\u6211\u4eec\u77e5\u9053\uff0c\u7a0b\u5e8f\u662f\u5b58\u50a8\u5728\u78c1\u76d8\u4e0a\u5230\u9759\u6001\u6587\u4ef6\uff1b\u8fdb\u7a0b\u662f\u5bf9\u7a0b\u5e8f\u5230\u4e00\u6b21\u8fd0\u884c\u8fc7\u7a0b\u3002\u5728\u8fdb\u7a0b\u5f00\u59cb\u8fd0\u884c\u65f6\uff0c\u8fdb\u7a0b\u7684\u4ee3\u7801\u548c\u6570\u636e\u7b49\u5185\u5bb9\u5fc5\u987b\u88c5\u5165\u5230\u8fdb\u7a0b\u7528\u6237\u7a7a\u95f4\u5230\u9002\u5f53\u533a\u57df\u3002\u8fd9\u4e9b\u533a\u57df\u4e5f\u5c31\u662f\u6240\u8c13\u7684\u4ee3\u7801\u6bb5\u548c\u6570\u636e\u6bb5\u7b49\uff0c\u800c\u88ab\u88c5\u5165\u7684\u6570\u636e\u548c\u4ee3\u7801\u7b49\u5185\u5bb9\u88ab\u79f0\u4e3a\u8fdb\u7a0b\u7684\u53ef\u6267\u884c\u6620\u50cf\u3002\u4ece\u4e0a\u9762\u90fd\u63cf\u8ff0\u4e2d\u53ef\u4ee5\u53d1\u73b0\uff0c\u8fdb\u7a0b\u5728\u8fd0\u884c\u65f6\u5e76\u4e0d\u662f\u5c06\u7a0b\u5e8f\u4e00\u4e0b\u5b50\u5c31\u88c5\u5165\u5230\u7269\u7406\u5185\u5b58\uff0c\u800c\u53ea\u662f\u5c06\u7a0b\u5e8f\u88c5\u5165\u5230\u8fdb\u7a0b\u7684\u7528\u6237\u7a7a\u95f4\uff0c\u8fd9\u4e2a\u88c5\u5165\u7684\u8fc7\u7a0b\u79f0\u4e3a\u865a\u5b58\u6620\u5c04\u3002<\/p>\n
\u4e00\u4e2a\u6e90\u7a0b\u5e8f\u5728\u6210\u4e3a\u53ef\u6267\u884c\u6587\u4ef6\u7684\u8fc7\u7a0b\u4e2d\u4f1a\u7ecf\u5386\u9884\u5904\u7406\u3001\u7f16\u8bd1\u3001\u6c47\u7f16\u548c\u94fe\u63a5\u56db\u4e2a\u9636\u6bb5\u3002\u56e0\u6b64\uff0c\u8fdb\u7a0b\u8981\u6210\u529f\u8fd0\u884c\u4e0d\u4ec5\u8981\u5728\u5176\u7528\u6237\u7a7a\u95f4\u88c5\u5165\u8fdb\u7a0b\u6620\u50cf\uff0c\u4e5f\u8981\u88c5\u5165\u8be5\u8fdb\u7a0b\u6240\u7528\u5230\u5230\u51fd\u6570\u5e93\u4ee5\u53ca\u94fe\u63a5\u7a0b\u5e8f\u7b49\u3002\u6240\u4ee5\uff0c\u4e00\u4e2a\u8fdb\u7a0b\u5230\u7528\u6237\u7a7a\u95f4\u5c31\u88ab\u5206\u4e3a\u82e5\u5e72\u4e2a\u5185\u5b58\u533a\u57df\u3002linux\u4f7f\u7528mm_struct\u7ed3\u6784\u6765\u63cf\u8ff0\u4e00\u4e2a\u8fdb\u7a0b\u5230\u7528\u6237\u5730\u5740\u7a7a\u95f4\uff0c\u4f7f\u7528vm_area_struct\u7ed3\u6784\u6765\u63cf\u8ff0\u8fdb\u7a0b\u5730\u5740\u7a7a\u95f4\u4e2d\u7684\u4e00\u4e2a\u5185\u5b58\u533a\u57df\u3002\u56e0\u6b64\uff0c\u4e00\u4e2avm_area_struct\u7ed3\u6784\u53ef\u80fd\u4ee3\u8868\u8fdb\u7a0b\u5230\u6570\u636e\u6bb5\uff0c\u4e5f\u53ef\u80fd\u4ee3\u8868\u94fe\u63a5\u7a0b\u5e8f\u5230\u4ee3\u7801\u6bb5\u7b49\u3002<\/p>\n
