Tracking mmap isn't good enough. To collect stacks from the place an
individual block is allocated you need hooks at that spot. Not
the underlying large-scale system allocator.
RTC doesn't work for all applications. It might not be suitable
for ksh in this case. I wish it were otherwise.
There are several Sun Studio support forums on developers.sun.com.
They are a good way of getting help specific to the Sun Studio tools.
I have also cc:ed Leonard Li who is our RTC engineer.
Oops. NOW I have cc:ed Leonard Li.
--chris
Roland Mainz wrote:
> Hi!
>
> ----
>
> While doing some tests with ksh93 and "dbx" (Sun Studio 11) I found the
> following issue ("bcheck -all" is the same as "dbx -check all" without
> interactive prompting for each hit; ksh93 was built using
> http://svn.genunix.org/repos/on/branches/ksh93/gisburn/scripts/buildksh93.ksh):
> -- snip --
> % bcheck -all ./arch/sol10.sun4/bin/ksh
> Reading ksh
> Reading ld.so.1
> Reading rtcapihook.so
> Reading libm.so.2
> Reading libsecdb.so.1
> Reading libc.so.1
> Reading libdl.so.1
> Reading libnsl.so.1
> Reading libcmd.so.1
> Reading rtcaudit.so
> Reading libmapmalloc.so.1
> Reading libgen.so.1
> Reading libc_psr.so.1
> Reading rtcboot.so
> Reading librtc.so
> access checking - ON
> memuse checking - ON
> Running: ksh
> (process id 24663)
> RTC: Enabling Error Checking...
> RTC: Using UltraSparc trap mechanism
> RTC: See `help rtc showmap' and `help rtc limitations' for details.
> RTC: Running program...
> $
> $ RTC: program wrote over private RTC data -- disabling Error Checking
> file: memerror.c line: 297
> -- snip --
>
> The problem here seems that the RTC subsystem is unable to track memory
> allocations done by the vmalloc subsystem of libast (see
> http://www.opensolaris.org/os/project/ksh93-integration/docs/ksh93r/man/man3/vmalloc/).
>
>
> The question is now how to fix that problem. rtc_api(3x) seems to
> indicate that calls to allocations and deallocations need to be
> "annouced" to the RTC subsystem via |_rtc_record_free()|,
> |_rtc_record_malloc()| and |_rtc_record_realloc()|, however the
> allocators in libc/watchmalloc/libmapmalloc/etc. do not seems to use
> this API (= % nm /usr/lib/libmapmalloc.so | fgrep -i rtc # returns
> nothing).
>
> The question is now: What's the right solution ? Should libast's vmalloc
> call |_rtc_record*()| or does dbx need to be modified ? And why is this
> mess needed - after all vmalloc seems to use |mmap()| - why isn't this
> tracked automatically by dbx ?
>
> ----
>
> Bye,
> Roland
>
