tracing/probes: Support $argN in return probe (kprobe and fprobe)
Support accessing $argN in the return probe events. This will help users to record entry data in function return (exit) event for simplfing the function entry/exit information in one event, and record the result values (e.g. allocated object/initialized object) at function exit. For example, if we have a function `int init_foo(struct foo *obj, int param)` sometimes we want to check how `obj` is initialized. In such case, we can define a new return event like below; # echo 'r init_foo retval=$retval param=$arg2 field1=+0($arg1)' >> kprobe_events Thus it records the function parameter `param` and its result `obj->field1` (the dereference will be done in the function exit timing) value at once. This also support fprobe, BTF args and'$arg*'. So if CONFIG_DEBUG_INFO_BTF is enabled, we can trace both function parameters and the return value by following command. # echo 'f target_function%return $arg* $retval' >> dynamic_events Link: https://lore.kernel.org/all/170952365552.229804.224112990211602895.stgit@devnote2/ Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
This commit is contained in:
Masami Hiramatsu (Google)
parent
c18f9eabee
commit
25f00e40ce
@ -5755,6 +5755,7 @@ static const char readme_msg[] =
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"\t $stack<index>, $stack, $retval, $comm,\n"
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#endif
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"\t +|-[u]<offset>(<fetcharg>), \\imm-value, \\\"imm-string\"\n"
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"\t kernel return probes support: $retval, $arg<N>, $comm\n"
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"\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, char, string, symbol,\n"
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"\t b<bit-width>@<bit-offset>/<container-size>, ustring,\n"
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"\t symstr, <type>\\[<array-size>\\]\n"
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@ -390,8 +390,8 @@ static int get_eprobe_size(struct trace_probe *tp, void *rec)
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/* Note that we don't verify it, since the code does not come from user space */
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static int
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process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
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void *base)
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process_fetch_insn(struct fetch_insn *code, void *rec, void *edata,
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void *dest, void *base)
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{
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unsigned long val;
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int ret;
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@ -438,7 +438,7 @@ __eprobe_trace_func(struct eprobe_data *edata, void *rec)
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return;
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entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
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store_trace_args(&entry[1], &edata->ep->tp, rec, sizeof(*entry), dsize);
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store_trace_args(&entry[1], &edata->ep->tp, rec, NULL, sizeof(*entry), dsize);
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trace_event_buffer_commit(&fbuffer);
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}
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@ -4,6 +4,7 @@
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* Copyright (C) 2022 Google LLC.
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*/
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#define pr_fmt(fmt) "trace_fprobe: " fmt
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#include <asm/ptrace.h>
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#include <linux/fprobe.h>
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#include <linux/module.h>
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@ -129,8 +130,8 @@ static bool trace_fprobe_is_registered(struct trace_fprobe *tf)
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* from user space.
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*/
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static int
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process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
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void *base)
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process_fetch_insn(struct fetch_insn *code, void *rec, void *edata,
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void *dest, void *base)
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{
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struct pt_regs *regs = rec;
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unsigned long val;
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@ -152,6 +153,9 @@ retry:
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case FETCH_OP_ARG:
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val = regs_get_kernel_argument(regs, code->param);
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break;
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case FETCH_OP_EDATA:
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val = *(unsigned long *)((unsigned long)edata + code->offset);
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break;
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#endif
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case FETCH_NOP_SYMBOL: /* Ignore a place holder */
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code++;
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@ -184,7 +188,7 @@ __fentry_trace_func(struct trace_fprobe *tf, unsigned long entry_ip,
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if (trace_trigger_soft_disabled(trace_file))
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return;
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dsize = __get_data_size(&tf->tp, regs);
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dsize = __get_data_size(&tf->tp, regs, NULL);
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entry = trace_event_buffer_reserve(&fbuffer, trace_file,
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sizeof(*entry) + tf->tp.size + dsize);
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@ -194,7 +198,7 @@ __fentry_trace_func(struct trace_fprobe *tf, unsigned long entry_ip,
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fbuffer.regs = regs;
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entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
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entry->ip = entry_ip;
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store_trace_args(&entry[1], &tf->tp, regs, sizeof(*entry), dsize);
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store_trace_args(&entry[1], &tf->tp, regs, NULL, sizeof(*entry), dsize);
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trace_event_buffer_commit(&fbuffer);
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}
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@ -211,10 +215,23 @@ fentry_trace_func(struct trace_fprobe *tf, unsigned long entry_ip,
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NOKPROBE_SYMBOL(fentry_trace_func);
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/* function exit handler */
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static int trace_fprobe_entry_handler(struct fprobe *fp, unsigned long entry_ip,
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unsigned long ret_ip, struct pt_regs *regs,
