From: jpoimboe at redhat.com (Josh Poimboeuf)
Subject: [PATCH 2/4] x86/kprobes: Fix frame pointer annotations
Date: Wed, 8 May 2019 13:48:48 -0500 [thread overview]
Message-ID: <20190508184848.qerg3flv3ej3xsev@treble> (raw)
In-Reply-To: <20190508153907.GM2589@hirez.programming.kicks-ass.net>
On Wed, May 08, 2019 at 05:39:07PM +0200, Peter Zijlstra wrote:
> On Wed, May 08, 2019 at 07:42:48AM -0500, Josh Poimboeuf wrote:
> > On Wed, May 08, 2019 at 02:04:16PM +0200, Peter Zijlstra wrote:
>
> > > Do the x86_64 variants also want some ORC annotation?
> >
> > Maybe so. Though it looks like regs->ip isn't saved. The saved
> > registers might need to be tweaked. I'll need to look into it.
>
> What all these sites do (and maybe we should look at unifying them
> somehow) is turn a CALL frame (aka RET-IP) into an exception frame (aka
> pt_regs).
>
> So regs->ip will be the return address (which is fixed up to be the CALL
> address in the handler).
But from what I can tell, trampoline_handler() hard-codes regs->ip to
point to kretprobe_trampoline(), and the original return address is
placed in regs->sp.
Masami, is there a reason why regs->ip doesn't have the original return
address and regs->sp doesn't have the original SP? I think that would
help the unwinder understand things.
--
Josh
WARNING: multiple messages have this Message-ID (diff)
From: jpoimboe@redhat.com (Josh Poimboeuf)
Subject: [PATCH 2/4] x86/kprobes: Fix frame pointer annotations
Date: Wed, 8 May 2019 13:48:48 -0500 [thread overview]
Message-ID: <20190508184848.qerg3flv3ej3xsev@treble> (raw)
Message-ID: <20190508184848.zhQQkcVw8GDtZwkCayIiw8M2tBEsRG8J42vvV_FUvME@z> (raw)
In-Reply-To: <20190508153907.GM2589@hirez.programming.kicks-ass.net>
On Wed, May 08, 2019@05:39:07PM +0200, Peter Zijlstra wrote:
> On Wed, May 08, 2019@07:42:48AM -0500, Josh Poimboeuf wrote:
> > On Wed, May 08, 2019@02:04:16PM +0200, Peter Zijlstra wrote:
>
> > > Do the x86_64 variants also want some ORC annotation?
> >
> > Maybe so. Though it looks like regs->ip isn't saved. The saved
> > registers might need to be tweaked. I'll need to look into it.
>
> What all these sites do (and maybe we should look at unifying them
> somehow) is turn a CALL frame (aka RET-IP) into an exception frame (aka
> pt_regs).
>
> So regs->ip will be the return address (which is fixed up to be the CALL
> address in the handler).
But from what I can tell, trampoline_handler() hard-codes regs->ip to
point to kretprobe_trampoline(), and the original return address is
placed in regs->sp.
Masami, is there a reason why regs->ip doesn't have the original return
address and regs->sp doesn't have the original SP? I think that would
help the unwinder understand things.
--
Josh
next prev parent reply other threads:[~2019-05-08 18:48 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-08 7:49 [PATCH 0/4] x86: int3 fallout peterz
2019-05-08 7:49 ` Peter Zijlstra
2019-05-08 7:49 ` [PATCH 1/4] x86/entry/32: Clean up return from interrupt preemption path peterz
2019-05-08 7:49 ` Peter Zijlstra
2019-05-08 7:49 ` [PATCH 2/4] x86/kprobes: Fix frame pointer annotations peterz
2019-05-08 7:49 ` Peter Zijlstra
2019-05-08 11:54 ` jpoimboe
2019-05-08 11:54 ` Josh Poimboeuf
2019-05-08 12:04 ` peterz
2019-05-08 12:04 ` Peter Zijlstra
[not found] ` <20190508124248.u5ukpbhnh4wpiccq@treble>
[not found] ` <20190508153907.GM2589@hirez.programming.kicks-ass.net>
2019-05-08 18:48 ` jpoimboe [this message]
2019-05-08 18:48 ` Josh Poimboeuf
2019-05-09 1:20 ` mhiramat
2019-05-09 1:20 ` Masami Hiramatsu
2019-05-09 8:14 ` peterz
2019-05-09 8:14 ` Peter Zijlstra
2019-05-09 9:27 ` peterz
2019-05-09 9:27 ` Peter Zijlstra
2019-05-09 14:00 ` jpoimboe
2019-05-09 14:00 ` Josh Poimboeuf
2019-05-09 14:01 ` mhiramat
2019-05-09 14:01 ` Masami Hiramatsu
2019-05-09 17:14 ` peterz
2019-05-09 17:14 ` Peter Zijlstra
2019-05-10 4:58 ` mhiramat
2019-05-10 4:58 ` Masami Hiramatsu
2019-05-10 12:31 ` peterz
2019-05-10 12:31 ` Peter Zijlstra
2019-05-11 0:52 ` mhiramat
2019-05-11 0:52 ` Masami Hiramatsu
2019-05-10 12:40 ` peterz
2019-05-10 12:40 ` Peter Zijlstra
2019-05-11 0:56 ` mhiramat
2019-05-11 0:56 ` Masami Hiramatsu
2019-05-13 8:15 ` peterz
2019-05-13 8:15 ` Peter Zijlstra
2019-05-09 16:20 ` luto
2019-05-09 16:20 ` Andy Lutomirski
2019-05-09 17:18 ` peterz
2019-05-09 17:18 ` Peter Zijlstra
2019-05-09 17:43 ` rostedt
2019-05-09 17:43 ` Steven Rostedt
2019-05-10 3:21 ` mhiramat
2019-05-10 3:21 ` Masami Hiramatsu
2019-05-10 12:14 ` peterz
2019-05-10 12:14 ` Peter Zijlstra
2019-05-10 12:17 ` peterz
2019-05-10 12:17 ` Peter Zijlstra
2019-05-10 14:54 ` rostedt
2019-05-10 14:54 ` Steven Rostedt
2019-05-09 17:37 ` rostedt
2019-05-09 17:37 ` Steven Rostedt
2019-05-09 18:26 ` peterz
2019-05-09 18:26 ` Peter Zijlstra
2019-05-09 18:36 ` rostedt
2019-05-09 18:36 ` Steven Rostedt
2019-05-08 7:49 ` [PATCH 3/4] x86/ftrace: Add pt_regs frame annotations peterz
2019-05-08 7:49 ` Peter Zijlstra
2019-05-08 7:49 ` [RFC][PATCH 4/4] x86_32: Provide consistent pt_regs peterz
2019-05-08 7:49 ` Peter Zijlstra
2019-05-08 11:57 ` jpoimboe
2019-05-08 11:57 ` Josh Poimboeuf
2019-05-08 20:58 ` torvalds
2019-05-08 20:58 ` Linus Torvalds
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