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-rw-r--r--kernel/trace/Kconfig11
-rw-r--r--kernel/trace/bpf_trace.c35
-rw-r--r--kernel/trace/trace_kprobe.c40
-rw-r--r--kernel/trace/trace_probe.h6
4 files changed, 7 insertions, 85 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig
index 9dc0deeaad2b..434c840e2d82 100644
--- a/kernel/trace/Kconfig
+++ b/kernel/trace/Kconfig
@@ -518,17 +518,6 @@ config FUNCTION_PROFILER
If in doubt, say N.
-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
- default n
- help
- Allows BPF to override the execution of a probed function and
- set a different return value. This is used for error injection.
-
config FTRACE_MCOUNT_RECORD
def_bool y
depends on DYNAMIC_FTRACE
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index 1865b0d4cdeb..506efe6e8ed9 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -13,10 +13,6 @@
#include <linux/filter.h>
#include <linux/uaccess.h>
#include <linux/ctype.h>
-#include <linux/kprobes.h>
-#include <asm/kprobes.h>
-
-#include "trace_probe.h"
#include "trace.h"
u64 bpf_get_stackid(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
@@ -80,29 +76,6 @@ unsigned int trace_call_bpf(struct trace_event_call *call, void *ctx)
}
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);
- return 0;
-}
-#else
-BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
-{
- return -EINVAL;
-}
-#endif
-
-static const struct bpf_func_proto bpf_override_return_proto = {
- .func = bpf_override_return,
- .gpl_only = true,
- .ret_type = RET_INTEGER,
- .arg1_type = ARG_PTR_TO_CTX,
- .arg2_type = ARG_ANYTHING,
-};
-
BPF_CALL_3(bpf_probe_read, void *, dst, u32, size, const void *, unsafe_ptr)
{
int ret;
@@ -578,10 +551,6 @@ static const struct bpf_func_proto *kprobe_prog_func_proto(enum bpf_func_id func
return &bpf_get_stackid_proto;
case BPF_FUNC_perf_event_read_value:
return &bpf_perf_event_read_value_proto;
- case BPF_FUNC_override_return:
- pr_warn_ratelimited("%s[%d] is installing a program with bpf_override_return helper that may cause unexpected behavior!",
- current->comm, task_pid_nr(current));
- return &bpf_override_return_proto;
default:
return tracing_func_proto(func_id);
}
@@ -797,10 +766,6 @@ int perf_event_attach_bpf_prog(struct perf_event *event,
struct bpf_prog_array *new_array;
int ret = -EEXIST;
- /* Kprobe override only works for ftrace based kprobes. */
- if (prog->kprobe_override && !trace_kprobe_ftrace(event->tp_event))
- return -EINVAL;
-
mutex_lock(&bpf_event_mutex);
if (event->prog)
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index 8e3c9ec1faf7..abf92e478cfb 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -42,7 +42,6 @@ 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)
{
@@ -88,12 +87,6 @@ static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk)
return nhit;
}
-int trace_kprobe_ftrace(struct trace_event_call *call)
-{
- struct trace_kprobe *tk = (struct trace_kprobe *)call->data;
- return kprobe_ftrace(&tk->rp.kp);
-}
-
static int register_kprobe_event(struct trace_kprobe *tk);
static int unregister_kprobe_event(struct trace_kprobe *tk);
@@ -1177,7 +1170,7 @@ static int kretprobe_event_define_fields(struct trace_event_call *event_call)
#ifdef CONFIG_PERF_EVENTS
/* Kprobe profile handler */
-static int
+static void
kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
{
struct trace_event_call *call = &tk->tp.call;
@@ -1186,29 +1179,12 @@ kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
int size, __size, dsize;
int rctx;
- if (bpf_prog_array_valid(call)) {
- 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 instruction skipping. Also reset our state so
- * we are clean the next pass through.
- */
- if (__this_cpu_read(bpf_kprobe_override)) {
- __this_cpu_write(bpf_kprobe_override, 0);
- reset_current_kprobe();
- return 1;
- }
- if (!ret)
- return 0;
- }
+ if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs))
+ return;
head = this_cpu_ptr(call->perf_events);
if (hlist_empty(head))
- return 0;
+ return;
dsize = __get_data_size(&tk->tp, regs);
__size = sizeof(*entry) + tk->tp.size + dsize;
@@ -1217,14 +1193,13 @@ kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
entry = perf_trace_buf_alloc(size, NULL, &rctx);
if (!entry)
- return 0;
+ return;
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, NULL);
- return 0;
}
NOKPROBE_SYMBOL(kprobe_perf_func);
@@ -1300,7 +1275,6 @@ 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);
@@ -1308,9 +1282,9 @@ 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)
- ret = kprobe_perf_func(tk, regs);
+ kprobe_perf_func(tk, regs);
#endif
- return ret;
+ return 0; /* We don't tweek kernel, so just return 0 */
}
NOKPROBE_SYMBOL(kprobe_dispatcher);
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index adbb3f7d1fb5..903273c93e61 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -253,7 +253,6 @@ 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);
#else
/* uprobes do not support symbol fetch methods */
#define fetch_symbol_u8 NULL
@@ -279,11 +278,6 @@ alloc_symbol_cache(const char *sym, long offset)
{
return NULL;
}
-
-static inline int trace_kprobe_ftrace(struct trace_event_call *call)
-{
- return 0;
-}
#endif /* CONFIG_KPROBE_EVENTS */
struct probe_arg {
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-26 07:01:24 +0000