From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1944) id 30EB03852C5D; Wed, 23 Nov 2022 14:50:43 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 30EB03852C5D DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1669215043; bh=55nunTb008j5HvmdLKN2+R4H45av2Rb2UBgGEBUxb3g=; h=From:To:Subject:Date:From; b=uITFyygTR7YMH2BuD6p/g90sg8rZom48y9ZTtKVbCVeHFdiYGvvr3ARwN4kTfhlPm h4G84r9XMvTD4xFZ3rz6Pmox8GyX9pZHNK+MWCzyv/EwS61QnNFsZX+bTUOtVAuxz4 HwerPGQmkC3/GSdjIQvP3I+ne9xa2wVnWXoYnPII= Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Szabolcs Nagy To: glibc-cvs@sourceware.org Subject: [glibc/arm/morello/main] morello: Provide documentation about the morello port. X-Act-Checkin: glibc X-Git-Author: Szabolcs Nagy X-Git-Refname: refs/heads/arm/morello/main X-Git-Oldrev: c38427f52d5386a25650ed982fa9a4af596a3f34 X-Git-Newrev: ae90dd111bc393178a39cc6166170aa7c3656296 Message-Id: <20221123145043.30EB03852C5D@sourceware.org> Date: Wed, 23 Nov 2022 14:50:43 +0000 (GMT) List-Id: https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=ae90dd111bc393178a39cc6166170aa7c3656296 commit ae90dd111bc393178a39cc6166170aa7c3656296 Author: Szabolcs Nagy Date: Wed Oct 19 16:08:54 2022 +0100 morello: Provide documentation about the morello port. Diff: --- manual/README.morello | 37 +++++++++++++++++++++++++++++++++++++ 1 file changed, 37 insertions(+) diff --git a/manual/README.morello b/manual/README.morello new file mode 100644 index 0000000000..cf30eeaee5 --- /dev/null +++ b/manual/README.morello @@ -0,0 +1,37 @@ +Morello glibc port +================== + +Morello is a prototype security architecture, led by Arm, based on CHERI. +https://www.morello-project.org/ +https://www.cl.cam.ac.uk/research/security/ctsrd/cheri/ + +Toolchain components of the morello port are maintained in upstream branches. +The morello port is implemented as an ABI variant of the aarch64 port that is +also called the purecap ABI. Morello specific ABI documents are at: +https://github.com/ARM-software/abi-aa +https://git.morello-project.org/morello/kernel/linux/-/wikis/home + +Areas with significant morello or CHERI specific changes outside the usual +target specific changes: + +- Early start code including ELF entry and auxv, +- Dynamic linker and relocation processing, +- malloc with narrow capability support, +- printf %#p to pretty print capabilities. + +Limitations of the morello port: + +- Building requires --disable-werror. +- Profiling and --enable-profile are not supported (gprof, sprof, LD_PROFILE). +- LD_AUDIT is not supported (la_symbind, PLT hooks, require new API redesign). +- VDSO is not supported (depends on Linux work). +- static-pie is not supported (requires start code redesign). +- POSIX message queue async notify does not work (pointers passed via an fd). +- Process shared robust mutex does not work (pointers in shared memory). +- Purecap pldd only supports purecap ABI processes (not lp64). +- malloc bounds narrowing has large overhead (locks and hash table lookup). +- malloc bounds narrowing can break code expecting page granularity protection. + Use GLIBC_TUNABLES=glibc.mem.cap_narrowing=0 env var as a workaround. +- string functions are not optimized. +- Executable stack is not supported. +- Internal pointer protection and pointer mangling are disabled.