On Mon, May 19, 2025 at 04:26:27PM +0530, Ekansh Gupta wrote:
>
>
> On 5/19/2025 3:50 PM, Dmitry Baryshkov wrote:
> > On Tue, May 13, 2025 at 09:58:24AM +0530, Ekansh Gupta wrote:
> >> fastrpc_req_munmap_impl() is called to unmap any buffer. The buffer is
> >> getting removed from the list after it is unmapped from DSP. This can
> >> create potential race conditions if any other thread removes the entry
> >> from list while unmap operation is ongoing. Remove the entry before
> >> calling unmap operation.
> >>
> >> Fixes: 2419e55e532de ("misc: fastrpc: add mmap/unmap support")
> >> Cc: [email protected]
> >> Signed-off-by: Ekansh Gupta <[email protected]>
> >> ---
> >> drivers/misc/fastrpc.c | 29 ++++++++++++++++++++++-------
> >> 1 file changed, 22 insertions(+), 7 deletions(-)
> >>
> >
> >> +err_copy:
> >> + if (req.flags == ADSP_MMAP_REMOTE_HEAP_ADDR) {
> >> + spin_lock_irqsave(&fl->cctx->lock, flags);
> >> + list_del(&buf->node);
> >> + spin_unlock_irqrestore(&fl->cctx->lock, flags);
> >> + } else {
> >> + spin_lock(&fl->lock);
> >> + list_del(&buf->node);
> >> + spin_unlock(&fl->lock);
> >> + }
> > Can we store the spinlock pointer in the struct fastrpc_buf instead?
> this spinlock is used for multiple lists(bufs, maps and ctx).
pointer, not a spinlock itself.
> >
> >> err_assign:
> >> fastrpc_req_munmap_impl(fl, buf);
> >>
> >> --
> >> 2.34.1
> >>
>
--
With best wishes
Dmitry