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void *entry_data)
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{
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struct trace_fprobe *tf = container_of(fp, struct trace_fprobe, fp);
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if (tf->tp.entry_arg)
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store_trace_entry_data(entry_data, &tf->tp, regs);
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return 0;
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}
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NOKPROBE_SYMBOL(trace_fprobe_entry_handler)
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static nokprobe_inline void
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__fexit_trace_func(struct trace_fprobe *tf, unsigned long entry_ip,
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unsigned long ret_ip, struct pt_regs *regs,
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struct trace_event_file *trace_file)
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void *entry_data, struct trace_event_file *trace_file)
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{
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struct fexit_trace_entry_head *entry;
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struct trace_event_buffer fbuffer;
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@ -227,7 +244,7 @@ __fexit_trace_func(struct trace_fprobe *tf, unsigned long entry_ip,
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if (trace_trigger_soft_disabled(trace_file))
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return;
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dsize = __get_data_size(&tf->tp, regs);
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dsize = __get_data_size(&tf->tp, regs, entry_data);
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entry = trace_event_buffer_reserve(&fbuffer, trace_file,
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sizeof(*entry) + tf->tp.size + dsize);
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@ -238,19 +255,19 @@ __fexit_trace_func(struct trace_fprobe *tf, unsigned long entry_ip,
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entry = fbuffer.entry = ring_buffer_event_data(fbuffer.event);
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entry->func = entry_ip;
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entry->ret_ip = ret_ip;
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store_trace_args(&entry[1], &tf->tp, regs, sizeof(*entry), dsize);
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store_trace_args(&entry[1], &tf->tp, regs, entry_data, sizeof(*entry), dsize);
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trace_event_buffer_commit(&fbuffer);
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}
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static void
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fexit_trace_func(struct trace_fprobe *tf, unsigned long entry_ip,
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unsigned long ret_ip, struct pt_regs *regs)
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unsigned long ret_ip, struct pt_regs *regs, void *entry_data)
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{
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struct event_file_link *link;
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trace_probe_for_each_link_rcu(link, &tf->tp)
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__fexit_trace_func(tf, entry_ip, ret_ip, regs, link->file);
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__fexit_trace_func(tf, entry_ip, ret_ip, regs, entry_data, link->file);
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}
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NOKPROBE_SYMBOL(fexit_trace_func);
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@ -269,7 +286,7 @@ static int fentry_perf_func(struct trace_fprobe *tf, unsigned long entry_ip,
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if (hlist_empty(head))
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return 0;
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dsize = __get_data_size(&tf->tp, regs);
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dsize = __get_data_size(&tf->tp, regs, NULL);
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__size = sizeof(*entry) + tf->tp.size + dsize;
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size = ALIGN(__size + sizeof(u32), sizeof(u64));
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size -= sizeof(u32);
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@ -280,7 +297,7 @@ static int fentry_perf_func(struct trace_fprobe *tf, unsigned long entry_ip,
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entry->ip = entry_ip;
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memset(&entry[1], 0, dsize);
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store_trace_args(&entry[1], &tf->tp, regs, sizeof(*entry), dsize);
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store_trace_args(&entry[1], &tf->tp, regs, NULL, sizeof(*entry), dsize);
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perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
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head, NULL);
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return 0;
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@ -289,7 +306,8 @@ NOKPROBE_SYMBOL(fentry_perf_func);
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static void
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fexit_perf_func(struct trace_fprobe *tf, unsigned long entry_ip,
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unsigned long ret_ip, struct pt_regs *regs)
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unsigned long ret_ip, struct pt_regs *regs,
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void *entry_data)
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{
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struct trace_event_call *call = trace_probe_event_call(&tf->tp);
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struct fexit_trace_entry_head *entry;
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@ -301,7 +319,7 @@ fexit_perf_func(struct trace_fprobe *tf, unsigned long entry_ip,
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if (hlist_empty(head))
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return;
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dsize = __get_data_size(&tf->tp, regs);
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dsize = __get_data_size(&tf->tp, regs, entry_data);
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__size = sizeof(*entry) + tf->tp.size + dsize;
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size = ALIGN(__size + sizeof(u32), sizeof(u64));
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size -= sizeof(u32);
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@ -312,7 +330,7 @@ fexit_perf_func(struct trace_fprobe *tf, unsigned long entry_ip,
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entry->func = entry_ip;
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entry->ret_ip = ret_ip;
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store_trace_args(&entry[1], &tf->tp, regs, sizeof(*entry), dsize);
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store_trace_args(&entry[1], &tf->tp, regs, entry_data, sizeof(*entry), dsize);
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perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
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head, NULL);
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}
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@ -343,10 +361,10 @@ static void fexit_dispatcher(struct fprobe *fp, unsigned long entry_ip,
