Help text and malloc snarfoo

[Ken McDonell <kenj@xxxxxxxxxxxxxxxx>]

Continuation of a discussion from IRC, with conclusions and a patch ...

The current state of play is described as follows ... things noted as
WRONG are indeed so, and the attached patch addresses all of them.

Nathan, unless you want otherwise, I'll leave you to merge this patch
with your changes (that I suspect address only the dbpmda issue) and
I'll keep my changes local and uncommitted awaiting the true gospel from
oss.sgi.com.

-------------------

src/pmcd/src/dopdus.c
        DoText()
            if AGENT_DSO calls version.*.text() (separate cases for
                one.text, two.text and four.text)
            otherwise buffer is malloc'd via __pmDecodeText()

            if (DSO AND PMDA_INTERFACE_1) OR (not DSO) free(buffer)

src/dbpmda/src/pmda.c
        calls __pmDecodeText() & free(buffer)

src/dbpmda/src/dso.c
        calls version.*.text() depending on PMDA_INTERFACE_x & free(buffer)
        WRONG - should not call free() unless using PMDA_INTERFACE_1

src/libpcp/src/p_text.c
        in __pmDecodeText(), buffer is malloc'd

src/libpcp/src/help.c
        below pmLookupText()
            if PM_CONTEXT_HOST buffer is malloc'd via __pmDecodeText()
            if PM_CONTEXT_LOCAL calls calls version.*.text() then
                strdup's buffer
                WRONG ... should not strdup for PMDA_INTERFACE_1
        so in both cases PMAPI contract for client is honoured and

man/man3/pmdatext.3
        is just plain WRONG ... the returned buffer should never be
        free'd
        client must free()

libpcp_pmda/src/help.c
        pmdaGetHelp() and pmdaGetInDomHelp() return a pointer into
        the mmap'd help file

libpcp_pmda/src/callback.c
        pmdaText() calls pmdaGetHelp() or pmdaGetInDomHelp(), and so
        returns a non-malloc'd buffer

libpcp_pmda/src/mainloop.c
        __pmdaMainPDU() calls version.*.text() then free's the result
        buffer
        WRONG - should not call free() unless using PMDA_INTERFACE_1

pmdas/mmv/mmv.c
        mmv_text() returns static buffer else pointer into mmap
        area

pmdas/sample/src/sample.c
        sample_text() calls pmdaText()

pmdas/summary/mainloop.c
        calls version.two.text()

patch.pcp
Description: Text Data