| Message ID | 20240223235728.13981-2-alexei.starovoitov@gmail.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | mm: Cleanup and identify various users of kernel virtual address space | expand |
On Fri, Feb 23, 2024 at 03:57:26PM -0800, Alexei Starovoitov wrote: > From: Alexei Starovoitov <ast@kernel.org> > > There are various users of get_vm_area() + ioremap_page_range() APIs. > Enforce that get_vm_area() was requested as VM_IOREMAP type and range passed to > ioremap_page_range() matches created vm_area to avoid accidentally ioremap-ing > into wrong address range. Nit: overly long lines in the commit message here. Otherwise looks good: Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index d12a17fc0c17..f42f98a127d5 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -307,8 +307,21 @@ static int vmap_range_noflush(unsigned long addr, unsigned long end, int ioremap_page_range(unsigned long addr, unsigned long end, phys_addr_t phys_addr, pgprot_t prot) { + struct vm_struct *area; int err; + area = find_vm_area((void *)addr); + if (!area || !(area->flags & VM_IOREMAP)) { + WARN_ONCE(1, "vm_area at addr %lx is not marked as VM_IOREMAP\n", addr); + return -EINVAL; + } + if (addr != (unsigned long)area->addr || + (void *)end != area->addr + get_vm_area_size(area)) { + WARN_ONCE(1, "ioremap request [%lx,%lx) doesn't match vm_area [%lx, %lx)\n", + addr, end, (long)area->addr, + (long)area->addr + get_vm_area_size(area)); + return -ERANGE; + } err = vmap_range_noflush(addr, end, phys_addr, pgprot_nx(prot), ioremap_max_page_shift); flush_cache_vmap(addr, end);