bhyve: memory leak in topology_parse()

[andy_omniosce.org]

Summary

This was identified in the illumos port using the umem allocator:

umem_alloc_16 leak: 1 buffer, 16 bytes
            ADDR          BUFADDR        TIMESTAMP           THREAD
                            CACHE          LASTLOG         CONTENTS
          81e460           817fd0     570a4304d986                1
                           7d6668           79aa80                0
                 libc.so.1`strdup+0x25
                 topology_parse+0x2b
                 main+0x1c5

[corvink]

usr.sbin/bhyve/bootrom.c

205 ↗

(On Diff #102841)

Just as a note, this memory leak should be solved by my D33433 patch too.

[andy_omniosce.org]

Dropping the fix for bootrom.c

This is addressed by D33433

[rew]

what purpose is ostr serving here?

[andy_omniosce.org]

In D34301#777509, @rew wrote:

what purpose is ostr serving here?

It's keeping track of the address of the buffer that needs to be freed at the end. The problem with str is that it's used with strsep() which will change the pointer, leaving it eventually as NULL, and so the original version just did free(NULL); at best, and worse in the case that an unknown key was found.

[jhb]

In some other places that use strsep the pattern is to name this variable tofree which might be a more obvious name than o[riginal]str.

[andy_omniosce.org]

Renamed 'ostr' to 'tofree'

[andy_omniosce.org]

In D34301#778155, @jhb wrote:

In some other places that use strsep the pattern is to name this variable tofree which might be a more obvious name than o[riginal]str.

Yes, that's better, thanks; updated.