From: Peter Zijlstra <peterz@infradead.org>
To: x86@kernel.org
Cc: linux-kernel@vger.kernel.org, Kyle Huey <me@kylehuey.com>,
Alexandre Chartre <alexandre.chartre@oracle.com>,
Robert O'Callahan <rocallahan@gmail.com>,
"Paul E. McKenney" <paulmck@kernel.org>,
Frederic Weisbecker <frederic@kernel.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <sean.j.christopherson@intel.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
Petr Mladek <pmladek@suse.com>,
Steven Rostedt <rostedt@goodmis.org>,
Joel Fernandes <joel@joelfernandes.org>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Juergen Gross <jgross@suse.com>, Brian Gerst <brgerst@gmail.com>,
Andy Lutomirski <luto@kernel.org>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Daniel Thompson <daniel.thompson@linaro.org>,
Peter Zijlstra <peterz@infradead.org>
Subject: [PATCH 06/13] x86/debug: Simplify #DB signal code
Date: Wed, 02 Sep 2020 15:25:55 +0200 [thread overview]
Message-ID: <20200902133200.967434217@infradead.org> (raw)
In-Reply-To: 20200902132549.496605622@infradead.org
There's no point in calculating si_code if we're not going to use it.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
---
arch/x86/kernel/traps.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -786,15 +786,14 @@ static __always_inline unsigned long deb
static void handle_debug(struct pt_regs *regs, unsigned long dr6)
{
struct task_struct *tsk = current;
- bool user_icebp;
- int si_code;
+ bool icebp;
/*
* If dr6 has no reason to give us about the origin of this trap,
* then it's very likely the result of an icebp/int01 trap.
* User wants a sigtrap for that.
*/
- user_icebp = !dr6;
+ icebp = !dr6;
/* Store the virtualized DR6 value */
tsk->thread.debugreg6 = dr6;
@@ -813,6 +812,11 @@ static void handle_debug(struct pt_regs
goto out;
}
+ /*
+ * Reload dr6, the notifier might have changed it.
+ */
+ dr6 = tsk->thread.debugreg6;
+
if (WARN_ON_ONCE((dr6 & DR_STEP) && !user_mode(regs))) {
/*
* Historical junk that used to handle SYSENTER single-stepping.
@@ -825,9 +829,8 @@ static void handle_debug(struct pt_regs
regs->flags &= ~X86_EFLAGS_TF;
}
- si_code = get_si_code(tsk->thread.debugreg6);
- if (tsk->thread.debugreg6 & (DR_STEP | DR_TRAP_BITS) || user_icebp)
- send_sigtrap(regs, 0, si_code);
+ if (dr6 & (DR_STEP | DR_TRAP_BITS) || icebp)
+ send_sigtrap(regs, 0, get_si_code(dr6));
out:
cond_local_irq_disable(regs);
next prev parent reply other threads:[~2020-09-02 14:00 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-02 13:25 [PATCH 00/13] x86/debug: Untangle handle_debug() Peter Zijlstra
2020-09-02 13:25 ` [PATCH 01/13] x86/entry: Fix AC assertion Peter Zijlstra
2020-09-02 15:58 ` Brian Gerst
2020-09-02 16:24 ` Jürgen Groß
2020-09-02 16:31 ` peterz
2020-09-02 17:02 ` Brian Gerst
2020-09-02 16:26 ` Andrew Cooper
2020-09-04 13:16 ` [tip: x86/urgent] " tip-bot2 for Peter Zijlstra
2020-09-02 13:25 ` [PATCH 02/13] x86/debug: Allow a single level of #DB recursion Peter Zijlstra
2020-09-02 23:59 ` Sasha Levin
2020-09-03 16:12 ` Josh Poimboeuf
2020-09-02 13:25 ` [PATCH 03/13] x86/debug: Sync BTF earlier Peter Zijlstra
2020-09-04 13:16 ` [tip: x86/entry] " tip-bot2 for Peter Zijlstra
2020-09-02 13:25 ` [PATCH 04/13] x86/debug: Move kprobe_debug_handler() into exc_debug_kernel() Peter Zijlstra
2020-09-04 13:16 ` [tip: x86/entry] " tip-bot2 for Peter Zijlstra
2020-09-02 13:25 ` [PATCH 05/13] x86/debug: Remove handle_debug(.user) argument Peter Zijlstra
2020-09-04 13:16 ` [tip: x86/entry] " tip-bot2 for Peter Zijlstra
2020-09-02 13:25 ` Peter Zijlstra [this message]
2020-09-04 13:16 ` [tip: x86/entry] x86/debug: Simplify #DB signal code tip-bot2 for Peter Zijlstra
2020-09-02 13:25 ` [PATCH 07/13] x86/debug: Move historical SYSENTER junk into exc_debug_kernel() Peter Zijlstra
2020-09-04 13:16 ` [tip: x86/entry] " tip-bot2 for Peter Zijlstra
2020-09-02 13:25 ` [PATCH 08/13] x86/debug: Move cond_local_irq_enable() block into exc_debug_user() Peter Zijlstra
2020-09-04 13:16 ` [tip: x86/entry] " tip-bot2 for Peter Zijlstra
2020-09-02 13:25 ` [PATCH 09/13] x86/debug: Remove the historical junk Peter Zijlstra
2020-09-04 13:16 ` [tip: x86/entry] " tip-bot2 for Peter Zijlstra
2020-09-02 13:25 ` [PATCH 10/13] x86/debug: Remove aout_dump_debugregs() Peter Zijlstra
2020-09-04 13:16 ` [tip: x86/entry] " tip-bot2 for Peter Zijlstra
2020-09-02 13:26 ` [PATCH 11/13] x86/debug: Simplify hw_breakpoint_handler() Peter Zijlstra
2020-09-04 13:16 ` [tip: x86/entry] " tip-bot2 for Peter Zijlstra
2020-09-02 13:26 ` [RFC][PATCH 12/13] x86/debug: Support negative polarity DR6 bits Peter Zijlstra
2020-09-04 13:16 ` [tip: x86/entry] " tip-bot2 for Peter Zijlstra
2020-09-02 13:26 ` [RFC][PATCH 13/13] x86/debug: Change thread.debugreg6 to thread.virtual_dr6 Peter Zijlstra
2020-09-04 13:16 ` [tip: x86/entry] " tip-bot2 for Peter Zijlstra
2020-09-03 15:21 ` [PATCH 00/13] x86/debug: Untangle handle_debug() Daniel Thompson
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=20200902133200.967434217@infradead.org \
--to=peterz@infradead.org \
--cc=alexandre.chartre@oracle.com \
--cc=boris.ostrovsky@oracle.com \
--cc=brgerst@gmail.com \
--cc=daniel.thompson@linaro.org \
--cc=frederic@kernel.org \
--cc=jgross@suse.com \
--cc=joel@joelfernandes.org \
--cc=jpoimboe@redhat.com \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=me@kylehuey.com \
--cc=mhiramat@kernel.org \
--cc=paulmck@kernel.org \
--cc=pbonzini@redhat.com \
--cc=pmladek@suse.com \
--cc=rocallahan@gmail.com \
--cc=rostedt@goodmis.org \
--cc=sean.j.christopherson@intel.com \
--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 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).