Re: [Qemu-devel] [PATCH v6 01/17] pci: fix unaligned access in pci_xxx_quad()
On Mon, May 30, 2016 at 06:22:35PM +0300, Dmitry Fleytman wrote: > > > On 30 May 2016, at 18:19 PM, Michael S. Tsirkin wrote: > > > > On Mon, May 30, 2016 at 06:14:56PM +0300, Dmitry Fleytman wrote: > >>Does DSN generation function pass unaligned offsets? > >>It does not look like it does… > >> > >> > >> It does according to clang sanitiser. > > > > > > Oh so it's a clang false positive? > > I think not. > The capability itself is 8-bytes aligned but 64-bit serial number inside of > it is not because of 32 bit header in front of it. Oh right. Things like this should really go into commit log in the future. For now a code comment in pci set/get that explains that alignment in capabilities is generally at dword not qword boundary would be enough. > > > > -- > > MST
Re: [Qemu-devel] [PATCH v6 01/17] pci: fix unaligned access in pci_xxx_quad()
> On 30 May 2016, at 18:19 PM, Michael S. Tsirkin wrote: > > On Mon, May 30, 2016 at 06:14:56PM +0300, Dmitry Fleytman wrote: >>Does DSN generation function pass unaligned offsets? >>It does not look like it does… >> >> >> It does according to clang sanitiser. > > > Oh so it's a clang false positive? I think not. The capability itself is 8-bytes aligned but 64-bit serial number inside of it is not because of 32 bit header in front of it. > > -- > MST
Re: [Qemu-devel] [PATCH v6 01/17] pci: fix unaligned access in pci_xxx_quad()
On Mon, May 30, 2016 at 06:14:56PM +0300, Dmitry Fleytman wrote: > Does DSN generation function pass unaligned offsets? > It does not look like it does… > > > It does according to clang sanitiser. Oh so it's a clang false positive? -- MST
Re: [Qemu-devel] [PATCH v6 01/17] pci: fix unaligned access in pci_xxx_quad()
> On 30 May 2016, at 18:11 PM, Michael S. Tsirkin wrote:
>
> On Mon, May 30, 2016 at 06:05:57PM +0300, Dmitry Fleytman wrote:
>>
>>> On 30 May 2016, at 17:47 PM, Michael S. Tsirkin wrote:
>>>
>>> On Mon, May 30, 2016 at 12:14:26PM +0300, Leonid Bloch wrote:
From: Dmitry Fleytman
Replace legacy cpu_to_le64w()/le64_to_cpup()
calls with stq_le_p()/ldq_le_p().
Signed-off-by: Dmitry Fleytman
Signed-off-by: Leonid Bloch
>>>
>>
>> Hi Michael,
>>
>>> Could you please add a code comment to clarify what's going on a bit more?
>>> Something to the point that capabilities are guaranteed to
>>> be dword-aligned only.
>>>
>>
>> Just to clarify, do you want to add these comments to
>> pci_set/get_quad functions or to the new DSN-generation function?
>
> pci_set/get_quad
>
>>> Also, this isn't a dependency of this patchset I think -
>>> as far as I could say the only user of this is
>>> pcie: Introduce function for DSN capability creation
>>> but that merely accesses a capability, and all callers pass in
>>> an aligned offset.
>>
>> Right, this issue appeared after introduction of DSN generation function.
>
> Does DSN generation function pass unaligned offsets?
> It does not look like it does…
It does according to clang sanitiser.
>
>> All other callers pass aligned offsets so far.
>>
>> Thanks,
>> Dmitry
>>
>>>
---
include/hw/pci/pci.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index ef6ba51..ee238ad 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -468,13 +468,13 @@ pci_get_long(const uint8_t *config)
static inline void
pci_set_quad(uint8_t *config, uint64_t val)
{
-cpu_to_le64w((uint64_t *)config, val);
+stq_le_p(config, val);
}
static inline uint64_t
pci_get_quad(const uint8_t *config)
{
-return le64_to_cpup((const uint64_t *)config);
+return ldq_le_p(config);
}
static inline void
--
2.5.5
Re: [Qemu-devel] [PATCH v6 01/17] pci: fix unaligned access in pci_xxx_quad()
On Mon, May 30, 2016 at 06:05:57PM +0300, Dmitry Fleytman wrote:
>
> > On 30 May 2016, at 17:47 PM, Michael S. Tsirkin wrote:
> >
> > On Mon, May 30, 2016 at 12:14:26PM +0300, Leonid Bloch wrote:
> >> From: Dmitry Fleytman
> >>
> >> Replace legacy cpu_to_le64w()/le64_to_cpup()
> >> calls with stq_le_p()/ldq_le_p().
> >>
> >> Signed-off-by: Dmitry Fleytman
> >> Signed-off-by: Leonid Bloch
> >
>
> Hi Michael,
>
> > Could you please add a code comment to clarify what's going on a bit more?
> > Something to the point that capabilities are guaranteed to
> > be dword-aligned only.
> >
>
> Just to clarify, do you want to add these comments to
> pci_set/get_quad functions or to the new DSN-generation function?
pci_set/get_quad
> > Also, this isn't a dependency of this patchset I think -
> > as far as I could say the only user of this is
> > pcie: Introduce function for DSN capability creation
> > but that merely accesses a capability, and all callers pass in
> > an aligned offset.
>
> Right, this issue appeared after introduction of DSN generation function.
