{"id":8100,"date":"2023-12-13T20:51:27","date_gmt":"2023-12-13T12:51:27","guid":{"rendered":"https:\/\/yanjingang.com\/blog\/?p=8100"},"modified":"2023-12-18T14:37:09","modified_gmt":"2023-12-18T06:37:09","slug":"ebpf-%e4%bd%bf%e7%94%a8uprobe%e6%8e%a2%e6%b5%8b%e7%94%a8%e6%88%b7%e7%a9%ba%e9%97%b4%e7%a8%8b%e5%ba%8f%e7%9a%84%e5%87%bd%e6%95%b0%e8%b0%83%e7%94%a8","status":"publish","type":"post","link":"https:\/\/yanjingang.com\/blog\/?p=8100","title":{"rendered":"eBPF\u2014\u4f7f\u7528uprobe\u63a2\u6d4b\u7528\u6237\u7a0b\u5e8f\u51fd\u6570\u8c03\u7528"},"content":{"rendered":"<p>\u4e0a\u4e00\u6b21\uff0c\u6211\u4eec\u901a\u8fc7kprobe\u5b9e\u73b0\u4e00\u4e2a\u7b80\u5355\u7684\u5185\u6838\u7cfb\u7edf\u8c03\u7528\u6355\u83b7\uff0c\u4e86\u89e3\u4e86\u5982\u4f55\u5728\u5185\u6838\u51fd\u6570\u7684\u51fa\u5165\u53e3\u52a8\u6001\u6ce8\u5165\u81ea\u5b9a\u4e49\u4ee3\u7801\uff0c\u5e76\u901a\u8fc7ring buffer\u4f20\u9012\u5230\u7528\u6237\u7a7a\u95f4\u3002\u4eca\u5929\uff0c\u6211\u5f00\u59cb\u5e26\u5927\u5bb6\u901a\u8fc7uprobe\u5b9e\u73b0\u4e00\u4e2a\u5bf9\u7528\u6237\u7a7a\u95f4\u81ea\u5b9a\u4e49\u7a0b\u5e8f\u7684\u7279\u5b9a\u51fd\u6570\u51fa\u5165\u53e3\u8fdb\u884c\u4ee3\u7801\u6ce8\u5165\u548c\u63a2\u6d4b\u7684\u65b9\u6cd5\u3002<\/p>\n<h1><span id=\"lwptoc\">\u4e00\u3001\u6982\u8ff0<\/span><\/h1>\n<p><a href=\"https:\/\/yanjingang.com\/blog\/wp-content\/uploads\/2023\/12\/ebpf-tracing.png\"><img loading=\"lazy\" class=\"alignnone size-full wp-image-8095\" src=\"https:\/\/yanjingang.com\/blog\/wp-content\/uploads\/2023\/12\/ebpf-tracing.png\" alt=\"\" width=\"794\" height=\"436\" srcset=\"https:\/\/yanjingang.com\/blog\/wp-content\/uploads\/2023\/12\/ebpf-tracing.png 794w, https:\/\/yanjingang.com\/blog\/wp-content\/uploads\/2023\/12\/ebpf-tracing-300x165.png 300w, https:\/\/yanjingang.com\/blog\/wp-content\/uploads\/2023\/12\/ebpf-tracing-768x422.png 768w, https:\/\/yanjingang.com\/blog\/wp-content\/uploads\/2023\/12\/ebpf-tracing-624x343.png 624w\" sizes=\"(max-width: 794px) 100vw, 794px\" \/><\/a><\/p>\n<h4>1. \u4ec0\u4e48\u662fuprobe?<\/h4>\n<p>uprobe\u662f\u4e00\u79cd\u7528\u6237\u7a7a\u95f4\u63a2\u9488\uff0cuprobe\u63a2\u9488\u5141\u8bb8\u5728\u7528\u6237\u7a7a\u95f4\u7a0b\u5e8f\u4e2d\u52a8\u6001\u63d2\u6869\uff0c\u63d2\u6869\u4f4d\u7f6e\u5305\u62ec\uff1a<span style=\"color: #ff0000;\">\u51fd\u6570\u5165\u53e3\u3001\u7279\u5b9a\u504f\u79fb\u5904\uff0c\u4ee5\u53ca\u51fd\u6570\u8fd4\u56de\u5904<\/span>\u3002\u5f53\u6211\u4eec\u5b9a\u4e49uprobe\u65f6\uff0c\u5185\u6838\u4f1a\u5728\u9644\u52a0\u7684\u6307\u4ee4\u4e0a\u521b\u5efa\u5feb\u901f\u65ad\u70b9\u6307\u4ee4\uff08x86\u673a\u5668\u4e0a\u4e3aint3\u6307\u4ee4\uff09\uff0c\u5f53\u7a0b\u5e8f\u6267\u884c\u5230\u8be5\u6307\u4ee4\u65f6\uff0c\u5185\u6838\u5c06\u89e6\u53d1\u4e8b\u4ef6\uff0c\u7a0b\u5e8f\u9677\u5165\u5230\u5185\u6838\u6001\uff0c\u5e76\u4ee5\u56de\u8c03\u51fd\u6570\u7684\u65b9\u5f0f\u8c03\u7528\u63a2\u9488\u51fd\u6570\uff0c\u6267\u884c\u5b8c\u63a2\u9488\u51fd\u6570\u518d\u8fd4\u56de\u5230\u7528\u6237\u6001\u7ee7\u7eed\u6267\u884c\u540e\u5e8f\u7684\u6307\u4ee4\u3002<\/p>\n<p>uprobe\u57fa\u4e8e\u6587\u4ef6\uff0c\u5f53\u4e00\u4e2a<span