On 06/13/16 20:43, Kees Cook wrote: > On Mon, Jun 13, 2016 at 10:44:25PM +0300, Topi Miettinen wrote: >> Add a flag to /proc/self/maps to show that the memory area is locked. >> >> Signed-off-by: Topi Miettinen <[email protected]> >> --- >> fs/proc/task_mmu.c | 3 ++- >> 1 file changed, 2 insertions(+), 1 deletion(-) >> >> diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c >> index 4648c7f..8229509 100644 >> --- a/fs/proc/task_mmu.c >> +++ b/fs/proc/task_mmu.c > > If you change the maps format, you'll need to update task_nommu.c too. > >> @@ -313,13 +313,14 @@ show_map_vma(struct seq_file *m, struct vm_area_struct >> *vma, int is_pid) >> end -= PAGE_SIZE; >> >> seq_setwidth(m, 25 + sizeof(void *) * 6 - 1); > > I think the width needs to be adjusted for the new character. > >> - seq_printf(m, "%08lx-%08lx %c%c%c%c %08llx %02x:%02x %lu ", >> + seq_printf(m, "%08lx-%08lx %c%c%c%c%c %08llx %02x:%02x %lu ", > > Have you checked that no userspace tools that parse "maps" will break with > this flag addition? > >> start, >> end, >> flags & VM_READ ? 'r' : '-', >> flags & VM_WRITE ? 'w' : '-', >> flags & VM_EXEC ? 'x' : '-', >> flags & VM_MAYSHARE ? 's' : 'p', >> + flags & VM_LOCKED ? 'l' : '-', > > IIUC, the smaps file already includes the locked information in VmFlags as > "lo" (see show_smap_vma_flags), so I think you probably don't want this > patch at all.
Yes. the amount of locked memory is also shown: Locked: 8 kB VmFlags: rd wr mr mw me lo ac sd Sorry, I didn't notice that. I'll drop the patch. -Topi > > -Kees > >> pgoff, >> MAJOR(dev), MINOR(dev), ino); >> >> -- >> 2.8.1 >
