Hello, On Fri, Sep 30, 2016 at 12:03:20AM +0800, zijun_hu wrote: > From: zijun_hu <[email protected]> > > it will cause memory leakage for pcpu_embed_first_chunk() to go to > label @out_free if the chunk spans over 3/4 VMALLOC area. all memory > are allocated and recorded into array @areas for each CPU group, but > the memory allocated aren't be freed before returning after going to > label @out_free > > in order to fix this bug, we check chunk spanned area immediately > after completing memory allocation for all CPU group, we go to label > @out_free_areas other than @out_free to free all memory allocated if > the checking is failed. > > Signed-off-by: zijun_hu <[email protected]> ... > @@ -2000,6 +2001,21 @@ int __init pcpu_embed_first_chunk(size_t > reserved_size, size_t dyn_size, > areas[group] = ptr; > > base = min(ptr, base); > + if (ptr > areas[j]) > + j = group; > + } > + max_distance = areas[j] - base; > + max_distance += ai->unit_size * ai->groups[j].nr_units; > + > + /* warn if maximum distance is further than 75% of vmalloc space */ > + if (max_distance > VMALLOC_TOTAL * 3 / 4) { > + pr_warn("max_distance=0x%lx too large for vmalloc space > 0x%lx\n", > + max_distance, VMALLOC_TOTAL); > +#ifdef CONFIG_NEED_PER_CPU_PAGE_FIRST_CHUNK > + /* and fail if we have fallback */ > + rc = -EINVAL; > + goto out_free_areas; > +#endif
Isn't it way simpler to make the error path jump to out_free_areas? There's another similar case after pcpu_setup_first_chunk() failure too. Also, can you please explain how you tested the changes? Thanks. -- tejun
