{"id":321,"date":"2024-03-28T00:24:03","date_gmt":"2024-03-27T16:24:03","guid":{"rendered":"https:\/\/cococat.top\/?p=321"},"modified":"2024-03-28T00:24:03","modified_gmt":"2024-03-27T16:24:03","slug":"ld-so","status":"publish","type":"post","link":"https:\/\/cococat.top\/index.php\/2024\/03\/28\/ld-so\/","title":{"rendered":"ld.so \u76f8\u5173\u77e5\u8bc6"},"content":{"rendered":"

1. \u5f15\u5b50<\/h2>\n

\u4eca\u5929\u5728\u5de5\u4f5c\u4e2d\u7528 ldd<\/code> \u68c0\u67e5 tengine<\/code> \u7684\u53ef\u6267\u884c\u6587\u4ef6\u65f6\uff0c\u51fa\u4e8e\u597d\u5947\u770b\u4e86\u4e00\u4e0b\u91cc\u9762\u6d89\u53ca\u7684 ld-linux-x86-64.so.2 <\/code> \u52a8\u6001\u94fe\u63a5\u5e93\uff0c\u7136\u540e\u67e5\u5230\u4e86\u8fd9\u6837\u4e00\u4e2a\u795e\u5947\u7684\u95ee\u7b54\uff1a<\/p>\n

https:\/\/unix.stackexchange.com\/questions\/400621\/what-is-lib64-ld-linux-x86-64-so-2-and-why-can-it-be-used-to-execute-file<\/a><\/p>\n

\u6211\u4eec\u5e73\u5e38\u4e60\u60ef\u4e8e\u7528 chmod<\/code> \u53bb\u66f4\u6539\u6587\u4ef6\u7684\u6743\u9650\uff0c\u4f46\u662f\u4ece\u6765\u6ca1\u6709\u60f3\u8fc7\u4e00\u4e2a\u95ee\u9898\uff1a\u5982\u679c\u7531\u4e8e\u4e00\u4e9b\u8bef\u64cd\u4f5c\u800c\u8ba9 chmod<\/code> \u672c\u8eab\u7684 X \u6743\u9650\u6ca1\u6709\u4e86\uff0c\u90a3\u8be5\u600e\u4e48\u6551\u56de\u6765\uff1f\u8fd9\u4e2a\u95ee\u7b54\u7ed9\u51fa\u4e86\u4e00\u79cd\u89e3\u51b3\u65b9\u6848\uff1a<\/p>\n