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struct trace_fprobe *tf = container_of(fp, struct trace_fprobe, fp);
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if (trace_probe_test_flag(&tf->tp, TP_FLAG_TRACE))
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fexit_trace_func(tf, entry_ip, ret_ip, regs);
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fexit_trace_func(tf, entry_ip, ret_ip, regs, entry_data);
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#ifdef CONFIG_PERF_EVENTS
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if (trace_probe_test_flag(&tf->tp, TP_FLAG_PROFILE))
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fexit_perf_func(tf, entry_ip, ret_ip, regs);
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fexit_perf_func(tf, entry_ip, ret_ip, regs, entry_data);
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#endif
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}
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NOKPROBE_SYMBOL(fexit_dispatcher);
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@ -1109,6 +1127,11 @@ static int __trace_fprobe_create(int argc, const char *argv[])
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goto error; /* This can be -ENOMEM */
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}
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if (is_return && tf->tp.entry_arg) {
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tf->fp.entry_handler = trace_fprobe_entry_handler;
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tf->fp.entry_data_size = traceprobe_get_entry_data_size(&tf->tp);
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}
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ret = traceprobe_set_print_fmt(&tf->tp,
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is_return ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL);
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if (ret < 0)
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@ -740,6 +740,9 @@ static unsigned int number_of_same_symbols(char *func_name)
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return ctx.count;
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}
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static int trace_kprobe_entry_handler(struct kretprobe_instance *ri,
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struct pt_regs *regs);
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static int __trace_kprobe_create(int argc, const char *argv[])
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{
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/*
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@ -948,6 +951,11 @@ static int __trace_kprobe_create(int argc, const char *argv[])
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if (ret)
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goto error; /* This can be -ENOMEM */
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}
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/* entry handler for kretprobe */
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if (is_return && tk->tp.entry_arg) {
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tk->rp.entry_handler = trace_kprobe_entry_handler;
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tk->rp.data_size = traceprobe_get_entry_data_size(&tk->tp);
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}
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ptype = is_return ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL;
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ret = traceprobe_set_print_fmt(&tk->tp, ptype);
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@ -1303,8 +1311,8 @@ static const struct file_operations kprobe_profile_ops = {
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/* Note that we don't verify it, since the code does not come from user space */
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static int
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process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
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void *base)
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process_fetch_insn(struct fetch_insn *code, void *rec, void *edata,
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void *dest, void *base)
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{
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struct pt_regs *regs = rec;
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unsigned long val;
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@ -1329,6 +1337,9 @@ retry:
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case FETCH_OP_ARG:
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val = regs_get_kernel_argument(regs, code->param);
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break;
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case FETCH_OP_EDATA:
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val = *(unsigned long *)((unsigned long)edata + code->offset);
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break;
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#endif
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case FETCH_NOP_SYMBOL: /* Ignore a place holder */
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code++;
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@ -1359,7 +1370,7 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
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if (trace_trigger_soft_disabled(trace_file))
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return;
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dsize = __get_data_size(&tk->tp, regs);
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dsize = __get_data_size(&tk->tp, regs, NULL);
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entry = trace_event_buffer_reserve(&fbuffer, trace_file,
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sizeof(*entry) + tk->tp.size + dsize);
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@ -1368,7 +1379,7 @@ __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,
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fbuffer.regs = regs;
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entry->ip = (unsigned long)tk->rp.kp.addr;
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store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
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store_trace_args(&entry[1], &tk->tp, regs, NULL, sizeof(*entry), dsize);
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trace_event_buffer_commit(&fbuffer);
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}
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@ -1384,6 +1395,31 @@ kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs)
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NOKPROBE_SYMBOL(kprobe_trace_func);
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/* Kretprobe handler */
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static int trace_kprobe_entry_handler(struct kretprobe_instance *ri,
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struct pt_regs *regs)
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{
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struct kretprobe *rp = get_kretprobe(ri);
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struct trace_kprobe *tk;
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/*
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* There is a small chance that get_kretprobe(ri) returns NULL when
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* the kretprobe is unregister on another CPU between kretprobe's
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* trampoline_handler and this function.
