Re: CFT: snmalloc as libc malloc

Shawn Webb <shawn.webb_at_hardenedbsd.org> wrote on
Date: Sun, 12 Feb 2023 19:44:24 UTC :

> On Sat, Feb 11, 2023 at 05:10:02PM +0000, David Chisnall wrote:
> > On 10 Feb 2023, at 16:23, Shawn Webb <shawn.webb@hardenedbsd.org> wrote:
> > > 
> > > So I took a little bit of a different approach, which should provide
> > > the same end result as your submodule approach. Note that I'm doing
> > > this in HardenedBSD 14-CURRENT (the hardened/current/master branch).
> > > 
> > > 1. git cherry-pick -xs a5c83c69817d03943b8be982dd815c7e263d1a83
> > > 2. git rm -f .gitmodules contrib/snmalloc
> > > 3. git commit
> > > 4. git subtree add -P contrib/snmalloc \
> > > git@github.com:microsoft/snmalloc.git main
> > > 
> > > I believe this should leave me with a tree that populates
> > > contrib/snmalloc and pulls in your non-contrib/ changes, leading me to
> > > end up in the same end state as your submodule approach.
> > > 
> > > I am seeing some build errors. I've uploaded a WITHOUT_CLEAN=yes log
> > > to:
> > > 
> > > https://hardenedbsd.org/~shawn/2023-02-10_snmalloc-01.log.txt
> > > 
> > > Note that this is with llvm 15.0.7 that just landed in FreeBSD main.
> > 
> > The error is a bit confusing, because nullptr_t has been in libc++ since C++11. Does HardenedBSD change anything in include orders? Can you add -v to the end of the compile command:
> > 
> > 
> > c++ -target x86_64-unknown-freebsd14.0 --sysroot=/usr/obj/data/src/hardenedbsd/amd64.amd64/tmp -B/usr/obj/data/src/hardenedbsd/amd64.amd64/tmp/usr/bin -fomit-frame-pointer -O2 -pipe -fno-common -DHARDENEDBSD -DNO__SCCSID -DNO__RCSID -I/data/src/hardenedbsd/lib/libc/include -I/data/src/hardenedbsd/include -I/data/src/hardenedbsd/lib/libc/amd64 -DNLS -ftls-model=initial-exec -D__DBINTERFACE_PRIVATE -I/data/src/hardenedbsd/contrib/gdtoa -I/data/src/hardenedbsd/contrib/libc-vis -DINET6 -I/usr/obj/data/src/hardenedbsd/amd64.amd64/lib/libc -I/data/src/hardenedbsd/lib/libc/resolv -D_ACL_PRIVATE -DPOSIX_MISTAKE -I/data/src/hardenedbsd/lib/libmd -I/data/src/hardenedbsd/lib/libc/locale -DBROKEN_DES -DPORTMAP -DDES_BUILTIN -I/data/src/hardenedbsd/lib/libc/rpc -DWANT_HYPERV -DYP -DNS_CACHING -DSYMBOL_VERSIONING -g -gz=zlib -mretpoline -fPIC -flto -MD -MF.depend.malloc.o -MTmalloc.o -Wno-format-zero-length -fstack-protector-strong -Wsystem-headers -Werror -Wall -Wno-format-y2k -Wno-uninitialized -Wdate-time -Wno-empty-body -Wno-string-plus-int -Wno-unused-const-variable -Wno-error=unused-but-set-variable -Wno-error=array-parameter -Wno-error=deprecated-non-prototype -Wno-error=unused-but-set-parameter -Wno-tautological-compare -Wno-unused-value -Wno-parentheses-equality -Wno-unused-function -Wno-enum-conversion -Wno-unused-local-typedef -Wno-address-of-packed-member -Wno-switch -Wno-switch-enum -Wno-knr-promoted-parameter -Qunused-arguments -I/data/src/hardenedbsd/lib/libutil -I/data/src/hardenedbsd/lib/msun/amd64 -I/data/src/hardenedbsd/lib/msun/x86 --include-directory-after /data/src/hardenedbsd/lib/msun/src -DHARDENEDBSD -I/data/src/hardenedbsd/contrib/snmalloc/src/snmalloc -std=c++20 -mcx16 -fno-exceptions -fno-rtti -DSNMALLOC_USE_THREAD_CLEANUP -DSNMALLOC_BOOTSTRAP_ALLOCATOR -DSNMALLOC_JEMALLOC3_EXPERIMENTAL -DSNMALLOC_JEMALLOC_NONSTANDARD -DSNMALLOC_PLATFORM_HAS_GETENTROPY -DSNMALLOC_STATIC_LIBRARY_PREFIX=__ -ftls-model=initial-exec -DSNMALLOC_CHECK_CLIENT -DSNMALLOC_FAIL_FAST=false -DNDEBUG -g -gz=zlib -mretpoline -flto -Wno-c++11-extensions -c /data/src/hardenedbsd/lib/libc/stdlib/snmalloc/malloc.cc -o malloc.o
> > 
> > 
> > 
> > That should dump the include paths. It’s possible that the libc++ headers are being included in the wrong order with respect to the C paths?
> 
> Hey David,
> 
> HardenedBSD doesn't have any changes to userland that would cause
> changes in include header paths (and the priorities of them.)
> 
> I made sure to `pkg delete -g gcc\* binutils\*` before running another
> buildworld, ending up with the same error.
> 
> I tried running your command above.

He asked that you add a -v to it. Implicitly also: capture
and report the extra text that the -v causes in the output.

That extra text covers what the sequence of include paths
searched are in the order searched. It shows even the paths
for which nothing is/will-be found for the specific
compile: where all did the compiler look? Any unexpected
places? Any missing places? Any examples of not being in
the required order?

> Here's the result:
> http://ix.io/4nS9

That does not include the extra text that would be generated
by having added the -v requested to that shown command line.
That tet would likely have been before the text that you did
include.

Did you add the -v option? Was there extra text?

> I think Mark might be on the right track with regards to llvm 15. I'll
> try importing the snmalloc patch (via the same subtree method) to a
> pre-llvm15 import branch and report back. It might be a few days
> before I get you a result.
> 
> BTW, I appreciate the work. One long-term goal I've had for
> HardenedBSD is to be able to switch between multiple heap
> implementations at buildworld-time. I think it would be nifty for
> users to have a choice of jemalloc, snmalloc, and GrapheneOS'
> hardened_malloc.


===
Mark Millard
marklmi at yahoo.com