From: Linus Torvalds <torvalds@linux-foundation.org>
To: Steven Rostedt <rostedt@goodmis.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 13:20:05 -0700 [thread overview]
Message-ID: <CAHk-=wiMG95TmkMm5AK7w73=mn+is8qnNztS7iJVfz23-A44Yg@mail.gmail.com> (raw)
In-Reply-To: <CAHk-=wgbC-wiSrdDYAh1ORF4EKmecY+MkNsJBF=BWf4W1bXXgA@mail.gmail.com>
On Mon, Apr 29, 2019 at 1:06 PM Linus Torvalds
<torvalds@linux-foundation.org> wrote:
>
> Only do the 'call' instructions one at a time. Why would you change
> _existing_ code?
Side note: if you want to, you can easily batch up rewriting 'call'
instructions to the same target using the exact same code. You just
need to change the int3 handler case to calculate the
bp_int3_call_return from the fixed one-time address to use sopmething
like
this_cpu_write(bp_call_return, int3_address-1+bp_int3_call_size);
instead (and you'd need to also teach the function that there's not
just a single int3 live at a time)
Linus
WARNING: multiple messages have this Message-ID (diff)
From: torvalds at linux-foundation.org (Linus Torvalds)
Subject: [PATCH 3/4] x86/ftrace: make ftrace_int3_handler() not to skip fops invocation
Date: Mon, 29 Apr 2019 13:20:05 -0700 [thread overview]
Message-ID: <CAHk-=wiMG95TmkMm5AK7w73=mn+is8qnNztS7iJVfz23-A44Yg@mail.gmail.com> (raw)
In-Reply-To: <CAHk-=wgbC-wiSrdDYAh1ORF4EKmecY+MkNsJBF=BWf4W1bXXgA@mail.gmail.com>
On Mon, Apr 29, 2019 at 1:06 PM Linus Torvalds
<torvalds at linux-foundation.org> wrote:
>
> Only do the 'call' instructions one at a time. Why would you change
> _existing_ code?
Side note: if you want to, you can easily batch up rewriting 'call'
instructions to the same target using the exact same code. You just
need to change the int3 handler case to calculate the
bp_int3_call_return from the fixed one-time address to use sopmething
like
this_cpu_write(bp_call_return, int3_address-1+bp_int3_call_size);
instead (and you'd need to also teach the function that there's not
just a single int3 live at a time)
Linus
WARNING: multiple messages have this Message-ID (diff)
From: torvalds@linux-foundation.org (Linus Torvalds)
Subject: [PATCH 3/4] x86/ftrace: make ftrace_int3_handler() not to skip fops invocation
Date: Mon, 29 Apr 2019 13:20:05 -0700 [thread overview]
Message-ID: <CAHk-=wiMG95TmkMm5AK7w73=mn+is8qnNztS7iJVfz23-A44Yg@mail.gmail.com> (raw)
Message-ID: <20190429202005.siq_bbNzeVPyEFs3ugYA-kIX3Wzh3PjHN6KsWQNzrPM@z> (raw)
In-Reply-To: <CAHk-=wgbC-wiSrdDYAh1ORF4EKmecY+MkNsJBF=BWf4W1bXXgA@mail.gmail.com>
On Mon, Apr 29, 2019 at 1:06 PM Linus Torvalds
<torvalds@linux-foundation.org> wrote:
>
> Only do the 'call' instructions one at a time. Why would you change
> _existing_ code?
