lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Mon, 31 Oct 2022 15:47:08 +0000 From: Mark Rutland <mark.rutland@....com> To: Masami Hiramatsu <mhiramat@...nel.org> Cc: linux-kernel@...r.kernel.org, catalin.marinas@....com, linux-arm-kernel@...ts.infradead.org, revest@...omium.org, rostedt@...dmis.org, will@...nel.org Subject: Re: [PATCH 3/4] ftrace: abstract DYNAMIC_FTRACE_WITH_ARGS accesses On Wed, Oct 26, 2022 at 12:17:54AM +0900, Masami Hiramatsu wrote: > On Tue, 25 Oct 2022 11:30:38 +0100 > Mark Rutland <mark.rutland@....com> wrote: > > > On Tue, Oct 25, 2022 at 05:40:01PM +0900, Masami Hiramatsu wrote: > > > Hi Mark, > > > > > > On Mon, 24 Oct 2022 15:08:45 +0100 > > > Mark Rutland <mark.rutland@....com> wrote: > > > > > > > In subsequent patches we'll arrange for architectures to have an > > > > ftrace_regs which is entirely distinct from pt_regs. In preparation for > > > > this, we need to minimize the use of pt_regs to where strictly necessary > > > > in the core ftrace code. > > > > > > > > This patch adds new ftrace_regs_{get,set}_*() helpers which can be used > > > > to manipulate ftrace_regs. When CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS=y, > > > > these can always be used on any ftrace_regs, and when > > > > CONFIG_HAVE_DYNAMIC_FTRACE_WITH_ARGS=n these can be used when regs are > > > > available. A new ftrace_regs_has_args(fregs) helper is added which code > > > > can use to check when these are usable. > > > > > > Can you also add the ftrace_regs_query_register_offset() as a wrapper of > > > regs_query_register_offset()? I would like to use it for fprobe_events. > > > > Sure! > > > > Just to check, with FTRACE_WITH_REGS, does fprobe always sample the full > > pt_regs, or do callers also need to check ftrace_regs_has_args(fregs)? > > No, please return -ENOENT or any error value if the given register > is not saved on arm64. Sure, that's what I intend to implement for arm64. I'll use -EINVAL to match the existing regs_query_register_offset() logic. > Others will just return regs_query_register_offset(&fregs->regs, name). That > is enough at this moment. Later we can improve it. Sorry, what I was trying to ask was whether fprobe currently always set FTRACE_OPS_FL_SAVE_REGS (which AFAICT it does); so I now agree that's sufficient -- sorry for the noise! Thanks, Mark.
Powered by blists - more mailing lists