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*/
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if (unlikely(!rp))
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return -ENOENT;
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tk = container_of(rp, struct trace_kprobe, rp);
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/* store argument values into ri->data as entry data */
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if (tk->tp.entry_arg)
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store_trace_entry_data(ri->data, &tk->tp, regs);
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return 0;
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}
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static nokprobe_inline void
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__kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
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struct pt_regs *regs,
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@ -1399,7 +1435,7 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
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if (trace_trigger_soft_disabled(trace_file))
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return;
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dsize = __get_data_size(&tk->tp, regs);
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dsize = __get_data_size(&tk->tp, regs, ri->data);
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entry = trace_event_buffer_reserve(&fbuffer, trace_file,
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sizeof(*entry) + tk->tp.size + dsize);
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@ -1409,7 +1445,7 @@ __kretprobe_trace_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
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fbuffer.regs = regs;
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entry->func = (unsigned long)tk->rp.kp.addr;
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entry->ret_ip = get_kretprobe_retaddr(ri);
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store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
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store_trace_args(&entry[1], &tk->tp, regs, ri->data, sizeof(*entry), dsize);
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trace_event_buffer_commit(&fbuffer);
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}
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@ -1557,7 +1593,7 @@ kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
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if (hlist_empty(head))
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return 0;
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dsize = __get_data_size(&tk->tp, regs);
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dsize = __get_data_size(&tk->tp, regs, NULL);
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__size = sizeof(*entry) + tk->tp.size + dsize;
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size = ALIGN(__size + sizeof(u32), sizeof(u64));
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size -= sizeof(u32);
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@ -1568,7 +1604,7 @@ kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs)
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entry->ip = (unsigned long)tk->rp.kp.addr;
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memset(&entry[1], 0, dsize);
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store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
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store_trace_args(&entry[1], &tk->tp, regs, NULL, sizeof(*entry), dsize);
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perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
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head, NULL);
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return 0;
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@ -1593,7 +1629,7 @@ kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
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if (hlist_empty(head))
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return;
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dsize = __get_data_size(&tk->tp, regs);
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dsize = __get_data_size(&tk->tp, regs, ri->data);
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__size = sizeof(*entry) + tk->tp.size + dsize;
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size = ALIGN(__size + sizeof(u32), sizeof(u64));
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size -= sizeof(u32);
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@ -1604,7 +1640,7 @@ kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri,
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entry->func = (unsigned long)tk->rp.kp.addr;
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entry->ret_ip = get_kretprobe_retaddr(ri);
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store_trace_args(&entry[1], &tk->tp, regs, sizeof(*entry), dsize);
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store_trace_args(&entry[1], &tk->tp, regs, ri->data, sizeof(*entry), dsize);
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perf_trace_buf_submit(entry, size, rctx, call->event.type, 1, regs,
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head, NULL);
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}
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@ -594,6 +594,8 @@ static int parse_btf_field(char *fieldname, const struct btf_type *type,
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return 0;
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}
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static int __store_entry_arg(struct trace_probe *tp, int argnum);
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static int parse_btf_arg(char *varname,
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struct fetch_insn **pcode, struct fetch_insn *end,
