From: peterz@infradead.org (Peter Zijlstra)
Subject: [RFC][PATCH] ftrace/x86: Emulate call function while updating in breakpoint handler
Date: Wed, 1 May 2019 21:13:24 +0200 [thread overview]
Message-ID: <20190501191324.GU7905@worktop.programming.kicks-ass.net> (raw)
Message-ID: <20190501191324.Hrm3I8AdbBw56fjYlDxcFbzOIJWvMEuecpaB61JlZa8@z> (raw)
In-Reply-To: <CAHk-=wjCoycqdVjvWkkFnVRQS9fHEzdmiAG4uUV8B04xv7ZVwA@mail.gmail.com>
On Wed, May 01, 2019@12:03:52PM -0700, Linus Torvalds wrote:
> On Wed, May 1, 2019@6:11 AM Peter Zijlstra <peterz@infradead.org> wrote:
> >
> > Here goes, compile tested only...
>
> Ugh, two different threads. This has the same bug (same source) as the
> one Steven posted:
This is what Steve started from; lets continue in the other thread.
> > --- a/arch/x86/entry/entry_32.S
> > +++ b/arch/x86/entry/entry_32.S
> > @@ -1479,6 +1479,13 @@ ENTRY(int3)
> > ASM_CLAC
> > pushl $-1 # mark this as an int
> >
> > + testl $SEGMENT_RPL_MASK, PT_CS(%esp)
> > + jnz .Lfrom_usermode_no_gap
> > + .rept 6
> > + pushl 5*4(%esp)
> > + .endr
> > +.Lfrom_usermode_no_gap:
>
> This will corrupt things horribly if you still use vm86 mode. Checking
> CS RPL is simply not correct.
I'll go fix; I never really understood that vm86 crud and I cobbled this
32bit thing together based on the 64bit version (that Josh did a while
ago).
next prev parent reply other threads:[~2019-05-01 19:13 UTC|newest]
Thread overview: 128+ 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 nstange
2019-04-27 10:06 ` Nicolai Stange
2019-04-27 10:06 ` [PATCH 1/4] x86/thread_info: introduce ->ftrace_int3_stack member nstange
2019-04-27 10:06 ` Nicolai Stange
2019-04-28 17:41 ` luto
2019-04-28 17:41 ` Andy Lutomirski
2019-04-28 17:51 ` rostedt
2019-04-28 17:51 ` Steven Rostedt
2019-04-28 18:08 ` luto
2019-04-28 18:08 ` Andy Lutomirski
2019-04-28 19:43 ` rostedt
2019-04-28 19:43 ` Steven Rostedt
2019-04-28 20:56 ` luto
2019-04-28 20:56 ` Andy Lutomirski
2019-04-28 21:22 ` nstange
2019-04-28 21:22 ` Nicolai Stange
2019-04-28 23:27 ` luto
2019-04-28 23:27 ` Andy Lutomirski
2019-04-27 10:06 ` [PATCH 2/4] ftrace: drop 'static' qualifier from ftrace_ops_list_func() nstange
2019-04-27 10:06 ` Nicolai Stange
2019-04-27 10:06 ` [PATCH 3/4] x86/ftrace: make ftrace_int3_handler() not to skip fops invocation nstange
2019-04-27 10:06 ` Nicolai Stange
2019-04-27 10:26 ` peterz
2019-04-27 10:26 ` Peter Zijlstra
2019-04-28 17:38 ` rostedt
2019-04-28 17:38 ` Steven Rostedt
2019-04-29 18:06 ` torvalds
2019-04-29 18:06 ` Linus Torvalds
2019-04-29 18:22 ` torvalds
2019-04-29 18:22 ` Linus Torvalds
2019-04-29 18:42 ` luto
2019-04-29 18:42 ` Andy Lutomirski
[not found] ` <CAHk-=whtt4K2f0KPtG-4Pykh3FK8UBOjD8jhXCUKB5nWDj_YRA@mail.gmail.com>
2019-04-29 18:56 ` luto
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 ` luto
2019-04-29 19:24 ` Andy Lutomirski
2019-04-29 20:07 ` torvalds
2019-04-29 20:07 ` Linus Torvalds
2019-04-30 13:56 ` peterz
2019-04-30 13:56 ` Peter Zijlstra
2019-04-30 16:06 ` torvalds
2019-04-30 16:06 ` Linus Torvalds
