diff mbox series

[U-Boot,v4,1/2] dlmalloc: fix malloc range at end of ram

Message ID 20190401200150.1630-2-simon.k.r.goldschmidt@gmail.com
State Superseded
Delegated to: Tom Rini
Headers show
Series spl: full-featured heap cleanups | expand

Commit Message

Simon Goldschmidt April 1, 2019, 8:01 p.m. UTC
If the malloc range passed to mem_malloc_init() is at the end of address
range and 'start + size' overflows to 0, following allocations fail as
mem_malloc_end is zero (which looks like uninitialized).

Fix this by subtracting 1 of 'start + size' overflows to zero.

Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
---

Changes in v4: None
Changes in v3: None

 common/dlmalloc.c | 4 ++++
 1 file changed, 4 insertions(+)

Comments

Simon Glass April 24, 2019, 3:54 a.m. UTC | #1
On Mon, 1 Apr 2019 at 14:01, Simon Goldschmidt
<simon.k.r.goldschmidt@gmail.com> wrote:
>
> If the malloc range passed to mem_malloc_init() is at the end of address
> range and 'start + size' overflows to 0, following allocations fail as
> mem_malloc_end is zero (which looks like uninitialized).
>
> Fix this by subtracting 1 of 'start + size' overflows to zero.
>
> Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
> ---
>
> Changes in v4: None
> Changes in v3: None
>
>  common/dlmalloc.c | 4 ++++
>  1 file changed, 4 insertions(+)

Reviewed-by: Simon Glass <sjg@chromium.org>
Tom Rini April 24, 2019, 11:26 a.m. UTC | #2
On Tue, Apr 23, 2019 at 09:54:10PM -0600, Simon Glass wrote:
> On Mon, 1 Apr 2019 at 14:01, Simon Goldschmidt
> <simon.k.r.goldschmidt@gmail.com> wrote:
> >
> > If the malloc range passed to mem_malloc_init() is at the end of address
> > range and 'start + size' overflows to 0, following allocations fail as
> > mem_malloc_end is zero (which looks like uninitialized).
> >
> > Fix this by subtracting 1 of 'start + size' overflows to zero.
> >
> > Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
> > ---
> >
> > Changes in v4: None
> > Changes in v3: None
> >
> >  common/dlmalloc.c | 4 ++++
> >  1 file changed, 4 insertions(+)
> 
> Reviewed-by: Simon Glass <sjg@chromium.org>

So, the problem with this patch is that it increases the generic malloc
code size ever so slightly and blows up smartweb :(
Simon Goldschmidt April 24, 2019, 11:49 a.m. UTC | #3
On Wed, Apr 24, 2019 at 1:27 PM Tom Rini <trini@konsulko.com> wrote:
>
> On Tue, Apr 23, 2019 at 09:54:10PM -0600, Simon Glass wrote:
> > On Mon, 1 Apr 2019 at 14:01, Simon Goldschmidt
> > <simon.k.r.goldschmidt@gmail.com> wrote:
> > >
> > > If the malloc range passed to mem_malloc_init() is at the end of address
> > > range and 'start + size' overflows to 0, following allocations fail as
> > > mem_malloc_end is zero (which looks like uninitialized).
> > >
> > > Fix this by subtracting 1 of 'start + size' overflows to zero.
> > >
> > > Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
> > > ---
> > >
> > > Changes in v4: None
> > > Changes in v3: None
> > >
> > >  common/dlmalloc.c | 4 ++++
> > >  1 file changed, 4 insertions(+)
> >
> > Reviewed-by: Simon Glass <sjg@chromium.org>
>
> So, the problem with this patch is that it increases the generic malloc
> code size ever so slightly and blows up smartweb :(

Ehrm, ok, so how do we proceed?

Regards,
Simon
Tom Rini April 24, 2019, 11:52 a.m. UTC | #4
On Wed, Apr 24, 2019 at 01:49:52PM +0200, Simon Goldschmidt wrote:
> On Wed, Apr 24, 2019 at 1:27 PM Tom Rini <trini@konsulko.com> wrote:
> >
> > On Tue, Apr 23, 2019 at 09:54:10PM -0600, Simon Glass wrote:
> > > On Mon, 1 Apr 2019 at 14:01, Simon Goldschmidt
> > > <simon.k.r.goldschmidt@gmail.com> wrote:
> > > >
> > > > If the malloc range passed to mem_malloc_init() is at the end of address
> > > > range and 'start + size' overflows to 0, following allocations fail as
> > > > mem_malloc_end is zero (which looks like uninitialized).
> > > >
> > > > Fix this by subtracting 1 of 'start + size' overflows to zero.
> > > >
> > > > Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
> > > > ---
> > > >
> > > > Changes in v4: None
> > > > Changes in v3: None
> > > >
> > > >  common/dlmalloc.c | 4 ++++
> > > >  1 file changed, 4 insertions(+)
> > >
> > > Reviewed-by: Simon Glass <sjg@chromium.org>
> >
> > So, the problem with this patch is that it increases the generic malloc
> > code size ever so slightly and blows up smartweb :(
> 
> Ehrm, ok, so how do we proceed?

