* [PATCH] modules: Fix display of wrong module .text address
@ 2018-04-17 8:20 Thomas Richter
2018-04-17 8:24 ` Christian Borntraeger
0 siblings, 1 reply; 5+ messages in thread
From: Thomas Richter @ 2018-04-17 8:20 UTC (permalink / raw)
To: jeyu, torvalds, linux-kernel
Cc: borntraeger, schwidefsky, brueckner, heiko.carstens, peterz, acme,
me, keescook, Thomas Richter
In kernel v4.16.0 the module .text address is displayed
wrong when using /sys/module/*/sections/.text file.
Commit ef0010a30935 ("vsprintf: don't use 'restricted_pointer()' when
not restricting")
is the first bad commit.
Here is the issue, using module qeth_l2 on s390 which is the
ethernet device driver:
[root@s35lp76 ~]# lsmod
Module Size Used by
qeth_l2 94208 1
...
[root@s35lp76 ~]# cat /proc/modules | egrep '^qeth_l2'
qeth_l2 94208 1 - Live 0x000003ff80401000
^ This is the correct address in memory
[root@s35lp76 ~]# cat /sys/module/qeth_l2/sections/.text
0x0000000018ea8363 <---- This is a wrong address
[root@s35lp76 ~]#
This breaks the perf tool which uses this address on s390
to calculate start of .text section in memory.
Fix this by printing the correct (unhashed) address.
Thanks to Jessica Yu for helping on this.
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Cc: Jessica Yu <jeyu@kernel.org>
---
kernel/module.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/module.c b/kernel/module.c
index a6e43a5806a1..77ab7211ddef 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1472,7 +1472,7 @@ static ssize_t module_sect_show(struct module_attribute *mattr,
{
struct module_sect_attr *sattr =
container_of(mattr, struct module_sect_attr, mattr);
- return sprintf(buf, "0x%pK\n", (void *)sattr->address);
+ return sprintf(buf, "%#lx\n", kptr_restrict < 2 ? sattr->address : 0);
}
static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
--
2.14.3
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] modules: Fix display of wrong module .text address
2018-04-17 8:20 [PATCH] modules: Fix display of wrong module .text address Thomas Richter
@ 2018-04-17 8:24 ` Christian Borntraeger
2018-04-17 16:10 ` Kees Cook
2018-04-17 16:20 ` Arnaldo Carvalho de Melo
0 siblings, 2 replies; 5+ messages in thread
From: Christian Borntraeger @ 2018-04-17 8:24 UTC (permalink / raw)
To: Thomas Richter, jeyu, torvalds, linux-kernel
Cc: schwidefsky, brueckner, heiko.carstens, peterz, acme, me,
keescook
On 04/17/2018 10:20 AM, Thomas Richter wrote:
> In kernel v4.16.0 the module .text address is displayed
> wrong when using /sys/module/*/sections/.text file.
> Commit ef0010a30935 ("vsprintf: don't use 'restricted_pointer()' when
> not restricting")
> is the first bad commit.
>
> Here is the issue, using module qeth_l2 on s390 which is the
> ethernet device driver:
>
> [root@s35lp76 ~]# lsmod
> Module Size Used by
> qeth_l2 94208 1
> ...
>
> [root@s35lp76 ~]# cat /proc/modules | egrep '^qeth_l2'
> qeth_l2 94208 1 - Live 0x000003ff80401000
> ^ This is the correct address in memory
> [root@s35lp76 ~]# cat /sys/module/qeth_l2/sections/.text
> 0x0000000018ea8363 <---- This is a wrong address
> [root@s35lp76 ~]#
>
> This breaks the perf tool which uses this address on s390
> to calculate start of .text section in memory.
>
> Fix this by printing the correct (unhashed) address.
>
> Thanks to Jessica Yu for helping on this.
>
> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
> Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
> Cc: Jessica Yu <jeyu@kernel.org>
CC stable?
