Re: [PATCH] Add getenv.so for catching invalid getenv() use via LD_PRELOAD

From: Duy Nguyen <pclouds@gmail.com>
Date: Jan 5, 2013, 11:37 UTC
Message-ID: <CACsJy8A-Q8uDC0fJzspU8khCtWnMgmz66L2G9hLmsRYFYLaumw@mail.gmail.com>
In-Reply-To: <20130105103900.GA4200@ftbfs.org>

On Sat, Jan 5, 2013 at 5:39 PM, Matt Kraai <kraai@ftbfs.org> wrote:

Show 7 quoted lines

> On Sat, Jan 05, 2013 at 03:55:46PM +0700, Nguyễn Thái Ngọc Duy wrote:
>>  Perhaps this will help the getenv bug hunting (I assume we do the
>>  hunting on Linux platform only). So far it catches this and is stuck
>>  at getenv in git_pager().
>
> It seems like a static analysis tool might be able to detect these
> problems.  Is there a way to do so using sparse?

That was my first thought. But this may involve flow analysis and I don't think sparse is up to it. ccc-analyzer is still pretty basic. And between static analysis and runtime check, I prefer the latter as it's more reliable as long as you have a good coverage test.

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>
>> +             n = backtrace(buffer, 100);
>> +             symbols = backtrace_symbols(buffer, n);
>> +             if (symbols) {
>> +                     for (i = 0;i < n; i++)
>
> s/;i/; i/

Thanks. I will fix it later if people actually want this.

-- 
Duy