Merge tag 'probes-fixes-v6.6-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull probes fixes from Masami Hiramatsu:
- Fix fprobe document to add a new ret_ip parameter for callback
functions. This has been introduced in v6.5 but the document was not
updated.
- Fix fprobe to check the number of active retprobes is not zero. This
number is passed from parameter or calculated by the parameter and it
can be zero which is not acceptable. But current code only check it
is not minus.
* tag 'probes-fixes-v6.6-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
fprobe: Fix to ensure the number of active retprobes is not zero
Documentation: probes: Add a new ret_ip callback parameter
diff --git a/Documentation/trace/fprobe.rst b/Documentation/trace/fprobe.rst
index 7a89551..196f523 100644
--- a/Documentation/trace/fprobe.rst
+++ b/Documentation/trace/fprobe.rst
@@ -91,9 +91,9 @@
.. code-block:: c
- int entry_callback(struct fprobe *fp, unsigned long entry_ip, struct pt_regs *regs, void *entry_data);
+ int entry_callback(struct fprobe *fp, unsigned long entry_ip, unsigned long ret_ip, struct pt_regs *regs, void *entry_data);
- void exit_callback(struct fprobe *fp, unsigned long entry_ip, struct pt_regs *regs, void *entry_data);
+ void exit_callback(struct fprobe *fp, unsigned long entry_ip, unsigned long ret_ip, struct pt_regs *regs, void *entry_data);
Note that the @entry_ip is saved at function entry and passed to exit handler.
If the entry callback function returns !0, the corresponding exit callback will be cancelled.
@@ -108,6 +108,10 @@
Note that this may not be the actual entry address of the function but
the address where the ftrace is instrumented.
+@ret_ip
+ This is the return address that the traced function will return to,
+ somewhere in the caller. This can be used at both entry and exit.
+
@regs
This is the `pt_regs` data structure at the entry and exit. Note that
the instruction pointer of @regs may be different from the @entry_ip
diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c
index 3b21f40..881f90f 100644
--- a/kernel/trace/fprobe.c
+++ b/kernel/trace/fprobe.c
@@ -189,7 +189,7 @@
{
int i, size;
- if (num < 0)
+ if (num <= 0)
return -EINVAL;
if (!fp->exit_handler) {
@@ -202,8 +202,8 @@
size = fp->nr_maxactive;
else
size = num * num_possible_cpus() * 2;
- if (size < 0)
- return -E2BIG;
+ if (size <= 0)
+ return -EINVAL;
fp->rethook = rethook_alloc((void *)fp, fprobe_exit_handler);
if (!fp->rethook)
