12:33 a.m.
On Fri, Sep 16, 2022 at 8:19 PM kernel test robot <lkp(a)intel.com> wrote:
commit: e7f78835d551bb2deb5aa3346d84c8f03ade313d [5364/5387]
RDMA/siw: Pass a pointer to virt_to_page()
config: riscv-randconfig-r013-20220916
(https://download.01.org/0day-ci/archive/20220917/202209170232.grVMomkJ-lk...)
compiler: riscv32-linux-gcc (GCC) 12.1.0
So if RISCV32 ...
31 if (paddr)
> 32 return virt_to_page((void *)paddr);
Think that passing a (void *) to virt_to_page() is a problem:
warning: cast to pointer from integer of different size
[-Wint-to-pointer-cast]
32 | return virt_to_page((void *)paddr);
I would think this is a problem with RISCV32.
What has this arch done?
This is a few lines up:
dma_addr_t paddr = siw_pbl_get_buffer(pbl, offset, NULL, idx);
dma_addr_t is a different size than (void *)?
Given that the patch raising this problem looked like this:
- return virt_to_page(paddr);
+ return virt_to_page((void *)paddr);
I doubt that it has created a bug that wasn't there before. Passing
a dma_addr_t to virt_to_page() might be wrong, but that is what the
driver has been doing all the time.
siw_pbl_get_buffer() claims to
"Gets physical address backed by PBL element."
Why is that even passed to virt_to_page() if it's no virtual address
but a dma_addr_t to begin with?
I certainly don't understand SIW, but this bug, if it is a bug (or a type and
documentation bug) is clearly not new.
Yours,
Linus Walleij