> ---
> kernel/module.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/module.c b/kernel/module.c
> index a6e43a5806a1..77ab7211ddef 100644
> --- a/kernel/module.c
> +++ b/kernel/module.c
> @@ -1472,7 +1472,7 @@ static ssize_t module_sect_show(struct module_attribute *mattr,
> {
> struct module_sect_attr *sattr =
> container_of(mattr, struct module_sect_attr, mattr);
> - return sprintf(buf, "0x%pK\n", (void *)sattr->address);
> + return sprintf(buf, "%#lx\n", kptr_restrict < 2 ? sattr->address : 0);
> }
>
> static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] modules: Fix display of wrong module .text address
2018-04-17 8:24 ` Christian Borntraeger
@ 2018-04-17 16:10 ` Kees Cook
2018-04-17 16:20 ` Arnaldo Carvalho de Melo
1 sibling, 0 replies; 5+ messages in thread
From: Kees Cook @ 2018-04-17 16:10 UTC (permalink / raw)
To: Christian Borntraeger
Cc: Thomas Richter, Jessica Yu, Linus Torvalds, LKML,
Martin Schwidefsky, brueckner, Heiko Carstens, Peter Zijlstra,
Arnaldo Carvalho de Melo, Tobin C. Harding
On Tue, Apr 17, 2018 at 1:24 AM, Christian Borntraeger
<borntraeger@de.ibm.com> wrote:
>
>
> On 04/17/2018 10:20 AM, Thomas Richter wrote:
>> In kernel v4.16.0 the module .text address is displayed
>> wrong when using /sys/module/*/sections/.text file.
>> Commit ef0010a30935 ("vsprintf: don't use 'restricted_pointer()' when
>> not restricting")
>> is the first bad commit.
>>
>> Here is the issue, using module qeth_l2 on s390 which is the
>> ethernet device driver:
>>
>> [root@s35lp76 ~]# lsmod
>> Module Size Used by
>> qeth_l2 94208 1
>> ...
>>
>> [root@s35lp76 ~]# cat /proc/modules | egrep '^qeth_l2'
>> qeth_l2 94208 1 - Live 0x000003ff80401000
>> ^ This is the correct address in memory
>> [root@s35lp76 ~]# cat /sys/module/qeth_l2/sections/.text
>> 0x0000000018ea8363 <---- This is a wrong address
>> [root@s35lp76 ~]#
>>
>> This breaks the perf tool which uses this address on s390
>> to calculate start of .text section in memory.
>>
>> Fix this by printing the correct (unhashed) address.
>>
>> Thanks to Jessica Yu for helping on this.
>>
>> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
>> Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
>> Cc: Jessica Yu <jeyu@kernel.org>
>
> CC stable?
>
>> ---
>> kernel/module.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/kernel/module.c b/kernel/module.c
>> index a6e43a5806a1..77ab7211ddef 100644
>> --- a/kernel/module.c
>> +++ b/kernel/module.c
>> @@ -1472,7 +1472,7 @@ static ssize_t module_sect_show(struct module_attribute *mattr,
>> {
>> struct module_sect_attr *sattr =
>> container_of(mattr, struct module_sect_attr, mattr);
>> - return sprintf(buf, "0x%pK\n", (void *)sattr->address);
>> + return sprintf(buf, "%#lx\n", kptr_restrict < 2 ? sattr->address : 0);
Can we use %px instead, just to make the hash-bypass reports easier to grep for?
-Kees
>> }
>>
>> static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
>>
>
--
Kees Cook
Pixel Security
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] modules: Fix display of wrong module .text address
2018-04-17 8:24 ` Christian Borntraeger
2018-04-17 16:10 ` Kees Cook
@ 2018-04-17 16:20 ` Arnaldo Carvalho de Melo
2018-04-17 17:34 ` Christian Borntraeger
1 sibling, 1 reply; 5+ messages in thread
From: Arnaldo Carvalho de Melo @ 2018-04-17 16:20 UTC (permalink / raw)
To: Christian Borntraeger
Cc: Thomas Richter, jeyu, torvalds, linux-kernel, schwidefsky,
brueckner, heiko.carstens, peterz, me, keescook
Em Tue, Apr 17, 2018 at 10:24:35AM +0200, Christian Borntraeger escreveu:
>
>
> On 04/17/2018 10:20 AM, Thomas Richter wrote:
> > In kernel v4.16.0 the module .text address is displayed
> > wrong when using /sys/module/*/sections/.text file.
> > Commit ef0010a30935 ("vsprintf: don't use 'restricted_pointer()' when
> > not restricting")
> > is the first bad commit.
> >
> > Here is the issue, using module qeth_l2 on s390 which is the
> > ethernet device driver:
> >
> > [root@s35lp76 ~]# lsmod
> > Module Size Used by
> > qeth_l2 94208 1
> > ...
