From: Peter Zijlstra <peterz@infradead.org>
To: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>,
"Masami Hiramatsu (Google)" <mhiramat@kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Ingo Molnar <mingo@kernel.org>,
Suleiman Souhlal <suleiman@google.com>, bpf <bpf@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>, Borislav Petkov <bp@suse.de>,
X86 ML <x86@kernel.org>
Subject: Re: [PATCH] x86,retpoline: Be sure to emit INT3 after JMP *%\reg
Date: Sun, 11 Sep 2022 17:14:10 +0200 [thread overview]
Message-ID: <Yx37QmkpvPoyHFMN@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20220909164809.k5vkeujwpvywkpmt@treble>
On Fri, Sep 09, 2022 at 09:48:09AM -0700, Josh Poimboeuf wrote:
> On Fri, Sep 09, 2022 at 10:16:13AM +0200, Peter Zijlstra wrote:
> > +++ b/arch/x86/net/bpf_jit_comp.c
> > @@ -419,7 +419,9 @@ static void emit_indirect_jump(u8 **ppro
> > OPTIMIZER_HIDE_VAR(reg);
> > emit_jump(&prog, &__x86_indirect_thunk_array[reg], ip);
> > } else {
> > - EMIT2(0xFF, 0xE0 + reg);
> > + EMIT2(0xFF, 0xE0 + reg); /* jmp *%\reg */
> > + if (IS_ENABLED(CONFIG_RETPOLINE) || IS_ENABLED(CONFIG_SLS))
> > + EMIT1(0xCC); /* int3 */
> > }
>
> Hm, if you have retpolines disabled at runtime, why would you want this.
Because I don't think eIBRS guarantees it will not SLS.
next prev parent reply other threads:[~2022-09-11 15:14 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-08 1:34 [PATCH v2 0/2] x86/kprobes: Fixes for CONFIG_RETHUNK Masami Hiramatsu (Google)
2022-09-08 1:34 ` [PATCH v2 1/2] x86/kprobes: Fix kprobes instruction boudary check with CONFIG_RETHUNK Masami Hiramatsu (Google)
2022-09-08 5:08 ` Josh Poimboeuf
2022-09-08 9:30 ` Peter Zijlstra
2022-09-08 10:04 ` [PATCH] x86,retpoline: Be sure to emit INT3 after JMP *%\reg Peter Zijlstra
2022-09-08 14:01 ` Alexei Starovoitov
2022-09-09 8:16 ` Peter Zijlstra
2022-09-09 14:19 ` Alexei Starovoitov
2022-09-09 16:48 ` Josh Poimboeuf
2022-09-11 15:14 ` Peter Zijlstra [this message]
2022-09-15 14:24 ` [tip: x86/core] " tip-bot2 for Peter Zijlstra
2022-09-08 10:08 ` [PATCH v2 1/2] x86/kprobes: Fix kprobes instruction boudary check with CONFIG_RETHUNK Peter Zijlstra
2022-09-08 13:03 ` Masami Hiramatsu
2022-09-08 15:01 ` [PATCH v3 0/2] x86/kprobes: Fixes for CONFIG_RETHUNK Masami Hiramatsu (Google)
2022-09-08 15:01 ` [PATCH v3 1/2] x86/kprobes: Fix kprobes instruction boudary check with CONFIG_RETHUNK Masami Hiramatsu (Google)
2022-09-08 15:01 ` [PATCH v3 2/2] x86/kprobes: Fix optprobe optimization " Masami Hiramatsu (Google)
2022-12-15 3:31 ` Nadav Amit
2022-12-18 14:28 ` Masami Hiramatsu
2022-09-08 19:31 ` [PATCH v3 0/2] x86/kprobes: Fixes for CONFIG_RETHUNK Josh Poimboeuf
2022-09-08 1:34 ` [PATCH v2 2/2] x86/kprobes: Fix optprobe optimization check with CONFIG_RETHUNK Masami Hiramatsu (Google)
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