Re: [Qemu-devel] [RFC][PATCH 11/14 v9] introduce a new monitor command 'dump' to dump guest's memory

[HATAYAMA Daisuke]

From: Wen Congyang <address@hidden>
Subject: [RFC][PATCH 11/14 v9] introduce a new monitor command 'dump' to dump 
guest's memory
Date: Wed, 14 Mar 2012 10:11:35 +0800

> +/*
> + * QEMU dump
> + *
> + * Copyright Fujitsu, Corp. 2011
> + *

Now 2012.

> +    /*
> +     * calculate phdr_num
> +     *
> +     * the type of phdr->num is uint16_t, so we should avoid overflow

e_phnum is correct.

> +     */
> +    s->phdr_num = 1; /* PT_NOTE */
> +    if (s->list.num < (1 << 16) - 2) {

s->list.num < UINT16_MAX is better.

> +        s->phdr_num += s->list.num;
> +        s->have_section = false;
> +    } else {
> +        s->have_section = true;
> +        s->phdr_num = PN_XNUM;
> +
> +        /* the type of shdr->sh_info is uint32_t, so we should avoid 
> overflow */
> +        if (s->list.num > (1ULL << 32) - 2) {

s->list.num < UINT32_MAX is better.

> +            s->sh_info = 0xffffffff;

UINT32_MAX is better. Is it rough around here?

> +        } else {
> +            s->sh_info += s->list.num;
> +        }
> +    }

Now orders of processings in positive and negative cases for e_phnum
and sh_info are different. It's better to make them sorted in the same
order.

  if (phdr_num not overflow?) {
    not overflow case;
  } else {
    overflow case;
    if (sh_info not overflow?) {
      not overflow case;
    } else {
      overflow case;
    }
  }

is better.

Thanks.
HATAYAMA, Daisuke