A good question.  Take a look at spl/u-boot-spl.map on smartweb and see
if, of the malloc functions it doesn't discard there's something that
maybe could be optimized somewhere?
Simon Glass April 24, 2019, 11:58 p.m. UTC | #5
Hi,

On Wed, 24 Apr 2019 at 05:53, Tom Rini <trini@konsulko.com> wrote:
>
> On Wed, Apr 24, 2019 at 01:49:52PM +0200, Simon Goldschmidt wrote:
> > On Wed, Apr 24, 2019 at 1:27 PM Tom Rini <trini@konsulko.com> wrote:
> > >
> > > On Tue, Apr 23, 2019 at 09:54:10PM -0600, Simon Glass wrote:
> > > > On Mon, 1 Apr 2019 at 14:01, Simon Goldschmidt
> > > > <simon.k.r.goldschmidt@gmail.com> wrote:
> > > > >
> > > > > If the malloc range passed to mem_malloc_init() is at the end of address
> > > > > range and 'start + size' overflows to 0, following allocations fail as
> > > > > mem_malloc_end is zero (which looks like uninitialized).
> > > > >
> > > > > Fix this by subtracting 1 of 'start + size' overflows to zero.
> > > > >
> > > > > Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
> > > > > ---
> > > > >
> > > > > Changes in v4: None
> > > > > Changes in v3: None
> > > > >
> > > > >  common/dlmalloc.c | 4 ++++
> > > > >  1 file changed, 4 insertions(+)
> > > >
> > > > Reviewed-by: Simon Glass <sjg@chromium.org>
> > >
> > > So, the problem with this patch is that it increases the generic malloc
> > > code size ever so slightly and blows up smartweb :(
> >
> > Ehrm, ok, so how do we proceed?
>
> A good question.  Take a look at spl/u-boot-spl.map on smartweb and see
> if, of the malloc functions it doesn't discard there's something that
> maybe could be optimized somewhere?

I wonder if we should have a Kconfig option like SPL_CHECKS which
enables these sorts of minor checks, which may only fix one board at
the cost of code size?

Then it could be enabled by default, but disabled on this board?

Regards,
Simon
Simon Goldschmidt April 25, 2019, 7:32 a.m. UTC | #6
On Thu, Apr 25, 2019 at 1:59 AM Simon Glass <sjg@chromium.org> wrote:
>
> Hi,
>
> On Wed, 24 Apr 2019 at 05:53, Tom Rini <trini@konsulko.com> wrote:
> >
> > On Wed, Apr 24, 2019 at 01:49:52PM +0200, Simon Goldschmidt wrote:
> > > On Wed, Apr 24, 2019 at 1:27 PM Tom Rini <trini@konsulko.com> wrote:
> > > >
> > > > On Tue, Apr 23, 2019 at 09:54:10PM -0600, Simon Glass wrote:
> > > > > On Mon, 1 Apr 2019 at 14:01, Simon Goldschmidt
> > > > > <simon.k.r.goldschmidt@gmail.com> wrote:
> > > > > >
> > > > > > If the malloc range passed to mem_malloc_init() is at the end of address
> > > > > > range and 'start + size' overflows to 0, following allocations fail as
> > > > > > mem_malloc_end is zero (which looks like uninitialized).
> > > > > >
> > > > > > Fix this by subtracting 1 of 'start + size' overflows to zero.
> > > > > >
> > > > > > Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
> > > > > > ---
> > > > > >
> > > > > > Changes in v4: None
> > > > > > Changes in v3: None
> > > > > >
> > > > > >  common/dlmalloc.c | 4 ++++
> > > > > >  1 file changed, 4 insertions(+)
> > > > >
> > > > > Reviewed-by: Simon Glass <sjg@chromium.org>
> > > >
> > > > So, the problem with this patch is that it increases the generic malloc
> > > > code size ever so slightly and blows up smartweb :(
> > >
> > > Ehrm, ok, so how do we proceed?
> >
> > A good question.  Take a look at spl/u-boot-spl.map on smartweb and see
> > if, of the malloc functions it doesn't discard there's something that
> > maybe could be optimized somewhere?
>
> I wonder if we should have a Kconfig option like SPL_CHECKS which
> enables these sorts of minor checks, which may only fix one board at
> the cost of code size?
>
> Then it could be enabled by default, but disabled on this board?

For a bigger change, this might be an idea, but for a change that I can cut
down to 16 or even 8 bytes code size increasement, I don't think having a
new option would be good.

Anyway, I just tried at work and I don't get the overflow. Tom, which gcc
are you using to get the size error? It works for me on Debian 9 but doesn't
work with Ubuntu (both times, default cross compiler toolchain installed).