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struct traceprobe_parse_context *ctx)
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@ -618,11 +620,7 @@ static int parse_btf_arg(char *varname,
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return -EOPNOTSUPP;
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}
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if (ctx->flags & TPARG_FL_RETURN) {
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if (strcmp(varname, "$retval") != 0) {
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trace_probe_log_err(ctx->offset, NO_BTFARG);
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return -ENOENT;
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}
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if (ctx->flags & TPARG_FL_RETURN && !strcmp(varname, "$retval")) {
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code->op = FETCH_OP_RETVAL;
|
||||
/* Check whether the function return type is not void */
|
||||
if (query_btf_context(ctx) == 0) {
|
||||
@ -654,11 +652,21 @@ static int parse_btf_arg(char *varname,
|
||||
const char *name = btf_name_by_offset(ctx->btf, params[i].name_off);
|
||||
|
||||
if (name && !strcmp(name, varname)) {
|
||||
code->op = FETCH_OP_ARG;
|
||||
if (ctx->flags & TPARG_FL_TPOINT)
|
||||
code->param = i + 1;
|
||||
else
|
||||
code->param = i;
|
||||
if (tparg_is_function_entry(ctx->flags)) {
|
||||
code->op = FETCH_OP_ARG;
|
||||
if (ctx->flags & TPARG_FL_TPOINT)
|
||||
code->param = i + 1;
|
||||
else
|
||||
code->param = i;
|
||||
} else if (tparg_is_function_return(ctx->flags)) {
|
||||
code->op = FETCH_OP_EDATA;
|
||||
ret = __store_entry_arg(ctx->tp, i);
|
||||
if (ret < 0) {
|
||||
/* internal error */
|
||||
return ret;
|
||||
}
|
||||
code->offset = ret;
|
||||
}
|
||||
tid = params[i].type;
|
||||
goto found;
|
||||
}
|
||||
@ -755,6 +763,110 @@ static int check_prepare_btf_string_fetch(char *typename,
|
||||
|
||||
#endif
|
||||
|
||||
#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
|
||||
|
||||
static int __store_entry_arg(struct trace_probe *tp, int argnum)
|
||||
{
|
||||
struct probe_entry_arg *earg = tp->entry_arg;
|
||||
bool match = false;
|
||||
int i, offset;
|
||||
|
||||
if (!earg) {
|
||||
earg = kzalloc(sizeof(*tp->entry_arg), GFP_KERNEL);
|
||||
if (!earg)
|
||||
return -ENOMEM;
|
||||
earg->size = 2 * tp->nr_args + 1;
|
||||
earg->code = kcalloc(earg->size, sizeof(struct fetch_insn),
|
||||
GFP_KERNEL);
|
||||
if (!earg->code) {
|
||||
kfree(earg);
|
||||
return -ENOMEM;
|
||||
}
|
||||
/* Fill the code buffer with 'end' to simplify it */
|
||||
for (i = 0; i < earg->size; i++)
|
||||
earg->code[i].op = FETCH_OP_END;
|
||||
tp->entry_arg = earg;
|
||||
}
|
||||
|
||||
offset = 0;
|
||||
for (i = 0; i < earg->size - 1; i++) {
|
||||
switch (earg->code[i].op) {
|
||||
case FETCH_OP_END:
|
||||
earg->code[i].op = FETCH_OP_ARG;
|
||||
earg->code[i].param = argnum;
|
||||
earg->code[i + 1].op = FETCH_OP_ST_EDATA;
|
||||
earg->code[i + 1].offset = offset;
|
||||
return offset;
|
||||
case FETCH_OP_ARG:
|
||||
match = (earg->code[i].param == argnum);
|
||||
break;
|
||||
case FETCH_OP_ST_EDATA:
|
||||
offset = earg->code[i].offset;
|
||||
if (match)
|
||||
return offset;
|
||||
offset += sizeof(unsigned long);
|
||||
break;
|
||||
default:
|
||||
break;
|
||||
}
|
||||
}
|
||||
return -ENOSPC;
|
||||
}
|
||||
|
||||
int traceprobe_get_entry_data_size(struct trace_probe *tp)
|
||||
{
|
||||
struct probe_entry_arg *earg = tp->entry_arg;
|
||||
int i, size = 0;
|
||||
|
||||
if (!earg)
|
||||
return 0;
|
||||
|
||||
for (i = 0; i < earg->size; i++) {
|
||||
switch (earg->code[i].op) {
|
||||
case FETCH_OP_END:
|
||||
goto out;
|
||||
case FETCH_OP_ST_EDATA:
|
||||
size = earg->code[i].offset + sizeof(unsigned long);
|
||||
break;
|
||||
default:
|
||||
break;
|
||||
}
|
||||
}
|
||||
out:
|
||||
return size;
|
||||
}
|
||||
|
||||
void store_trace_entry_data(void *edata, struct trace_probe *tp, struct pt_regs *regs)
|
||||
{
|
||||
struct probe_entry_arg *earg = tp->entry_arg;
|
||||
unsigned long val;
|
||||
int i;
|
||||
|
||||
if (!earg)
|
||||
return;
|
||||
|
||||
for (i = 0; i < earg->size; i++) {
|
||||
struct fetch_insn *code = &earg->code[i];
|
||||
|
||||
switch (code->op) {
|
||||
case FETCH_OP_ARG:
|
||||
val = regs_get_kernel_argument(regs, code->param);
|
||||
break;
|
||||
case FETCH_OP_ST_EDATA:
|
||||
*(unsigned long *)((unsigned long)edata + code->offset) = val;
|
||||
break;
|
||||
case FETCH_OP_END:
|
||||
goto end;
|
||||
default:
|
||||
break;
|
||||
}
|
||||
}
|
||||
end:
|
||||
return;
|
||||
}
|
||||
NOKPROBE_SYMBOL(store_trace_entry_data)
|
||||
#endif
|
||||
|
||||
#define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
|
||||
|
||||
/* Parse $vars. @orig_arg points '$', which syncs to @ctx->offset */
|
||||
@ -830,7 +942,7 @@ static int parse_probe_vars(char *orig_arg, const struct fetch_type *t,
|
||||
|
||||
#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
|
||||
len = str_has_prefix(arg, "arg");
|
||||
if (len && tparg_is_function_entry(ctx->flags)) {
|
||||
if (len) {
|
||||
ret = kstrtoul(arg + len, 10, ¶m);
|
||||
if (ret)
|
||||
goto inval;
|
||||
@ -839,15 +951,29 @@ static int parse_probe_vars(char *orig_arg, const struct fetch_type *t,
|
||||
err = TP_ERR_BAD_ARG_NUM;
|
||||
goto inval;
|
||||
}
|
||||
param--; /* argN starts from 1, but internal arg[N] starts from 0 */
|
||||
|
||||
code->op = FETCH_OP_ARG;
|
||||
code->param = (unsigned int)param - 1;
|
||||
/*
|
||||
* The tracepoint probe will probe a stub function, and the
|
||||
* first parameter of the stub is a dummy and should be ignored.
|
||||
*/
|
||||
if (ctx->flags & TPARG_FL_TPOINT)
|
||||
code->param++;
|
||||
if (tparg_is_function_entry(ctx->flags)) {
|
||||
code->op = FETCH_OP_ARG;
|
||||
code->param = (unsigned int)param;
|
||||
/*
|
||||
* The tracepoint probe will probe a stub function, and the
|
||||
* first parameter of the stub is a dummy and should be ignored.
