From: Peter Zijlstra <peterz@infradead.org>
To: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>, Ingo Molnar <mingo@kernel.org>,
Oleg Nesterov <oleg@redhat.com>,
LKML <linux-kernel@vger.kernel.org>,
Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>,
"David S . Miller" <davem@davemloft.net>, X86 ML <x86@kernel.org>,
Andrew Cooper <andrew.cooper3@citrix.com>,
Steven Rostedt <rostedt@goodmis.org>
Subject: Re: [RFC PATCH 1/1] x86/kprobes: Use int3 instead of debug trap for single-step
Date: Tue, 2 Mar 2021 14:58:01 +0100 [thread overview]
Message-ID: <YD5EaUKI8lswWPMq@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <YD39U0sz+IjV60VE@hirez.programming.kicks-ass.net>
On Tue, Mar 02, 2021 at 09:54:43AM +0100, Peter Zijlstra wrote:
> +static void kprobe_emulate_jcc(struct kprobe *p, struct pt_regs *regs)
> +{
> + bool invert = p->ainsn.jcc.type & 1;
> + bool match;
> +
> + if (p->ainsn.jcc.type < 0xc) {
> + match = regs->flags & jcc_mask[p->ainsn.jcc.type >> 1];
> + } else {
> + match = ((regs->flags & X86_EFLAGS_SF) >> X86_EFLAGS_SF_BIT) ^
> + ((regs->flags & X86_EFLAGS_OF) >> X86_EFLAGS_OF_BIT);
> + if (p->ainsn.jcc.type >= 0xe)
> + match = match && (regs->flags & X86_EFLAGS_ZF);
> + }
> + __kprobe_emulate_jmp(p, regs, (match && !invert) || (!match && invert));
Also, isn't that: 'match ^ invert' ?
> +}
next prev parent reply other threads:[~2021-03-02 16:39 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-23 23:24 Why do kprobes and uprobes singlestep? Andy Lutomirski
2021-02-24 1:17 ` Masami Hiramatsu
2021-02-24 19:45 ` Andy Lutomirski
2021-02-25 2:22 ` Masami Hiramatsu
2021-02-25 6:03 ` Andy Lutomirski
2021-02-25 9:11 ` Masami Hiramatsu
2021-03-01 14:08 ` [RFC PATCH 0/1] x86/kprobes: Remoev single-step trap from x86 kprobes Masami Hiramatsu
2021-03-01 14:08 ` [RFC PATCH 1/1] x86/kprobes: Use int3 instead of debug trap for single-step Masami Hiramatsu
2021-03-02 8:06 ` Peter Zijlstra
2021-03-02 8:38 ` Peter Zijlstra
2021-03-02 8:41 ` Peter Zijlstra
2021-03-02 8:54 ` Peter Zijlstra
2021-03-02 12:51 ` Masami Hiramatsu
2021-03-02 13:58 ` Peter Zijlstra [this message]
2021-03-02 15:25 ` [PATCH -tip 0/3] x86/kprobes: Remoev single-step trap from x86 kprobes Masami Hiramatsu
2021-03-02 15:25 ` [PATCH -tip 1/3] x86/kprobes: Retrieve correct opcode for group instruction Masami Hiramatsu
2021-03-23 15:15 ` [tip: x86/core] " tip-bot2 for Masami Hiramatsu
2021-03-02 15:25 ` [PATCH -tip 2/3] x86/kprobes: Identify far indirect JMP correctly Masami Hiramatsu
2021-03-23 15:15 ` [tip: x86/core] " tip-bot2 for Masami Hiramatsu
2021-03-02 15:25 ` [PATCH -tip 3/3] x86/kprobes: Use int3 instead of debug trap for single-step Masami Hiramatsu
2021-03-23 15:15 ` [tip: x86/core] " tip-bot2 for Masami Hiramatsu
2021-03-17 14:55 ` [PATCH -tip 0/3] x86/kprobes: Remoev single-step trap from x86 kprobes Masami Hiramatsu
2021-03-17 16:26 ` Peter Zijlstra
2021-03-17 17:45 ` Andy Lutomirski
2021-02-25 9:59 ` Why do kprobes and uprobes singlestep? Peter Zijlstra
2021-03-01 16:51 ` Oleg Nesterov
2021-03-02 1:36 ` Andy Lutomirski
2021-03-02 20:24 ` Alexei Starovoitov
2021-03-02 21:02 ` Andy Lutomirski
2021-03-03 1:22 ` Alexei Starovoitov
2021-03-03 1:46 ` Andy Lutomirski
2021-03-03 2:18 ` Alexei Starovoitov
2021-03-03 13:27 ` Oleg Nesterov
2021-03-03 18:11 ` Daniel Xu
2021-03-03 19:14 ` Andy Lutomirski
2021-03-02 20:25 ` Oleg Nesterov
2021-03-02 20:35 ` Andy Lutomirski
2021-03-02 20:28 ` Oleg Nesterov
2021-03-02 2:22 ` Masami Hiramatsu
2021-03-02 2:48 ` Andy Lutomirski
2021-03-02 20:31 ` Oleg Nesterov
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