\u8fdb\u7a0b\u7684\u865a\u5b58\u6620\u5c04\u6240\u505a\u7684\u53ea\u662f\u5c06\u78c1\u76d8\u4e0a\u5230\u6587\u4ef6\u6620\u5c04\u5230\u8be5\u8fdb\u7a0b\u7684\u7528\u6237\u5730\u5740\u7a7a\u95f4\uff0c\u5e76\u6ca1\u6709\u5efa\u7acb\u865a\u62df\u5185\u5b58\u5230\u7269\u7406\u5185\u5b58\u7684\u6620\u5c04\u3002\u5f53\u67d0\u4e2a\u53ef\u6267\u884c\u6620\u50cf\u6620\u5c04\u5230\u8fdb\u7a0b\u7528\u6237\u7a7a\u95f4\u5e76\u5f00\u59cb\u6267\u884c\u65f6\uff0c\u53ea\u6709\u5f88\u5c11\u4e00\u90e8\u5206\u865a\u62df\u9875\u88ab\u88c5\u5165\u4e86\u7269\u7406\u5185\u5b58\u3002\u5728\u8fdb\u7a0b\u540e\u7eed\u5230\u6267\u884c\u8fc7\u7a0b\u4e2d\uff0c\u5982\u679c\u9700\u8981\u8bbf\u95ee\u5230\u6570\u636e\u5e76\u4e0d\u5728\u7269\u7406\u5185\u5b58\u4e2d\uff0c\u5219\u4ea7\u751f\u4e00\u4e2a\u7f3a\u9875\u4e2d\u65ad\uff08\u5176\u5b9e\u662f\u5f02\u5e38\uff09\uff0c\u5c06\u6240\u9700\u9875\u4ece\u4ea4\u6362\u533a\u6216\u78c1\u76d8\u4e2d\u8c03\u5165\u7269\u7406\u5185\u5b58\uff0c\u8fd9\u4e2a\u8fc7\u7a0b\u5373\u865a\u62df\u5185\u5b58\u4e2d\u5230\u8bf7\u9875\u673a\u5236\u3002<\/p>\n
\u90a3\u4e48\u5bf9\u4e8e\u4e00\u4e2a\u4efb\u610f\u7684\u8fdb\u7a0b\uff0c\u6211\u4eec\u53ef\u4ee5\u901a\u8fc7\u4e0b\u9762\u5230\u65b9\u6cd5\u67e5\u770b\u5176\u5730\u5740\u7a7a\u95f4\u4e2d\u5230\u5185\u5b58\u533a\u57df\u3002<\/p>\n
\u6211\u4eec\u5148\u770b\u4e00\u4e2a\u7b80\u5355\u7684\u6d4b\u8bd5\u7a0b\u5e8f\uff1a<\/p>\n
#include < stdio.h >\r\n#include < stdlib.h >\r\n\r\nint main()\r\n{\r\n\tint i=1;\r\n\tchar *str=NULL;\r\n\tprintf(\"hello,world!\\n\");\r\n\tstr=(char *)malloc(sizeof(char)*1119);\r\n\r\n\tsleep(1000);\r\n\r\n\treturn 0;\r\n}<\/pre>\n\u8fd9\u4e2a\u7a0b\u5e8f\u4e2d\u4f7f\u7528\u5230\u4e86malloc\u51fd\u6570\uff0c\u56e0\u6b64str\u53d8\u91cf\u5b58\u50a8\u4e8e\u5806\u4e2d\u3002\u6211\u4eec\u901a\u8fc7\u6253\u5370\/proc\/3530\/maps\u6587\u4ef6\uff0c\u5373\u53ef\u770b\u5230\u8be5\u8fdb\u7a0b\u7684\u5185\u5b58\u7a7a\u95f4\u5212\u5206\u3002\u5176\u4e2d3530\u662f\u8be5\u8fdb\u7a0b\u7684id\u3002<\/p>\n
edsionte@edsionte-desktop:~$ cat \/proc\/3530\/maps\r\n0014a000-00165000 r-xp 00000000 08:07 398276 \/lib\/ld-2.11.1.so\r\n00165000-00166000 r--p 0001a000 08:07 398276 \/lib\/ld-2.11.1.so\r\n00166000-00167000 rw-p 0001b000 08:07 398276 \/lib\/ld-2.11.1.so\r\n001d8000-0032b000 r-xp 00000000 08:07 421931 \/lib\/tls\/i686\/cmov\/libc-2.11.1.so\r\n0032b000-0032c000 ---p 00153000 08:07 421931 \/lib\/tls\/i686\/cmov\/libc-2.11.1.so\r\n0032c000-0032e000 r--p 00153000 08:07 421931 \/lib\/tls\/i686\/cmov\/libc-2.11.1.so\r\n0032e000-0032f000 rw-p 00155000 08:07 421931 \/lib\/tls\/i686\/cmov\/libc-2.11.1.so\r\n0032f000-00332000 rw-p 00000000 00:00 0\r\n00441000-00442000 