From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Chengming Zhou <zhouchengming@bytedance.com>,
Muchun Song <songmuchun@bytedance.com>
Subject: [for-linus][PATCH 06/17] ftrace: Do not let direct or IPMODIFY ftrace_ops be added to module and set trampolines
Date: Tue, 04 Aug 2020 16:57:49 -0400 [thread overview]
Message-ID: <20200804205812.775534405@goodmis.org> (raw)
In-Reply-To: 20200804205743.419135730@goodmis.org
From: Chengming Zhou <zhouchengming@bytedance.com>
When inserting a module, we find all ftrace_ops referencing it on the
ftrace_ops_list. But FTRACE_OPS_FL_DIRECT and FTRACE_OPS_FL_IPMODIFY
flags are special, and should not be set automatically. So warn and
skip ftrace_ops that have these two flags set and adding new code.
Also check if only one ftrace_ops references the module, in which case
we can use a trampoline as an optimization.
Link: https://lkml.kernel.org/r/20200728180554.65203-2-zhouchengming@bytedance.com
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/ftrace.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index d052f856f1cf..f433cb44300a 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -6199,9 +6199,17 @@ static int referenced_filters(struct dyn_ftrace *rec)
for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
if (ops_references_rec(ops, rec)) {
+ if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_DIRECT))
+ continue;
+ if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_IPMODIFY))
+ continue;
cnt++;
if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
rec->flags |= FTRACE_FL_REGS;
+ if (cnt == 1 && ops->trampoline)
+ rec->flags |= FTRACE_FL_TRAMP;
+ else
+ rec->flags &= ~FTRACE_FL_TRAMP;
}
}
--
2.26.2
next prev parent reply other threads:[~2020-08-04 20:58 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-04 20:57 [for-linus][PATCH 00/17] tracing: Last minute fixes for this merge window Steven Rostedt
2020-08-04 20:57 ` [for-linus][PATCH 01/17] tracing: Simplify defining of the next event id Steven Rostedt
2020-08-04 20:57 ` [for-linus][PATCH 02/17] tracing: Save one trace_event->type by using __TRACE_LAST_TYPE Steven Rostedt
2020-08-04 20:57 ` [for-linus][PATCH 03/17] tracing/hwlat: Drop the duplicate assignment in start_kthread() Steven Rostedt
2020-08-04 20:57 ` [for-linus][PATCH 04/17] tracing/hwlat: Honor the tracing_cpumask Steven Rostedt
2020-08-04 20:57 ` [for-linus][PATCH 05/17] ftrace: Setup correct FTRACE_FL_REGS flags for module Steven Rostedt
2020-08-09 15:53 ` Sasha Levin
2020-08-04 20:57 ` Steven Rostedt [this message]
2020-08-04 20:57 ` [for-linus][PATCH 07/17] tracing: Remove outdated comment in stack handling Steven Rostedt
2020-08-04 20:57 ` [for-linus][PATCH 09/17] tracepoint: Mark __tracepoint_strings __used Steven Rostedt
2020-08-04 20:57 ` [for-linus][PATCH 10/17] tracepoint: Use __used attribute definitions from compiler_attributes.h Steven Rostedt
2020-08-04 20:57 ` [for-linus][PATCH 11/17] ftrace: Fix ftrace_trace_task return value Steven Rostedt
2020-08-04 20:57 ` [for-linus][PATCH 12/17] kprobes: Fix NULL pointer dereference at kprobe_ftrace_handler Steven Rostedt
2020-08-04 20:57 ` [for-linus][PATCH 13/17] tracing/uprobe: Remove dead code in trace_uprobe_register() Steven Rostedt
2020-08-04 20:57 ` [for-linus][PATCH 14/17] kprobes: Remove show_registers() function prototype Steven Rostedt
2020-08-04 20:57 ` [for-linus][PATCH 15/17] lib/bootconfig: Add override operator support Steven Rostedt
2020-08-04 20:57 ` [for-linus][PATCH 16/17] tools/bootconfig: Add testcases for value override operator Steven Rostedt
2020-08-04 20:58 ` [for-linus][PATCH 17/17] Documentation: bootconfig: Add bootconfig " Steven Rostedt
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