RFR(xs): 8076475: Misuses of strncpy/strncat

[Thomas Stüfe]

Dmitry, Thanks for the review!

Still need a second review and also a sponsor.

.. Thomas
On Apr 10, 2015 10:46 AM, "Dmitry Samersoff" <dmitry.samersoff at oracle.com>
wrote:

> Thomas,
>
> Looks good for me!
>
> Thank you for doing it.
>
> -Dmitry
>
> On 2015-04-10 10:50, Thomas Stüfe wrote:
> > Hi Dimitry,
> >
> > see new version here:
> >
> > http://cr.openjdk.java.net/~stuefe/webrevs/8076475/webrev.01/webrev/
> >
> >
> > On Wed, Apr 8, 2015 at 2:40 PM, Dmitry Samersoff
> > <dmitry.samersoff at oracle.com <mailto:dmitry.samersoff at oracle.com>>
> wrote:
> >
> >     Thomas,
> >
> >     ** agent/src/os/bsd/libproc_impl.c
> >     ** agent/src/os/linux/libproc_impl.c
> >
> >     newlib->name has the size of (PATH_MAX + NAME_MAX + 1)
> >
> >     see ./src/os/bsd/libproc_impl.h:92
> >
> >     So no truncation is actually possible here.
> >
> >     To make this code nice-looking it's better to add:
> >
> >     if (strlen(libname) >  sizeof(newlib->name)) {
> >     //  Bail out with debug message
> >      ...
> >     }
> >     strcpy(newlib->name, libname);
> >
> >     rather than use snprintf here.
> >
> >
> > I changed the coding according to your suggestions.
> >
> > There is still the strlen vs strnlen question Kim mentioned, but we use
> > strlen all over the place, and I am not sure if all platforms support it
> > (AIX was known to have a broken strnlen implementation, one would need
> > to check that first before changing strlen to strnlen)
> >
> >
> >     ** arguments.cpp:3466
> >
> >     It might be better to use snprintf here.
> >
> >
> > Agree, done
> >
> >
> >     ** arguments.cpp:3629
> >
> >     It's better to just replace strncat/strncpy to strcat/strcpy
> >     in the original code - as soon as we allocating memory with respect
> to
> >     variable lenght, we don't need to check this length again.
> >
> >
> > Sorry, I disagree here - I think using snprintf makes the code more
> > readable. It comes down to a matter of taste, so lets see what others
> think.
> >
> >
> >
> >     ** vmError.cpp:222
> >
> >     It's better to keep original code.
> >
> >
> > Agree, done
> >
> > Best Regards, Thomas
> >
> >
> >
> >     Other changes looks good for me!
> >     -Dmitry
> >
> >
> >     On 2015-04-08 11:09, Thomas Stüfe wrote:
> >     > Hi,
> >     >
> >     > please review these small fixes around use of strncpy/strncat.
> >     >
> >     > Bug report: https://bugs.openjdk.java.net/browse/JDK-8076475
> >     > Webrev:
> >     >
> http://cr.openjdk.java.net/~stuefe/webrevs/8076475/webrev.00/webrev/
> >     >
> >     > Changes in detail are:
> >     >
> >     > agent/src/os/bsd/libproc_impl.c
> >     > agent/src/os/linux/libproc_impl.c:
> >     >                 - missing \0 on truncation. Replaced with
> >     snprintf, add
> >     > truncation handling
> >     >
> >     > src/os/bsd/dtrace/libjvm_db.c
> >     > src/os/solaris/dtrace/libjvm_db.c
> >     >                 @@ -580,17 +580,18 @@
> >     >                 - overwrite on truncation
> >     >                 @@ -1093,13 +1094,13 @@
> >     >                 - overwrite on truncation
> >     >
> >     > src/share/vm/compiler/compileBroker.hpp
> >     >                 - missing \0 on truncation.
> >     >
> >     > src/share/tools/hsdis/hsdis.c
> >     >                 - missing \0
> >     >
> >     > src/os/bsd/vm/decoder_machO.cpp
> >     >                 - missing \0 on truncation.
> >     >
> >     > src/share/vm/compiler/compilerOracle.cpp
> >     >                 - Replaced with jio_snprintf, less awkward and
> >     does not
> >     > restrict each part to 255 chars each.
> >     >
> >     > src/share/vm/compiler/disassembler.cpp
> >     >                 - missing \0 on truncation.
> >     >
> >     > src/share/vm/runtime/arguments.cpp
> >     >                 @@ -2703,11 +2703,11 @@
> >     >                 - replaced with strdup, easier to read
> >     >                 @@ -3294,12 +3294,11 @@
> >     >                 - the same
> >     >                 @@ -3627,18 +3626,14 @@
> >     >                 - replace strncpy/strncat sequence with
> jio_snprintf -
> >     > easier to read.
> >     >                 - replace malloc/strncpy with os::strdup
> >     >
> >     > src/share/vm/utilities/ostream.cpp
> >     >                 - avoid \0 padding
> >     >
> >     > src/share/vm/utilities/vmError.cp
> >     >                 @@ -219,7 +219,7 @@
> >     >                 - avoid \0 padding
> >     >                 @@ -463,14 +463,7 @@
> >     >                 - simplified
> >     >
> >     > Kind regards, Thomas
> >     >
> >
> >
> >     --
> >     Dmitry Samersoff
> >     Oracle Java development team, Saint Petersburg, Russia
> >     * I would love to change the world, but they won't give me the
> sources.
> >
> >
>
>
> --
> Dmitry Samersoff
> Oracle Java development team, Saint Petersburg, Russia
> * I would love to change the world, but they won't give me the sources.
>