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From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: x86@kernel.org, "Paul E. McKenney" <paulmck@kernel.org>,
	Andy Lutomirski <luto@kernel.org>,
	Alexandre Chartre <alexandre.chartre@oracle.com>,
	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>,
	Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	Will Deacon <will@kernel.org>,
	"Peter Zijlstra (Intel)" <peterz@infradead.org>
Subject: [patch V4 part 4 04/24] x86/int3: Inline bsearch()
Date: Tue, 05 May 2020 15:49:30 +0200	[thread overview]
Message-ID: <20200505135313.731774429@linutronix.de> (raw)
In-Reply-To: 20200505134926.578885807@linutronix.de

From: Peter Zijlstra <peterz@infradead.org>

Avoid calling out to bsearch() by inlining it, for normal kernel configs
this was the last external call and poke_int3_handler() is now fully self
sufficient -- no calls to external code.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 arch/x86/kernel/alternative.c |    8 ++++----
 arch/x86/kernel/traps.c       |    5 +++++
 2 files changed, 9 insertions(+), 4 deletions(-)

--- a/arch/x86/kernel/alternative.c
+++ b/arch/x86/kernel/alternative.c
@@ -979,7 +979,7 @@ static __always_inline void *text_poke_a
 	return _stext + tp->rel_addr;
 }
 
-static int noinstr patch_cmp(const void *key, const void *elt)
+static __always_inline int patch_cmp(const void *key, const void *elt)
 {
 	struct text_poke_loc *tp = (struct text_poke_loc *) elt;
 
@@ -1023,9 +1023,9 @@ int noinstr poke_int3_handler(struct pt_
 	 * Skip the binary search if there is a single member in the vector.
 	 */
 	if (unlikely(desc->nr_entries > 1)) {
-		tp = bsearch(ip, desc->vec, desc->nr_entries,
-			     sizeof(struct text_poke_loc),
-			     patch_cmp);
+		tp = __bsearch(ip, desc->vec, desc->nr_entries,
+			       sizeof(struct text_poke_loc),
+			       patch_cmp);
 		if (!tp)
 			goto out_put;
 	} else {
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -566,6 +566,11 @@ DEFINE_IDTENTRY_ERRORCODE(exc_general_pr
 
 dotraplinkage void notrace do_int3(struct pt_regs *regs, long error_code)
 {
+	/*
+	 * poke_int3_handler() is completely self contained code; it does (and
+	 * must) *NOT* call out to anything, lest it hits upon yet another
+	 * INT3.
+	 */
 	if (poke_int3_handler(regs))
 		return;
 


  parent reply	other threads:[~2020-05-05 14:19 UTC|newest]

