All of lore.kernel.org
 help / color / mirror / Atom feed
From: Masami Hiramatsu <mhiramat@kernel.org>
To: Ingo Molnar <mingo@kernel.org>, mingo@redhat.com
Cc: x86@kernel.org, Steven Rostedt <rostedt@goodmis.org>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	linux-kernel@vger.kernel.org,
	Peter Zijlstra <peterz@infradead.org>,
	Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	"H . Peter Anvin" <hpa@zytor.com>,
	"Paul E . McKenney" <paulmck@linux.vnet.ibm.com>,
	Alexei Starovoitov <ast@kernel.org>,
	Alexei Starovoitov <ast@fb.com>
Subject: [BUGFIX PATCH] kprobes/x86: Remove IRQ disabling from jprobe handlers
Date: Tue,  3 Oct 2017 16:18:02 +0900	[thread overview]
Message-ID: <150701508194.32266.14458959863314097305.stgit@devbox> (raw)
In-Reply-To: <20170930231251.emiuyrapdgzpcylp@inn>
In-Reply-To: <20170930231251.emiuyrapdgzpcylp@inn>

Jprobe actually doesn't need to disable IRQs while calling
handlers, because Documentation/kprobes.txt says:

-----
 Probe handlers are run with preemption disabled.  Depending on the
 architecture and optimization state, handlers may also run with
 interrupts disabled (e.g., kretprobe handlers and optimized kprobe
 handlers run without interrupt disabled on x86/x86-64).
-----

So let's remove IRQ disabling from jprobes too.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
 arch/x86/kernel/kprobes/core.c |    2 --
 1 file changed, 2 deletions(-)

diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index b48e0efd668e..bd36f3c33cd0 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -1099,8 +1099,6 @@ int setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
 	 * raw stack chunk with redzones:
 	 */
 	__memcpy(kcb->jprobes_stack, (kprobe_opcode_t *)addr, MIN_STACK_SIZE(addr));
-	regs->flags &= ~X86_EFLAGS_IF;
-	trace_hardirqs_off();
 	regs->ip = (unsigned long)(jp->entry);
 
 	/*

  parent reply	other threads:[~2017-10-03  7:18 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-09-30 23:12 [kprobes/x86] a19b2e3d78: WARNING:at_kernel/locking/lockdep.c:#trace_hardirqs_off_caller kernel test robot
2017-09-30 23:12 ` kernel test robot
2017-10-02  7:33 ` Peter Zijlstra
2017-10-02  7:33   ` Peter Zijlstra
2017-10-02 15:46   ` Masami Hiramatsu
2017-10-02 15:46     ` Masami Hiramatsu
2017-10-02 16:05     ` Peter Zijlstra
2017-10-02 16:05       ` Peter Zijlstra
2017-10-03  1:10       ` Masami Hiramatsu
2017-10-03  1:10         ` Masami Hiramatsu
2017-10-02 16:19     ` Linus Torvalds
2017-10-02 16:19       ` Linus Torvalds
2017-10-03  2:26       ` Masami Hiramatsu
2017-10-03  2:26         ` Masami Hiramatsu
2017-10-03  7:18 ` Masami Hiramatsu [this message]
2017-10-03  9:33   ` [BUGFIX PATCH] kprobes/x86: Remove IRQ disabling from jprobe handlers Ingo Molnar
2017-10-03 15:24     ` Masami Hiramatsu
2017-10-03 17:11       ` Ingo Molnar
2017-10-04  6:18         ` Masami Hiramatsu
2017-10-04 10:41           ` Ingo Molnar
2017-10-04 14:08             ` Masami Hiramatsu
2017-10-05  7:57               ` Ingo Molnar
2017-10-05  8:28                 ` Masami Hiramatsu
2017-10-03 17:43   ` [tip:x86/urgent] " tip-bot for Masami Hiramatsu

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=150701508194.32266.14458959863314097305.stgit@devbox \
    --to=mhiramat@kernel.org \
    --cc=ananth@linux.vnet.ibm.com \
    --cc=ast@fb.com \
    --cc=ast@kernel.org \
    --cc=hpa@zytor.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mingo@kernel.org \
    --cc=mingo@redhat.com \
    --cc=paulmck@linux.vnet.ibm.com \
    --cc=peterz@infradead.org \
    --cc=rostedt@goodmis.org \
    --cc=tglx@linutronix.de \
    --cc=x86@kernel.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.