Does DSN generation function pass unaligned offsets?
It does not look like it does...
> All other callers pass aligned offsets so far.
>
> Thanks,
> Dmitry
>
> >
> >> ---
> >> include/hw/pci/pci.h | 4 ++--
> >> 1 file changed, 2 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
> >> index ef6ba51..ee238ad 100644
> >> --- a/include/hw/pci/pci.h
> >> +++ b/include/hw/pci/pci.h
> >> @@ -468,13 +468,13 @@ pci_get_long(const uint8_t *config)
> >> static inline void
> >> pci_set_quad(uint8_t *config, uint64_t val)
> >> {
> >> -cpu_to_le64w((uint64_t *)config, val);
> >> +stq_le_p(config, val);
> >> }
> >>
> >> static inline uint64_t
> >> pci_get_quad(const uint8_t *config)
> >> {
> >> -return le64_to_cpup((const uint64_t *)config);
> >> +return ldq_le_p(config);
> >> }
> >>
> >> static inline void
> >> --
> >> 2.5.5
Re: [Qemu-devel] [PATCH v6 01/17] pci: fix unaligned access in pci_xxx_quad()
> On 30 May 2016, at 17:47 PM, Michael S. Tsirkin wrote:
>
> On Mon, May 30, 2016 at 12:14:26PM +0300, Leonid Bloch wrote:
>> From: Dmitry Fleytman
>>
>> Replace legacy cpu_to_le64w()/le64_to_cpup()
>> calls with stq_le_p()/ldq_le_p().
>>
>> Signed-off-by: Dmitry Fleytman
>> Signed-off-by: Leonid Bloch
>
Hi Michael,
> Could you please add a code comment to clarify what's going on a bit more?
> Something to the point that capabilities are guaranteed to
> be dword-aligned only.
>
Just to clarify, do you want to add these comments to
pci_set/get_quad functions or to the new DSN-generation function?
> Also, this isn't a dependency of this patchset I think -
> as far as I could say the only user of this is
> pcie: Introduce function for DSN capability creation
> but that merely accesses a capability, and all callers pass in
> an aligned offset.
Right, this issue appeared after introduction of DSN generation function.
All other callers pass aligned offsets so far.
Thanks,
Dmitry
>
>> ---
>> include/hw/pci/pci.h | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
>> index ef6ba51..ee238ad 100644
>> --- a/include/hw/pci/pci.h
>> +++ b/include/hw/pci/pci.h
>> @@ -468,13 +468,13 @@ pci_get_long(const uint8_t *config)
>> static inline void
>> pci_set_quad(uint8_t *config, uint64_t val)
>> {
>> -cpu_to_le64w((uint64_t *)config, val);
>> +stq_le_p(config, val);
>> }
>>
>> static inline uint64_t
>> pci_get_quad(const uint8_t *config)
>> {
>> -return le64_to_cpup((const uint64_t *)config);
>> +return ldq_le_p(config);
>> }
>>
>> static inline void
>> --
>> 2.5.5
Re: [Qemu-devel] [PATCH v6 01/17] pci: fix unaligned access in pci_xxx_quad()
On Mon, May 30, 2016 at 12:14:26PM +0300, Leonid Bloch wrote:
> From: Dmitry Fleytman
>
> Replace legacy cpu_to_le64w()/le64_to_cpup()
> calls with stq_le_p()/ldq_le_p().
>
> Signed-off-by: Dmitry Fleytman
> Signed-off-by: Leonid Bloch
Could you please add a code comment to clarify what's going on a bit more?
Something to the point that capabilities are guaranteed to
be dword-aligned only.
Also, this isn't a dependency of this patchset I think -
as far as I could say the only user of this is
pcie: Introduce function for DSN capability creation
but that merely accesses a capability, and all callers pass in
an aligned offset.
> ---
> include/hw/pci/pci.h | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
> index ef6ba51..ee238ad 100644
> --- a/include/hw/pci/pci.h
> +++ b/include/hw/pci/pci.h
> @@ -468,13 +468,13 @@ pci_get_long(const uint8_t *config)
> static inline void
> pci_set_quad(uint8_t *config, uint64_t val)
> {
> -cpu_to_le64w((uint64_t *)config, val);
> +stq_le_p(config, val);
> }
>
> static inline uint64_t
> pci_get_quad(const uint8_t *config)
> {
> -return le64_to_cpup((const uint64_t *)config);
> +return ldq_le_p(config);
> }
>
> static inline void
> --
> 2.5.5
[Qemu-devel] [PATCH v6 01/17] pci: fix unaligned access in pci_xxx_quad()
From: Dmitry Fleytman
Replace legacy cpu_to_le64w()/le64_to_cpup()
calls with stq_le_p()/ldq_le_p().
Signed-off-by: Dmitry Fleytman
Signed-off-by: Leonid Bloch
---
include/hw/pci/pci.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
index ef6ba51..ee238ad 100644
--- a/include/hw/pci/pci.h
+++ b/include/hw/pci/pci.h
@@ -468,13 +468,13 @@ pci_get_long(const uint8_t *config)
static inline void
pci_set_quad(uint8_t *config, uint64_t val)
{
-cpu_to_le64w((uint64_t *)config, val);
+stq_le_p(config, val);
}
static inline uint64_t
pci_get_quad(const uint8_t *config)
{
-return le64_to_cpup((const uint64_t *)config);
+return ldq_le_p(config);
}
static inline void
--
2.5.5