r-xp 00000000 00:00 0 [vdso]\r\n08048000-08049000 r-xp 00000000 08:09 326401 \/home\/edsionte\/test\r\n08049000-0804a000 r--p 00000000 08:09 326401 \/home\/edsionte\/test\r\n0804a000-0804b000 rw-p 00001000 08:09 326401 \/home\/edsionte\/test\r\n08958000-08979000 rw-p 00000000 00:00 0 [heap]\r\nb78ce000-b78cf000 rw-p 00000000 00:00 0\r\nb78dd000-b78e0000 rw-p 00000000 00:00 0\r\nbfa6a000-bfa7f000 rw-p 00000000 00:00 0 [stack]<\/pre>\n\u6bcf\u4e00\u884c\u4fe1\u606f\u4f9d\u6b21\u663e\u793a\u7684\u5185\u5bb9\u4e3a\u5185\u5b58\u533a\u57df\u5176\u5b9e\u5730\u5740-\u7ec8\u6b62\u5730\u5740\uff0c\u8bbf\u95ee\u6743\u9650\uff0c\u504f\u79fb\u91cf\uff0c\u4e3b\u8bbe\u5907\u53f7\uff1a\u6b21\u8bbe\u5907\u53f7\uff0cinode\uff0c\u6587\u4ef6\u3002<\/p>\n
\u4e0a\u9762\u7684\u4fe1\u606f\u4e0d\u4f46\u5305\u542b\u4e86test\u53ef\u6267\u884c\u5bf9\u8c61\u7684\u5404\u5185\u5b58\u533a\u57df\uff0c\u800c\u4e14\u8fd8\u5206\u522b\u663e\u793a\u4e86 \/lib\/ld-2.11.1.so\uff08\u52a8\u6001\u8fde\u63a5\u7a0b\u5e8f\uff09\u6587\u4ef6\u548c\/lib\/tls\/i686\/cmov\/libc-2.11.1.so\uff08C\u5e93\uff09\u6587\u4ef6\u7684\u5185\u5b58\u533a\u57df\u4fe1\u606f\u3002<\/p>\n
\u6211\u4eec\u4ece\u67d0\u4e2a\u5185\u5b58\u533a\u57df\u7684\u8bbf\u95ee\u6743\u9650\u4e0a\u53ef\u4ee5\u5927\u81f4\u5224\u65ad\u8be5\u533a\u57df\u7684\u7c7b\u578b\u3002\u5404\u4e2a\u5c5e\u6027\u7b26\u53f7\u7684\u610f\u4e49\u4e3a\uff1ar-read\uff0cw-write\uff0cx-execute\uff0cs-shared\uff0cp-private\u3002\u56e0\u6b64\uff0cr-x\u4e00\u822c\u4ee3\u8868\u7a0b\u5e8f\u7684\u4ee3\u7801\u6bb5\uff0c\u5373\u53ef\u8bfb\uff0c\u53ef\u6267\u884c\u3002rw-\u53ef\u80fd\u4ee3\u8868\u6570\u636e\u6bb5\uff0cBSS\u6bb5\u548c\u5806\u6808\u6bb5\u7b49\uff0c\u5373\u53ef\u8bfb\uff0c\u53ef\u5199\u3002\u5806\u6808\u6bb5\u4ece\u884c\u4fe1\u606f\u7684\u6587\u4ef6\u540d\u5c31\u53ef\u4ee5\u533a\u5206\uff1b\u5982\u679c\u67d0\u884c\u4fe1\u606f\u7684\u6587\u4ef6\u540d\u4e3a\u7a7a\uff0c\u90a3\u4e48\u53ef\u80fd\u662fBSS\u6bb5\u3002\u53e6\u5916\uff0c\u4e0a\u8ff0test\u8fdb\u7a0b\u5171\u4eab\u4e86\u5185\u6838\u52a8\u6001\u5e93\uff0c\u6240\u4ee5\u572800441000-00442000\u884c\u5904\u6587\u4ef6\u540d\u663e\u793a\u4e3avdso\uff08Virtual Dynamic Shared Object\uff09\u3002<\/p>\n
mmap\u7cfb\u7edf\u8c03\u7528<\/h4>\n
\u901a\u8fc7mmap\u7cfb\u7edf\u8c03\u7528\u53ef\u4ee5\u5728\u8fdb\u7a0b\u5230\u7528\u6237\u7a7a\u95f4\u4e2d\u521b\u5efa\u4e00\u4e2a\u65b0\u5230\u865a\u5b58\u533a\u3002\u8be5\u7cfb\u7edf\u8c03\u7528\u5230\u539f\u578b\u5982\u4e0b\uff1a<\/p>\n
