summaryrefslogtreecommitdiff
path: root/kernel/trace
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/trace')
-rw-r--r--kernel/trace/Kconfig4
-rw-r--r--kernel/trace/bpf_trace.c11
-rw-r--r--kernel/trace/trace_kprobe.c33
-rw-r--r--kernel/trace/trace_probe.h12
4 files changed, 27 insertions, 33 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index ae3a2d519e50..7114c885a78a 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -533,9 +533,7 @@ config FUNCTION_PROFILER
config BPF_KPROBE_OVERRIDE
bool "Enable BPF programs to override a kprobed function"
depends on BPF_EVENTS
- depends on KPROBES_ON_FTRACE
- depends on HAVE_KPROBE_OVERRIDE
- depends on DYNAMIC_FTRACE_WITH_REGS
+ depends on FUNCTION_ERROR_INJECTION
default n
help
Allows BPF to override the execution of a probed function and
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index f6d2327ecb59..f274468cbc45 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -14,7 +14,7 @@
#include <linux/uaccess.h>
#include <linux/ctype.h>
#include <linux/kprobes.h>
-#include <asm/kprobes.h>
+#include <linux/error-injection.h>
#include "trace_probe.h"
#include "trace.h"
@@ -83,9 +83,8 @@ EXPORT_SYMBOL_GPL(trace_call_bpf);
#ifdef CONFIG_BPF_KPROBE_OVERRIDE
BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
{
- __this_cpu_write(bpf_kprobe_override, 1);
regs_set_return_value(regs, rc);
- arch_ftrace_kprobe_override_function(regs);
+ override_function_with_return(regs);
return 0;
}
@@ -800,11 +799,11 @@ int perf_event_attach_bpf_prog(struct perf_event *event,
int ret = -EEXIST;
/*
- * Kprobe override only works for ftrace based kprobes, and only if they
- * are on the opt-in list.
+ * Kprobe override only works if they are on the function entry,
+ * and only if they are on the opt-in list.
*/
if (prog->kprobe_override &&
- (!trace_kprobe_ftrace(event->tp_event) ||
+ (!trace_kprobe_on_func_entry(event->tp_event) ||
!trace_kprobe_error_injectable(event->tp_event)))
return -EINVAL;
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 91f4b57dab82..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"
@@ -42,8 +43,6 @@ struct trace_kprobe {
(offsetof(struct trace_kprobe, tp.args) + \
(sizeof(struct probe_arg) * (n)))
-DEFINE_PER_CPU(int, bpf_kprobe_override);
-
static nokprobe_inline bool trace_kprobe_is_return(struct trace_kprobe *tk)
{
return tk->rp.handler != NULL;
@@ -88,13 +87,16 @@ static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk)
return nhit;
}
-int trace_kprobe_ftrace(struct trace_event_call *call)
+bool trace_kprobe_on_func_entry(struct trace_event_call *call)
{
struct trace_kprobe *tk = (struct trace_kprobe *)call->data;
- return kprobe_ftrace(&tk->rp.kp);
+
+ 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);
}
-int trace_kprobe_error_injectable(struct trace_event_call *call)
+bool trace_kprobe_error_injectable(struct trace_event_call *call)
{
struct trace_kprobe *tk = (struct trace_kprobe *)call->data;
unsigned long addr;
@@ -106,7 +108,7 @@ int trace_kprobe_error_injectable(struct trace_event_call *call)
} else {
addr = (unsigned long)tk->rp.kp.addr;
}
- return within_kprobe_error_injection_list(addr);
+ return within_error_injection_list(addr);
}
static int register_kprobe_event(struct trace_kprobe *tk);
@@ -1202,6 +1204,7 @@ kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
int rctx;
if (bpf_prog_array_valid(call)) {
+ unsigned long orig_ip = instruction_pointer(regs);
int ret;
ret = trace_call_bpf(call, regs);
@@ -1209,12 +1212,13 @@ kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *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 instruction skipping. Also reset our state so
- * we are clean the next pass through.
+ * 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 (__this_cpu_read(bpf_kprobe_override)) {
- __this_cpu_write(bpf_kprobe_override, 0);
+ if (orig_ip != instruction_pointer(regs)) {
reset_current_kprobe();
+ preempt_enable_no_resched();
return 1;
}
if (!ret)
@@ -1322,15 +1326,8 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs)
if (tk->tp.flags & TP_FLAG_TRACE)
kprobe_trace_func(tk, regs);
#ifdef CONFIG_PERF_EVENTS
- if (tk->tp.flags & TP_FLAG_PROFILE) {
+ if (tk->tp.flags & TP_FLAG_PROFILE)
ret = kprobe_perf_func(tk, regs);
- /*
- * The ftrace kprobe handler leaves it up to us to re-enable
- * preemption here before returning if we've modified the ip.
- */
- if (ret)
- preempt_enable_no_resched();
- }
#endif
return ret;
}
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 5e54d748c84c..e101c5bb9eda 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -252,8 +252,8 @@ struct symbol_cache;
unsigned long update_symbol_cache(struct symbol_cache *sc);
void free_symbol_cache(struct symbol_cache *sc);
struct symbol_cache *alloc_symbol_cache(const char *sym, long offset);
-int trace_kprobe_ftrace(struct trace_event_call *call);
-int trace_kprobe_error_injectable(struct trace_event_call *call);
+bool trace_kprobe_on_func_entry(struct trace_event_call *call);
+bool trace_kprobe_error_injectable(struct trace_event_call *call);
#else
/* uprobes do not support symbol fetch methods */
#define fetch_symbol_u8 NULL
@@ -280,14 +280,14 @@ alloc_symbol_cache(const char *sym, long offset)
return NULL;
}
-static inline int trace_kprobe_ftrace(struct trace_event_call *call)
+static inline bool trace_kprobe_on_func_entry(struct trace_event_call *call)
{
- return 0;
+ return false;
}
-static inline int trace_kprobe_error_injectable(struct trace_event_call *call)
+static inline bool trace_kprobe_error_injectable(struct trace_event_call *call)
{
- return 0;
+ return false;
}
#endif /* CONFIG_KPROBE_EVENTS */