Re: [Powertop] [PATCH 1/2] prevent segment fault for android built 2

[Alexandra Yates <alexandra.yates at linux.intel.com>]

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Rejecting this patch.  This is already handled on the Android patches.

On 07/06/2015 07:16 PM, Zhaoyang Huang wrote:
> Hi Daniel,
> Thank you for your feedback.
> I have noticed the patch you mentioned. However, under the android(use 
> bionic libc) environment, the bellowing condition maybe true which 
> will cause a NULL pointer access to buffer. I add another one more 
> condition to prevent it. This problem can also be reproduced by android.
>
> diff --git a/src/lib.cpp b/src/lib.cpp
> index 88fe5f3..8d1ca9f 100644
> --- a/src/lib.cpp
> +++ b/src/lib.cpp
> @@ -285,7 +285,7 @@ void align_string(char *buffer, size_t min_sz, 
> size_t max_sz)
>         /* start with mbsrtowcs() local mbstate_t * and
>          * NULL dst pointer*/
>         sz = mbsrtowcs(NULL, (const char **)&buffer, max_sz, NULL);
> -       if (sz == (size_t)-1) {
> +       if ((sz == (size_t)-1) && (NULL != buffer)) {
>                 buffer[min_sz] = 0x00;
>                 return;
>         }
> -- 
> 1.7.9.5
>
>
> On 7 July 2015 at 05:44, Daniel Leung <daniel.leung(a)linux.intel.com 
> <mailto:daniel.leung(a)linux.intel.com>> wrote:
>
>     On Wed,  1 Jul 2015 19:52:24 +0800
>     Zhaoyang Huang <zhaoyang.huang(a)linaro.org
>     <mailto:zhaoyang.huang(a)linaro.org>> wrote:
>
>     > the buffer will be turn into NULL after invoking the mbsrtowcs
>     function
>     > of bionic libc. Add a condition judgement for that
>     >
>     > Signed-off-by: Zhaoyang Huang <zhaoyang.huang(a)linaro.org
>     <mailto:zhaoyang.huang(a)linaro.org>>
>     > ---
>     >  src/lib.cpp |    2 +-
>     >  1 file changed, 1 insertion(+), 1 deletion(-)
>     >
>     > diff --git a/src/lib.cpp b/src/lib.cpp
>     > index 88fe5f3..8d1ca9f 100644
>     > --- a/src/lib.cpp
>     > +++ b/src/lib.cpp
>     > @@ -285,7 +285,7 @@ void align_string(char *buffer, size_t
>     min_sz, size_t max_sz)
>     >       /* start with mbsrtowcs() local mbstate_t * and
>     >        * NULL dst pointer*/
>     >       sz = mbsrtowcs(NULL, (const char **)&buffer, max_sz, NULL);
>     > -     if (sz == (size_t)-1) {
>     > +     if ((sz == (size_t)-1) && (NULL != buffer)) {
>     >               buffer[min_sz] = 0x00;
>     >               return;
>     >       }
>     > --
>     > 1.7.9.5
>     >
>
>     If you are on master branch, there is a patch
>     (patches/android/prevent_segfaults.patch) to workaround the NULL
>     pointer.
>
>     --
>     Daniel Leung <daniel.leung(a)linux.intel.com
>     <mailto:daniel.leung(a)linux.intel.com>>
>
>
>
>
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-- 
Thank you,
<Alexandra>