From: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx> Subject: fs/proc/task_mmu.c: do not show VmExe bigger than total executable virtual memory If start_code / end_code pointers are screwed then "VmExe" could be bigger than total executable virtual memory and "VmLib" becomes negative: VmExe: 294320 kB VmLib: 18446744073709327564 kB VmExe and VmLib documented as text segment and shared library code size. Now their sum will be always equal to mm->exec_vm which sums size of executable and not writable and not stack areas. I've seen this for huge (>2Gb) statically linked binary which has whole world inside. For it start_code .. end_code range also covers one of rodata sections. Probably this is bug in customized linker, elf loader or both. Anyway CONFIG_CHECKPOINT_RESTORE allows to change these pointers, thus we cannot trust them without validation. Link: http://lkml.kernel.org/r/150728955451.743749.11276392315459539583.stgit@buzz Signed-off-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx> Acked-by: Vlastimil Babka <vbabka@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/proc/task_mmu.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff -puN fs/proc/task_mmu.c~proc-do-not-show-vmexe-bigger-than-total-executable-virtual-memory fs/proc/task_mmu.c --- a/fs/proc/task_mmu.c~proc-do-not-show-vmexe-bigger-than-total-executable-virtual-memory +++ a/fs/proc/task_mmu.c @@ -47,8 +47,11 @@ void task_mem(struct seq_file *m, struct if (hiwater_rss < mm->hiwater_rss) hiwater_rss = mm->hiwater_rss; - text = (PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK)) >> 10; - lib = (mm->exec_vm << (PAGE_SHIFT-10)) - text; + /* split executable areas between text and lib */ + text = PAGE_ALIGN(mm->end_code) - (mm->start_code & PAGE_MASK); + text = min(text, mm->exec_vm << PAGE_SHIFT); + lib = (mm->exec_vm << PAGE_SHIFT) - text; + swap = get_mm_counter(mm, MM_SWAPENTS); seq_printf(m, "VmPeak:\t%8lu kB\n" @@ -76,7 +79,9 @@ void task_mem(struct seq_file *m, struct file << (PAGE_SHIFT-10), shmem << (PAGE_SHIFT-10), mm->data_vm << (PAGE_SHIFT-10), - mm->stack_vm << (PAGE_SHIFT-10), text, lib, + mm->stack_vm << (PAGE_SHIFT-10), + text >> 10, + lib >> 10, mm_pgtables_bytes(mm) >> 10, swap << (PAGE_SHIFT-10)); hugetlb_report_usage(m, mm); _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
