Messages in this thread | | | Date | Tue, 17 Jan 2023 20:43:09 -0500 | From | Steven Rostedt <> | Subject | Re: [RFC PATCH 1/9] fprobe: Pass entry_data to handlers |
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On Wed, 9 Nov 2022 00:49:23 +0900 "Masami Hiramatsu (Google)" <mhiramat@kernel.org> wrote:
> diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c > index e8143e368074..fa25d09c9d57 100644 > --- a/kernel/trace/fprobe.c > +++ b/kernel/trace/fprobe.c > @@ -17,14 +17,16 @@ > struct fprobe_rethook_node { > struct rethook_node node; > unsigned long entry_ip; > + char data[]; > }; > > static void fprobe_handler(unsigned long ip, unsigned long parent_ip, > struct ftrace_ops *ops, struct ftrace_regs *fregs) > { > struct fprobe_rethook_node *fpr; > - struct rethook_node *rh; > + struct rethook_node *rh = NULL; > struct fprobe *fp; > + void *entry_data = NULL; > int bit; > > fp = container_of(ops, struct fprobe, ops); > @@ -37,9 +39,6 @@ static void fprobe_handler(unsigned long ip, unsigned long parent_ip, > return; > } > > - if (fp->entry_handler) > - fp->entry_handler(fp, ip, ftrace_get_regs(fregs)); > - > if (fp->exit_handler) { > rh = rethook_try_get(fp->rethook); > if (!rh) { > @@ -48,9 +47,16 @@ static void fprobe_handler(unsigned long ip, unsigned long parent_ip, > } > fpr = container_of(rh, struct fprobe_rethook_node, node); > fpr->entry_ip = ip; > - rethook_hook(rh, ftrace_get_regs(fregs), true); > + if (fp->entry_data_size) > + entry_data = fpr->data; > } > > + if (fp->entry_handler) > + fp->entry_handler(fp, ip, ftrace_get_regs(fregs), entry_data); > + > + if (rh) > + rethook_hook(rh, ftrace_get_regs(fregs), true); > + > out: > ftrace_test_recursion_unlock(bit); > } > @@ -81,7 +87,8 @@ static void fprobe_exit_handler(struct rethook_node *rh, void *data, > > fpr = container_of(rh, struct fprobe_rethook_node, node); > > - fp->exit_handler(fp, fpr->entry_ip, regs); > + fp->exit_handler(fp, fpr->entry_ip, regs, > + fp->entry_data_size ? (void *)fpr->data : NULL); > } > NOKPROBE_SYMBOL(fprobe_exit_handler); > > @@ -146,7 +153,7 @@ static int fprobe_init_rethook(struct fprobe *fp, int num) > for (i = 0; i < size; i++) { > struct fprobe_rethook_node *node; > > - node = kzalloc(sizeof(*node), GFP_KERNEL); > + node = kzalloc(sizeof(*node) + fp->entry_data_size, GFP_KERNEL);
node = kzalloc(struct_size(node, data, fp->entry_data_size), GFP_KERNEL);
Should use struct_size() for any tail structure allocations.
-- Steve
> if (!node) { > rethook_free(fp->rethook); > fp->rethook = NULL; > diff --git a/lib/test_fprobe.c b/lib/test_fprobe.c > index e0381b3ec410..34fa5a5bbda1 100644
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