On Fri, Mar 24, 2017 at 02:44:10PM +0530, Aneesh Kumar K.V wrote: > > > On Friday 24 March 2017 02:34 PM, Kirill A. Shutemov wrote: > > On Mon, Mar 20, 2017 at 10:40:20AM +0530, Aneesh Kumar K.V wrote: > > > "Kirill A. Shutemov" <kirill.shute...@linux.intel.com> writes: > > > @@ -168,6 +182,10 @@ arch_get_unmapped_area_topdown(struct file *filp, > > > const unsigned long addr0, > > > > unsigned long addr = addr0; > > > > struct vm_unmapped_area_info info; > > > > > > > > + addr = mpx_unmapped_area_check(addr, len, flags); > > > > + if (IS_ERR_VALUE(addr)) > > > > + return addr; > > > > + > > > > /* requested length too big for entire address space */ > > > > if (len > TASK_SIZE) > > > > return -ENOMEM; > > > > @@ -192,6 +210,14 @@ arch_get_unmapped_area_topdown(struct file *filp, > > > > const unsigned long addr0, > > > > info.length = len; > > > > info.low_limit = PAGE_SIZE; > > > > info.high_limit = mm->mmap_base; > > > > + > > > > + /* > > > > + * If hint address is above DEFAULT_MAP_WINDOW, look for > > > > unmapped area > > > > + * in the full address space. > > > > + */ > > > > + if (addr > DEFAULT_MAP_WINDOW) > > > > + info.high_limit += TASK_SIZE - DEFAULT_MAP_WINDOW; > > > > + > > > > > > Is this ok for 32 bit application ? > > > > DEFAULT_MAP_WINDOW is equal to TASK_SIZE on 32-bit, so it's nop and will > > be compile out. > > > > That is not about CONFIG_X86_32 but about 32 bit application on a 64 bit > kernel. I guess we will never find addr > DEFAULT_MAP_WINDOW with > a 32 bit app ?
I have local change to avoid this within 32-bit syscall, but I'll need to recheck everthing. -- Kirill A. Shutemov