Side note: if you want to, you can easily batch up rewriting 'call'
instructions to the same target using the exact same code. You just
need to change the int3 handler case to calculate the
bp_int3_call_return from the fixed one-time address to use sopmething
like
this_cpu_write(bp_call_return, int3_address-1+bp_int3_call_size);
instead (and you'd need to also teach the function that there's not
just a single int3 live at a time)
Linus
next prev parent reply other threads:[~2019-04-29 20:25 UTC|newest]
Thread overview: 192+ 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 ` Nicolai Stange
2019-04-27 10:06 ` nstange
2019-04-27 10:06 ` [PATCH 1/4] x86/thread_info: introduce ->ftrace_int3_stack member Nicolai Stange
2019-04-27 10:06 ` Nicolai Stange
2019-04-27 10:06 ` nstange
2019-04-28 17:41 ` Andy Lutomirski
2019-04-28 17:41 ` Andy Lutomirski
2019-04-28 17:41 ` luto
2019-04-28 17:51 ` Steven Rostedt
2019-04-28 17:51 ` Steven Rostedt
2019-04-28 17:51 ` rostedt
2019-04-28 18:08 ` Andy Lutomirski
2019-04-28 18:08 ` Andy Lutomirski
2019-04-28 18:08 ` luto
2019-04-28 19:43 ` Steven Rostedt
2019-04-28 19:43 ` Steven Rostedt
2019-04-28 19:43 ` rostedt
2019-04-28 20:56 ` Andy Lutomirski
2019-04-28 20:56 ` Andy Lutomirski
2019-04-28 20:56 ` luto
2019-04-28 21:22 ` Nicolai Stange
2019-04-28 21:22 ` Nicolai Stange
2019-04-28 21:22 ` nstange
2019-04-28 23:27 ` Andy Lutomirski
2019-04-28 23:27 ` Andy Lutomirski
2019-04-28 23:27 ` luto
2019-04-27 10:06 ` [PATCH 2/4] ftrace: drop 'static' qualifier from ftrace_ops_list_func() Nicolai Stange
2019-04-27 10:06 ` Nicolai Stange
2019-04-27 10:06 ` nstange
2019-04-27 10:06 ` [PATCH 3/4] x86/ftrace: make ftrace_int3_handler() not to skip fops invocation Nicolai Stange
2019-04-27 10:06 ` Nicolai Stange
2019-04-27 10:06 ` nstange
2019-04-27 10:26 ` Peter Zijlstra
2019-04-27 10:26 ` Peter Zijlstra
2019-04-27 10:26 ` peterz
2019-04-28 17:38 ` Steven Rostedt
2019-04-28 17:38 ` Steven Rostedt
2019-04-28 17:38 ` rostedt
2019-04-29 18:06 ` Linus Torvalds
2019-04-29 18:06 ` Linus Torvalds
2019-04-29 18:06 ` torvalds
2019-04-29 18:22 ` Linus Torvalds
2019-04-29 18:22 ` Linus Torvalds
2019-04-29 18:22 ` torvalds
2019-04-29 18:42 ` Andy Lutomirski
2019-04-29 18:42 ` Andy Lutomirski
2019-04-29 18:42 ` luto
[not found] ` <CAHk-=whtt4K2f0KPtG-4Pykh3FK8UBOjD8jhXCUKB5nWDj_YRA@mail.gmail.com>
2019-04-29 18:56 ` Andy Lutomirski
2019-04-29 18:56 ` Andy Lutomirski
2019-04-29 18:56 ` luto
[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 19:24 ` Andy Lutomirski
2019-04-29 19:24 ` luto
2019-04-29 20:07 ` Linus Torvalds
2019-04-29 20:07 ` Linus Torvalds
2019-04-29 20:07 ` torvalds
2019-04-30 13:56 ` Peter Zijlstra
2019-04-30 13:56 ` Peter Zijlstra
2019-04-30 13:56 ` peterz
2019-04-30 16:06 ` Linus Torvalds
2019-04-30 16:06 ` Linus Torvalds
2019-04-30 16:06 ` torvalds
2019-04-30 16:33 ` Andy Lutomirski
2019-04-30 16:33 ` Andy Lutomirski
2019-04-30 16:33 ` luto
2019-04-30 17:03 ` Steven Rostedt
2019-04-30 17:03 ` Steven Rostedt
2019-04-30 17:03 ` rostedt
2019-04-30 17:20 ` Steven Rostedt
2019-04-30 17:20 ` Steven Rostedt
2019-04-30 17:20 ` rostedt
2019-04-30 17:49 ` [RFC][PATCH] ftrace/x86: Emulate call function while updating in breakpoint handler Steven Rostedt
2019-04-30 17:49 ` Steven Rostedt
2019-04-30 17:49 ` rostedt
2019-04-30 18:33 ` Linus Torvalds
2019-04-30 18:33 ` Linus Torvalds
2019-04-30 18:33 ` torvalds
2019-04-30 19:00 ` Steven Rostedt
2019-04-30 19:00 ` Steven Rostedt
2019-04-30 19:00 ` rostedt
2019-04-30 21:08 ` Steven Rostedt
2019-04-30 21:08 ` Steven Rostedt
2019-04-30 21:08 ` rostedt
2019-05-01 13:11 ` Peter Zijlstra
2019-05-01 13:11 ` Peter Zijlstra