|
||||
*/
|
||||
if (ctx->flags & TPARG_FL_TPOINT)
|
||||
code->param++;
|
||||
} else if (tparg_is_function_return(ctx->flags)) {
|
||||
/* function entry argument access from return probe */
|
||||
ret = __store_entry_arg(ctx->tp, param);
|
||||
if (ret < 0) /* This error should be an internal error */
|
||||
return ret;
|
||||
|
||||
code->op = FETCH_OP_EDATA;
|
||||
code->offset = ret;
|
||||
} else {
|
||||
err = TP_ERR_NOFENTRY_ARGS;
|
||||
goto inval;
|
||||
}
|
||||
return 0;
|
||||
}
|
||||
#endif
|
||||
@ -1037,7 +1163,8 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
|
||||
break;
|
||||
default:
|
||||
if (isalpha(arg[0]) || arg[0] == '_') { /* BTF variable */
|
||||
if (!tparg_is_function_entry(ctx->flags)) {
|
||||
if (!tparg_is_function_entry(ctx->flags) &&
|
||||
!tparg_is_function_return(ctx->flags)) {
|
||||
trace_probe_log_err(ctx->offset, NOSUP_BTFARG);
|
||||
return -EINVAL;
|
||||
}
|
||||
@ -1423,6 +1550,7 @@ int traceprobe_parse_probe_arg(struct trace_probe *tp, int i, const char *arg,
|
||||
struct probe_arg *parg = &tp->args[i];
|
||||
const char *body;
|
||||
|
||||
ctx->tp = tp;
|
||||
body = strchr(arg, '=');
|
||||
if (body) {
|
||||
if (body - arg > MAX_ARG_NAME_LEN) {
|
||||
@ -1479,7 +1607,8 @@ static int argv_has_var_arg(int argc, const char *argv[], int *args_idx,
|
||||
if (str_has_prefix(argv[i], "$arg")) {
|
||||
trace_probe_log_set_index(i + 2);
|
||||
|
||||
if (!tparg_is_function_entry(ctx->flags)) {
|
||||
if (!tparg_is_function_entry(ctx->flags) &&
|
||||
!tparg_is_function_return(ctx->flags)) {
|
||||
trace_probe_log_err(0, NOFENTRY_ARGS);
|
||||
return -EINVAL;
|
||||
}
|
||||
@ -1802,6 +1931,12 @@ void trace_probe_cleanup(struct trace_probe *tp)
|
||||
for (i = 0; i < tp->nr_args; i++)
|
||||
traceprobe_free_probe_arg(&tp->args[i]);
|
||||
|
||||
if (tp->entry_arg) {
|
||||
kfree(tp->entry_arg->code);
|
||||
kfree(tp->entry_arg);
|
||||
tp->entry_arg = NULL;
|
||||
}
|
||||
|
||||
if (tp->event)
|
||||
trace_probe_unlink(tp);
|
||||
}
|
||||
|
||||
@ -92,6 +92,7 @@ enum fetch_op {
|
||||
FETCH_OP_ARG, /* Function argument : .param */
|
||||
FETCH_OP_FOFFS, /* File offset: .immediate */
|
||||
FETCH_OP_DATA, /* Allocated data: .data */
|
||||
FETCH_OP_EDATA, /* Entry data: .offset */
|
||||
// Stage 2 (dereference) op
|
||||
FETCH_OP_DEREF, /* Dereference: .offset */
|
||||
FETCH_OP_UDEREF, /* User-space Dereference: .offset */
|
||||
@ -102,6 +103,7 @@ enum fetch_op {
|
||||
FETCH_OP_ST_STRING, /* String: .offset, .size */
|
||||
FETCH_OP_ST_USTRING, /* User String: .offset, .size */
|
||||
FETCH_OP_ST_SYMSTR, /* Kernel Symbol String: .offset, .size */
|
||||
FETCH_OP_ST_EDATA, /* Store Entry Data: .offset */
|
||||
// Stage 4 (modify) op
|
||||
FETCH_OP_MOD_BF, /* Bitfield: .basesize, .lshift, .rshift */
|
||||
// Stage 5 (loop) op
|
||||
@ -232,6 +234,11 @@ struct probe_arg {
|
||||
const struct fetch_type *type; /* Type of this argument */
|
||||
};
|
||||
|
||||
struct probe_entry_arg {
|
||||
struct fetch_insn *code;
|
||||
unsigned int size; /* The entry data size */
|
||||
};
|
||||
|
||||
struct trace_uprobe_filter {
|
||||
rwlock_t rwlock;
|
||||
int nr_systemwide;
|
||||
@ -253,6 +260,7 @@ struct trace_probe {
|
||||
struct trace_probe_event *event;
|
||||
ssize_t size; /* trace entry size */
|
||||
unsigned int nr_args;
|
||||
struct probe_entry_arg *entry_arg; /* This is only for return probe */
|
||||
struct probe_arg args[];
|
||||
};
|
||||
|
||||
@ -355,6 +363,18 @@ int trace_probe_create(const char *raw_command, int (*createfn)(int, const char
|
||||