style=\"color: #ff0000;\">\u4e8c\u8fdb\u5236\u6587\u4ef6<\/span>\u4e2d\u7684\u4e00\u4e2a\u51fd\u6570\u88ab\u8ddf\u8e2a\u65f6\uff0c\u6240\u6709\u4f7f\u7528\u5230\u8fd9\u4e2a\u6587\u4ef6\u7684\u8fdb\u7a0b\u90fd\u4f1a\u88ab\u63d2\u6869\uff0c\u5305\u62ec\u90a3\u4e9b\u5c1a\u672a\u542f\u52a8\u7684\u8fdb\u7a0b\uff0c\u8fd9\u6837\u5c31\u53ef\u4ee5\u5728\u5168\u7cfb\u7edf\u8303\u56f4\u5185\u8ddf\u8e2a\u7cfb\u7edf\u8c03\u7528\u3002<\/p>\n<p>uprobe\u9002\u7528\u4e8e\u5728\u7528\u6237\u6001\u53bb\u89e3\u6790\u4e00\u4e9b\u5185\u6838\u6001\u63a2\u9488\u65e0\u6cd5\u89e3\u6790\u7684\u6d41\u91cf\uff0c\u4f8b\u5982http2\u6d41\u91cf\uff08\u62a5\u6587header\u88ab\u7f16\u7801\uff0c\u5185\u6838\u65e0\u6cd5\u89e3\u7801\uff09\u3001https\u6d41\u91cf\uff08\u52a0\u5bc6\u6d41\u91cf\uff0c\u5185\u6838\u65e0\u6cd5\u89e3\u5bc6\uff09\u7b49\u3002<\/p>\n<h4>2. libbpf uprobe\u76f8\u5173\u51fd\u6570<\/h4>\n<h6>2.1 <span class=\"sig-name descname\"><span class=\"pre\">bpf_program__attach_uprobe()<\/span><\/span><\/h6>\n<p>bpf_program__attach_uprobe()\u53ef\u4ee5\u5c06BPF\u7a0b\u5e8f\u9644\u52a0\u5230\u901a\u8fc7\u4e8c\u8fdb\u5236\u8def\u5f84\u548c\u504f\u79fb\u91cf\u627e\u5230\u7684\u7528\u6237\u7a7a\u95f4\u51fd\u6570\u4e2d\u3002\u53ef\u4ee5\u9009\u62e9\u6307\u5b9a\u8981\u9644\u52a0\u7684\u7279\u5b9a\u8fdb\u7a0b\uff0c\u8fd8\u53ef\u4ee5\u9009\u62e9\u5c06\u7a0b\u5e8f\u9644\u52a0\u5230\u51fd\u6570\u51fa\u53e3\u6216\u5165\u53e3\u3002<\/p>\n<p>\u51fd\u6570\u5b9a\u4e49\uff1a<\/p>\n<div>\n<div>\n<pre class=\"pure-highlightjs\"><code class=\"\">struct bpf_link *<span style=\"color: #ff0000;\">bpf_program__attach_uprobe<\/span>(\r\n\u00a0 \u00a0 const struct bpf_program *prog,\r\n\u00a0 \u00a0 bool retprobe,\r\n  \u00a0 pid_t pid,\r\n\u00a0 \u00a0 const char *binary_path,\r\n\u00a0 \u00a0 size_t func_offset)<\/code><\/pre>\n<\/div>\n<\/div>\n<p>\u53c2\u6570\uff1a<\/p>\n<ul>\n<li>prog\uff1a\u8981\u9644\u52a0\u7684 BPF \u7a0b\u5e8f<\/li>\n<li>retprobe\uff1a\u9644\u52a0\u5230\u51fd\u6570\u51fa\u53e3<\/li>\n<li>pid\uff1a\u9644\u52a0 uprobe \u7684\u8fdb\u7a0b ID\uff080 \u8868\u793a\u81ea\u8eab\u8fdb\u7a0b\uff0c-1 \u8868\u793a\u6240\u6709\u8fdb\u7a0b\uff09<\/li>\n<li>binary_path\uff1a\u5305\u542b\u51fd\u6570\u7b26\u53f7\u7684\u4e8c\u8fdb\u5236\u6587\u4ef6\u7684\u8def\u5f84<\/li>\n<li>func_offset \uff1a\u51fd\u6570\u7b26\u53f7\u4e8c\u8fdb\u5236\u5185\u7684\u504f\u79fb\u91cf<\/li>\n<\/ul>\n<p>\u8fd4\u56de\u503c\uff1a<\/p>\n<ul>\n<li>\u65b0\u521b\u5efa\u7684BPF\u94fe\u63a5\u5f15\u7528\uff1b\u6216\u51fa\u9519\u65f6\u8fd4\u56de NULL\uff0c\u9519\u8bef\u4ee3\u7801\u5b58\u50a8\u5728 errno \u4e2d<\/li>\n<\/ul>\n<h6>2.2 <span class=\"sig-name descname\"><span class=\"pre\">bpf_program__attach_uprobe_opts()<\/span><\/span><\/h6>\n<p>bpf_program__attach_uprobe_opts() \u4e0e bpf_program__attach_uprobe() \u7c7b\u4f3c\uff0c\u53ea\u662f\u5177\u6709\u7528\u4e8e\u5404\u79cd\u914d\u7f6e\u7684\u9009\u9879\u7ed3\u6784\u3002<\/p>\n<p>\u51fd\u6570\u5b9a\u4e49\uff1a<\/p>\n<pre class=\"pure-highlightjs\"><code class=\"\">struct bpf_link *<span style=\"color: #ff0000;\">bpf_program__attach_uprobe_opts<\/span>(\r\n    const struct bpf_program *prog, \r\n    pid_t pid,\r\n    const char *binary_path, \r\n    size_t func_offset,\r\n    const struct bpf_uprobe_opts *opts)<\/code><\/pre>\n<p>\u53c2\u6570\uff1a<\/p>\n<ul>\n<li>prog \u2013 \u8981\u9644\u52a0\u7684 BPF \u7a0b\u5e8f<\/li>\n<li>pid \u2013 \u9644\u52a0 uprobe \u7684\u8fdb\u7a0b ID\uff0c0 \u8868\u793a\u81ea\u8eab\uff08\u81ea\u5df1\u7684\u8fdb\u7a0b\uff09\uff0c-1 \u8868\u793a\u6240\u6709\u8fdb\u7a0b<\/li>\n<li>binary_path \u2013 \u5305\u542b\u51fd\u6570\u7b26\u53f7\u7684\u4e8c\u8fdb\u5236\u6587\u4ef6\u7684\u8def\u5f84<\/li>\n<li>func_offset \u2013 \u51fd\u6570\u7b26\u53f7\u4e8c\u8fdb\u5236\u5185\u7684\u504f\u79fb\u91cf<\/li>\n<li>opts \u2013 \u66f4\u6539\u7a0b\u5e8f\u9644\u4ef6\u7684\u9009\u9879\uff08retprobe\u4e5f\u88ab\u5c01\u88c5\u5230\u4e86\u8fd9\u91cc\uff09<\/li>\n<\/ul>\n<p>\u8fd4\u56de\u503c\uff1a<\/p>\n<ul>\n<li>\u65b0\u521b\u5efa\u7684BPF\u94fe\u63a5\u5f15\u7528\uff1b\u6216\u51fa\u9519\u65f6\u8fd4\u56de NULL\uff0c\u9519\u8bef\u4ee3\u7801\u5b58\u50a8\u5728 errno \u4e2d<\/li>\n<\/ul>\n<h6>2.3 bpf_program__attach_usdt()<\/h6>\n<p>bpf_program__attach_usdt() \u4e0e bpf_program__attach_uprobe_opts() \u7c7b\u4f3c\uff0c\u53ea\u4e0d\u8fc7\u5b83\u8986\u76d6\u4e86 USDT\uff08\u7528\u6237\u7a7a\u95f4\u9759\u6001\u5b9a\u4e49\u8ddf\u8e2a\u70b9\uff09\u9644\u4ef6\uff0c\u800c\u4e0d\u662f\u9644\u52a0\u5230\u7528\u6237\u7a7a\u95f4\u51fd\u6570\u5165\u53e3\u6216\u51fa\u53e3\u3002<\/p>\n<p>\u51fd\u6570\u5b9a\u4e49\uff1a<\/p>\n<pre class=\"pure-highlightjs\"><code class=\"\">struct bpf_link *<span style=\"color: #ff0000;\">bpf_program__attach_usdt<\/span>(\r\n    const struct bpf_program *prog,\r\n    pid_t pid, \r\n    const char *binary_path,\r\n    const char *usdt_provider,\r\n    const char *usdt_name,\r\n    const struct bpf_usdt_opts *opts)<\/code><\/pre>\n<p>\u53c2\u6570\uff1a<\/p>\n<ul>\n<li>prog \u2013 \u8981\u9644\u52a0\u7684 BPF \u7a0b\u5e8f<\/li>\n<li>pid \u2013 \u9644\u52a0 uprobe \u7684\u8fdb\u7a0b ID\uff0c0 \u8868\u793a\u81ea\u8eab\uff08\u81ea\u5df1\u7684\u8fdb\u7a0b\uff09\uff0c-1 \u8868\u793a\u6240\u6709\u8fdb\u7a0b<\/li>\n<li>binary_path \u2013 \u5305\u542b\u63d0\u4f9b\u7684 USDT \u63a2\u9488\u7684\u4e8c\u8fdb\u5236\u6587\u4ef6\u7684\u8def\u5f84<\/li>\n<li>usdt_provider \u2013 USDT \u63d0\u4f9b\u5546\u540d\u79f0<\/li>\n<li>usdt_name \u2013 USDT \u63a2\u9488\u540d\u79f0<\/li>\n<li>opts \u2013 \u66f4\u6539\u7a0b\u5e8f\u9644\u4ef6\u7684\u9009\u9879<\/li>\n<\/ul>\n<p>\u8fd4\u56de\u503c\uff1a<\/p>\n<ul>\n<li>\u65b0\u521b\u5efa\u7684BPF\u94fe\u63a5\u5f15\u7528\uff1b\u6216\u51fa\u9519\u65f6\u8fd4\u56de NULL\uff0c\u9519\u8bef\u4ee3\u7801\u5b58\u50a8\u5728 errno \u4e2d<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<h1>\u4e8c\u3001\u5b9e\u8df5<\/h1>\n<p>\u4e3a\u4e86\u65b9\u4fbf\u5bf9\u7528\u6237\u7a7a\u95f4\u7279\u5b9a\u7a0b\u5e8f\u7684\u5de5\u4f5c\u72b6\u6001\u63a2\u6d4b\uff0c\u6211\u4eec\u5c06\u7f16\u5199\u4e00\u4e2a\u7b80\u5355\u7684\u7528\u6237\u7a7a\u95f4\u7a0b\u5e8f\uff0c\u5e76\u4f7f\u7528uprobe\u5bf9\u5176\u5185\u90e8\u7684\u51fd\u6570\u5de5\u4f5c\u72b6\u6001\u8fdb\u884c\u63a2\u6d4b\u3002<\/p>\n<h4>1. \u51c6\u5907\u7528\u6237\u7a7a\u95f4\u81ea\u5b9a\u4e49\u7a0b\u5e8f<\/h4>\n<h6>1.1 \u81ea\u5b9a\u4e49\u7a0b\u5e8f<\/h6>\n<p>\u7f16\u5199\u4e00\u4e2a\u7b80\u5355\u7684utest.cc\u7a0b\u5e8f\uff0c\u91cc\u8fb9\u5305\u542b2\u4e2a\u51fd\u6570\uff1autest_add\u3001utest_sub\uff0c\u542f\u52a8\u540e\u65e0\u9650\u5faa\u73af\u8c03\u7528\u8fd9\u4e24\u4e2a\u51fd\u6570\uff0c\u4f5c\u4e3a\u88ab\u63a2\u9488\u6ce8\u5165\u7684\u7528\u6237\u7a7a\u95f4\u81ea\u5b9a\u4e49\u7a0b\u5e8f\u3002<\/p>\n<pre class=\"pure-highlightjs\"><code class=\"\">\/**\r\n * \u7528\u6237\u7a7a\u95f4\u81ea\u5b9a\u4e49\u7a0b\u5e8f\r\n*\/\r\n#include &lt;iostream&gt;\r\n#include &lt;stdio.h&gt;\r\n#include &lt;unistd.h&gt;\r\n\r\nint <span style=\"color: #ff0000;\">utest_add<\/span>(int a, int b){\r\n    return a + b;\r\n}\r\n\r\nint <span style=\"color: #ff0000;\">utest_sub<\/span>(int a, int b){\r\n    return a - b;\r\n}\r\n\r\nint main(int argc, char **argv){\r\n    int err, i;\r\n\r\n    for (i = 0;; i++) {\r\n        <span style=\"color: #ff0000;\">utest_add<\/span>(i, i + 1);\r\n        <span style=\"color: #ff0000;\">utest_sub<\/span>(i * i, i);\r\n        \r\n        std::cout &lt;&lt; \"i = \" &lt;&lt; i &lt;&lt; std::endl;\r\n\r\n        sleep(1);\r\n        }\r\n}<\/code><\/pre>\n<h6>1.2 \u7f16\u8bd1<\/h6>\n<p>\u914d\u7f6e\u4e00\u4e2a\u7b80\u5355\u7684cmake exec\u7f16\u8bd1\u6587\u4ef6\uff1a<\/p>\n<pre class=\"pure-highlightjs\"><code class=\"\">cmake_minimum_required(VERSION 3.16)\r\nproject(utest)\r\n\r\n# utest exec\r\nset(CMAKE_CXX_FLAGS \"${CMAKE_CXX_FLAGS} -Werror -ggdb -rdynamic\")  # \u5e26\u7b26\u53f7\r\nadd_executable(utest utest.cc)<\/code><\/pre>\n<h6>1.3 \u67e5\u770b\u51fd\u6570\u7b26\u53f7<\/h6>\n<p>\u7f16\u8bd1\uff1a<\/p>\n<pre class=\"pure-highlightjs\"><code class=\"\">mkdir build &amp;&amp; cd build\r\ncmake ..\r\nmake<\/code><\/pre>\n<p>\u786e\u5b9a\u7f16\u8bd1\u597d\u7684\u51fd\u6570\u7b26\u53f7\uff1a<\/p>\n<pre class=\"pure-highlightjs\"><code class=\"\">objdump -T utest |grep <span style=\"color: #ff0000;\">utest_add<\/span>\r\n        00000000000011e9 g DF .text 0000000000000018  Base <span style=\"color: #ff0000;\">_Z9utest_addii\r\n<\/span>objdump -T utest |grep <span style=\"color: #ff0000;\">utest_sub<\/span>\r\n        0000000000001201 g DF .text 0000000000000016 Base <span style=\"color: #ff0000;\">_Z9utest_subii<\/span><\/code><\/pre>\n<p>\u542f\u52a8\u6d4b\u8bd5\u7a0b\u5e8f\uff08\u7b49\u5f85uprobe\u63a2\u9488\u6ce8\u5165\uff09\uff1a<\/p>\n<pre class=\"pure-highlightjs\"><code class=\"\">.\/utest \r\n    i = 0\r\n    i = 1\r\n    ...<\/code><\/pre>\n<h4>2. uprobe ebpf\u7a0b\u5e8f\u5b9e\u4f8b<\/h4>\n<h6>2.1 ebpf\u63a2\u6d4b\u51fd\u6570<\/h6>\n<p>\u6211\u4eec\u7f16\u5199\u4e00\u4e2auprobe.bpf.c\u7a0b\u5e8f\uff0c\u901a\u8fc7 SEC \u5b8f\u6765\u5b9a\u4e49 uprobe \u63a2\u9488\uff0c\u5e76\u4f7f\u7528 BPF_KRETPROBE \u5b8f\u6765\u5b9a\u4e49\u63a2\u9488\u51fd\u6570\u3002<\/p>\n<p>\u5728 SEC \u5b8f\u4e2d\uff0c\u6211\u4eec\u9700\u8981\u6307\u5b9a uprobe \u7684\u7c7b\u578b\uff0c\u4e5f\u53ef\u4ee5\u5728SEC\u5b8f\u4e2d\u76f4\u63a5\u5b9a\u4e49\u53f7\u8981\u6355\u83b7\u7684\u4e8c\u8fdb\u5236\u6587\u4ef6\u7684\u8def\u5f84\u548c\u8981\u6355\u83b7\u7684\u51fd\u6570\u540d\u79f0\u3002<\/p>\n<ul>\n<li>\u5982\u5df2\u7ecf\u6307\u5b9a\u4e8c\u8fdb\u5236\u8def\u5f84\u548c\u51fd\u6570\u540d\u79f0\uff0c\u53ef\u76f4\u63a5\u4f7f\u7528xxx_bpf__attach(skel)\u9644\u52a0 xxx.bpf.c \u7a0b\u5e8f\u5230\u8ddf\u8e2a\u70b9\uff1b<\/li>\n<li>\u5982\u672a\u5728SEC\u4e2d\u6307\u5b9a\u4e8c\u8fdb\u5236\u8def\u5f84\u548c\u51fd\u6570\u540d\u79f0\uff0c\u5219\u9700\u8981\u4f7f\u7528bpf_program__attach_uprobe\u8fdb\u884c\u6307\u5b9a\u53c2\u6570\u9644\u52a0\uff09\u3002<\/li>\n<\/ul>\n<pre class=\"pure-highlightjs\"><code class=\"\">\/**\r\n * \u901a\u8fc7\u4f7f\u7528 uprobe\uff08\u7528\u6237\u7a7a\u95f4\u63a2\u9488\uff09\u5728\u7528\u6237\u7a7a\u95f4\u7a0b\u5e8f\u51fd\u6570\u7684\u5165\u53e3\u548c\u9000\u51fa\u5904\u653e\u7f6e\u94a9\u5b50\uff0c\u5b9e\u73b0\u5bf9\u8be5\u7528\u6237\u6001\u51fd\u6570\u8c03\u7528\u7684\u8ddf\u8e2a\r\n*\/\r\n#include \"vmlinux.h\"\r\n#include &lt;bpf\/bpf_helpers.h&gt;\r\n#include &lt;bpf\/bpf_tracing.h&gt;\r\n\r\nchar LICENSE[] SEC(\"license\") = \"Dual BSD\/GPL\";\r\n\r\n\/\/ <span style=\"color: #ff0000;\">\u901a\u8fc7 SEC \u5b8f\u6765\u5b9a\u4e49 uprobe \u63a2\u9488\uff08\u672a\u5728SEC\u4e2d\u6307\u5b9a\u4e8c\u8fdb\u5236\u8def\u5f84\u548c\u51fd\u6570\u540d\u79f0\uff0c\u5219\u9700\u8981\u4f7f\u7528bpf_program__attach_uprobe\u8fdb\u884c\u6307\u5b9a\u53c2\u6570\u9644\u52a0\uff09<\/span>\r\nSEC(\"uprobe\")\r\nint BPF_KPROBE(<span style=\"color: #ff0000;\">utest_add<\/span>, int a, int b)\r\n{\r\n    bpf_printk(\"utest_add ENTRY: a = %d, b = %d\", a, b);\r\n    return 0;\r\n}\r\n\r\nSEC(\"uretprobe\")\r\nint BPF_KRETPROBE(<span style=\"color: #ff0000;\">urettest_add<\/span>, int ret)\r\n{\r\n    bpf_printk(\"utest_add EXIT: return = %d\", ret);\r\n    return 0;\r\n}\r\n\r\n\/\/<span style=\"color: #ff0000;\"> \u5728 SEC \u5b8f\u4e2d\u6307\u5b9a\u8981\u6355\u83b7\u7684 \u4e8c\u8fdb\u5236\u6587\u4ef6\u7684\u8def\u5f84 \u548c \u8981\u6355\u83b7\u7684\u51fd\u6570\u540d\u79f0\uff08\u5df2\u7ecf\u6307\u5b9a\u4e8c\u8fdb\u5236\u8def\u5f84\u548c\u51fd\u6570\u540d\u79f0\uff0c\u53ef\u76f4\u63a5\u4f7f\u7528xxx_bpf__attach(skel)\u9644\u52a0 xxx.bpf.c \u7a0b\u5e8f\u5230\u8ddf\u8e2a\u70b9\uff09<\/span>\r\nSEC(\"uprobe\/\/home\/work\/project\/libbpf-demo\/examples\/test\/utest\/build\/utest:<span style=\"color: #ff0000;\">_Z9utest_subii<\/span>\")\r\nint BPF_KPROBE(<span style=\"color: #ff0000;\">utest_sub<\/span>, int a, int b)\r\n{\r\n    bpf_printk(\"utest_sub ENTRY: a = %d, b = %d\", a, b);\r\n    return 0;\r\n}\r\n\r\nSEC(\"uretprobe\/\/home\/work\/project\/libbpf-demo\/examples\/test\/utest\/build\/utest:<span style=\"color: #ff0000;\">_Z9utest_subii<\/span>\")\r\nint BPF_KRETPROBE(<span style=\"color: #ff0000;\">urettest_sub<\/span>, int ret)\r\n{\r\n    bpf_printk(\"utest_sub EXIT: return = %d\", ret);\r\n    return 0;\r\n}<\/code><\/pre>\n<h6>2.2 \u7528\u6237\u7a7a\u95f4\u7a0b\u5e8f<\/h6>\n<p>\u7f16\u5199\u4e00\u4e2auprobe.c\u7a0b\u5e8f\uff0c\u4f7f\u7528bpf_program__attach_uprobe_opts()\u6216uprobe_bpf__attach()\u52a0\u8f7d\u63a2\u9488\u7a0b\u5e8f\u3002<\/p>\n<pre