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authorIngo Molnar <mingo@kernel.org>2018-02-06 21:12:31 +0100
committerIngo Molnar <mingo@kernel.org>2018-02-06 21:12:31 +0100
commit82845079160817cc6ac64e5321bbd935e0a47b3a (patch)
tree0886d1d52428e9db14536cae4b37db896e7c360a /kernel/trace/trace_kprobe.c
parent32e839dda3ba576943365f0f5817ce5c843137dc (diff)
parent68c5735eaa5e680e701c9a2d1e3c7880bdf5ab66 (diff)
downloadlwn-82845079160817cc6ac64e5321bbd935e0a47b3a.tar.gz
lwn-82845079160817cc6ac64e5321bbd935e0a47b3a.zip
Merge branch 'linus' into sched/urgent, to resolve conflicts
Conflicts: arch/arm64/kernel/entry.S arch/x86/Kconfig include/linux/sched/mm.h kernel/fork.c Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/trace/trace_kprobe.c')
-rw-r--r--kernel/trace/trace_kprobe.c61
1 files changed, 53 insertions, 8 deletions
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 492700c5fb4d..1fad24acd444 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -21,6 +21,7 @@
#include <linux/module.h>
#include <linux/uaccess.h>
#include <linux/rculist.h>
+#include <linux/error-injection.h>
#include "trace_probe.h"
@@ -42,7 +43,6 @@ struct trace_kprobe {
(offsetof(struct trace_kprobe, tp.args) + \
(sizeof(struct probe_arg) * (n)))
-
static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk)
{
return tk->rp.handler != NULL;
@@ -87,6 +87,30 @@ static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk)
return nhit;
}
+bool trace_kprobe_on_func_entry(struct trace_event_call *call)
+{
+ struct trace_kprobe *tk = (struct trace_kprobe *)call->data;
+
+ return kprobe_on_func_entry(tk->rp.kp.addr,
+ tk->rp.kp.addr ? NULL : tk->rp.kp.symbol_name,
+ tk->rp.kp.addr ? 0 : tk->rp.kp.offset);
+}
+
+bool trace_kprobe_error_injectable(struct trace_event_call *call)
+{
+ struct trace_kprobe *tk = (struct trace_kprobe *)call->data;
+ unsigned long addr;
+
+ if (tk->symbol) {
+ addr = (unsigned long)
+ kallsyms_lookup_name(trace_kprobe_symbol(tk));
+ addr += tk->rp.kp.offset;
+ } else {
+ addr = (unsigned long)tk->rp.kp.addr;
+ }
+ return within_error_injection_list(addr);
+}
+
static int register_kprobe_event(struct trace_kprobe *tk);
static int unregister_kprobe_event(struct trace_kprobe *tk);
@@ -1170,7 +1194,7 @@ static int kretprobe_event_define_fields(struct trace_event_call *event_call)
#ifdef CONFIG_PERF_EVENTS
/* Kprobe profile handler */
-static void
+static int
kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
{
struct trace_event_call *call = &tk->tp.call;
@@ -1179,12 +1203,31 @@ kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
int size, __size, dsize;
int rctx;
- if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs))
- return;
+ if (bpf_prog_array_valid(call)) {
+ unsigned long orig_ip = instruction_pointer(regs);
+ int ret;
+
+ ret = trace_call_bpf(call, regs);
+
+ /*
+ * We need to check and see if we modified the pc of the
+ * pt_regs, and if so clear the kprobe and return 1 so that we
+ * don't do the single stepping.
+ * The ftrace kprobe handler leaves it up to us to re-enable
+ * preemption here before returning if we've modified the ip.
+ */
+ if (orig_ip != instruction_pointer(regs)) {
+ reset_current_kprobe();
+ preempt_enable_no_resched();
+ return 1;
+ }
+ if (!ret)
+ return 0;
+ }
head = this_cpu_ptr(call->perf_events);
if (hlist_empty(head))
- return;
+ return 0;
dsize = __get_data_size(&tk->tp, regs);
__size = sizeof(*entry) + tk->tp.size + dsize;
@@ -1193,13 +1236,14 @@ kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
entry = perf_trace_buf_alloc(size, NULL, &rctx);
if (!entry)
- return;
+ return 0;
entry->ip = (unsigned long)tk->rp.kp.addr;
memset(&entry[1], 0, dsize);
store_trace_args(sizeof(*entry), &tk->tp, regs, (u8 *)&entry[1], dsize);
perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
head, NULL);
+ return 0;
}
NOKPROBE_SYMBOL(kprobe_perf_func);
@@ -1275,6 +1319,7 @@ static int kprobe_register(struct trace_event_call *event,
static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
{
struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp);
+ int ret = 0;
raw_cpu_inc(*tk->nhit);
@@ -1282,9 +1327,9 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
kprobe_trace_func(tk, regs);
#ifdef CONFIG_PERF_EVENTS
if (tk->tp.flags & TP_FLAG_PROFILE)
- kprobe_perf_func(tk, regs);
+ ret = kprobe_perf_func(tk, regs);
#endif
- return 0; /* We don't tweek kernel, so just return 0 */
+ return ret;
}
NOKPROBE_SYMBOL(kprobe_dispatcher);