From: Steven Rostedt <rostedt@goodmis.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>,
Nicolai Stange <nstange@suse.de>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
"H. Peter Anvin" <hpa@zytor.com>,
"the arch/x86 maintainers" <x86@kernel.org>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Jiri Kosina <jikos@kernel.org>, Miroslav Benes <mbenes@suse.cz>,
Petr Mladek <pmladek@suse.com>,
Joe Lawrence <joe.lawrence@redhat.com>,
Shuah Khan <shuah@kernel.org>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Tim Chen <tim.c.chen@linux.intel.com>,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Mimi Zohar <zohar@linux.ibm.com>, Juergen Gross <jgross@suse.com>,
Nick Desaulniers <ndesaulniers@google.com>,
Nayna Jain <nayna@linux.ibm.com>,
Masahiro Yamada <yamada.masahiro@socionext.com>,
Andy Lutomirski <luto@kernel.org>, Joerg Roedel <jroedel@suse.de>,
Linux List Kernel Mailing <linux-kernel@vger.kernel.org>,
live-patching@vger.kernel.org,
"open list:KERNEL SELFTEST FRAMEWORK"
<linux-kselftest@vger.kernel.org>
Subject: Re: [PATCH 3/4] x86/ftrace: make ftrace_int3_handler() not to skip fops invocation
Date: Mon, 29 Apr 2019 14:52:50 -0400 [thread overview]
Message-ID: <20190429145250.1a5da6ed@gandalf.local.home> (raw)
In-Reply-To: <CAHk-=wh5OpheSU8Em_Q3Hg8qw_JtoijxOdPtHru6d+5K8TWM=A@mail.gmail.com>
On Mon, 29 Apr 2019 11:06:58 -0700
Linus Torvalds <torvalds@linux-foundation.org> wrote:
> +void replace_call(void *addr, const void *opcode, size_t len, void *target)
> +{
> + bp_int3_call_target = target;
> + bp_int3_call_return = addr + len;
> + bp_int3_handler_irqoff = emulate_call_irqoff;
> + text_poke_bp(addr, opcode, len, emulate_call_irqon);
> +}
Note, the function tracer does not use text poke. It does it in batch
mode. It can update over 40,000 calls in one go:
add int3 breakpoint to all 40,000 call sites.
sync()
change the last four bytes of each of those call sites
sync()
remove int3 from the 40,000 call site with new call.
It's a bit more intrusive than the static call updates we were
discussing before.
-- Steve
next prev parent reply other threads:[~2019-04-29 18:52 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-27 10:06 [PATCH 0/4] x86/ftrace: make ftrace_int3_handler() not to skip fops invocation Nicolai Stange
2019-04-27 10:06 ` [PATCH 1/4] x86/thread_info: introduce ->ftrace_int3_stack member Nicolai Stange
2019-04-28 17:41 ` Andy Lutomirski
2019-04-28 17:51 ` Steven Rostedt
2019-04-28 18:08 ` Andy Lutomirski
2019-04-28 19:43 ` Steven Rostedt
2019-04-28 20:56 ` Andy Lutomirski
2019-04-28 21:22 ` Nicolai Stange
2019-04-28 23:27 ` Andy Lutomirski
2019-04-27 10:06 ` [PATCH 2/4] ftrace: drop 'static' qualifier from ftrace_ops_list_func() Nicolai Stange
2019-04-27 10:06 ` [PATCH 3/4] x86/ftrace: make ftrace_int3_handler() not to skip fops invocation Nicolai Stange
2019-04-27 10:26 ` Peter Zijlstra
2019-04-28 17:38 ` Steven Rostedt
2019-04-29 18:06 ` Linus Torvalds
2019-04-29 18:22 ` Linus Torvalds
2019-04-29 18:42 ` Andy Lutomirski
[not found] ` <CAHk-=whtt4K2f0KPtG-4Pykh3FK8UBOjD8jhXCUKB5nWDj_YRA@mail.gmail.com>
2019-04-29 18:56 ` Andy Lutomirski
[not found] ` <CAHk-=wgewK4eFhF3=0RNtk1KQjMANFH6oDE=8m=84RExn2gxhw@mail.gmail.com>
[not found] ` <CAHk-=whay7eN6+2gZjY-ybRbkbcqAmgrLwwszzHx8ws3c=S-MA@mail.gmail.com>
2019-04-29 19:24 ` Andy Lutomirski
2019-04-29 20:07 ` Linus Torvalds
2019-04-30 13:56 ` Peter Zijlstra
2019-04-30 16:06 ` Linus Torvalds
2019-04-30 16:33 ` Andy Lutomirski
2019-04-30 17:03 ` Steven Rostedt
2019-04-30 17:20 ` Steven Rostedt
2019-04-30 17:49 ` [RFC][PATCH] ftrace/x86: Emulate call function while updating in breakpoint handler Steven Rostedt
2019-04-30 18:33 ` Linus Torvalds
2019-04-30 19:00 ` Steven Rostedt
2019-04-30 21:08 ` Steven Rostedt
2019-05-01 13:11 ` Peter Zijlstra
2019-05-01 18:58 ` Steven Rostedt
2019-05-01 19:03 ` Peter Zijlstra
2019-05-01 19:03 ` Linus Torvalds
2019-05-01 19:13 ` Peter Zijlstra
2019-05-01 19:13 ` Steven Rostedt
2019-05-01 19:33 ` Jiri Kosina
2019-05-01 19:41 ` Peter Zijlstra
2019-04-30 21:53 ` [RFC][PATCH v2] " Steven Rostedt
2019-05-01 1:35 ` Steven Rostedt
2019-05-01 1:58 ` Linus Torvalds
2019-05-01 8:26 ` Nicolai Stange
2019-05-01 13:22 ` Steven Rostedt
2019-04-29 20:16 ` [PATCH 3/4] x86/ftrace: make ftrace_int3_handler() not to skip fops invocation Linus Torvalds
2019-04-29 22:08 ` Sean Christopherson
2019-04-29 22:22 ` Linus Torvalds
2019-04-30 0:08 ` Sean Christopherson
2019-04-30 0:45 ` Sean Christopherson
2019-04-30 2:26 ` Linus Torvalds
2019-04-30 10:40 ` Peter Zijlstra
2019-04-30 11:17 ` Jiri Kosina
2019-04-29 22:06 ` Linus Torvalds
2019-04-30 11:18 ` Peter Zijlstra
2019-04-29 18:52 ` Steven Rostedt [this message]
[not found] ` <CAHk-=wjm93jLtVxTX4HZs6K4k1Wqh3ujjmapqaYtcibVk_YnzQ@mail.gmail.com>
2019-04-29 19:07 ` Steven Rostedt
2019-04-29 20:06 ` Linus Torvalds
2019-04-29 20:20 ` Linus Torvalds
2019-04-29 20:30 ` Steven Rostedt
2019-04-29 21:38 ` Linus Torvalds
2019-04-29 22:07 ` Steven Rostedt
2019-04-30 9:24 ` Nicolai Stange
2019-04-30 10:46 ` Peter Zijlstra
2019-04-30 13:44 ` Steven Rostedt
2019-04-30 14:20 ` Peter Zijlstra
2019-04-30 14:36 ` Steven Rostedt
2019-04-27 10:06 ` [PATCH 4/4] selftests/livepatch: add "ftrace a live patched function" test Nicolai Stange
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