2019-05-01 13:11 ` peterz
2019-05-01 18:58 ` Steven Rostedt
2019-05-01 18:58 ` Steven Rostedt
2019-05-01 18:58 ` rostedt
2019-05-01 19:03 ` Peter Zijlstra
2019-05-01 19:03 ` Peter Zijlstra
2019-05-01 19:03 ` peterz
2019-05-01 19:03 ` Linus Torvalds
2019-05-01 19:03 ` Linus Torvalds
2019-05-01 19:03 ` torvalds
2019-05-01 19:13 ` Peter Zijlstra
2019-05-01 19:13 ` Peter Zijlstra
2019-05-01 19:13 ` peterz
2019-05-01 19:13 ` Steven Rostedt
2019-05-01 19:13 ` Steven Rostedt
2019-05-01 19:13 ` rostedt
2019-05-01 19:33 ` Jiri Kosina
2019-05-01 19:33 ` Jiri Kosina
2019-05-01 19:33 ` jikos
2019-05-01 19:41 ` Peter Zijlstra
2019-05-01 19:41 ` Peter Zijlstra
2019-05-01 19:41 ` peterz
2019-04-30 21:53 ` [RFC][PATCH v2] " Steven Rostedt
2019-04-30 21:53 ` Steven Rostedt
2019-04-30 21:53 ` rostedt
2019-05-01 1:35 ` Steven Rostedt
2019-05-01 1:35 ` Steven Rostedt
2019-05-01 1:35 ` rostedt
2019-05-01 1:58 ` Linus Torvalds
2019-05-01 1:58 ` Linus Torvalds
2019-05-01 1:58 ` torvalds
2019-05-01 8:26 ` Nicolai Stange
2019-05-01 8:26 ` Nicolai Stange
2019-05-01 8:26 ` nstange
2019-05-01 13:22 ` Steven Rostedt
2019-05-01 13:22 ` Steven Rostedt
2019-05-01 13:22 ` 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 20:16 ` Linus Torvalds
2019-04-29 20:16 ` torvalds
2019-04-29 22:08 ` Sean Christopherson
2019-04-29 22:08 ` Sean Christopherson
2019-04-29 22:08 ` sean.j.christopherson
2019-04-29 22:22 ` Linus Torvalds
2019-04-29 22:22 ` Linus Torvalds
2019-04-29 22:22 ` torvalds
2019-04-30 0:08 ` Sean Christopherson
2019-04-30 0:08 ` Sean Christopherson
2019-04-30 0:08 ` sean.j.christopherson
2019-04-30 0:45 ` Sean Christopherson
2019-04-30 0:45 ` Sean Christopherson
2019-04-30 0:45 ` sean.j.christopherson
2019-04-30 2:26 ` Linus Torvalds
2019-04-30 2:26 ` Linus Torvalds
2019-04-30 2:26 ` torvalds
2019-04-30 10:40 ` Peter Zijlstra
2019-04-30 10:40 ` Peter Zijlstra
2019-04-30 10:40 ` peterz
2019-04-30 11:17 ` Jiri Kosina
2019-04-30 11:17 ` Jiri Kosina
2019-04-30 11:17 ` jikos
2019-04-29 22:06 ` Linus Torvalds
2019-04-29 22:06 ` Linus Torvalds
2019-04-29 22:06 ` torvalds
2019-04-30 11:18 ` Peter Zijlstra
2019-04-30 11:18 ` Peter Zijlstra
2019-04-30 11:18 ` peterz
2019-04-29 18:52 ` Steven Rostedt
2019-04-29 18:52 ` Steven Rostedt
2019-04-29 18:52 ` rostedt
[not found] ` <CAHk-=wjm93jLtVxTX4HZs6K4k1Wqh3ujjmapqaYtcibVk_YnzQ@mail.gmail.com>
2019-04-29 19:07 ` Steven Rostedt
2019-04-29 19:07 ` Steven Rostedt
2019-04-29 19:07 ` rostedt
2019-04-29 20:06 ` Linus Torvalds
2019-04-29 20:06 ` Linus Torvalds
2019-04-29 20:06 ` torvalds
2019-04-29 20:20 ` Linus Torvalds [this message]
2019-04-29 20:20 ` Linus Torvalds
2019-04-29 20:20 ` torvalds
2019-04-29 20:30 ` Steven Rostedt
2019-04-29 20:30 ` Steven Rostedt
2019-04-29 20:30 ` rostedt
2019-04-29 21:38 ` Linus Torvalds
2019-04-29 21:38 ` Linus Torvalds
2019-04-29 21:38 ` torvalds
2019-04-29 22:07 ` Steven Rostedt
2019-04-29 22:07 ` Steven Rostedt
2019-04-29 22:07 ` rostedt
2019-04-30 9:24 ` Nicolai Stange
2019-04-30 9:24 ` Nicolai Stange
2019-04-30 9:24 ` nstange
2019-04-30 10:46 ` Peter Zijlstra
2019-04-30 10:46 ` Peter Zijlstra
2019-04-30 10:46 ` peterz
2019-04-30 13:44 ` Steven Rostedt
2019-04-30 13:44 ` Steven Rostedt
2019-04-30 13:44 ` rostedt
2019-04-30 14:20 ` Peter Zijlstra
2019-04-30 14:20 ` Peter Zijlstra
2019-04-30 14:20 ` peterz
2019-04-30 14:36 ` Steven Rostedt
2019-04-30 14:36 ` Steven Rostedt
2019-04-30 14:36 ` rostedt
2019-04-27 10:06 ` [PATCH 4/4] selftests/livepatch: add "ftrace a live patched function" test Nicolai Stange
2019-04-27 10:06 ` Nicolai Stange
2019-04-27 10:06 ` nstange
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