Regards,
Simon
Tom Rini April 25, 2019, 10:50 a.m. UTC | #7
On Thu, Apr 25, 2019 at 09:32:22AM +0200, Simon Goldschmidt wrote:
> On Thu, Apr 25, 2019 at 1:59 AM Simon Glass <sjg@chromium.org> wrote:
> >
> > Hi,
> >
> > On Wed, 24 Apr 2019 at 05:53, Tom Rini <trini@konsulko.com> wrote:
> > >
> > > On Wed, Apr 24, 2019 at 01:49:52PM +0200, Simon Goldschmidt wrote:
> > > > On Wed, Apr 24, 2019 at 1:27 PM Tom Rini <trini@konsulko.com> wrote:
> > > > >
> > > > > On Tue, Apr 23, 2019 at 09:54:10PM -0600, Simon Glass wrote:
> > > > > > On Mon, 1 Apr 2019 at 14:01, Simon Goldschmidt
> > > > > > <simon.k.r.goldschmidt@gmail.com> wrote:
> > > > > > >
> > > > > > > If the malloc range passed to mem_malloc_init() is at the end of address
> > > > > > > range and 'start + size' overflows to 0, following allocations fail as
> > > > > > > mem_malloc_end is zero (which looks like uninitialized).
> > > > > > >
> > > > > > > Fix this by subtracting 1 of 'start + size' overflows to zero.
> > > > > > >
> > > > > > > Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
> > > > > > > ---
> > > > > > >
> > > > > > > Changes in v4: None
> > > > > > > Changes in v3: None
> > > > > > >
> > > > > > >  common/dlmalloc.c | 4 ++++
> > > > > > >  1 file changed, 4 insertions(+)
> > > > > >
> > > > > > Reviewed-by: Simon Glass <sjg@chromium.org>
> > > > >
> > > > > So, the problem with this patch is that it increases the generic malloc
> > > > > code size ever so slightly and blows up smartweb :(
> > > >
> > > > Ehrm, ok, so how do we proceed?
> > >
> > > A good question.  Take a look at spl/u-boot-spl.map on smartweb and see
> > > if, of the malloc functions it doesn't discard there's something that
> > > maybe could be optimized somewhere?
> >
> > I wonder if we should have a Kconfig option like SPL_CHECKS which
> > enables these sorts of minor checks, which may only fix one board at
> > the cost of code size?
> >
> > Then it could be enabled by default, but disabled on this board?
> 
> For a bigger change, this might be an idea, but for a change that I can cut
> down to 16 or even 8 bytes code size increasement, I don't think having a
> new option would be good.
> 
> Anyway, I just tried at work and I don't get the overflow. Tom, which gcc
> are you using to get the size error? It works for me on Debian 9 but doesn't
> work with Ubuntu (both times, default cross compiler toolchain installed).

I'm using the gcc-7.3 from kernel.org that we use in travis/etc.
Simon Goldschmidt April 25, 2019, 7:24 p.m. UTC | #8
Am 25.04.2019 um 12:50 schrieb Tom Rini:
> On Thu, Apr 25, 2019 at 09:32:22AM +0200, Simon Goldschmidt wrote:
>> On Thu, Apr 25, 2019 at 1:59 AM Simon Glass <sjg@chromium.org> wrote:
>>>
>>> Hi,
>>>
>>> On Wed, 24 Apr 2019 at 05:53, Tom Rini <trini@konsulko.com> wrote:
>>>>
>>>> On Wed, Apr 24, 2019 at 01:49:52PM +0200, Simon Goldschmidt wrote:
>>>>> On Wed, Apr 24, 2019 at 1:27 PM Tom Rini <trini@konsulko.com> wrote:
>>>>>>
>>>>>> On Tue, Apr 23, 2019 at 09:54:10PM -0600, Simon Glass wrote:
>>>>>>> On Mon, 1 Apr 2019 at 14:01, Simon Goldschmidt
>>>>>>> <simon.k.r.goldschmidt@gmail.com> wrote:
>>>>>>>>
>>>>>>>> If the malloc range passed to mem_malloc_init() is at the end of address
>>>>>>>> range and 'start + size' overflows to 0, following allocations fail as
>>>>>>>> mem_malloc_end is zero (which looks like uninitialized).
>>>>>>>>
>>>>>>>> Fix this by subtracting 1 of 'start + size' overflows to zero.
>>>>>>>>
>>>>>>>> Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
>>>>>>>> ---
>>>>>>>>
>>>>>>>> Changes in v4: None
>>>>>>>> Changes in v3: None
>>>>>>>>
>>>>>>>>   common/dlmalloc.c | 4 ++++
>>>>>>>>   1 file changed, 4 insertions(+)
>>>>>>>
>>>>>>> Reviewed-by: Simon Glass <sjg@chromium.org>
>>>>>>
>>>>>> So, the problem with this patch is that it increases the generic malloc
>>>>>> code size ever so slightly and blows up smartweb :(
>>>>>
>>>>> Ehrm, ok, so how do we proceed?
>>>>
>>>> A good question.  Take a look at spl/u-boot-spl.map on smartweb and see
>>>> if, of the malloc functions it doesn't discard there's something that
>>>> maybe could be optimized somewhere?
>>>
>>> I wonder if we should have a Kconfig option like SPL_CHECKS which
>>> enables these sorts of minor checks, which may only fix one board at
>>> the cost of code size?
>>>
>>> Then it could be enabled by default, but disabled on this board?
>>
>> For a bigger change, this might be an idea, but for a change that I can cut
>> down to 16 or even 8 bytes code size increasement, I don't think having a
>> new option would be good.
>>
>> Anyway, I just tried at work and I don't get the overflow. Tom, which gcc
>> are you using to get the size error? It works for me on Debian 9 but doesn't
>> work with Ubuntu (both times, default cross compiler toolchain installed).
> 
> I'm using the gcc-7.3 from kernel.org that we use in travis/etc.