int trace_probe_print_args(struct trace_seq *s, struct probe_arg *args, int nr_args,
|
||||
u8 *data, void *field);
|
||||
|
||||
#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
|
||||
int traceprobe_get_entry_data_size(struct trace_probe *tp);
|
||||
/* This is a runtime function to store entry data */
|
||||
void store_trace_entry_data(void *edata, struct trace_probe *tp, struct pt_regs *regs);
|
||||
#else /* !CONFIG_HAVE_FUNCTION_ARG_ACCESS_API */
|
||||
static inline int traceprobe_get_entry_data_size(struct trace_probe *tp)
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
#define store_trace_entry_data(edata, tp, regs) do { } while (0)
|
||||
#endif
|
||||
|
||||
#define trace_probe_for_each_link(pos, tp) \
|
||||
list_for_each_entry(pos, &(tp)->event->files, list)
|
||||
#define trace_probe_for_each_link_rcu(pos, tp) \
|
||||
@ -381,6 +401,11 @@ static inline bool tparg_is_function_entry(unsigned int flags)
|
||||
return (flags & TPARG_FL_LOC_MASK) == (TPARG_FL_KERNEL | TPARG_FL_FENTRY);
|
||||
}
|
||||
|
||||
static inline bool tparg_is_function_return(unsigned int flags)
|
||||
{
|
||||
return (flags & TPARG_FL_LOC_MASK) == (TPARG_FL_KERNEL | TPARG_FL_RETURN);
|
||||
}
|
||||
|
||||
struct traceprobe_parse_context {
|
||||
struct trace_event_call *event;
|
||||
/* BTF related parameters */
|
||||
@ -392,6 +417,7 @@ struct traceprobe_parse_context {
|
||||
const struct btf_type *last_type; /* Saved type */
|
||||
u32 last_bitoffs; /* Saved bitoffs */
|
||||
u32 last_bitsize; /* Saved bitsize */
|
||||
struct trace_probe *tp;
|
||||
unsigned int flags;
|
||||
int offset;
|
||||
};
|
||||
@ -506,7 +532,7 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
|
||||
C(NO_BTFARG, "This variable is not found at this probe point"),\
|
||||
C(NO_BTF_ENTRY, "No BTF entry for this probe point"), \
|
||||
C(BAD_VAR_ARGS, "$arg* must be an independent parameter without name etc."),\
|
||||
C(NOFENTRY_ARGS, "$arg* can be used only on function entry"), \
|
||||
C(NOFENTRY_ARGS, "$arg* can be used only on function entry or exit"), \
|
||||
C(DOUBLE_ARGS, "$arg* can be used only once in the parameters"), \
|
||||
C(ARGS_2LONG, "$arg* failed because the argument list is too long"), \
|
||||
C(ARGIDX_2BIG, "$argN index is too big"), \
|
||||
|
||||
@ -54,7 +54,7 @@ fetch_apply_bitfield(struct fetch_insn *code, void *buf)
|
||||
* If dest is NULL, don't store result and return required dynamic data size.
|
||||
*/
|
||||
static int
|
||||
process_fetch_insn(struct fetch_insn *code, void *rec,
|
||||
process_fetch_insn(struct fetch_insn *code, void *rec, void *edata,
|
||||
void *dest, void *base);
|
||||
static nokprobe_inline int fetch_store_strlen(unsigned long addr);
|
||||
static nokprobe_inline int
|
||||
@ -232,7 +232,7 @@ array:
|
||||
|
||||
/* Sum up total data length for dynamic arrays (strings) */
|
||||
static nokprobe_inline int
|
||||
__get_data_size(struct trace_probe *tp, struct pt_regs *regs)
|
||||
__get_data_size(struct trace_probe *tp, struct pt_regs *regs, void *edata)
|
||||
{
|
||||
struct probe_arg *arg;
|
||||
int i, len, ret = 0;
|
||||
@ -240,7 +240,7 @@ __get_data_size(struct trace_probe *tp, struct pt_regs *regs)
|
||||
for (i = 0; i < tp->nr_args; i++) {
|
||||
arg = tp->args + i;
|
||||
if (unlikely(arg->dynamic)) {
|
||||
len = process_fetch_insn(arg->code, regs, NULL, NULL);
|
||||
len = process_fetch_insn(arg->code, regs, edata, NULL, NULL);
|
||||
if (len > 0)
|
||||
ret += len;
|
||||
}
|
||||
@ -251,7 +251,7 @@ __get_data_size(struct trace_probe *tp, struct pt_regs *regs)
|
||||
|
||||
/* Store the value of each argument */
|
