From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
stable@vger.kernel.org,
Chengming Zhou <zhouchengming@bytedance.com>,
Muchun Song <songmuchun@bytedance.com>
Subject: [for-linus][PATCH 05/17] ftrace: Setup correct FTRACE_FL_REGS flags for module
Date: Tue, 04 Aug 2020 16:57:48 -0400 [thread overview]
Message-ID: <20200804205812.638727187@goodmis.org> (raw)
In-Reply-To: 20200804205743.419135730@goodmis.org
From: Chengming Zhou <zhouchengming@bytedance.com>
When module loaded and enabled, we will use __ftrace_replace_code
for module if any ftrace_ops referenced it found. But we will get
wrong ftrace_addr for module rec in ftrace_get_addr_new, because
rec->flags has not been setup correctly. It can cause the callback
function of a ftrace_ops has FTRACE_OPS_FL_SAVE_REGS to be called
with pt_regs set to NULL.
So setup correct FTRACE_FL_REGS flags for rec when we call
referenced_filters to find ftrace_ops references it.
Link: https://lkml.kernel.org/r/20200728180554.65203-1-zhouchengming@bytedance.com
Cc: stable@vger.kernel.org
Fixes: 8c4f3c3fa9681 ("ftrace: Check module functions being traced on reload")
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 | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index c141d347f71a..d052f856f1cf 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -6198,8 +6198,11 @@ static int referenced_filters(struct dyn_ftrace *rec)
int cnt = 0;
for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {
- if (ops_references_rec(ops, rec))
- cnt++;
+ if (ops_references_rec(ops, rec)) {
+ cnt++;
+ if (ops->flags & FTRACE_OPS_FL_SAVE_REGS)
+ rec->flags |= FTRACE_FL_REGS;
+ }
}
return cnt;
@@ -6378,8 +6381,8 @@ void ftrace_module_enable(struct module *mod)
if (ftrace_start_up)
cnt += referenced_filters(rec);
- /* This clears FTRACE_FL_DISABLED */
- rec->flags = cnt;
+ rec->flags &= ~FTRACE_FL_DISABLED;
+ rec->flags += cnt;
if (ftrace_start_up && cnt) {
int failed = __ftrace_replace_code(rec, 1);
--
2.26.2
next prev parent reply other threads:[~2020-08-04 20:59 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 ` Steven Rostedt [this message]
2020-08-09 15:53 ` [for-linus][PATCH 05/17] ftrace: Setup correct FTRACE_FL_REGS flags for module Sasha Levin
2020-08-04 20:57 ` [for-linus][PATCH 06/17] ftrace: Do not let direct or IPMODIFY ftrace_ops be added to module and set trampolines Steven Rostedt
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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