Hi Michal, Earlier I posted a patchset to clean up these in a different way, but patches sent to your below mail address are all rejected.
<[email protected]>: host mail.kerne.org[104.131.33.237] said: 454 4.1.1 <[email protected]>: Recipient address rejected: User unknown in virtual mailbox table (in reply to RCPT TO command) On 10/16/17 at 03:44pm, Michal Hocko wrote: > From: Michal Hocko <[email protected]> > diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c > index 6466153f2bf0..09456e2add18 100644 > --- a/fs/binfmt_elf.c > +++ b/fs/binfmt_elf.c > @@ -341,6 +341,29 @@ create_elf_tables(struct linux_binprm *bprm, struct > elfhdr *exec, > > #ifndef elf_map > > +static unsigned long elf_vm_mmap(struct file *filep, unsigned long addr, > + unsigned long size, int prot, int type, unsigned long off) > +{ > + unsigned long map_addr; > + > + /* > + * If caller requests the mapping at a specific place, make sure we fail > + * rather than potentially clobber an existing mapping which can have > + * security consequences (e.g. smash over the stack area). > + */ > + map_addr = vm_mmap(filep, addr, size, prot, type & ~MAP_FIXED, off); > + if (BAD_ADDR(map_addr)) > + return map_addr; > + > + if ((type & MAP_FIXED) && map_addr != addr) { > + pr_info("Uhuuh, elf segement at %p requested but the memory is > mapped already\n", > + (void*)addr); > + return -EAGAIN; > + } > + > + return map_addr; > +} > + > static unsigned long elf_map(struct file *filep, unsigned long addr, > struct elf_phdr *eppnt, int prot, int type, > unsigned long total_size) > @@ -366,11 +389,11 @@ static unsigned long elf_map(struct file *filep, > unsigned long addr, > */ > if (total_size) { > total_size = ELF_PAGEALIGN(total_size); > - map_addr = vm_mmap(filep, addr, total_size, prot, type, off); > + map_addr = elf_vm_mmap(filep, addr, total_size, prot, type, > off); > if (!BAD_ADDR(map_addr)) > vm_munmap(map_addr+size, total_size-size); Here we will still take the map total, then unmap the rest way. I am wondering why we don't fix those issues we figured out, but add another level of wrapper elf_vm_mmap() to hack it. So we will have elf_map() -> elf_vm_mmap() -> vm_mmap(), not even counting vm_mmap_pgoff(), then finally enter into do_mmap_pgoff(), to do the maping for elf program. Thanks Baoquan > } else > - map_addr = vm_mmap(filep, addr, size, prot, type, off); > + map_addr = elf_vm_mmap(filep, addr, size, prot, type, off); > > return(map_addr); > } > @@ -1215,7 +1238,7 @@ static int load_elf_library(struct file *file) > eppnt++; > > /* Now use mmap to map the library into memory. */ > - error = vm_mmap(file, > + error = elf_vm_mmap(file, > ELF_PAGESTART(eppnt->p_vaddr), > (eppnt->p_filesz + > ELF_PAGEOFFSET(eppnt->p_vaddr)), > -- > 2.14.2 >
