On Thu, Mar 08, 2018 at 07:24:47AM +0100, Julia Lawall wrote: > On Wed, 7 Mar 2018, Matthew Wilcox wrote: > > On Wed, Mar 07, 2018 at 10:18:21PM +0100, Julia Lawall wrote: > > > > Otherwise, yes, please. We could build a coccinelle rule for > > > > additional replacements... > > > > > > A potential semantic patch and the changes it generates are attached > > > below. Himanshu Jha helped with its development. Working on this > > > uncovered one bug, where the allocated array is too large, because the > > > size provided for it was a structure size, but actually only pointers to > > > that structure were to be stored in it. > > > > This is cool! Thanks for doing the coccinelle patch! Diffstat: > > > > 50 files changed, 81 insertions(+), 124 deletions(-) > > > > I find that pretty compelling. I'll repost the kvmalloc_struct patch > > imminently. > > Thanks. So it's OK to replace kmalloc and kzalloc, even though they > didn't previously consider vmalloc and even though kmalloc doesn't zero?
We'll also need to replace the corresponding places where those structs are freed with kvfree(). Can coccinelle handle that too? > There are a few other cases that use GFP_NOFS and GFP_NOWAIT, but I didn't > transform those because the comment says that the flags should be > GFP_KERNEL based. Should those be transformed too? The problem with non-GFP_KERNEL allocations is that vmalloc may have to allocate page tables, which is always done with an implicit GFP_KERNEL allocation. There's an intent to get rid of GFP_NOFS, but that's not been realised yet (and I'm not sure of our strategy to eliminate it ... I'll send a separate email about that). I'm not sure why anything's trying to allocate with GFP_NOWAIT; can you send a list of those places? _______________________________________________ Cocci mailing list Cocci@systeme.lip6.fr https://systeme.lip6.fr/mailman/listinfo/cocci
