From: Peter Zijlstra <peterz@infradead.org>
To: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
Ingo Molnar <mingo@kernel.org>, Juergen Gross <jgross@suse.com>,
Andrew Cooper <andrew.cooper3@citrix.com>
Subject: Re: [PATCH] objtool: Fix SYSCALL instruction handling and INSN_CONTEXT_SWITCH
Date: Fri, 4 Apr 2025 16:54:12 +0200 [thread overview]
Message-ID: <20250404145412.GP25239@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <iqalk74mk6onmntltkpodnbtp7zxxgx3u3ycuipmkizcmz7uvm@b7j7kubwzpl6>
On Fri, Apr 04, 2025 at 07:46:52AM -0700, Josh Poimboeuf wrote:
> On Fri, Apr 04, 2025 at 12:49:38PM +0200, Peter Zijlstra wrote:
> > On Thu, Apr 03, 2025 at 11:48:13AM -0700, Josh Poimboeuf wrote:
> >
> > > The real problem here is that INSN_CONTEXT_SWITCH is ambiguous. It can
> > > represent both call semantics (SYSCALL, SYSENTER) and return semantics
> > > (SYSRET, IRET, RETS, RETU). Those differ significantly: calls preserve
> > > control flow whereas returns terminate it.
> >
> > Does that not rather suggest we should perhaps have INSN_SYSCALL /
> > INSN_SYSRET to replace the single ambiguous thing?
>
> Is there any reason to have INSN_SYSCALL in the first place?
This xen hyperclal thing?
next prev parent reply other threads:[~2025-04-04 14:54 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-03 18:48 [PATCH] objtool: Fix SYSCALL instruction handling and INSN_CONTEXT_SWITCH Josh Poimboeuf
2025-04-03 18:57 ` Andrew Cooper
2025-04-03 19:05 ` Josh Poimboeuf
2025-04-03 19:15 ` Andrew Cooper
2025-04-03 19:20 ` Josh Poimboeuf
2025-04-04 7:40 ` Jürgen Groß
2025-04-04 10:49 ` Peter Zijlstra
2025-04-04 14:46 ` Josh Poimboeuf
2025-04-04 14:54 ` Peter Zijlstra [this message]
2025-04-04 15:02 ` Josh Poimboeuf
2025-04-04 15:03 ` Juergen Gross
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