diff mbox series

[v3,11/28] module: Use RCU in __is_module_percpu_address().

Message ID	20250108090457.512198-12-bigeasy@linutronix.de (mailing list archive)
State	New
Headers	show Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E31491F3D46; Wed, 8 Jan 2025 09:05:19 +0000 (UTC) From: Sebastian Andrzej Siewior <bigeasy@linutronix.de> To: linux-modules@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Daniel Gomez <da.gomez@samsung.com>, Luis Chamberlain <mcgrof@kernel.org>, "Paul E . McKenney" <paulmck@kernel.org>, Peter Zijlstra <peterz@infradead.org>, Petr Pavlu <petr.pavlu@suse.com>, Sami Tolvanen <samitolvanen@google.com>, Thomas Gleixner <tglx@linutronix.de>, Sebastian Andrzej Siewior <bigeasy@linutronix.de> Subject: [PATCH v3 11/28] module: Use RCU in __is_module_percpu_address(). Date: Wed, 8 Jan 2025 10:04:40 +0100 Message-ID: <20250108090457.512198-12-bigeasy@linutronix.de> In-Reply-To: <20250108090457.512198-1-bigeasy@linutronix.de> References: <20250108090457.512198-1-bigeasy@linutronix.de> Precedence: bulk MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable
Series	module: Use RCU instead of RCU-sched. \| expand [v3,00/28] module: Use RCU instead of RCU-sched. [v3,01/28] module: Extend the preempt disabled section in dereference_symbol_descriptor(). [v3,02/28] module: Begin to move from RCU-sched to RCU. [v3,03/28] module: Use proper RCU assignment in add_kallsyms(). [v3,04/28] module: Use RCU in find_kallsyms_symbol(). [v3,05/28] module: Use RCU in module_get_kallsym(). [v3,06/28] module: Use RCU in find_module_all(). [v3,07/28] module: Use RCU in __find_kallsyms_symbol_value(). [v3,08/28] module: Use RCU in module_kallsyms_on_each_symbol(). [v3,09/28] module: Remove module_assert_mutex_or_preempt() from try_add_tainted_module(). [v3,10/28] module: Use RCU in find_symbol(). [v3,11/28] module: Use RCU in __is_module_percpu_address(). [v3,12/28] module: Allow __module_address() to be called from RCU section. [v3,13/28] module: Use RCU in search_module_extables(). [v3,14/28] module: Use RCU in all users of __module_address(). [v3,15/28] module: Use RCU in all users of __module_text_address(). [v3,16/28] ARM: module: Use RCU in all users of __module_text_address(). [v3,17/28] arm64: module: Use RCU in all users of __module_text_address(). [v3,18/28] LoongArch/orc: Use RCU in all users of __module_address(). [v3,19/28] LoongArch: ftrace: Use RCU in all users of __module_text_address(). [v3,20/28] powerpc/ftrace: Use RCU in all users of __module_text_address(). [v3,21/28] cfi: Use RCU while invoking __module_address(). [v3,22/28] x86: Use RCU in all users of __module_address(). [v3,23/28] jump_label: Use RCU in all users of __module_address(). [v3,24/28] jump_label: Use RCU in all users of __module_text_address(). [v3,25/28] bpf: Use RCU in all users of __module_text_address(). [v3,26/28] kprobes: Use RCU in all users of __module_text_address(). [v3,27/28] static_call: Use RCU in all users of __module_text_address(). [v3,28/28] bug: Use RCU instead RCU-sched to protect module_bug_list.

Checks

Context	Check	Description
mcgrof/vmtest-modules-next-PR	fail	PR summary
mcgrof/vmtest-modules-next-VM_Test-0	success	Logs for Run CI tests
mcgrof/vmtest-modules-next-VM_Test-2	success	Logs for setup / Setup kdevops environment
mcgrof/vmtest-modules-next-VM_Test-1	success	Logs for cleanup / Archive results and cleanup

Commit Message

Sebastian Andrzej Siewior Jan. 8, 2025, 9:04 a.m. UTC

The modules list can be accessed under RCU assumption.

Use RCU protection instead preempt_disable().

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 kernel/module/main.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff mbox series

Patch

diff --git a/kernel/module/main.c b/kernel/module/main.c
index 71e73deed76c0..126f7f05dedf8 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -450,8 +450,7 @@  bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
 	struct module *mod;
 	unsigned int cpu;
 
-	preempt_disable();
-
+	guard(rcu)();
 	list_for_each_entry_rcu(mod, &modules, list) {
 		if (mod->state == MODULE_STATE_UNFORMED)
 			continue;
@@ -468,13 +467,10 @@  bool __is_module_percpu_address(unsigned long addr, unsigned long *can_addr)
 						per_cpu_ptr(mod->percpu,
 							    get_boot_cpu_id());
 				}
-				preempt_enable();
 				return true;
 			}
 		}
 	}
-
-	preempt_enable();
 	return false;
 }