Ok, so I have gcc-7.3 on my Ubuntu machine as well. I don't know why 6.3 
seems to produce smaller binaries (I thought they were getting smaller 
with new versions, not larger).

However, I've stripped down that patch to +8 Bytes only and sent v5.

Regards,
Simon
Heiko Schocher April 29, 2019, 1:06 p.m. UTC | #9
Hello Simon,

Am 25.04.2019 um 21:24 schrieb Simon Goldschmidt:
> Am 25.04.2019 um 12:50 schrieb Tom Rini:
>> On Thu, Apr 25, 2019 at 09:32:22AM +0200, Simon Goldschmidt wrote:
>>> On Thu, Apr 25, 2019 at 1:59 AM Simon Glass <sjg@chromium.org> wrote:
>>>>
>>>> Hi,
>>>>
>>>> On Wed, 24 Apr 2019 at 05:53, Tom Rini <trini@konsulko.com> wrote:
>>>>>
>>>>> On Wed, Apr 24, 2019 at 01:49:52PM +0200, Simon Goldschmidt wrote:
>>>>>> On Wed, Apr 24, 2019 at 1:27 PM Tom Rini <trini@konsulko.com> wrote:
>>>>>>>
>>>>>>> On Tue, Apr 23, 2019 at 09:54:10PM -0600, Simon Glass wrote:
>>>>>>>> On Mon, 1 Apr 2019 at 14:01, Simon Goldschmidt
>>>>>>>> <simon.k.r.goldschmidt@gmail.com> wrote:
>>>>>>>>>
>>>>>>>>> If the malloc range passed to mem_malloc_init() is at the end of address
>>>>>>>>> range and 'start + size' overflows to 0, following allocations fail as
>>>>>>>>> mem_malloc_end is zero (which looks like uninitialized).
>>>>>>>>>
>>>>>>>>> Fix this by subtracting 1 of 'start + size' overflows to zero.
>>>>>>>>>
>>>>>>>>> Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
>>>>>>>>> ---
>>>>>>>>>
>>>>>>>>> Changes in v4: None
>>>>>>>>> Changes in v3: None
>>>>>>>>>
>>>>>>>>>   common/dlmalloc.c | 4 ++++
>>>>>>>>>   1 file changed, 4 insertions(+)
>>>>>>>>
>>>>>>>> Reviewed-by: Simon Glass <sjg@chromium.org>
>>>>>>>
>>>>>>> So, the problem with this patch is that it increases the generic malloc
>>>>>>> code size ever so slightly and blows up smartweb :(
>>>>>>
>>>>>> Ehrm, ok, so how do we proceed?
>>>>>
>>>>> A good question.  Take a look at spl/u-boot-spl.map on smartweb and see
>>>>> if, of the malloc functions it doesn't discard there's something that
>>>>> maybe could be optimized somewhere?
>>>>
>>>> I wonder if we should have a Kconfig option like SPL_CHECKS which
>>>> enables these sorts of minor checks, which may only fix one board at
>>>> the cost of code size?
>>>>
>>>> Then it could be enabled by default, but disabled on this board?
>>>
>>> For a bigger change, this might be an idea, but for a change that I can cut
>>> down to 16 or even 8 bytes code size increasement, I don't think having a
>>> new option would be good.
>>>
>>> Anyway, I just tried at work and I don't get the overflow. Tom, which gcc
>>> are you using to get the size error? It works for me on Debian 9 but doesn't
>>> work with Ubuntu (both times, default cross compiler toolchain installed).
>>
>> I'm using the gcc-7.3 from kernel.org that we use in travis/etc.
> 
> Ok, so I have gcc-7.3 on my Ubuntu machine as well. I don't know why 6.3 seems to produce smaller 
> binaries (I thought they were getting smaller with new versions, not larger).
> 
> However, I've stripped down that patch to +8 Bytes only and sent v5.

Thanks!

Sorry for digging so late in, but I was on vacation...

Hmm.. the smartweb board has only 4k sram for SPL, and I have no chance
to convert it to DM to get rid of some compiler warnings ...