Thread overview: 94+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-05 13:49 [patch V4 part 4 00/24] x86/entry: Entry/exception code rework, nasty exceptions Thomas Gleixner
2020-05-05 13:49 ` [patch V4 part 4 01/24] x86/int3: Ensure that poke_int3_handler() is not traced Thomas Gleixner
2020-05-14  4:57   ` Andy Lutomirski
2020-05-19 19:58   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:49 ` [patch V4 part 4 02/24] x86/int3: Avoid atomic instrumentation Thomas Gleixner
2020-05-08 13:27   ` Masami Hiramatsu
2020-05-14  4:57   ` Andy Lutomirski
2020-05-14  9:32     ` Peter Zijlstra
2020-05-14 12:51       ` Thomas Gleixner
2020-05-14 13:15         ` Peter Zijlstra
2020-05-14 14:55           ` Andy Lutomirski
2020-05-14 15:06           ` Thomas Gleixner
2020-05-14 15:08             ` Andy Lutomirski
2020-05-14 15:10               ` Peter Zijlstra
2020-05-19 19:58   ` [tip: x86/entry] " tip-bot2 for Peter Zijlstra
2020-05-05 13:49 ` [patch V4 part 4 03/24] lib/bsearch: Provide __always_inline variant Thomas Gleixner
2020-05-14  4:58   ` Andy Lutomirski
2020-05-19 19:58   ` [tip: x86/entry] " tip-bot2 for Peter Zijlstra
2020-05-05 13:49 ` Thomas Gleixner [this message]
2020-05-14  4:58   ` [patch V4 part 4 04/24] x86/int3: Inline bsearch() Andy Lutomirski
2020-05-19 19:58   ` [tip: x86/entry] " tip-bot2 for Peter Zijlstra
2020-05-05 13:49 ` [patch V4 part 4 05/24] x86/entry: Provide IDTENTRY_RAW Thomas Gleixner
2020-05-14  4:59   ` Andy Lutomirski
2020-05-19 19:58   ` [tip: x86/entry] x86/idtentry: " tip-bot2 for Thomas Gleixner
2020-05-05 13:49 ` [patch V4 part 4 06/24] x86/entry: Convert INT3 exception to IDTENTRY_RAW Thomas Gleixner
2020-05-14  5:01   ` Andy Lutomirski
2020-05-19 19:58   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:49 ` [patch V4 part 4 07/24] x86/traps: Split int3 handler up Thomas Gleixner
2020-05-14  5:03   ` Andy Lutomirski
2020-05-14  9:39     ` Peter Zijlstra
2020-05-19 19:58   ` [tip: x86/entry] " tip-bot2 for Peter Zijlstra
2020-05-05 13:49 ` [patch V4 part 4 08/24] x86/entry: Provide IDTENTRY_IST Thomas Gleixner
2020-05-14 16:39   ` Andy Lutomirski
2020-05-14 18:44     ` Thomas Gleixner
2020-05-19 19:58   ` [tip: x86/entry] x86/idtentry: " tip-bot2 for Thomas Gleixner
2020-05-05 13:49 ` [patch V4 part 4 09/24] x86/mce: Move nmi_enter/exit() into the entry point Thomas Gleixner
2020-05-15  5:23   ` Andy Lutomirski
2020-05-19 19:58   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:49 ` [patch V4 part 4 10/24] x86/entry: Convert Machine Check to IDTENTRY_IST Thomas Gleixner
2020-05-15  5:24   ` Andy Lutomirski
2020-05-19 19:58   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:49 ` [patch V4 part 4 11/24] x86/mce: Use untraced rd/wrmsr in the MCE offline/crash check Thomas Gleixner
2020-05-15  5:24   ` Andy Lutomirski
2020-05-19 19:58   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:49 ` [patch V4 part 4 12/24] x86/idtentry: Provide IDTENTRY_XEN for XEN/PV Thomas Gleixner
2020-05-15  5:25   ` Andy Lutomirski
2020-05-19 19:58   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:49 ` [patch V4 part 4 13/24] x86/entry: Convert NMI to IDTENTRY_NMI Thomas Gleixner
2020-05-15  5:26   ` Andy Lutomirski
2020-05-19 19:58   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:49 ` [patch V4 part 4 14/24] x86/nmi: Protect NMI entry against instrumentation Thomas Gleixner
2020-05-15  5:26   ` Andy Lutomirski
2020-05-19 19:58   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:49 ` [patch V4 part 4 15/24] x86/db: Split out dr6/7 handling Thomas Gleixner
2020-05-07 17:18   ` Alexandre Chartre
2020-05-08  8:59     ` Peter Zijlstra
2020-05-08 11:58       ` Thomas Gleixner
2020-05-08 12:45         ` Peter Zijlstra
2020-05-14  2:24   ` Mathieu Desnoyers
2020-05-14 17:28     ` Thomas Gleixner
2020-05-14 17:46       ` Mathieu Desnoyers
2020-05-15 14:32         ` Thomas Gleixner
2020-05-14 18:06     ` Steven Rostedt
2020-05-15  5:37   ` Andy Lutomirski
2020-05-19 19:58   ` [tip: x86/entry] " tip-bot2 for Peter Zijlstra
2020-05-05 13:49 ` [patch V4 part 4 16/24] x86/entry: Convert Debug exception to IDTENTRY_DB Thomas Gleixner
2020-05-15  5:27   ` Andy Lutomirski
2020-05-19 19:58   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:49 ` [patch V4 part 4 17/24] x86/entry/64: Remove error code clearing from #DB and #MCE ASM stub Thomas Gleixner
2020-05-15  5:27   ` Andy Lutomirski
2020-05-19 19:58   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:49 ` [patch V4 part 4 18/24] x86/entry: Provide IDTRENTRY_NOIST variants for #DB and #MC Thomas Gleixner
2020-05-15  5:29   ` Andy Lutomirski
2020-05-19 19:58   ` [tip: x86/entry] x86/idtentry: " tip-bot2 for Thomas Gleixner
2020-05-05 13:49 ` [patch V4 part 4 19/24] x86/entry: Implement user mode C entry points for #DB and #MCE Thomas Gleixner
2020-05-15  5:32   ` Andy Lutomirski
2020-05-19 19:58   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:49 ` [patch V4 part 4 20/24] x86/traps: Restructure #DB handling Thomas Gleixner
2020-05-15  5:39   ` Andy Lutomirski
2020-05-19 19:58   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:49 ` [patch V4 part 4 21/24] x86/traps: Address objtool noinstr complaints in #DB Thomas Gleixner
2020-05-15  5:39   ` Andy Lutomirski
2020-05-19 19:58   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:49 ` [patch V4 part 4 22/24] x86/mce: Address objtools noinstr complaints Thomas Gleixner
2020-05-15  5:40   ` Andy Lutomirski
2020-05-19 19:58   ` [tip: x86/entry] " tip-bot2 for Thomas Gleixner
2020-05-05 13:49 ` [patch V4 part 4 23/24] x86/entry: Provide IDTENTRY_DF Thomas Gleixner
2020-05-15  5:41   ` Andy Lutomirski
2020-05-15 15:01     ` Thomas Gleixner
2020-05-19 19:58   ` [tip: x86/entry] x86/idtentry: " tip-bot2 for Thomas Gleixner
2020-05-19 19:58   ` [tip: x86/entry] x86/entry: Convert double fault exception to IDTENTRY_DF tip-bot2 for Thomas Gleixner
2020-05-05 13:49 ` [patch V4 part 4 24/24] " Thomas Gleixner
2020-05-07 19:55   ` Alexandre Chartre
2020-05-15  5:42   ` Andy Lutomirski

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