unimore/kernel-hacking-2024-linux-steffo
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uprobes/tracing: Introduce is_trace_uprobe_enabled()

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probe_event_enable/disable() check tu->consumer != NULL to avoid the
wrong uprobe_register/unregister().

We are going to kill this pointer and "struct uprobe_trace_consumer",
so we add the new helper, is_trace_uprobe_enabled(), which can rely
on TP_FLAG_TRACE/TP_FLAG_PROFILE instead.

Note: the current logic doesn't look optimal, it is not clear why
TP_FLAG_TRACE/TP_FLAG_PROFILE are mutually exclusive, we will probably
change this later.

Also kill the unused TP_FLAG_UPROBE.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
This commit is contained in:
Oleg Nesterov 2013-01-31 19:15:30 +01:00
parent 7e4e28c539
commit b64b007797
2 changed files with 7 additions and 3 deletions
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1
kernel/trace/trace_probe.h
View file

@ -66,7 +66,6 @@
#define TP_FLAG_TRACE 1
#define TP_FLAG_PROFILE 2
#define TP_FLAG_REGISTERED 4
#define TP_FLAG_UPROBE 8
/* data_rloc: data relative location, compatible with u32 */

9
kernel/trace/trace_uprobe.c
View file

@ -539,12 +539,17 @@ print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *e
return TRACE_TYPE_PARTIAL_LINE;
}
static inline bool is_trace_uprobe_enabled(struct trace_uprobe *tu)
{
return tu->flags & (TP_FLAG_TRACE | TP_FLAG_PROFILE);
}
static int probe_event_enable(struct trace_uprobe *tu, int flag)
{
struct uprobe_trace_consumer *utc;
int ret = 0;
if (tu->consumer)
if (is_trace_uprobe_enabled(tu))
return -EINTR;
utc = kzalloc(sizeof(struct uprobe_trace_consumer), GFP_KERNEL);
@ -568,7 +573,7 @@ static int probe_event_enable(struct trace_uprobe *tu, int flag)
static void probe_event_disable(struct trace_uprobe *tu, int flag)
{
if (!tu->consumer)
if (!is_trace_uprobe_enabled(tu))
return;
uprobe_unregister(tu->inode, tu->offset, &tu->consumer->cons);