| Message ID | 20230810074704.2042664-2-xiaolei.wang@windriver.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Bail out in __stack_depot_save() if the stack_table is not allocated and delete the kmemleak_initialized judgment in set_track_prepare() | expand |
On 8/10/23 09:47, Xiaolei Wang wrote: > The __stack_depot_save() may be used by some subsystems even before > the stack depot is initialized. Does that currently happen, or only after patch 2/2 it starts happening via kmemleak? > So add a check of stack_table in > __stack_depot_save() to make sure no oops in this case. > > Fixes: 56a61617dd22 ("mm: use stack_depot for recording kmemleak's backtrace") In case it's only after 2/2 I don't think this is truly "Fixes"? > Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com> > --- > lib/stackdepot.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/lib/stackdepot.c b/lib/stackdepot.c > index 2f5aa851834e..a0651d013a0d 100644 > --- a/lib/stackdepot.c > +++ b/lib/stackdepot.c > @@ -376,7 +376,7 @@ depot_stack_handle_t __stack_depot_save(unsigned long *entries, > */ > nr_entries = filter_irq_stacks(entries, nr_entries); > > - if (unlikely(nr_entries == 0) || stack_depot_disabled) > + if (unlikely(nr_entries == 0) || stack_depot_disabled || unlikely(!stack_table)) > goto fast_exit; > > hash = hash_stack(entries, nr_entries);
On 8/10/23 8:53 PM, Vlastimil Babka wrote: > CAUTION: This email comes from a non Wind River email account! > Do not click links or open attachments unless you recognize the sender and know the content is safe. > > On 8/10/23 09:47, Xiaolei Wang wrote: >> The __stack_depot_save() may be used by some subsystems even before >> the stack depot is initialized. > Does that currently happen, or only after patch 2/2 it starts happening via > kmemleak? Yes, currently it happens after patch 2/2 it starts happening via kmemleak, The reason why I take it as the first patch is because I think this can avoid exceptions when there is only patch2, such as when we use git bisect to debug > >> So add a check of stack_table in >> __stack_depot_save() to make sure no oops in this case. >> >> Fixes: 56a61617dd22 ("mm: use stack_depot for recording kmemleak's backtrace") > In case it's only after 2/2 I don't think this is truly "Fixes"? Yes, it is indeed for patch2 at present, it is to fix the situation that kmemleak has no backtrace in the boot phase, and at the same time, it can also prevent patch2 from entering the stable kernel and causing panic thanks xiaolei > >> Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com> >> --- >> lib/stackdepot.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/lib/stackdepot.c b/lib/stackdepot.c >> index 2f5aa851834e..a0651d013a0d 100644 >> --- a/lib/stackdepot.c >> +++ b/lib/stackdepot.c >> @@ -376,7 +376,7 @@ depot_stack_handle_t __stack_depot_save(unsigned long *entries, >> */ >> nr_entries = filter_irq_stacks(entries, nr_entries); >> >> - if (unlikely(nr_entries == 0) || stack_depot_disabled) >> + if (unlikely(nr_entries == 0) || stack_depot_disabled || unlikely(!stack_table)) >> goto fast_exit; >> >> hash = hash_stack(entries, nr_entries);
diff --git a/lib/stackdepot.c b/lib/stackdepot.c index 2f5aa851834e..a0651d013a0d 100644 --- a/lib/stackdepot.c +++ b/lib/stackdepot.c @@ -376,7 +376,7 @@ depot_stack_handle_t __stack_depot_save(unsigned long *entries, */ nr_entries = filter_irq_stacks(entries, nr_entries); - if (unlikely(nr_entries == 0) || stack_depot_disabled) + if (unlikely(nr_entries == 0) || stack_depot_disabled || unlikely(!stack_table)) goto fast_exit; hash = hash_stack(entries, nr_entries);
The __stack_depot_save() may be used by some subsystems even before the stack depot is initialized. So add a check of stack_table in __stack_depot_save() to make sure no oops in this case. Fixes: 56a61617dd22 ("mm: use stack_depot for recording kmemleak's backtrace") Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com> --- lib/stackdepot.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)