\/lib64\/ld-linux-x86-64.so.2 \/bin\/chmod +x \/bin\/chmod<\/code><\/pre>\n
\u4e4d\u4e00\u770b\u7b80\u76f4\u662f\u9b54\u6cd5\uff0c\u5728\u523b\u677f\u5370\u8c61\u91cc\u52a8\u6001\u94fe\u63a5\u5e93\u6587\u4ef6 .so<\/code> \u6839\u672c\u4e0d\u53ef\u4ee5\u76f4\u63a5\u8fd0\u884c\uff0c\u8fd9\u91cc\u4e0d\u4ec5\u76f4\u63a5\u8fd0\u884c\u4e86\u4e00\u4e2a\u52a8\u6001\u94fe\u63a5\u5e93\u6587\u4ef6\uff0c\u8fd8\u7ed9\u5b83\u4f20\u5165\u4e86\u53c2\u6570\u3002<\/p>\n
2. \u539f\u7406<\/h2>\n
2.1. ld.so \u7b80\u4ecb<\/h3>\n
\u5b9e\u9645\u4e0a\uff0c\u6211\u4eec\u53ef\u4ee5\u65e0\u53c2\u8fd0\u884c ld-linux-x86-64.so.2<\/code> \uff08\u5728 centos<\/code> \u884d\u751f\u7684\u53d1\u884c\u7248\u4e0a\u53ef\u4ee5\u65e0\u53c2\uff0c\u5728 Ubuntu \u4e0a\u9700\u8981\u52a0 --help<\/code> \uff09\uff0c\u5c31\u4f1a\u5f97\u5230\u5982\u4e0b\u7684\u8f93\u51fa\uff1a<\/p>\n
You have invoked 'ld.so', the program interpreter for dynamically-linked ELF programs.  Usually, the program interpreter is invoked automatically when a dynamically-linked executable is started.\n\nYou may invoke the program interpreter program directly from the command line to load and run an ELF executable file; this is like executing that file itself, but always uses the program interpreter you invoked, instead of the program interpreter specified in the executable file you run.  Invoking the program interpreter directly provides access to additional diagnostics, and changing the dynamic linker behavior without setting environment variables (which would be inherited by subprocesses).\n\n[\u7701\u7565\u4e00\u4e9b\u53c2\u6570\u8bf4\u660e]<\/code><\/pre>\n
\u4ece\u8fd9\u4e9b\u4fe1\u606f\u4e2d\u6211\u4eec\u53ef\u4ee5\u5f97\u77e5\uff0c\u8fd9\u4e2a ld.so<\/code> \u5b9e\u9645\u4e0a\u662f\u4e00\u4e2a\u52a8\u6001\u94fe\u63a5\u7a0b\u5e8f\u7684\u201c\u89e3\u91ca\u5668\u201d\uff08interpreter\uff09\uff0c\u800c\u5f53\u6211\u4eec\u6267\u884c\u4e00\u4e2a\u52a8\u6001\u94fe\u63a5\u7a0b\u5e8f\u65f6\uff0c\u7b49\u6548\u7684\u547d\u4ee4\u5b9e\u9645\u4e0a\u662f\u628a\u539f\u59cb\u547d\u4ee4\u4f5c\u4e3a\u53c2\u6570\u4f20\u7ed9\u8fd9\u4e2a .so\u3002\u5373\u5f53\u6211\u4eec\u5728\u7ec8\u7aef\u91cc\u6267\u884c chmod<\/code> \u65f6\uff0c\u5b9e\u9645\u4e0a\u6267\u884c\u7684\u547d\u4ee4\u662f ld-linux-x86-64.so.2 \/bin\/chmod<\/code> \uff0c\u800c\u5176\u4f5c\u7528\u662f\u52a0\u8f7d\u8fd0\u884c\u53ef\u6267\u884c\u6587\u4ef6\u6240\u9700\u7684\u6240\u6709 .so\uff0c\u4ece\u800c\u4e3a\u52a8\u6001\u94fe\u63a5\u7a0b\u5e8f\u7684\u8fd0\u884c\u63d0\u4f9b\u6761\u4ef6\u3002<\/p>\n
\n
\u6b64\u5916\uff0c\u5b9e\u9645\u4e0a\u8fd8\u6709\u5f88\u591a .so \u90fd\u662f\u53ef\u4ee5\u8fd0\u884c\u7684\uff0c\u4f8b\u5982\u5e38\u89c1\u7684 libc.so<\/code> \uff0c\u76f4\u63a5\u8fd0\u884c\u4e5f\u53ef\u4ee5\u8f93\u51fa\u4e00\u6bb5\u7248\u672c\u548c\u8bf4\u660e\u4fe1\u606f\u3002\u6839\u636e\u7f51\u4e0a\u7684\u8bf4\u660e<\/a>\uff0c\u53ea\u8981\u5e93\u4e2d\u5305\u542b main() \u51fd\u6570\u5373\u53ef\u3002<\/p>\n<\/blockquote>\n
2.2. ld.so \u7684\u8be6\u7ec6\u4ecb\u7ecd<\/h3>\n
TODO: https:\/\/www.man7.org\/linux\/man-pages\/man8\/ld.so.8.html<\/a><\/p>\n
2.3. ld \u4e0e ld.so<\/h3>\n
\u7f16\u8bd1\u65f6\uff0c\u94fe\u63a5\u5668 ld<\/code> \u662f\u6211\u4eec\u719f\u6089\u7684\u8001\u670b\u53cb\uff0c\u5bf9\u4e8e\u6240\u6709\u53c2\u4e0e\u94fe\u63a5\u7684\u53ef\u91cd\u5b9a\u5411\u76ee\u6807\u6587\u4ef6\uff08.o\uff09\uff0cld<\/code>\u4f1a\u6267\u884c\u7b26\u53f7\u89e3\u6790\uff08\u5c06\u5bf9\u7b26\u53f7\u7684\u5f15\u7528\u4e0e\u7b26\u53f7\u8868\u4e2d\u7684\u552f\u4e00\u786e\u5b9a\u7b26\u53f7\u5173\u8054\u8d77\u6765\uff09\u4e0e\u91cd\u5b9a\u5411\uff08\u5c06\u5404\u4e2a\u6587\u4ef6\u4e2d\u7684\u4ee3\u7801\u6bb5\u3001\u6570\u636e\u6bb5\u5206\u522b\u5408\u5e76\uff0c\u968f\u540e\u5373\u53ef\u8ba1\u7b97\u6bcf\u4e2a\u7b26\u53f7\u5728\u865a\u62df\u5185\u5b58\u4e2d\u7684\u5730\u5740\uff0c\u518d\u628a\u6240\u6709\u7684\u7b26\u53f7\u5f15\u7528\u4fee\u6539\u4e3a\u8fd9\u4e2a\u5730\u5740\uff09\u3002\u8fd9\u90e8\u5206\u53ef\u4ee5\u91cd\u65b0\u8bfb\u4e0b CSAPP<\/a><\/p>\n
