linux-kernel - [tip: sched/core] arm, smp: Remove trace_.*

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 13 Jan 2023 12:31:11 -0000
From:   "tip-bot2 for Peter Zijlstra" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     "Peter Zijlstra (Intel)" <peterz@...radead.org>,
        Ingo Molnar <mingo@...nel.org>,
        Tony Lindgren <tony@...mide.com>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>,
        Frederic Weisbecker <frederic@...nel.org>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [tip: sched/core] arm, smp: Remove trace_.*_rcuidle() usage

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     08a56e07cd3cb91dc700ba0a879d17e4879dd617
Gitweb:        https://git.kernel.org/tip/08a56e07cd3cb91dc700ba0a879d17e4879dd617
Author:        Peter Zijlstra <peterz@...radead.org>
AuthorDate:    Thu, 12 Jan 2023 20:43:37 +01:00
Committer:     Ingo Molnar <mingo@...nel.org>
CommitterDate: Fri, 13 Jan 2023 11:48:15 +01:00

arm, smp: Remove trace_.*_rcuidle() usage

None of these functions should ever be ran with RCU disabled anymore.

Specifically, do_handle_IPI() is only called from handle_IPI() which
explicitly does irq_enter()/irq_exit() which ensures RCU is watching.

The problem with smp_cross_call() was, per commit description:

   7c64cc0531fa ("arm: Use _rcuidle for smp_cross_call() tracepoints")

... that cpuidle_enter_state_coupled() already had RCU disabled, but that's
long been fixed by commit:

  1098582a0f6c ("sched,idle,rcu: Push rcu_idle deeper into the idle path")

Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Signed-off-by: Ingo Molnar <mingo@...nel.org>
Tested-by: Tony Lindgren <tony@...mide.com>
Tested-by: Ulf Hansson <ulf.hansson@...aro.org>
Reviewed-by: Ulf Hansson <ulf.hansson@...aro.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@...el.com>
Acked-by: Frederic Weisbecker <frederic@...nel.org>
Link: https://lore.kernel.org/r/20230112195540.743432118@infradead.org
---
 arch/arm/kernel/smp.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index 36e6efa..0b8c257 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -638,7 +638,7 @@ static void do_handle_IPI(int ipinr)
 	unsigned int cpu = smp_processor_id();
 
 	if ((unsigned)ipinr < NR_IPI)
-		trace_ipi_entry_rcuidle(ipi_types[ipinr]);
+		trace_ipi_entry(ipi_types[ipinr]);
 
 	switch (ipinr) {
 	case IPI_WAKEUP:
@@ -685,7 +685,7 @@ static void do_handle_IPI(int ipinr)
 	}
 
 	if ((unsigned)ipinr < NR_IPI)
-		trace_ipi_exit_rcuidle(ipi_types[ipinr]);
+		trace_ipi_exit(ipi_types[ipinr]);
 }
 
 /* Legacy version, should go away once all irqchips have been converted */
@@ -708,7 +708,7 @@ static irqreturn_t ipi_handler(int irq, void *data)
 
 static void smp_cross_call(const struct cpumask *target, unsigned int ipinr)
 {
-	trace_ipi_raise_rcuidle(target, ipi_types[ipinr]);
+	trace_ipi_raise(target, ipi_types[ipinr]);
 	__ipi_send_mask(ipi_desc[ipinr], target);
 }