Messages in this thread | | | Subject | Re: [PATCH 2/2] mm: vmalloc: Pass proper vm_start into debugobjects | From | Chintan Pandya <> | Date | Tue, 17 Apr 2018 10:40:57 +0530 |
| |
On 4/17/2018 8:39 AM, Anshuman Khandual wrote: > On 04/16/2018 05:39 PM, Chintan Pandya wrote: >> >> >> On 4/13/2018 5:31 PM, Anshuman Khandual wrote: >>> On 04/13/2018 05:03 PM, Chintan Pandya wrote: >>>> Client can call vunmap with some intermediate 'addr' >>>> which may not be the start of the VM area. Entire >>>> unmap code works with vm->vm_start which is proper >>>> but debug object API is called with 'addr'. This >>>> could be a problem within debug objects. >>>> >>>> Pass proper start address into debug object API. >>>> >>>> Signed-off-by: Chintan Pandya <cpandya@codeaurora.org> >>>> --- >>>> mm/vmalloc.c | 4 ++-- >>>> 1 file changed, 2 insertions(+), 2 deletions(-) >>>> >>>> diff --git a/mm/vmalloc.c b/mm/vmalloc.c >>>> index 9ff21a1..28034c55 100644 >>>> --- a/mm/vmalloc.c >>>> +++ b/mm/vmalloc.c >>>> @@ -1526,8 +1526,8 @@ static void __vunmap(const void *addr, int >>>> deallocate_pages) >>>> return; >>>> } >>>> - debug_check_no_locks_freed(addr, get_vm_area_size(area)); >>>> - debug_check_no_obj_freed(addr, get_vm_area_size(area)); >>>> + debug_check_no_locks_freed(area->addr, get_vm_area_size(area)); >>>> + debug_check_no_obj_freed(area->addr, get_vm_area_size(area)); >>> >>> This kind of makes sense to me but I am not sure. We also have another >>> instance of this inside the function vm_unmap_ram() where we call for >> Right, I missed it. I plan to add below stub in v2. >> >> --- a/mm/vmalloc.c >> +++ b/mm/vmalloc.c >> @@ -1124,15 +1124,15 @@ void vm_unmap_ram(const void *mem, unsigned int >> count) >> BUG_ON(addr > VMALLOC_END); >> BUG_ON(!PAGE_ALIGNED(addr)); >> >> - debug_check_no_locks_freed(mem, size); >> - >> if (likely(count <= VMAP_MAX_ALLOC)) { >> + debug_check_no_locks_freed(mem, size); > > It should have been 'va->va_start' instead of 'mem' in here but as > said before it looks correct to me but I am not really sure.
vb_free() doesn't honor va->va_start. If mem is not va_start and deliberate, one will provide proper size. And that should be okay to do as per the code. So, I don't think this particular debug_check should have passed va_start in args.
>
Chintan -- Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project
| |