From: Andrii Nakryiko <andrii@xxxxxxxxxx> [ Upstream commit 3eaea21b4d27cff0017c20549aeb53034c58fc23 ] Move the logic of fetching temporary per-CPU uprobe buffer and storing uprobes args into it to a new helper function. Store data size as part of this buffer, simplifying interfaces a bit, as now we only pass single uprobe_cpu_buffer reference around, instead of pointer + dsize. This logic was duplicated across uprobe_dispatcher and uretprobe_dispatcher, and now will be centralized. All this is also in preparation to make this uprobe_cpu_buffer handling logic optional in the next patch. Link: https://lore.kernel.org/all/20240318181728.2795838-2-andrii@xxxxxxxxxx/ [Masami: update for v6.9-rc3 kernel] Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx> Reviewed-by: Jiri Olsa <jolsa@xxxxxxxxxx> Acked-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx> Stable-dep-of: 373b9338c972 ("uprobe: avoid out-of-bounds memory access of fetching args") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> Signed-off-by: Vamsi Krishna Brahmajosyula <vamsi-krishna.brahmajosyula@xxxxxxxxxxxx> --- kernel/trace/trace_uprobe.c | 79 +++++++++++++++++++------------------ 1 file changed, 41 insertions(+), 38 deletions(-) diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 127c78aec17d..e09eef65d32f 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -858,6 +858,7 @@ static const struct file_operations uprobe_profile_ops = { struct uprobe_cpu_buffer { struct mutex mutex; void *buf; + int dsize; }; static struct uprobe_cpu_buffer __percpu *uprobe_cpu_buffer; static int uprobe_buffer_refcnt; @@ -947,9 +948,26 @@ static void uprobe_buffer_put(struct uprobe_cpu_buffer *ucb) mutex_unlock(&ucb->mutex); } +static struct uprobe_cpu_buffer *prepare_uprobe_buffer(struct trace_uprobe *tu, + struct pt_regs *regs) +{ + struct uprobe_cpu_buffer *ucb; + int dsize, esize; + + esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); + dsize = __get_data_size(&tu->tp, regs); + + ucb = uprobe_buffer_get(); + ucb->dsize = tu->tp.size + dsize; + + store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize); + + return ucb; +} + static void __uprobe_trace_func(struct trace_uprobe *tu, unsigned long func, struct pt_regs *regs, - struct uprobe_cpu_buffer *ucb, int dsize, + struct uprobe_cpu_buffer *ucb, struct trace_event_file *trace_file) { struct uprobe_trace_entry_head *entry; @@ -960,14 +978,14 @@ static void __uprobe_trace_func(struct trace_uprobe *tu, WARN_ON(call != trace_file->event_call); - if (WARN_ON_ONCE(tu->tp.size + dsize > PAGE_SIZE)) + if (WARN_ON_ONCE(ucb->dsize > PAGE_SIZE)) return; if (trace_trigger_soft_disabled(trace_file)) return; esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); - size = esize + tu->tp.size + dsize; + size = esize + ucb->dsize; entry = trace_event_buffer_reserve(&fbuffer, trace_file, size); if (!entry) return; @@ -981,14 +999,14 @@ static void __uprobe_trace_func(struct trace_uprobe *tu, data = DATAOF_TRACE_ENTRY(entry, false); } - memcpy(data, ucb->buf, tu->tp.size + dsize); + memcpy(data, ucb->buf, ucb->dsize); trace_event_buffer_commit(&fbuffer); } /* uprobe handler */ static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs, - struct uprobe_cpu_buffer *ucb, int dsize) + struct uprobe_cpu_buffer *ucb) { struct event_file_link *link; @@ -997,7 +1015,7 @@ static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs, rcu_read_lock(); trace_probe_for_each_link_rcu(link, &tu->tp) - __uprobe_trace_func(tu, 0, regs, ucb, dsize, link->file); + __uprobe_trace_func(tu, 0, regs, ucb, link->file); rcu_read_unlock(); return 0; @@ -1005,13 +1023,13 @@ static int uprobe_trace_func(struct trace_uprobe *tu, struct pt_regs *regs, static void uretprobe_trace_func(struct trace_uprobe *tu, unsigned long func, struct pt_regs *regs, - struct uprobe_cpu_buffer *ucb, int dsize) + struct uprobe_cpu_buffer *ucb) { struct event_file_link *link; rcu_read_lock(); trace_probe_for_each_link_rcu(link, &tu->tp) - __uprobe_trace_func(tu, func, regs, ucb, dsize, link->file); + __uprobe_trace_func(tu, func, regs, ucb, link->file); rcu_read_unlock(); } @@ -1339,7 +1357,7 @@ static bool uprobe_perf_filter(struct uprobe_consumer *uc, static void __uprobe_perf_func(struct trace_uprobe *tu, unsigned long func, struct pt_regs *regs, - struct uprobe_cpu_buffer *ucb, int dsize) + struct uprobe_cpu_buffer *ucb) { struct trace_event_call *call = trace_probe_event_call(&tu->tp); struct uprobe_trace_entry_head *entry; @@ -1360,7 +1378,7 @@ static void __uprobe_perf_func(struct trace_uprobe *tu, esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); - size = esize + tu->tp.size + dsize; + size = esize + ucb->dsize; size = ALIGN(size + sizeof(u32), sizeof(u64)) - sizeof(u32); if (WARN_ONCE(size > PERF_MAX_TRACE_SIZE, "profile buffer not large enough")) return; @@ -1383,13 +1401,10 @@ static void __uprobe_perf_func(struct trace_uprobe *tu, data = DATAOF_TRACE_ENTRY(entry, false); } - memcpy(data, ucb->buf, tu->tp.size + dsize); - - if (size - esize > tu->tp.size + dsize) { - int len = tu->tp.size + dsize; + memcpy(data, ucb->buf, ucb->dsize); - memset(data + len, 0, size - esize - len); - } + if (size - esize > ucb->dsize) + memset(data + ucb->dsize, 0, size - esize - ucb->dsize); perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs, head, NULL); @@ -1399,21 +1414,21 @@ static void __uprobe_perf_func(struct trace_uprobe *tu, /* uprobe profile handler */ static int uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs, - struct uprobe_cpu_buffer *ucb, int dsize) + struct uprobe_cpu_buffer *ucb) { if (!uprobe_perf_filter(&tu->consumer, 0, current->mm)) return UPROBE_HANDLER_REMOVE; if (!is_ret_probe(tu)) - __uprobe_perf_func(tu, 0, regs, ucb, dsize); + __uprobe_perf_func(tu, 0, regs, ucb); return 0; } static void uretprobe_perf_func(struct trace_uprobe *tu, unsigned long func, struct pt_regs *regs, - struct uprobe_cpu_buffer *ucb, int dsize) + struct uprobe_cpu_buffer *ucb) { - __uprobe_perf_func(tu, func, regs, ucb, dsize); + __uprobe_perf_func(tu, func, regs, ucb); } int bpf_get_uprobe_info(const struct perf_event *event, u32 *fd_type, @@ -1479,10 +1494,8 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) struct trace_uprobe *tu; struct uprobe_dispatch_data udd; struct uprobe_cpu_buffer *ucb; - int dsize, esize; int ret = 0; - tu = container_of(con, struct trace_uprobe, consumer); tu->nhit++; @@ -1494,18 +1507,14 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) if (WARN_ON_ONCE(!uprobe_cpu_buffer)) return 0; - dsize = __get_data_size(&tu->tp, regs); - esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); - - ucb = uprobe_buffer_get(); - store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize); + ucb = prepare_uprobe_buffer(tu, regs); if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE)) - ret |= uprobe_trace_func(tu, regs, ucb, dsize); + ret |= uprobe_trace_func(tu, regs, ucb); #ifdef CONFIG_PERF_EVENTS if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE)) - ret |= uprobe_perf_func(tu, regs, ucb, dsize); + ret |= uprobe_perf_func(tu, regs, ucb); #endif uprobe_buffer_put(ucb); return ret; @@ -1517,7 +1526,6 @@ static int uretprobe_dispatcher(struct uprobe_consumer *con, struct trace_uprobe *tu; struct uprobe_dispatch_data udd; struct uprobe_cpu_buffer *ucb; - int dsize, esize; tu = container_of(con, struct trace_uprobe, consumer); @@ -1529,18 +1537,13 @@ static int uretprobe_dispatcher(struct uprobe_consumer *con, if (WARN_ON_ONCE(!uprobe_cpu_buffer)) return 0; - dsize = __get_data_size(&tu->tp, regs); - esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu)); - - ucb = uprobe_buffer_get(); - store_trace_args(ucb->buf, &tu->tp, regs, esize, dsize); - + ucb = prepare_uprobe_buffer(tu, regs); if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE)) - uretprobe_trace_func(tu, func, regs, ucb, dsize); + uretprobe_trace_func(tu, func, regs, ucb); #ifdef CONFIG_PERF_EVENTS if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE)) - uretprobe_perf_func(tu, func, regs, ucb, dsize); + uretprobe_perf_func(tu, func, regs, ucb); #endif uprobe_buffer_put(ucb); return 0; -- 2.39.4