2019-04-30 16:33 ` luto
2019-04-30 16:33 ` Andy Lutomirski
2019-04-30 17:03 ` rostedt
2019-04-30 17:03 ` Steven Rostedt
2019-04-30 17:20 ` 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 rostedt
2019-04-30 17:49 ` Steven Rostedt
2019-04-30 18:33 ` torvalds
2019-04-30 18:33 ` Linus Torvalds
2019-04-30 19:00 ` rostedt
2019-04-30 19:00 ` Steven Rostedt
2019-04-30 21:08 ` rostedt
2019-04-30 21:08 ` Steven Rostedt
2019-05-01 13:11 ` peterz
2019-05-01 13:11 ` Peter Zijlstra
2019-05-01 18:58 ` rostedt
2019-05-01 18:58 ` Steven Rostedt
2019-05-01 19:03 ` peterz
2019-05-01 19:03 ` Peter Zijlstra
2019-05-01 19:03 ` torvalds
2019-05-01 19:03 ` Linus Torvalds
2019-05-01 19:13 ` peterz [this message]
2019-05-01 19:13 ` Peter Zijlstra
2019-05-01 19:13 ` rostedt
2019-05-01 19:13 ` Steven Rostedt
2019-05-01 19:33 ` jikos
2019-05-01 19:33 ` Jiri Kosina
2019-05-01 19:41 ` peterz
2019-05-01 19:41 ` Peter Zijlstra
2019-04-30 21:53 ` [RFC][PATCH v2] " rostedt
2019-04-30 21:53 ` Steven Rostedt
2019-05-01 1:35 ` rostedt
2019-05-01 1:35 ` Steven Rostedt
2019-05-01 1:58 ` torvalds
2019-05-01 1:58 ` Linus Torvalds
2019-05-01 8:26 ` nstange
2019-05-01 8:26 ` Nicolai Stange
2019-05-01 13:22 ` rostedt
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 torvalds
2019-04-29 20:16 ` Linus Torvalds
2019-04-29 22:08 ` sean.j.christopherson
2019-04-29 22:08 ` Sean Christopherson
2019-04-29 22:22 ` torvalds
2019-04-29 22:22 ` Linus Torvalds
2019-04-30 0:08 ` sean.j.christopherson
2019-04-30 0:08 ` Sean Christopherson
2019-04-30 0:45 ` sean.j.christopherson
2019-04-30 0:45 ` Sean Christopherson
2019-04-30 2:26 ` torvalds
2019-04-30 2:26 ` Linus Torvalds
2019-04-30 10:40 ` peterz
2019-04-30 10:40 ` Peter Zijlstra
2019-04-30 11:17 ` jikos
2019-04-30 11:17 ` Jiri Kosina
2019-04-29 22:06 ` torvalds
2019-04-29 22:06 ` Linus Torvalds
2019-04-30 11:18 ` peterz
2019-04-30 11:18 ` Peter Zijlstra
2019-04-29 18:52 ` rostedt
2019-04-29 18:52 ` Steven Rostedt
[not found] ` <CAHk-=wjm93jLtVxTX4HZs6K4k1Wqh3ujjmapqaYtcibVk_YnzQ@mail.gmail.com>
2019-04-29 19:07 ` rostedt
2019-04-29 19:07 ` Steven Rostedt
2019-04-29 20:06 ` torvalds
2019-04-29 20:06 ` Linus Torvalds
2019-04-29 20:20 ` torvalds
2019-04-29 20:20 ` Linus Torvalds
2019-04-29 20:30 ` rostedt
2019-04-29 20:30 ` Steven Rostedt
2019-04-29 21:38 ` torvalds
2019-04-29 21:38 ` Linus Torvalds
2019-04-29 22:07 ` rostedt
2019-04-29 22:07 ` Steven Rostedt
2019-04-30 9:24 ` nstange
2019-04-30 9:24 ` Nicolai Stange
2019-04-30 10:46 ` peterz
2019-04-30 10:46 ` Peter Zijlstra
2019-04-30 13:44 ` rostedt
2019-04-30 13:44 ` Steven Rostedt
2019-04-30 14:20 ` peterz
2019-04-30 14:20 ` Peter Zijlstra
2019-04-30 14:36 ` rostedt
2019-04-30 14:36 ` Steven Rostedt
2019-04-27 10:06 ` [PATCH 4/4] selftests/livepatch: add "ftrace a live patched function" test nstange
2019-04-27 10:06 ` Nicolai Stange
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190501191324.GU7905@worktop.programming.kicks-ass.net \
--to=peterz@infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).