I am unsure what to do now with this hardware ...

bye,
Heiko
Simon Goldschmidt April 29, 2019, 1:16 p.m. UTC | #10
Hello Heiko,

On Mon, Apr 29, 2019 at 3:06 PM Heiko Schocher <hs@denx.de> wrote:
>
> Hello Simon,
>
> Am 25.04.2019 um 21:24 schrieb Simon Goldschmidt:
> > Am 25.04.2019 um 12:50 schrieb Tom Rini:
> >> On Thu, Apr 25, 2019 at 09:32:22AM +0200, Simon Goldschmidt wrote:
> >>> On Thu, Apr 25, 2019 at 1:59 AM Simon Glass <sjg@chromium.org> wrote:
> >>>>
> >>>> Hi,
> >>>>
> >>>> On Wed, 24 Apr 2019 at 05:53, Tom Rini <trini@konsulko.com> wrote:
> >>>>>
> >>>>> On Wed, Apr 24, 2019 at 01:49:52PM +0200, Simon Goldschmidt wrote:
> >>>>>> On Wed, Apr 24, 2019 at 1:27 PM Tom Rini <trini@konsulko.com> wrote:
> >>>>>>>
> >>>>>>> On Tue, Apr 23, 2019 at 09:54:10PM -0600, Simon Glass wrote:
> >>>>>>>> On Mon, 1 Apr 2019 at 14:01, Simon Goldschmidt
> >>>>>>>> <simon.k.r.goldschmidt@gmail.com> wrote:
> >>>>>>>>>
> >>>>>>>>> If the malloc range passed to mem_malloc_init() is at the end of address
> >>>>>>>>> range and 'start + size' overflows to 0, following allocations fail as
> >>>>>>>>> mem_malloc_end is zero (which looks like uninitialized).
> >>>>>>>>>
> >>>>>>>>> Fix this by subtracting 1 of 'start + size' overflows to zero.
> >>>>>>>>>
> >>>>>>>>> Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
> >>>>>>>>> ---
> >>>>>>>>>
> >>>>>>>>> Changes in v4: None
> >>>>>>>>> Changes in v3: None
> >>>>>>>>>
> >>>>>>>>>   common/dlmalloc.c | 4 ++++
> >>>>>>>>>   1 file changed, 4 insertions(+)
> >>>>>>>>
> >>>>>>>> Reviewed-by: Simon Glass <sjg@chromium.org>
> >>>>>>>
> >>>>>>> So, the problem with this patch is that it increases the generic malloc
> >>>>>>> code size ever so slightly and blows up smartweb :(
> >>>>>>
> >>>>>> Ehrm, ok, so how do we proceed?
> >>>>>
> >>>>> A good question.  Take a look at spl/u-boot-spl.map on smartweb and see
> >>>>> if, of the malloc functions it doesn't discard there's something that
> >>>>> maybe could be optimized somewhere?
> >>>>
> >>>> I wonder if we should have a Kconfig option like SPL_CHECKS which
> >>>> enables these sorts of minor checks, which may only fix one board at
> >>>> the cost of code size?
> >>>>
> >>>> Then it could be enabled by default, but disabled on this board?
> >>>
> >>> For a bigger change, this might be an idea, but for a change that I can cut
> >>> down to 16 or even 8 bytes code size increasement, I don't think having a
> >>> new option would be good.
> >>>
> >>> Anyway, I just tried at work and I don't get the overflow. Tom, which gcc
> >>> are you using to get the size error? It works for me on Debian 9 but doesn't
> >>> work with Ubuntu (both times, default cross compiler toolchain installed).
> >>
> >> I'm using the gcc-7.3 from kernel.org that we use in travis/etc.
> >
> > Ok, so I have gcc-7.3 on my Ubuntu machine as well. I don't know why 6.3 seems to produce smaller
> > binaries (I thought they were getting smaller with new versions, not larger).
> >
> > However, I've stripped down that patch to +8 Bytes only and sent v5.
>
> Thanks!
>
> Sorry for digging so late in, but I was on vacation...
>
> Hmm.. the smartweb board has only 4k sram for SPL, and I have no chance
> to convert it to DM to get rid of some compiler warnings ...
>
> I am unsure what to do now with this hardware ...

And things even get worse: as I wrote in the other thread, after updating to
Ubuntu 19.04 as build system, I get gcc 8.3 as cross compiler and smartweb
fails to build with that compiler (as the SPL binary is exactly 4k now).

