to do is push the OKI67001 stuff into mainline
>> > irrespective of DT or not, so that I can then add noMMU build _and_
>> > boot tests to my build system, which should ensure that problems
>> > like that get detected before they're pushed upstream.
>>
>> That seems like a step backwards. How have !MMU changes been handled
>> until now? Someone external has been relied on for testing?
>
> No, they've had no testing as far as I'm aware.  noMMU never got to the
> stage when it was merged that it had any platforms before Hiyok went
> silent.
>
> The only real testing I'm aware of is when I recreated the OKI67001
> support a while back and got my board to boot.

Uwe has been busy pushing various patches for M3/M4 support, I don't
know how far it is from having some real hardware usable though. Uwe?

> As for qemu, software emulations while nice and convenient don't
> accurately reflect real hardware.

Oh, agreed, it doesn't beat hardware-based testing but in the absence
of hardware it's better than nothing.


-Olof

Build breakage due to latest ARM fixes

[Russell King - ARM Linux]

On Sun, Aug 04, 2013 at 11:47:04AM -0700, Olof Johansson wrote:
> On Sun, Aug 4, 2013 at 11:37 AM, Russell King - ARM Linux
> <linux@arm.linux.org.uk> wrote:
> > On Sun, Aug 04, 2013 at 11:20:21AM -0700, Olof Johansson wrote:
> >> On Sun, Aug 4, 2013 at 5:53 AM, Russell King - ARM Linux
> >> <linux@arm.linux.org.uk> wrote:
> >> > On Sat, Aug 03, 2013 at 01:07:31AM +0100, Russell King - ARM Linux wrote:
> >> >> I'll look into that.  Obviously, I never build nommu because it isn't
> >> >> part of the build system and the nommu platform I do have - OKI67001 -
> >> >> doesn't have mainline kernel support.  (And if it did, it would not be
> >> >> DT, so I doubt it's submittable.)
> >> >
> >> > Okay, what I'm going to do is push the OKI67001 stuff into mainline
> >> > irrespective of DT or not, so that I can then add noMMU build _and_
> >> > boot tests to my build system, which should ensure that problems
> >> > like that get detected before they're pushed upstream.
> >>
> >> That seems like a step backwards. How have !MMU changes been handled
> >> until now? Someone external has been relied on for testing?
> >
> > No, they've had no testing as far as I'm aware.  noMMU never got to the
> > stage when it was merged that it had any platforms before Hiyok went
> > silent.
> >
> > The only real testing I'm aware of is when I recreated the OKI67001
> > support a while back and got my board to boot.
> 
> Uwe has been busy pushing various patches for M3/M4 support, I don't
> know how far it is from having some real hardware usable though. Uwe?
> 
> > As for qemu, software emulations while nice and convenient don't
> > accurately reflect real hardware.
> 
> Oh, agreed, it doesn't beat hardware-based testing but in the absence
> of hardware it's better than nothing.

Let's summarise this then:

"Hardware based testing is better than software testing".
"I have OKI 67001 hardware".
"I have OKI 67001 patches".
"We're going to not merge the patches but you can use software testing
 instead".

That's utterly idiotic if you ask me - and as long as you hold that view
I'm damned well totally uninterested in noMMU.

Thanks but no thanks.  If I break noMMU builds in future, so be it - I
don't give a damn about them.

Build breakage due to latest ARM fixes

[Olof Johansson]

