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uprobes: encapsulate preparation of uprobe args buffer 

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@kernel.org/
[Masami: update for v6.9-rc3 kernel]

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
This commit is contained in:
Andrii Nakryiko 2024-03-18 11:17:26 -07:00 committed by Masami Hiramatsu (Google)
parent e67572cd22
commit 3eaea21b4d
1 changed files with 41 additions and 37 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

78
kernel/trace/trace_uprobe.c
View File

@ -854,6 +854,7 @@ 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;
@ -943,9 +944,26 @@ 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, NULL);
ucb = uprobe_buffer_get();
ucb->dsize = tu->tp.size + dsize;
store_trace_args(ucb->buf, &tu->tp, regs, NULL, 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;
@ -956,14 +974,14 @@ 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;
@ -977,14 +995,14 @@ 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;
@ -993,7 +1011,7 @@ 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;
@ -1001,13 +1019,13 @@ 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();
}
@ -1335,7 +1353,7 @@ 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;
@ -1356,7 +1374,7 @@ 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;
@ -1379,13 +1397,10 @@ static void __uprobe_perf_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);
if (size - esize > tu->tp.size + dsize) {
int len = tu->tp.size + 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);
@ -1395,21 +1410,21 @@ 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,
@ -1475,10 +1490,8 @@ 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++;
@ -1490,18 +1503,14 @@ 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, NULL);
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
ucb = uprobe_buffer_get();
store_trace_args(ucb->buf, &tu->tp, regs, NULL, 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;
@ -1513,7 +1522,6 @@ 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);
@ -1525,18 +1533,14 @@ static int uretprobe_dispatcher(struct uprobe_consumer *con,
if (WARN_ON_ONCE(!uprobe_cpu_buffer))
return 0;
dsize = __get_data_size(&tu->tp, regs, NULL);
esize = SIZEOF_TRACE_ENTRY(is_ret_probe(tu));
ucb = uprobe_buffer_get();
store_trace_args(ucb->buf, &tu->tp, regs, NULL, 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;