Regards,
Simon
Tom Rini April 29, 2019, 1:19 p.m. UTC | #11
On Mon, Apr 29, 2019 at 03:06:39PM +0200, Heiko Schocher wrote:
> Hello Simon,
> 
> Am 25.04.2019 um 21:24 schrieb Simon Goldschmidt:
> >Am 25.04.2019 um 12:50 schrieb Tom Rini:
> >>On Thu, Apr 25, 2019 at 09:32:22AM +0200, Simon Goldschmidt wrote:
> >>>On Thu, Apr 25, 2019 at 1:59 AM Simon Glass <sjg@chromium.org> wrote:
> >>>>
> >>>>Hi,
> >>>>
> >>>>On Wed, 24 Apr 2019 at 05:53, Tom Rini <trini@konsulko.com> wrote:
> >>>>>
> >>>>>On Wed, Apr 24, 2019 at 01:49:52PM +0200, Simon Goldschmidt wrote:
> >>>>>>On Wed, Apr 24, 2019 at 1:27 PM Tom Rini <trini@konsulko.com> wrote:
> >>>>>>>
> >>>>>>>On Tue, Apr 23, 2019 at 09:54:10PM -0600, Simon Glass wrote:
> >>>>>>>>On Mon, 1 Apr 2019 at 14:01, Simon Goldschmidt
> >>>>>>>><simon.k.r.goldschmidt@gmail.com> wrote:
> >>>>>>>>>
> >>>>>>>>>If the malloc range passed to mem_malloc_init() is at the end of address
> >>>>>>>>>range and 'start + size' overflows to 0, following allocations fail as
> >>>>>>>>>mem_malloc_end is zero (which looks like uninitialized).
> >>>>>>>>>
> >>>>>>>>>Fix this by subtracting 1 of 'start + size' overflows to zero.
> >>>>>>>>>
> >>>>>>>>>Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
> >>>>>>>>>---
> >>>>>>>>>
> >>>>>>>>>Changes in v4: None
> >>>>>>>>>Changes in v3: None
> >>>>>>>>>
> >>>>>>>>>  common/dlmalloc.c | 4 ++++
> >>>>>>>>>  1 file changed, 4 insertions(+)
> >>>>>>>>
> >>>>>>>>Reviewed-by: Simon Glass <sjg@chromium.org>
> >>>>>>>
> >>>>>>>So, the problem with this patch is that it increases the generic malloc
> >>>>>>>code size ever so slightly and blows up smartweb :(
> >>>>>>
> >>>>>>Ehrm, ok, so how do we proceed?
> >>>>>
> >>>>>A good question.  Take a look at spl/u-boot-spl.map on smartweb and see
> >>>>>if, of the malloc functions it doesn't discard there's something that
> >>>>>maybe could be optimized somewhere?
> >>>>
> >>>>I wonder if we should have a Kconfig option like SPL_CHECKS which
> >>>>enables these sorts of minor checks, which may only fix one board at
> >>>>the cost of code size?
> >>>>
> >>>>Then it could be enabled by default, but disabled on this board?
> >>>
> >>>For a bigger change, this might be an idea, but for a change that I can cut
> >>>down to 16 or even 8 bytes code size increasement, I don't think having a
> >>>new option would be good.
> >>>
> >>>Anyway, I just tried at work and I don't get the overflow. Tom, which gcc
> >>>are you using to get the size error? It works for me on Debian 9 but doesn't
> >>>work with Ubuntu (both times, default cross compiler toolchain installed).
> >>
> >>I'm using the gcc-7.3 from kernel.org that we use in travis/etc.
> >
> >Ok, so I have gcc-7.3 on my Ubuntu machine as well. I don't know why 6.3
> >seems to produce smaller binaries (I thought they were getting smaller
> >with new versions, not larger).
> >
> >However, I've stripped down that patch to +8 Bytes only and sent v5.
> 
> Thanks!
> 
> Sorry for digging so late in, but I was on vacation...
> 
> Hmm.. the smartweb board has only 4k sram for SPL, and I have no chance
> to convert it to DM to get rid of some compiler warnings ...
> 
> I am unsure what to do now with this hardware ...

Well, with regards to SPL + DM, this is one of the cases wherein we just
have-to allow for the SPL driver code at least to be a one-off.  If the
"whatever ROM loads of our code" stage can set things up enough such
that we can hand off to a full U-Boot, that's great.  If not, this is
then a case where TPL comes in to play, and that really is as one-off as
needed, to load a more general SPL and so forth.

