On Wed, Aug 19, 2020 at 07:46:50PM +0530, Sumit Semwal wrote: ... > Userspace can set the name for a region of memory by calling > prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, start, len, (unsigned long)name); > Setting the name to NULL clears it. > > The name is stored in a user pointer in the shared union in vm_area_struct > that points to a null terminated string inside the user process. vmas > that point to the same address and are otherwise mergeable will be merged, > but vmas that point to equivalent strings at different addresses will not > be merged. ... Guys, could you please enlighen me, I don't understand -- we pass some random user-space pointer and save it in vm_area_struct then in procfs we treat it as "string" and print out? What prevents me to put some crap here then unmap this pointer the kernel will cause page fault in procfs output (in best scenario)?
