On 23-Apr-20 9:04 PM, David Marchand wrote:
On Thu, Apr 23, 2020 at 6:34 PM Burakov, Anatoly
<anatoly.bura...@intel.com> wrote:
diff --git a/lib/librte_eal/common/eal_common_memory.c
b/lib/librte_eal/common/eal_common_memory.c
index cc7d54e0c..2d9564b28 100644
--- a/lib/librte_eal/common/eal_common_memory.c
+++ b/lib/librte_eal/common/eal_common_memory.c
@@ -177,6 +177,20 @@ eal_get_virtual_area(void *requested_addr, size_t *size,
after_len = RTE_PTR_DIFF(map_end, aligned_end);
if (after_len > 0)
munmap(aligned_end, after_len);
+
+ /*
+ * Exclude this pages from a core dump.
+ */
+ if (madvise(aligned_addr, *size, MADV_DONTDUMP) != 0)
+ RTE_LOG(WARNING, EAL, "Madvise with MADV_DONTDUMP failed:
%s\n",
+ strerror(errno));> + } else {
+ /*
+ * Exclude this pages from a core dump.
+ */
+ if (madvise(mapped_addr, map_sz, MADV_DONTDUMP) != 0)
+ RTE_LOG(WARNING, EAL, "Madvise with MADV_DONTDUMP failed:
%s\n",
+ strerror(errno));
}
return aligned_addr;
For the contents of this patch,
MADV_DONTDUMP does not seem POSIX, but as I said [1], there seems to
be a MADV_NOCORE option on FreeBSD.
1:
http://inbox.dpdk.org/dev/cajfav8y9ytt-7njuz+md6u8+3xuqyrgp28kd7jy2923epac...@mail.gmail.com/
Oh, right, so this would probably not compile on FreeBSD. Perhaps this
function would have to be OS-specific after all (or call into an
OS-specific madvise() after reserving the memory area).
Acked-by: Anatoly Burakov <anatoly.bura...@intel.com>
However, even though this is good to have, after some more thought, i
believe the fix is incomplete, because this is not the only place we're
reserving anonymous memory. We're also doing so in
`eal_memalloc.c:free_seg()`, so an `madvise()` call should also be added
there.
@David, now that i think of it, the PROT_NONE patch also was incomplete,
as we only set PROT_NONE to memory that's initially reserved, but not
when it's unmapped and returned back to the pool of anonymous memory.
So, eal_memalloc.c should also remap anonymous memory with PROT_NONE.
I can't disagree if you say so :-).
Nice to have that kind of power! *evil laugh*
@Li Feng, would you be so kind as to provide a patch replacing PROT_READ
with PROT_NONE in eal_memalloc.c as well? Thank you very much!
Once we have the proper fixes, I'd like to get this Cc: sta...@dpdk.org.
Thanks.
--
Thanks,
Anatoly