But, I'm fine with saying smartweb keeps and maintains whatever SPL code
it needs to use.  It's just that in this case, it's not at all a DM
thing, it's a change in malloc.
Tom Rini April 29, 2019, 1:20 p.m. UTC | #12
On Mon, Apr 29, 2019 at 03:16:02PM +0200, Simon Goldschmidt wrote:
> Hello Heiko,
> 
> On Mon, Apr 29, 2019 at 3:06 PM Heiko Schocher <hs@denx.de> wrote:
> >
> > Hello Simon,
> >
> > Am 25.04.2019 um 21:24 schrieb Simon Goldschmidt:
> > > Am 25.04.2019 um 12:50 schrieb Tom Rini:
> > >> On Thu, Apr 25, 2019 at 09:32:22AM +0200, Simon Goldschmidt wrote:
> > >>> On Thu, Apr 25, 2019 at 1:59 AM Simon Glass <sjg@chromium.org> wrote:
> > >>>>
> > >>>> Hi,
> > >>>>
> > >>>> On Wed, 24 Apr 2019 at 05:53, Tom Rini <trini@konsulko.com> wrote:
> > >>>>>
> > >>>>> On Wed, Apr 24, 2019 at 01:49:52PM +0200, Simon Goldschmidt wrote:
> > >>>>>> On Wed, Apr 24, 2019 at 1:27 PM Tom Rini <trini@konsulko.com> wrote:
> > >>>>>>>
> > >>>>>>> On Tue, Apr 23, 2019 at 09:54:10PM -0600, Simon Glass wrote:
> > >>>>>>>> On Mon, 1 Apr 2019 at 14:01, Simon Goldschmidt
> > >>>>>>>> <simon.k.r.goldschmidt@gmail.com> wrote:
> > >>>>>>>>>
> > >>>>>>>>> If the malloc range passed to mem_malloc_init() is at the end of address
> > >>>>>>>>> range and 'start + size' overflows to 0, following allocations fail as
> > >>>>>>>>> mem_malloc_end is zero (which looks like uninitialized).
> > >>>>>>>>>
> > >>>>>>>>> Fix this by subtracting 1 of 'start + size' overflows to zero.
> > >>>>>>>>>
> > >>>>>>>>> Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
> > >>>>>>>>> ---
> > >>>>>>>>>
> > >>>>>>>>> Changes in v4: None
> > >>>>>>>>> Changes in v3: None
> > >>>>>>>>>
> > >>>>>>>>>   common/dlmalloc.c | 4 ++++
> > >>>>>>>>>   1 file changed, 4 insertions(+)
> > >>>>>>>>
> > >>>>>>>> Reviewed-by: Simon Glass <sjg@chromium.org>
> > >>>>>>>
> > >>>>>>> So, the problem with this patch is that it increases the generic malloc
> > >>>>>>> code size ever so slightly and blows up smartweb :(
> > >>>>>>
> > >>>>>> Ehrm, ok, so how do we proceed?
> > >>>>>
> > >>>>> A good question.  Take a look at spl/u-boot-spl.map on smartweb and see
> > >>>>> if, of the malloc functions it doesn't discard there's something that
> > >>>>> maybe could be optimized somewhere?
> > >>>>
> > >>>> I wonder if we should have a Kconfig option like SPL_CHECKS which
> > >>>> enables these sorts of minor checks, which may only fix one board at
> > >>>> the cost of code size?
> > >>>>
> > >>>> Then it could be enabled by default, but disabled on this board?
> > >>>
> > >>> For a bigger change, this might be an idea, but for a change that I can cut
> > >>> down to 16 or even 8 bytes code size increasement, I don't think having a
> > >>> new option would be good.
> > >>>
> > >>> Anyway, I just tried at work and I don't get the overflow. Tom, which gcc
> > >>> are you using to get the size error? It works for me on Debian 9 but doesn't
> > >>> work with Ubuntu (both times, default cross compiler toolchain installed).
> > >>
> > >> I'm using the gcc-7.3 from kernel.org that we use in travis/etc.
> > >
> > > Ok, so I have gcc-7.3 on my Ubuntu machine as well. I don't know why 6.3 seems to produce smaller
> > > binaries (I thought they were getting smaller with new versions, not larger).
> > >
> > > However, I've stripped down that patch to +8 Bytes only and sent v5.
> >
> > Thanks!
> >
> > Sorry for digging so late in, but I was on vacation...
> >
> > Hmm.. the smartweb board has only 4k sram for SPL, and I have no chance
> > to convert it to DM to get rid of some compiler warnings ...
> >
> > I am unsure what to do now with this hardware ...
> 
> And things even get worse: as I wrote in the other thread, after updating to
> Ubuntu 19.04 as build system, I get gcc 8.3 as cross compiler and smartweb
> fails to build with that compiler (as the SPL binary is exactly 4k now).

Which reminds me that fixing the various warnings we get with gcc-8.x
would be a good general thing to do. :(
Simon Glass April 29, 2019, 3:53 p.m. UTC | #13
Hi,