class=\"pure-highlightjs\"><code class=\"\">\/**\r\n * ebpf \u7528\u6237\u7a7a\u95f4\u7a0b\u5e8f(loader)\r\n*\/\r\n#include &lt;errno.h&gt;\r\n#include &lt;stdio.h&gt;\r\n#include &lt;signal.h&gt;\r\n#include &lt;unistd.h&gt;\r\n#include &lt;sys\/resource.h&gt;\r\n#include &lt;bpf\/libbpf.h&gt;\r\n#include \"uprobe.skel.h\"\r\n\r\nstatic int libbpf_print_fn(enum libbpf_print_level level, const char *format, va_list args)\r\n{\r\n    return vfprintf(stderr, format, args);\r\n}\r\n\r\nstatic volatile sig_atomic_t stop;\r\nstatic void sig_int(int signo)\r\n{\r\n    stop = 1;\r\n}\r\n\r\nint main(int argc, char **argv)\r\n{\r\n    struct uprobe_bpf *skel;\r\n    int err, i;\r\n    LIBBPF_OPTS(bpf_uprobe_opts, uprobe_opts);\r\n\r\n    \/* \u8bbe\u7f6elibbpf\u9519\u8bef\u548c\u8c03\u8bd5\u4fe1\u606f\u56de\u8c03 *\/\r\n    libbpf_set_print(libbpf_print_fn);\r\n\r\n    \/* \u52a0\u8f7d\u5e76\u9a8c\u8bc1 kprobe.bpf.c \u5e94\u7528\u7a0b\u5e8f *\/\r\n    skel = uprobe_bpf__open_and_load();\r\n    if (!skel) {\r\n        fprintf(stderr, \"Failed to open and load BPF skeleton\\n\");\r\n        return 1;\r\n    }\r\n\r\n    \/* \u9644\u52a0\u8ddf\u8e2a\u70b9\u5904\u7406 *\/\r\n    uprobe_opts.func_name = \"<span style=\"color: #ff0000;\">_Z9utest_addii<\/span>\";\r\n    uprobe_opts.retprobe = <span style=\"color: #ff0000;\">false<\/span>;\r\n    \/* uprobe \u671f\u671b\u8981\u9644\u52a0\u7684\u51fd\u6570\u7684\u76f8\u5bf9\u504f\u79fb\u91cf\u3002\r\n     *   \u5982\u679c\u6211\u4eec\u63d0\u4f9b\u51fd\u6570\u540d\u79f0\uff0clibbpf \u4f1a\u81ea\u52a8\u4e3a\u6211\u4eec\u627e\u5230\u504f\u79fb\u91cf\u3002\r\n     *   \u5982\u679c\u672a\u6307\u5b9a\u51fd\u6570\u540d\u79f0\uff0clibbpf \u5c06\u5c1d\u8bd5\u4f7f\u7528\u51fd\u6570\u504f\u79fb\u91cf\u4ee3\u66ff\u3002\r\n     *\/\r\n    skel-&gt;links.utest_add = <span style=\"color: #ff0000;\">bpf_program__attach_uprobe_opts<\/span>(\r\n        skel-&gt;progs.<span style=\"color: #ff0000;\">utest_add<\/span>,\r\n        -1,    \/\/ uprobe \u7684\u8fdb\u7a0b ID\uff0c0 \u8868\u793a\u81ea\u8eab\uff08\u81ea\u5df1\u7684\u8fdb\u7a0b\uff09\uff0c-1 \u8868\u793a\u6240\u6709\u8fdb\u7a0b\r\n        \"\/home\/work\/project\/libbpf-demo\/examples\/test\/utest\/build\/utest\",\r\n        0,    \/\/ offset for function\r\n        &amp;uprobe_opts);\r\n    if (!skel-&gt;links.utest_add) {\r\n        err = -errno;\r\n        fprintf(stderr, \"Failed to attach uprobe: %d\\n\", err);\r\n        goto cleanup;\r\n    }\r\n\r\n    \/* \u5c06 uretprobe \u9644\u52a0\u5230\u4f7f\u7528\u76f8\u540c\u4e8c\u8fdb\u5236\u53ef\u6267\u884c\u6587\u4ef6\u7684\u4efb\u4f55\u73b0\u6709\u6216\u672a\u6765\u8fdb\u7a0b *\/\r\n    uprobe_opts.func_name = \"<span style=\"color: #ff0000;\">_Z9utest_addii<\/span>\";\r\n    uprobe_opts.retprobe = <span style=\"color: #ff0000;\">true<\/span>;\r\n    skel-&gt;links.urettest_add = <span style=\"color: #ff0000;\">bpf_program__attach_uprobe_opts<\/span>(\r\n        skel-&gt;progs.