> >
> > [root@s35lp76 ~]# cat /proc/modules | egrep '^qeth_l2'
> > qeth_l2 94208 1 - Live 0x000003ff80401000
> > ^ This is the correct address in memory
> > [root@s35lp76 ~]# cat /sys/module/qeth_l2/sections/.text
> > 0x0000000018ea8363 <---- This is a wrong address
> > [root@s35lp76 ~]#
> >
> > This breaks the perf tool which uses this address on s390
> > to calculate start of .text section in memory.
> >
> > Fix this by printing the correct (unhashed) address.
> >
> > Thanks to Jessica Yu for helping on this.
> >
> > Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
> > Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
> > Cc: Jessica Yu <jeyu@kernel.org>
>
> CC stable?
Adding the missing:
Fixes: ef0010a30935 ("vsprintf: don't use 'restricted_pointer()' when not restricting")
Should be enough?
- Arnaldo
> > ---
> > kernel/module.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/kernel/module.c b/kernel/module.c
> > index a6e43a5806a1..77ab7211ddef 100644
> > --- a/kernel/module.c
> > +++ b/kernel/module.c
> > @@ -1472,7 +1472,7 @@ static ssize_t module_sect_show(struct module_attribute *mattr,
> > {
> > struct module_sect_attr *sattr =
> > container_of(mattr, struct module_sect_attr, mattr);
> > - return sprintf(buf, "0x%pK\n", (void *)sattr->address);
> > + return sprintf(buf, "%#lx\n", kptr_restrict < 2 ? sattr->address : 0);
> > }
> >
> > static void free_sect_attrs(struct module_sect_attrs *sect_attrs)
> >
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] modules: Fix display of wrong module .text address
2018-04-17 16:20 ` Arnaldo Carvalho de Melo
@ 2018-04-17 17:34 ` Christian Borntraeger
0 siblings, 0 replies; 5+ messages in thread
From: Christian Borntraeger @ 2018-04-17 17:34 UTC (permalink / raw)
To: Arnaldo Carvalho de Melo
Cc: Thomas Richter, jeyu, torvalds, linux-kernel, schwidefsky,
brueckner, heiko.carstens, peterz, me, keescook
On 04/17/2018 06:20 PM, Arnaldo Carvalho de Melo wrote:
> Em Tue, Apr 17, 2018 at 10:24:35AM +0200, Christian Borntraeger escreveu:
>>
>>
>> On 04/17/2018 10:20 AM, Thomas Richter wrote:
>>> In kernel v4.16.0 the module .text address is displayed
>>> wrong when using /sys/module/*/sections/.text file.
>>> Commit ef0010a30935 ("vsprintf: don't use 'restricted_pointer()' when
>>> not restricting")
>>> is the first bad commit.
>>>
>>> Here is the issue, using module qeth_l2 on s390 which is the
>>> ethernet device driver:
>>>
>>> [root@s35lp76 ~]# lsmod
>>> Module Size Used by
>>> qeth_l2 94208 1
>>> ...
>>>
>>> [root@s35lp76 ~]# cat /proc/modules | egrep '^qeth_l2'
>>> qeth_l2 94208 1 - Live 0x000003ff80401000
>>> ^ This is the correct address in memory
>>> [root@s35lp76 ~]# cat /sys/module/qeth_l2/sections/.text
>>> 0x0000000018ea8363 <---- This is a wrong address
>>> [root@s35lp76 ~]#
>>>
>>> This breaks the perf tool which uses this address on s390
>>> to calculate start of .text section in memory.
>>>
>>> Fix this by printing the correct (unhashed) address.
>>>
>>> Thanks to Jessica Yu for helping on this.
>>>
>>> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
>>> Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
>>> Cc: Jessica Yu <jeyu@kernel.org>
>>
>> CC stable?
>
> Adding the missing:
>
> Fixes: ef0010a30935 ("vsprintf: don't use 'restricted_pointer()' when not restricting")
>
> Should be enough?
Even better.
^ permalink raw reply [flat|nested] 5+ messages in thread
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2018-04-17 8:20 [PATCH] modules: Fix display of wrong module .text address Thomas Richter
2018-04-17 8:24 ` Christian Borntraeger
2018-04-17 16:10 ` Kees Cook
2018-04-17 16:20 ` Arnaldo Carvalho de Melo
2018-04-17 17:34 ` Christian Borntraeger
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