On Mon, 29 Apr 2019 at 07:19, Tom Rini <trini@konsulko.com> wrote:
>
> On Mon, Apr 29, 2019 at 03:06:39PM +0200, Heiko Schocher wrote:
> > Hello Simon,
> >
> > Am 25.04.2019 um 21:24 schrieb Simon Goldschmidt:
> > >Am 25.04.2019 um 12:50 schrieb Tom Rini:
> > >>On Thu, Apr 25, 2019 at 09:32:22AM +0200, Simon Goldschmidt wrote:
> > >>>On Thu, Apr 25, 2019 at 1:59 AM Simon Glass <sjg@chromium.org> wrote:
> > >>>>
> > >>>>Hi,
> > >>>>
> > >>>>On Wed, 24 Apr 2019 at 05:53, Tom Rini <trini@konsulko.com> wrote:
> > >>>>>
> > >>>>>On Wed, Apr 24, 2019 at 01:49:52PM +0200, Simon Goldschmidt wrote:
> > >>>>>>On Wed, Apr 24, 2019 at 1:27 PM Tom Rini <trini@konsulko.com> wrote:
> > >>>>>>>
> > >>>>>>>On Tue, Apr 23, 2019 at 09:54:10PM -0600, Simon Glass wrote:
> > >>>>>>>>On Mon, 1 Apr 2019 at 14:01, Simon Goldschmidt
> > >>>>>>>><simon.k.r.goldschmidt@gmail.com> wrote:
> > >>>>>>>>>
> > >>>>>>>>>If the malloc range passed to mem_malloc_init() is at the end of address
> > >>>>>>>>>range and 'start + size' overflows to 0, following allocations fail as
> > >>>>>>>>>mem_malloc_end is zero (which looks like uninitialized).
> > >>>>>>>>>
> > >>>>>>>>>Fix this by subtracting 1 of 'start + size' overflows to zero.
> > >>>>>>>>>
> > >>>>>>>>>Signed-off-by: Simon Goldschmidt <simon.k.r.goldschmidt@gmail.com>
> > >>>>>>>>>---
> > >>>>>>>>>
> > >>>>>>>>>Changes in v4: None
> > >>>>>>>>>Changes in v3: None
> > >>>>>>>>>
> > >>>>>>>>>  common/dlmalloc.c | 4 ++++
> > >>>>>>>>>  1 file changed, 4 insertions(+)
> > >>>>>>>>
> > >>>>>>>>Reviewed-by: Simon Glass <sjg@chromium.org>
> > >>>>>>>
> > >>>>>>>So, the problem with this patch is that it increases the generic malloc
> > >>>>>>>code size ever so slightly and blows up smartweb :(
> > >>>>>>
> > >>>>>>Ehrm, ok, so how do we proceed?
> > >>>>>
> > >>>>>A good question.  Take a look at spl/u-boot-spl.map on smartweb and see
> > >>>>>if, of the malloc functions it doesn't discard there's something that
> > >>>>>maybe could be optimized somewhere?
> > >>>>
> > >>>>I wonder if we should have a Kconfig option like SPL_CHECKS which
> > >>>>enables these sorts of minor checks, which may only fix one board at
> > >>>>the cost of code size?
> > >>>>
> > >>>>Then it could be enabled by default, but disabled on this board?
> > >>>
> > >>>For a bigger change, this might be an idea, but for a change that I can cut
> > >>>down to 16 or even 8 bytes code size increasement, I don't think having a
> > >>>new option would be good.
> > >>>
> > >>>Anyway, I just tried at work and I don't get the overflow. Tom, which gcc
> > >>>are you using to get the size error? It works for me on Debian 9 but doesn't
> > >>>work with Ubuntu (both times, default cross compiler toolchain installed).
> > >>
> > >>I'm using the gcc-7.3 from kernel.org that we use in travis/etc.
> > >
> > >Ok, so I have gcc-7.3 on my Ubuntu machine as well. I don't know why 6.3
> > >seems to produce smaller binaries (I thought they were getting smaller
> > >with new versions, not larger).
> > >
> > >However, I've stripped down that patch to +8 Bytes only and sent v5.
> >
> > Thanks!
> >
> > Sorry for digging so late in, but I was on vacation...
> >
> > Hmm.. the smartweb board has only 4k sram for SPL, and I have no chance
> > to convert it to DM to get rid of some compiler warnings ...
> >
> > I am unsure what to do now with this hardware ...
>
> Well, with regards to SPL + DM, this is one of the cases wherein we just
> have-to allow for the SPL driver code at least to be a one-off.  If the
> "whatever ROM loads of our code" stage can set things up enough such
> that we can hand off to a full U-Boot, that's great.  If not, this is
> then a case where TPL comes in to play, and that really is as one-off as
> needed, to load a more general SPL and so forth.

I think DM in SPL is a good thing, so long as there is space. If not,
then we should allow non-DM also. I wonder if we need our policy to be
written down somewhere?

>
> But, I'm fine with saying smartweb keeps and maintains whatever SPL code
> it needs to use.  It's just that in this case, it's not at all a DM
> thing, it's a change in malloc.

Regards,
Simon
diff mbox series

Patch

diff --git a/common/dlmalloc.c b/common/dlmalloc.c
index edaad299bb..51d3bd671a 100644
--- a/common/dlmalloc.c
+++ b/common/dlmalloc.c
@@ -603,6 +603,10 @@  void mem_malloc_init(ulong start, ulong size)
 	mem_malloc_start = start;
 	mem_malloc_end = start + size;
 	mem_malloc_brk = start;
+	if (start && size && !mem_malloc_end) {
+		/* overflow: malloc area is at end of address range */
+		mem_malloc_end--;
+	}
 
 	debug("using memory %#lx-%#lx for malloc()\n", mem_malloc_start,
 	      mem_malloc_end);