Messages in this thread | | | Date | Mon, 18 Oct 2021 09:07:16 +0800 | From | Li Fei1 <> | Subject | Re: [PATCH] virt: acrn: Prefer array_syze and struct_size over open coded arithmetic |
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On Fri, Oct 15, 2021 at 05:52:48PM +0200, Len Baker wrote: > Hi Li, > > On Tue, Oct 12, 2021 at 09:34:29AM +0800, Li Fei1 wrote: > > On Mon, Oct 11, 2021 at 12:39:02PM +0200, Len Baker wrote: > > > As noted in the "Deprecated Interfaces, Language Features, Attributes, > > > and Conventions" documentation [1], size calculations (especially > > > multiplication) should not be performed in memory allocator (or similar) > > > function arguments due to the risk of them overflowing. This could lead > > > to values wrapping around and a smaller allocation being made than the > > > caller was expecting. Using those allocations could lead to linear > > > overflows of heap memory and other misbehaviors. > > > > > > So, use the array_size() helper to do the arithmetic instead of the > > > argument "count * size" in the vzalloc() function. > > > > > > Also, take the opportunity to add a flexible array member of struct > > > vm_memory_region_op to the vm_memory_region_batch structure. And then, > > > change the code accordingly and use the struct_size() helper to do the > > > arithmetic instead of the argument "size + size * count" in the kzalloc > > > function. > > > > > > This code was detected with the help of Coccinelle and audited and fixed > > > manually. > > > > > > [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments > > > > > > Signed-off-by: Len Baker <len.baker@gmx.com> > > > > Hi Baker > > > > Thanks for helping us to fix this issue. This patch looks good to me. > > Please add Signed-off-by: Fei Li <fei1.li@intel.com>. > > I can't add the "Signed-off-by" tag by myself. However, if you are in the > path to forward the patch to the mainline (maintainer's tree), you can > add by yourself the "Signed-off-by" tag before send a "pull" to Linus. > See [1] for more information. > > [1] https://www.kernel.org/doc/html/latest/process/submitting-patches.html#sign-your-work-the-developer-s-certificate-of-origin > > If you don't have a maintainer's tree, you can give (as a maintainer) an > "Acked-by" tag that then I can add to the patch. More info in [2].
Acked-by: Fei Li <fei1.li@intel.com>
thanks.
> > [2] https://www.kernel.org/doc/html/latest/process/submitting-patches.html#when-to-use-acked-by-cc-and-co-developed-by > > > Only two minor comments. > > > > > > > --- > > > drivers/virt/acrn/acrn_drv.h | 10 ++++++---- > > > drivers/virt/acrn/mm.c | 9 ++++----- > > > 2 files changed, 10 insertions(+), 9 deletions(-) > > > > > > diff --git a/drivers/virt/acrn/acrn_drv.h b/drivers/virt/acrn/acrn_drv.h > > > index 1be54efa666c..fcc2e3e5232a 100644 > > > --- a/drivers/virt/acrn/acrn_drv.h > > > +++ b/drivers/virt/acrn/acrn_drv.h > > > @@ -48,6 +48,7 @@ struct vm_memory_region_op { > > > * @reserved: Reserved. > > > * @regions_num: The number of vm_memory_region_op. > > > * @regions_gpa: Physical address of a vm_memory_region_op array. > > > + * @regions_op: Flexible array of vm_memory_region_op. > > One Tab please. > > Sorry, but if I use only one tab, the parameters description are not all > aligned. > > > > * > > > * HC_VM_SET_MEMORY_REGIONS uses this structure to manage EPT mappings of > > > * multiple memory regions of a User VM. A &struct vm_memory_region_batch > > > @@ -55,10 +56,11 @@ struct vm_memory_region_op { > > > * ACRN Hypervisor. > > > */ > > > struct vm_memory_region_batch { > > > - u16 vmid; > > > - u16 reserved[3]; > > > - u32 regions_num; > > > - u64 regions_gpa; > > > + u16 vmid; > > > + u16 reserved[3]; > > > + u32 regions_num; > > > + u64 regions_gpa; > > > + struct vm_memory_region_op regions_op[]; > > Please use Whitespace instead of Tab. > > Sorry, but I don't understand. Do you prefer something like?: > > diff --git a/drivers/virt/acrn/acrn_drv.h b/drivers/virt/acrn/acrn_drv.h > index fcc2e3e5232a..5663c17ad37c 100644 > --- a/drivers/virt/acrn/acrn_drv.h > +++ b/drivers/virt/acrn/acrn_drv.h > @@ -56,11 +56,11 @@ struct vm_memory_region_op { > * ACRN Hypervisor. > */ > struct vm_memory_region_batch { > - u16 vmid; > - u16 reserved[3]; > - u32 regions_num; > - u64 regions_gpa; > - struct vm_memory_region_op regions_op[]; > + u16 vmid; > + u16 reserved[3]; > + u32 regions_num; > + u64 regions_gpa; > + struct vm_memory_region_op regions_op[]; > }; > > /** > > Moreover, for the v2 I will fix the typo "syze->size" in the subject as > suggested Kees ;) > > Regards, > Len
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