From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752652AbeCTJ6m (ORCPT ); Tue, 20 Mar 2018 05:58:42 -0400 Received: from terminus.zytor.com ([198.137.202.136]:60351 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751916AbeCTJ6h (ORCPT ); Tue, 20 Mar 2018 05:58:37 -0400 Date: Tue, 20 Mar 2018 02:57:50 -0700 From: tip-bot for Josh Poimboeuf Message-ID: Cc: jbaron@akamai.com, tglx@linutronix.de, jpoimboe@redhat.com, hpa@zytor.com, peterz@infradead.org, liwang@redhat.com, mingo@kernel.org, linux-kernel@vger.kernel.org, bp@suse.de Reply-To: bp@suse.de, linux-kernel@vger.kernel.org, mingo@kernel.org, liwang@redhat.com, peterz@infradead.org, hpa@zytor.com, jpoimboe@redhat.com, tglx@linutronix.de, jbaron@akamai.com In-Reply-To: <7121e6e595374f06616c505b6e690e275c0054d1.1521483452.git.jpoimboe@redhat.com> References: <7121e6e595374f06616c505b6e690e275c0054d1.1521483452.git.jpoimboe@redhat.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:core/urgent] jump_label: Disable jump labels in __exit code Git-Commit-ID: c3fb3dfce2ad4e17e6f1d090b56e3d9f09a3f509 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: c3fb3dfce2ad4e17e6f1d090b56e3d9f09a3f509 Gitweb: https://git.kernel.org/tip/c3fb3dfce2ad4e17e6f1d090b56e3d9f09a3f509 Author: Josh Poimboeuf AuthorDate: Mon, 19 Mar 2018 13:18:57 -0500 Committer: Thomas Gleixner CommitDate: Tue, 20 Mar 2018 10:51:25 +0100 jump_label: Disable jump labels in __exit code With the following commit: 333522447063 ("jump_label: Explicitly disable jump labels in __init code") ... we explicitly disabled jump labels in __init code, so they could be detected and not warned about in the following commit: dc1dd184c2f0 ("jump_label: Warn on failed jump_label patching attempt") In-kernel __exit code has the same issue. It's never used, so it's freed along with the rest of initmem. But jump label entries in __exit code aren't explicitly disabled, so we get the following warning when enabling pr_debug() in __exit code: can't patch jump_label at dmi_sysfs_exit+0x0/0x2d WARNING: CPU: 0 PID: 22572 at kernel/jump_label.c:376 __jump_label_update+0x9d/0xb0 Fix the warning by disabling all jump labels in initmem (which includes both __init and __exit code). Fixes: dc1dd184c2f0 ("jump_label: Warn on failed jump_label patching attempt") Reported-and-tested-by: Li Wang Signed-off-by: Josh Poimboeuf Signed-off-by: Thomas Gleixner Cc: Peter Zijlstra Cc: Jason Baron Cc: Borislav Petkov Link: https://lkml.kernel.org/r/7121e6e595374f06616c505b6e690e275c0054d1.1521483452.git.jpoimboe@redhat.com --- include/linux/jump_label.h | 4 ++-- init/main.c | 2 +- kernel/jump_label.c | 7 ++++--- 3 files changed, 7 insertions(+), 6 deletions(-) diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h index 2168cc6b8b30..b46b541c67c4 100644 --- a/include/linux/jump_label.h +++ b/include/linux/jump_label.h @@ -151,7 +151,7 @@ extern struct jump_entry __start___jump_table[]; extern struct jump_entry __stop___jump_table[]; extern void jump_label_init(void); -extern void jump_label_invalidate_init(void); +extern void jump_label_invalidate_initmem(void); extern void jump_label_lock(void); extern void jump_label_unlock(void); extern void arch_jump_label_transform(struct jump_entry *entry, @@ -199,7 +199,7 @@ static __always_inline void jump_label_init(void) static_key_initialized = true; } -static inline void jump_label_invalidate_init(void) {} +static inline void jump_label_invalidate_initmem(void) {} static __always_inline bool static_key_false(struct static_key *key) { diff --git a/init/main.c b/init/main.c index 969eaf140ef0..21efbf6ace93 100644 --- a/init/main.c +++ b/init/main.c @@ -1001,7 +1001,7 @@ static int __ref kernel_init(void *unused) /* need to finish all async __init code before freeing the memory */ async_synchronize_full(); ftrace_free_init_mem(); - jump_label_invalidate_init(); + jump_label_invalidate_initmem(); free_initmem(); mark_readonly(); system_state = SYSTEM_RUNNING; diff --git a/kernel/jump_label.c b/kernel/jump_label.c index e7214093dcd1..01ebdf1f9f40 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -16,6 +16,7 @@ #include #include #include +#include #ifdef HAVE_JUMP_LABEL @@ -421,15 +422,15 @@ void __init jump_label_init(void) cpus_read_unlock(); } -/* Disable any jump label entries in __init code */ -void __init jump_label_invalidate_init(void) +/* Disable any jump label entries in __init/__exit code */ +void __init jump_label_invalidate_initmem(void) { struct jump_entry *iter_start = __start___jump_table; struct jump_entry *iter_stop = __stop___jump_table; struct jump_entry *iter; for (iter = iter_start; iter < iter_stop; iter++) { - if (init_kernel_text(iter->code)) + if (init_section_contains((void *)(unsigned long)iter->code, 1)) iter->code = 0; } }