||||
static nokprobe_inline void
|
||||
store_trace_args(void *data, struct trace_probe *tp, void *rec,
|
||||
store_trace_args(void *data, struct trace_probe *tp, void *rec, void *edata,
|
||||
int header_size, int maxlen)
|
||||
{
|
||||
struct probe_arg *arg;
|
||||
@ -266,7 +266,7 @@ store_trace_args(void *data, struct trace_probe *tp, void *rec,
|
||||
/* Point the dynamic data area if needed */
|
||||
if (unlikely(arg->dynamic))
|
||||
*dl = make_data_loc(maxlen, dyndata - base);
|
||||
ret = process_fetch_insn(arg->code, rec, dl, base);
|
||||
ret = process_fetch_insn(arg->code, rec, edata, dl, base);
|
||||
if (arg->dynamic && likely(ret > 0)) {
|
||||
dyndata += ret;
|
||||
maxlen -= ret;
|
||||
|
||||
@ -211,8 +211,8 @@ static unsigned long translate_user_vaddr(unsigned long file_offset)
|
||||
|
||||
/* Note that we don't verify it, since the code does not come from user space */
|
||||
static int
|
||||
process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
|
||||
void *base)
|
||||
process_fetch_insn(struct fetch_insn *code, void *rec, void *edata,
|
||||
void *dest, void *base)
|
||||
{
|
||||
struct pt_regs *regs = rec;
|
||||
unsigned long val;
|
||||
@ -1490,11 +1490,11 @@ 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);
|
||||
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, esize, dsize);
|
||||
store_trace_args(ucb->buf, &tu->tp, regs, NULL, esize, dsize);
|
||||
|
||||
if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
|
||||
ret |= uprobe_trace_func(tu, regs, ucb, dsize);
|
||||
@ -1525,11 +1525,11 @@ static int uretprobe_dispatcher(struct uprobe_consumer *con,
|
||||
if (WARN_ON_ONCE(!uprobe_cpu_buffer))
|
||||
return 0;
|
||||
|
||||
dsize = __get_data_size(&tu->tp, regs);
|
||||
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, esize, dsize);
|
||||
store_trace_args(ucb->buf, &tu->tp, regs, NULL, esize, dsize);
|
||||
|
||||
if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE))
|
||||
uretprobe_trace_func(tu, func, regs, ucb, dsize);
|
||||
|
||||
@ -34,7 +34,9 @@ check_error 'f vfs_read ^$stack10000' # BAD_STACK_NUM
|
||||
|
||||
check_error 'f vfs_read ^$arg10000' # BAD_ARG_NUM
|
||||
|
||||
if !grep -q 'kernel return probes support:' README; then
|
||||
check_error 'f vfs_read $retval ^$arg1' # BAD_VAR
|
||||
fi
|
||||
check_error 'f vfs_read ^$none_var' # BAD_VAR
|
||||
check_error 'f vfs_read ^'$REG # BAD_VAR
|
||||
|
||||
@ -99,7 +101,9 @@ if grep -q "<argname>" README; then
|
||||
check_error 'f vfs_read args=^$arg*' # BAD_VAR_ARGS
|
||||
check_error 'f vfs_read +0(^$arg*)' # BAD_VAR_ARGS
|
||||
check_error 'f vfs_read $arg* ^$arg*' # DOUBLE_ARGS
|
||||
if !grep -q 'kernel return probes support:' README; then
|
||||
check_error 'f vfs_read%return ^$arg*' # NOFENTRY_ARGS
|
||||
fi
|
||||
check_error 'f vfs_read ^hoge' # NO_BTFARG
|
||||
check_error 'f kfree ^$arg10' # NO_BTFARG (exceed the number of parameters)
|
||||
check_error 'f kfree%return ^$retval' # NO_RETVAL
|
||||
|
||||
@ -108,7 +108,9 @@ if grep -q "<argname>" README; then
|
||||
check_error 'p vfs_read args=^$arg*' # BAD_VAR_ARGS
|
||||
check_error 'p vfs_read +0(^$arg*)' # BAD_VAR_ARGS
|
||||
check_error 'p vfs_read $arg* ^$arg*' # DOUBLE_ARGS
|
||||
if !grep -q 'kernel return probes support:' README; then
|
||||
check_error 'r vfs_read ^$arg*' # NOFENTRY_ARGS
|
||||
fi
|
||||
check_error 'p vfs_read+8 ^$arg*' # NOFENTRY_ARGS
|
||||
check_error 'p vfs_read ^hoge' # NO_BTFARG
|
||||
check_error 'p kfree ^$arg10' # NO_BTFARG (exceed the number of parameters)
|
||||
|
||||
Loading…
Reference in New Issue
Block a user