\u7b80\u5355\u6765\u8bf4\uff0c\u5bf9\u4e8e\u52a8\u6001\u94fe\u63a5\u7a0b\u5e8f\uff0cld<\/code> \u4f5c\u7528\u4e8e\u7f16\u8bd1\u671f\uff0c\u800c ld.so<\/code> \u4f5c\u7528\u4e8e\u8fd0\u884c\u65f6\u3002<\/p>\n
3. execve()<\/code>\u7cfb\u7edf\u8c03\u7528<\/h2>\n
\u5728 stackexchange \u7684\u539f\u56de\u7b54\u91cc\uff0c\u7b54\u4e3b\u63d0\u5230\u4e86 execve()<\/code> \u8fd9\u4e2a syscall\uff0c\u8fd9\u91cc\u4e5f\u7a0d\u5fae\u5b66\u4e60\u4e0b\u3002\u5176\u7cfb\u7edf\u8c03\u7528\u7684\u51fd\u6570\u7b7e\u540d\u662f\uff1a<\/p>\n
int execve(const char *pathname, char *const argv[], char *const envp[]);<\/code><\/pre>\n
\u8fd9\u4e2a\u7cfb\u7edf\u8c03\u7528\u7684\u4e3b\u8981\u4f5c\u7528\u662f\u628a pathname<\/code> \u6307\u5b9a\u7684\u7a0b\u5e8f\u52a0\u8f7d\u5230\u5f53\u524d\u8fdb\u7a0b\u7684\u5185\u5b58\u7a7a\u95f4\u5185\uff0c\u5c06\u5f53\u524d\u8fdb\u7a0b\u7684\u5806\u3001\u6808\u548c\u6240\u6709\u7684\u6bb5\u6570\u636e\u90fd\u7528\u65b0\u8fdb\u7a0b\u7684\u76f8\u5e94\u90e8\u5206\u4ee3\u66ff\uff0c\u7136\u540e\u4ece\u65b0\u7a0b\u5e8f\u7684\u521d\u59cb\u5316\u4ee3\u7801\u548c main<\/code> \u51fd\u6570\u5f00\u59cb\u8fd0\u884c\u3002\u540c\u65f6\uff0c\u8fdb\u7a0b\u7684ID\u5c06\u4fdd\u6301\u4e0d\u53d8\u3002<\/p>\n
\u5f53\u6211\u4eec\u5728\u7ec8\u7aef\u4e2d\u8f93\u5165\u547d\u4ee4\u65f6\uff0cshell \u4f1a fork()<\/code> \u4e00\u4e2a\u5b50\u8fdb\u7a0b\u51fa\u6765\uff0c\u968f\u540e\u8c03\u7528 execve()<\/code> \u6765\u6267\u884c\u6211\u4eec\u8f93\u5165\u7684\u547d\u4ee4\u3002\u867d\u7136\u6b64 syscall \u4f1a\u8fdb\u884c\u6267\u884c\u6743\u9650\u68c0\u67e5\uff0c\u4f46\u662f\u7531\u4e8e\u8fd9\u91cc\u68c0\u67e5\u7684\u5bf9\u8c61\u662f ld.so<\/code>\uff0c\u56e0\u6b64\u68c0\u67e5\u901a\u8fc7\u3002<\/p>\n
4. \u64cd\u4f5c\u7cfb\u7edf\u662f\u5982\u4f55\u5224\u65ad\u4e00\u4e2a\u53ef\u6267\u884c\u6587\u4ef6\u662f\u9759\u6001\u94fe\u63a5\u8fd8\u662f\u52a8\u6001\u94fe\u63a5\u7684<\/h2>\n
\u8fd9\u5c31\u8981\u6d89\u53ca\u5230 ELF \u6587\u4ef6\u683c\u5f0f\u4e86\uff0c\u8be6\u60c5\u8bf7\u53c2\u8003\u53e6\u4e00\u7bc7\u535a\u5ba2<\/a><\/p>\n
5. \u53c2\u8003<\/h2>\n
https:\/\/unix.stackexchange.com\/questions\/400621\/what-is-lib64-ld-linux-x86-64-so-2-and-why-can-it-be-used-to-execute-file<\/a>
\nhttps:\/\/unix.stackexchange.com\/questions\/223385\/why-and-how-are-some-shared-libraries-runnable-as-though-they-are-executables<\/a>
\nhttps:\/\/man7.org\/linux\/man-pages\/man2\/execve.2.html<\/a>
\nhttps:\/\/uclibc.org\/docs\/elf-64-gen.pdf<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"
1. \u5f15\u5b50 \u4eca\u5929\u5728\u5de5\u4f5c\u4e2d\u7528 ldd \u68c0\u67e5 tengine \u7684\u53ef\u6267\u884c\u6587\u4ef6\u65f6\uff0c\u51fa\u4e8e\u597d\u5947\u770b\u4e86\u4e00\u4e0b\u91cc\u9762\u6d89\u53ca\u7684 ld-l […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5],"tags":[19,20,27],"class_list":["post-321","post","type-post","status-publish","format-standard","hentry","category-linux","tag-ld","tag-linux","tag-27"],"_links":{"self":[{"href":"https:\/\/cococat.top\/index.php\/wp-json\/wp\/v2\/posts\/321","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cococat.top\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cococat.top\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cococat.top\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/cococat.top\/index.php\/wp-json\/wp\/v2\/comments?post=321"}],"version-history":[{"count":0,"href":"https:\/\/cococat.top\/index.php\/wp-json\/wp\/v2\/posts\/321\/revisions"}],"wp:attachment":[{"href":"https:\/\/cococat.top\/index.php\/wp-json\/wp\/v2\/media?parent=321"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cococat.top\/index.php\/wp-json\/wp\/v2\/categories?post=321"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cococat.top\/index.php\/wp-json\/wp\/v2\/tags?post=321"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}