On Sun, Aug 4, 2013 at 12:01 PM, Russell King - ARM Linux
<linux@arm.linux.org.uk> wrote:
> On Sun, Aug 04, 2013 at 11:47:04AM -0700, Olof Johansson wrote:
>> On Sun, Aug 4, 2013 at 11:37 AM, Russell King - ARM Linux
>> <linux@arm.linux.org.uk> wrote:
>> > On Sun, Aug 04, 2013 at 11:20:21AM -0700, Olof Johansson wrote:
>> >> On Sun, Aug 4, 2013 at 5:53 AM, Russell King - ARM Linux
>> >> <linux@arm.linux.org.uk> wrote:
>> >> > On Sat, Aug 03, 2013 at 01:07:31AM +0100, Russell King - ARM Linux wrote:
>> >> >> I'll look into that.  Obviously, I never build nommu because it isn't
>> >> >> part of the build system and the nommu platform I do have - OKI67001 -
>> >> >> doesn't have mainline kernel support.  (And if it did, it would not be
>> >> >> DT, so I doubt it's submittable.)
>> >> >
>> >> > Okay, what I'm going to do is push the OKI67001 stuff into mainline
>> >> > irrespective of DT or not, so that I can then add noMMU build _and_
>> >> > boot tests to my build system, which should ensure that problems
>> >> > like that get detected before they're pushed upstream.
>> >>
>> >> That seems like a step backwards. How have !MMU changes been handled
>> >> until now? Someone external has been relied on for testing?
>> >
>> > No, they've had no testing as far as I'm aware.  noMMU never got to the
>> > stage when it was merged that it had any platforms before Hiyok went
>> > silent.
>> >
>> > The only real testing I'm aware of is when I recreated the OKI67001
>> > support a while back and got my board to boot.
>>
>> Uwe has been busy pushing various patches for M3/M4 support, I don't
>> know how far it is from having some real hardware usable though. Uwe?
>>
>> > As for qemu, software emulations while nice and convenient don't
>> > accurately reflect real hardware.
>>
>> Oh, agreed, it doesn't beat hardware-based testing but in the absence
>> of hardware it's better than nothing.
>
> Let's summarise this then:
>
> "Hardware based testing is better than software testing".
> "I have OKI 67001 hardware".
> "I have OKI 67001 patches".
> "We're going to not merge the patches but you can use software testing
>  instead".
>
> That's utterly idiotic if you ask me - and as long as you hold that view
> I'm damned well totally uninterested in noMMU.
>
> Thanks but no thanks.  If I break noMMU builds in future, so be it - I
> don't give a damn about them.

All I was really trying to say is that it's unfortunate to add a
non-DT enabled platform now that we've done so much work towards the
goal of getting rid of them.

Software vs hardware testing was mostly tangential and unrelated.


-Olof

Build breakage due to latest ARM fixes

[Uwe Kleine-König]

Hello,

On Sun, Aug 04, 2013 at 11:47:04AM -0700, Olof Johansson wrote:
> On Sun, Aug 4, 2013 at 11:37 AM, Russell King - ARM Linux
> > The only real testing I'm aware of is when I recreated the OKI67001
> > support a while back and got my board to boot.
> 
> Uwe has been busy pushing various patches for M3/M4 support, I don't
> know how far it is from having some real hardware usable though. Uwe?
On my efm32 devboard I have 3.11-rc running. The missing bits are
available in my efm32 branch at

	git://git.pengutronix.de/git/ukl/linux.git efm32
	http://git.pengutronix.de/?p=ukl/linux.git;a=shortlog;h=refs/heads/efm32

. It's not yet in a form ready for mainline but there isn't much
missing. There is one problem I didn't debug yet (/proc/devicetree
doesn't appear although I have the respective Kconfig symbol on); other
than that I didn't notice any no-mmu problems. Also Jonathan Austin does
some no-MMU work.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-K?nig            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |

Build breakage due to latest ARM fixes

[Jonathan Austin]

On 04/08/13 20:36, Uwe Kleine-K?nig wrote:
> Hello,
>
> On Sun, Aug 04, 2013 at 11:47:04AM -0700, Olof Johansson wrote:
>> On Sun, Aug 4, 2013 at 11:37 AM, Russell King - ARM Linux
>>> The only real testing I'm aware of is when I recreated the OKI67001
>>> support a while back and got my board to boot.
>>
>> Uwe has been busy pushing various patches for M3/M4 support, I don't
>> know how far it is from having some real hardware usable though. Uwe?
> On my efm32 devboard I have 3.11-rc running. The missing bits are
> available in my efm32 branch at
>
> 	git://git.pengutronix.de/git/ukl/linux.git efm32
> 	http://git.pengutronix.de/?p=ukl/linux.git;a=shortlog;h=refs/heads/efm32
>
> . It's not yet in a form ready for mainline but there isn't much
> missing. There is one problem I didn't debug yet (/proc/devicetree
> doesn't appear although I have the respective Kconfig symbol on); other
> than that I didn't notice any no-mmu problems. Also Jonathan Austin does
> some no-MMU work.
>

We use !MMU internally here for R-class stuff (see the recently added 
Cortex-R7 support).

Our CONFIG_MMU=n testing all happens on Versatile Express, and it should 
even be possible to run !MMU on TC2 (IE with an A-class processor). 
Perhaps if we feel that it isn't easy enough for people to test these 
configurations I can submit a vexpress_nommu defconfig or similar? It 
might need some additional patches to complete the story, but if it 
makes it easier to catch these breakages early then maybe it is worth it?

Jonny