diff options
| -rw-r--r-- | Documentation/trace/fprobe.rst | 8 | ||||
| -rw-r--r-- | kernel/trace/fprobe.c | 6 |
2 files changed, 9 insertions, 5 deletions
diff --git a/Documentation/trace/fprobe.rst b/Documentation/trace/fprobe.rst index 7a895514b537..196f52386aaa 100644 --- a/Documentation/trace/fprobe.rst +++ b/Documentation/trace/fprobe.rst @@ -91,9 +91,9 @@ The prototype of the entry/exit callback function are as follows: .. 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 @@ If the entry callback function returns !0, the corresponding exit callback will 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 3b21f4063258..881f90f0cbcf 100644 --- a/kernel/trace/fprobe.c +++ b/kernel/trace/fprobe.c @@ -189,7 +189,7 @@ static int fprobe_init_rethook(struct fprobe *fp, int num) { int i, size; - if (num < 0) + if (num <= 0) return -EINVAL; if (!fp->exit_handler) { @@ -202,8 +202,8 @@ static int fprobe_init_rethook(struct fprobe *fp, int num) 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) |