<span style=\"color: #ff0000;\">urettest_add<\/span>, \r\n        -1,    \/\/ uprobe \u7684\u8fdb\u7a0b ID\uff0c0 \u8868\u793a\u81ea\u8eab\uff08\u81ea\u5df1\u7684\u8fdb\u7a0b\uff09\uff0c-1 \u8868\u793a\u6240\u6709\u8fdb\u7a0b\r\n        \"\/home\/work\/project\/libbpf-demo\/examples\/test\/utest\/build\/utest\",\r\n        0,    \/\/ offset for function\r\n        &amp;uprobe_opts);\r\n    if (!skel-&gt;links.urettest_add) {\r\n        err = -errno;\r\n        fprintf(stderr, \"Failed to attach uprobe: %d\\n\", err);\r\n        goto cleanup;\r\n    }\r\n\r\n    \/* \u8ba9libbpf\u4e3a utest_sub\/urettest_sub \u6267\u884c\u81ea\u52a8\u9644\u52a0\r\n     *     \u6ce8\u610f\uff1a<span style=\"color: #ff0000;\">\u6b64\u65b9\u5f0f\u9700\u8981\u5728uprobe.bpf.c\u7684SEC\u4e2d\u63d0\u4f9b\u8def\u5f84\u548c\u7b26\u53f7\u4fe1\u606f<\/span>\r\n     *\/\r\n    err = <span style=\"color: #ff0000;\">uprobe_bpf__attach<\/span>(skel);\r\n    if (err) {\r\n        fprintf(stderr, \"Failed to auto-attach BPF skeleton: %d\\n\", err);\r\n        goto cleanup;\r\n    }\r\n\r\n    \/* Control-C \u505c\u6b62\u4fe1\u53f7 *\/\r\n    if (signal(SIGINT, sig_int) == SIG_ERR) {\r\n        fprintf(stderr, \"can't set signal handler: %s\\n\", strerror(errno));\r\n        goto cleanup;\r\n    }\r\n\r\n    printf(\"Successfully started! Please run `sudo cat \/sys\/kernel\/debug\/tracing\/trace_pipe` \"\r\n           \"to see output of the BPF programs.\\n\");\r\n\r\n    while (!stop) {\r\n        fprintf(stderr, \".\");\r\n        sleep(1);\r\n    }\r\n\r\ncleanup:\r\n    \/* \u9500\u6bc1\u6302\u8f7d\u7684ebpf\u7a0b\u5e8f *\/\r\n    uprobe_bpf__destroy(skel);\r\n    return -err;\r\n}\r\n<\/code><\/pre>\n<p>\u8fd9\u91cc\u8981\u6ce8\u610f\u7684\u662f\uff0c\u4f7f\u7528bpf_program__attach_uprobe\u52a0\u8f7d\u63a2\u9488\u65f6\uff0cfunc_name\u5fc5\u987b\u4e3aobjdump\u4e2d\u7684\u51fd\u6570\u7b26\u53f7\uff0c\u800c\u4e0d\u4ec5\u4ec5\u662f\u51fd\u6570\u540d\u3002<\/p>\n<h6>2.3 \u7f16\u8bd1&amp;\u8c03\u8bd5<\/h6>\n<pre class=\"pure-highlightjs\"><code class=\"\"># \u7f16\u8bd1\r\nmkdir build &amp;&amp; cd build\r\ncmake ..\r\nmake\r\n\r\n# \u542f\u52a8\r\nsudo .\/uprobe \r\n\r\n# \u76d1\u542c\u5185\u6838log\r\nsudo cat \/sys\/kernel\/debug\/tracing\/trace_pipe\r\n    utest-289573  [001] d...1 3661688.515533: bpf_trace_printk: utest_add ENTRY: a = 0, b = 1\r\n    utest-289573  [001] d...1 3661688.515542: bpf_trace_printk: utest_add EXIT: return = 1\r\n    utest-289573  [001] d...1 3661688.515543: bpf_trace_printk: utest_sub ENTRY: a = 0, b = 0\r\n    utest-289573  [001] d...1 3661688.515546: bpf_trace_printk: utest_sub EXIT: return = 0\r\n    \r\n    utest-289573  [001] d...1 3661689.515725: bpf_trace_printk: utest_add ENTRY: a = 1, b = 2\r\n    utest-289573  [001] d...1 3661689.515732: bpf_trace_printk: utest_add EXIT: return = 3\r\n    utest-289573  [001] d...1 3661689.515734: bpf_trace_printk: utest_sub ENTRY: a = 1, b = 1\r\n    utest-289573  [001] d...1 3661689.515735: bpf_trace_printk: utest_sub EXIT: return = 0\r\n    \r\n    utest-289573  [001] d...1 3661690.516228: bpf_trace_printk: utest_add ENTRY: a = 2, b = 3\r\n    utest-289573  [001] d...1 3661690.516236: bpf_trace_printk: utest_add EXIT: return = 5\r\n    utest-289573  [001] d...1 3661690.516238: bpf_trace_printk: utest_sub ENTRY: a = 4, b = 2\r\n    utest-289573  [001] d...1 3661690.516240: bpf_trace_printk: utest_sub EXIT: return = 2\r\n    \r\n    utest-289573  [001] d...1 3661691.516409: bpf_trace_printk: utest_add ENTRY: a = 3, b = 4\r\n    utest-289573  [001] d...1 3661691.516415: bpf_trace_printk: utest_add EXIT: return = 7\r\n    utest-289573  [001] d...1 3661691.516417: bpf_trace_printk: utest_sub ENTRY: a = 9, b = 3\r\n    utest-289573  [001] d...1 3661691.516419: bpf_trace_printk: utest_sub EXIT: return = 6<\/code><\/pre>\n<p>\u53ef\u4ee5\u770b\u5230\u5df2\u7ecf\u53ef\u4ee5\u63a2\u6d4b\u5230\u81ea\u5b9a\u4e49\u7a0b\u5e8f\u7684\u51fd\u6570\u8c03\u7528\u53c2\u6570\u548c\u8fd4\u56de\u503c\u3002<\/p>\n<p>&nbsp;<\/p>\n<h1>\u4e09\u3001\u603b\u7ed3<\/h1>\n<p>\u597d\u4e86\uff0c\u4eca\u5929\u5b66\u4e60\u4e86\u5982\u4f55\u901a\u8fc7uprobe \u5bf9\u7528\u6237\u7a7a\u95f4\u7684\u7a0b\u5e8f\u4e2d\u7684\u7279\u5b9a\u51fd\u6570\u51fa\u5165\u53e3 \u8fdb\u884c\u63a2\u9488\u4ee3\u7801\u6ce8\u5165\u548c\u53c2\u6570\u8fd4\u56de\u503c\u63a2\u6d4b\u3002\u4e0b\u4e00\u6b21\uff0c\u6211\u4eec\u5c06\u5c1d\u8bd5\u5bf9\u7a0b\u5e8f\u6216\u51fd\u6570\u7684cpu\u8d44\u6e90\u5360\u7528\u60c5\u51b5\u8fdb\u884c\u8ddf\u8e2a\u548c\u6293\u53d6\u3002\u5982\u679c\u4f60\u5bf9\u5176\u4ed6\u7684\u5185\u5bb9\u611f\u5174\u8da3\uff0c\u4e5f\u53ef\u4ee5\u544a\u8bc9\u6211\uff5e<\/p>\n<p>&nbsp;<\/p>\n<p>yan 23.12.13<\/p>\n<p>&nbsp;<\/p>\n<p>\u53c2\u8003\uff1a<\/p>\n<p><a href=\"https:\/\/libbpf-test.readthedocs.io\/en\/latest\/api.html\" target=\"_blank\" rel=\"noopener\">LIBBPF API<\/a><\/p>\n<p><a href=\"https:\/\/eunomia.dev\/zh\/tutorials\/5-uprobe-bashreadline\/#uprobe-bash-readline\" target=\"_blank\" rel=\"noopener\">\u5728 eBPF \u4e2d\u4f7f\u7528 uprobe \u6355\u83b7 bash \u7684 readline \u51fd\u6570\u8c03\u7528<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4e0a\u4e00\u6b21\uff0c\u6211\u4eec\u901a\u8fc7kprobe\u5b9e\u73b0\u4e00\u4e2a\u7b80\u5355\u7684\u5185\u6838\u7cfb\u7edf\u8c03\u7528\u6355\u83b7\uff0c\u4e86\u89e3\u4e86\u5982\u4f55\u5728\u5185\u6838\u51fd\u6570\u7684\u51fa\u5165\u53e3\u52a8\u6001\u6ce8\u5165\u81ea\u5b9a\u4e49\u4ee3\u7801\uff0c\u5e76 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[1317],"tags":[1332,877,1318,1331],"_links":{"self":[{"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/8100"}],"collection":[{"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=8100"}],"version-history":[{"count":3,"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/8100\/revisions"}],"predecessor-version":[{"id":8119,"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=\/wp\/v2\/posts\/8100\/revisions\/8119"}],"wp:attachment":[{"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=8100"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=8100"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/yanjingang.com\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=8100"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}