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authorSteven Rostedt (VMware) <rostedt@goodmis.org>2019-11-15 20:14:45 +0100
committerSteven Rostedt (VMware) <rostedt@goodmis.org>2019-11-15 20:25:08 +0100
commit128161f47bc3797b0d068da13e311770685d6e4f (patch)
tree3613e05d810e762cec293165aebe0f40ba4a58fc /kernel/trace
parentftrace: Add another check for match in register_ftrace_direct() (diff)
downloadlinux-128161f47bc3797b0d068da13e311770685d6e4f.tar.xz
linux-128161f47bc3797b0d068da13e311770685d6e4f.zip
ftrace: Add helper find_direct_entry() to consolidate code
Both unregister_ftrace_direct() and modify_ftrace_direct() needs to normalize the ip passed in to match the rec->ip, as it is acceptable to have the ip on the ftrace call site but not the start. There are also common validity checks with the record found by the ip, these should be done for both unregister_ftrace_direct() and modify_ftrace_direct(). Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/ftrace.c59
1 files changed, 29 insertions, 30 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 9fe33ebaf914..ef79c8393f53 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -5112,30 +5112,40 @@ int register_ftrace_direct(unsigned long ip, unsigned long addr)
}
EXPORT_SYMBOL_GPL(register_ftrace_direct);
-int unregister_ftrace_direct(unsigned long ip, unsigned long addr)
+static struct ftrace_func_entry *find_direct_entry(unsigned long *ip)
{
struct ftrace_func_entry *entry;
- struct ftrace_direct_func *direct;
struct dyn_ftrace *rec;
- int ret = -ENODEV;
- mutex_lock(&direct_mutex);
+ rec = lookup_rec(*ip, *ip);
+ if (!rec)
+ return NULL;
- entry = __ftrace_lookup_ip(direct_functions, ip);
+ entry = __ftrace_lookup_ip(direct_functions, rec->ip);
if (!entry) {
- /* OK if it is off by a little */
- rec = lookup_rec(ip, ip);
- if (!rec || rec->ip == ip)
- goto out_unlock;
+ WARN_ON(rec->flags & FTRACE_FL_DIRECT);
+ return NULL;
+ }
- entry = __ftrace_lookup_ip(direct_functions, rec->ip);
- if (!entry) {
- WARN_ON(rec->flags & FTRACE_FL_DIRECT);
- goto out_unlock;
- }
+ WARN_ON(!(rec->flags & FTRACE_FL_DIRECT));
- WARN_ON(!(rec->flags & FTRACE_FL_DIRECT));
- }
+ /* Passed in ip just needs to be on the call site */
+ *ip = rec->ip;
+
+ return entry;
+}
+
+int unregister_ftrace_direct(unsigned long ip, unsigned long addr)
+{
+ struct ftrace_direct_func *direct;
+ struct ftrace_func_entry *entry;
+ int ret = -ENODEV;
+
+ mutex_lock(&direct_mutex);
+
+ entry = find_direct_entry(&ip);
+ if (!entry)
+ goto out_unlock;
if (direct_functions->count == 1)
unregister_ftrace_function(&direct_ops);
@@ -5187,24 +5197,13 @@ int modify_ftrace_direct(unsigned long ip,
unsigned long old_addr, unsigned long new_addr)
{
struct ftrace_func_entry *entry;
- struct dyn_ftrace *rec;
int ret = -ENODEV;
mutex_lock(&direct_mutex);
- entry = __ftrace_lookup_ip(direct_functions, ip);
- if (!entry) {
- /* OK if it is off by a little */
- rec = lookup_rec(ip, ip);
- if (!rec || rec->ip == ip)
- goto out_unlock;
-
- entry = __ftrace_lookup_ip(direct_functions, rec->ip);
- if (!entry)
- goto out_unlock;
- ip = rec->ip;
- WARN_ON(!(rec->flags & FTRACE_FL_DIRECT));
- }
+ entry = find_direct_entry(&ip);
+ if (!entry)
+ goto out_unlock;
ret = -EINVAL;
if (entry->direct != old_addr)