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 <[email protected]>
> > Signed-off-by: Thomas Richter <[email protected]>
> > Cc: Jessica Yu <[email protected]>
>
> 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)
> >
