From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Adrian Hunter <adrian.hunter@intel.com>
Subject: [for-linus][PATCH 3/8] ftrace: Fix missing synchronize_rcu() removing trampoline from kallsyms
Date: Mon, 21 Sep 2020 20:26:23 -0400 [thread overview]
Message-ID: <20200922002659.875259952@goodmis.org> (raw)
In-Reply-To: 20200922002620.231334654@goodmis.org
From: Adrian Hunter <adrian.hunter@intel.com>
Add synchronize_rcu() after list_del_rcu() in
ftrace_remove_trampoline_from_kallsyms() to protect readers of
ftrace_ops_trampoline_list (in ftrace_get_trampoline_kallsym)
which is used when kallsyms is read.
Link: https://lkml.kernel.org/r/20200901091617.31837-1-adrian.hunter@intel.com
Fixes: fc0ea795f53c8d ("ftrace: Add symbols for ftrace trampolines")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/ftrace.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 656d7cb5a78c..e9f893388245 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -2782,6 +2782,7 @@ static void ftrace_remove_trampoline_from_kallsyms(struct ftrace_ops *ops)
{
lockdep_assert_held(&ftrace_lock);
list_del_rcu(&ops->list);
+ synchronize_rcu();
}
/*
--
2.28.0
next prev parent reply other threads:[~2020-09-22 0:27 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-22 0:26 [for-linus][PATCH 0/8] tracing: Fixes for 5.9 Steven Rostedt
2020-09-22 0:26 ` [for-linus][PATCH 1/8] kprobes: Fix to check probe enabled before disarm_kprobe_ftrace() Steven Rostedt
2020-09-22 0:26 ` [for-linus][PATCH 2/8] ftrace: Free the trampoline when ftrace_startup() fails Steven Rostedt
2020-09-22 0:26 ` Steven Rostedt [this message]
2020-09-22 0:26 ` [for-linus][PATCH 4/8] tracing: Make the space reserved for the pid wider Steven Rostedt
2020-09-22 0:26 ` [for-linus][PATCH 5/8] ftrace: Let ftrace_enable_sysctl take a kernel pointer buffer Steven Rostedt
2020-09-22 0:26 ` [for-linus][PATCH 6/8] tracing: fix double free Steven Rostedt
2020-09-22 0:26 ` [for-linus][PATCH 7/8] kprobes: tracing/kprobes: Fix to kill kprobes on initmem after boot Steven Rostedt
2020-09-22 0:26 ` [for-linus][PATCH 8/8] bootconfig: init: make xbc_namebuf static Steven Rostedt
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