Messages in this thread | | | Date | Tue, 20 Dec 2022 18:53:18 +0000 | From | Lorenzo Stoakes <> | Subject | Re: [PATCH 2/2] mm: vmalloc: Replace BUG_ON() by WARN_ON_ONCE() |
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On Tue, Dec 20, 2022 at 07:27:04PM +0100, Uladzislau Rezki (Sony) wrote: > Currently a vm_unmap_ram() functions triggers a BUG() if an area > is not found. Replace it by the WARN_ON_ONCE() error message and > keep machine alive instead of stopping it. > > The worst case is a memory leaking. > > Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> > --- > mm/vmalloc.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/mm/vmalloc.c b/mm/vmalloc.c > index 0fc38c36e0df..e05a0dc79ac5 100644 > --- a/mm/vmalloc.c > +++ b/mm/vmalloc.c > @@ -2255,10 +2255,12 @@ void vm_unmap_ram(const void *mem, unsigned int count) > } > > va = find_unlink_vmap_area(addr); > - BUG_ON(!va); > - debug_check_no_locks_freed((void *)va->va_start, > - (va->va_end - va->va_start)); > - free_unmap_vmap_area(va); > + > + if (!WARN_ON_ONCE(!va)) { > + debug_check_no_locks_freed((void *)va->va_start, > + (va->va_end - va->va_start)); > + free_unmap_vmap_area(va); > + } > } > EXPORT_SYMBOL(vm_unmap_ram); > > -- > 2.30.2 >
Absolutely in favour of this in principle (BUG_ON() is something we should resort to in only the direst of circumstances), one small nit - perhaps it'd be neater to simply make this a guard clause? E.g.:-
if (!WARN_ON_ONCE(!va)) return;
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