#include\r\nvoid *mmap(void *addr, size_t length, int prot, int flags, int fd, off_t offset);<\/pre>\n\u8be5\u51fd\u6570\u53ef\u4ee5\u5c06\u4ee5\u6253\u5f00\u7684\u6587\u4ef6\u6620\u5c04\u5230\u8fdb\u7a0b\u7528\u6237\u7a7a\u95f4\u5230\u4e00\u7247\u5185\u5b58\u533a\u4e0a\uff0c\u6267\u884c\u6210\u529f\u540e\uff0c\u8be5\u51fd\u6570\u8fd4\u56de\u8fd9\u6bb5\u6620\u5c04\u533a\u5230\u9996\u5730\u5740\u3002\u7528\u6237\u5f97\u5230\u8fd9\u7247\u865a\u5b58\u7684\u9996\u5730\u5740\u540e\uff0c\u5c31\u53ef\u4ee5\u50cf\u8bbf\u95ee\u5185\u5b58\u90a3\u6837\u8bbf\u95ee\u6587\u4ef6\u3002<\/p>\n
\u8be5\u7cfb\u7edf\u8c03\u7528\u7684\u53c2\u6570\u8bf4\u660e\u5982\u4e0b\uff1a<\/p>\n
addr<\/strong>\uff1a\u6620\u5c04\u5230\u7528\u6237\u5730\u5740\u7a7a\u95f4\u5230\u8d77\u59cb\u5730\u5740\uff1b
\n length<\/strong>\uff1a\u6620\u5c04\u533a\u4ee5\u5b57\u8282\u4e3a\u5355\u4f4d\u5230\u957f\u5ea6\uff1b
\n prot<\/strong>\uff1a\u5bf9\u6620\u5c04\u533a\u5230\u8bbf\u95ee\u6a21\u5f0f\u3002\u5305\u62ecPROT_EXEC\uff08\u53ef\u6267\u884c\uff09\uff0cPROT_READ \uff08\u53ef\u8bfb\uff09\uff0cPROT_WRITE\uff08\u53ef\u5199\uff09\uff0cPROT_NONE\uff08\u6587\u4ef6\u4e0d\u53ef\u8bbf\u95ee\uff09\u3002\u8fd9\u4e2a\u8bbf\u95ee\u6a21\u5f0f\u4e0d\u80fd\u8d85\u8fc7\u6240\u6620\u5c04\u6587\u4ef6\u5230\u6253\u5f00\u6a21\u5f0f\u3002\u6bd4\u5982\u88ab\u6620\u5c04\u7684\u6587\u4ef6\u6253\u5f00\u6a21\u5f0f\u4e3a\u53ea\u8bfb\uff0c\u90a3\u4e48\u6b64\u5904\u5230\u8bbf\u95ee\u6a21\u5f0f\u4e0d\u80fd\u662f\u53ef\u8bfb\u5199\u7684\u3002
\n flags<\/strong>\uff1a\u8fd9\u4e2a\u5b57\u6bb5\u6bd4\u8f83\u7075\u6d3b\uff0c\u4e0d\u540c\u5230\u6807\u5fd7\u6709\u4e0d\u540c\u7684\u529f\u80fd\uff0c\u5177\u4f53\u5982\u4e0b\uff1a
\nMAP_SHARED\uff1a\u521b\u5efa\u4e00\u4e2a\u53ef\u88ab\u5b50\u8fdb\u7a0b\u5171\u4eab\u7684\u6620\u5c04\u533a\uff1b
\nMAP_PRIVATE\uff1a\u521b\u5efa\u4e00\u4e2a\u201c\u5199\u5b9e\u590d\u5236\u201d\u7684\u6620\u5c04\u533a\uff1b
\nMAP_ANONYMOUS\uff1a\u521b\u5efa\u4e00\u4e2a\u533f\u540d\u5230\u6620\u5c04\u533a\uff0c\u8be5\u865a\u5b58\u533a\u4e0e\u8fdb\u7a0b\u65e0\u5173\uff1b
\n fd<\/strong>\uff1a\u6240\u8981\u6620\u5c04\u5230\u8fdb\u7a0b\u7528\u6237\u7a7a\u95f4\u7684\u6587\u4ef6\u63cf\u8ff0\u7b26\uff0c\u8be5\u6587\u4ef6\u5fc5\u987b\u4e3a\u4ee5\u6253\u5f00\u7684\u6587\u4ef6\uff1b
\n offset<\/strong>\uff1a\u6587\u4ef6\u7684\u8d77\u59cb\u6620\u5c04\u504f\u79fb\u91cf\uff1b<\/p>\nmmap()\u4e3e\u4f8b<\/h4>\n
\u5728\u8be5\u7a0b\u5e8f\u4e2d\uff0c\u9996\u5148\u4ee5\u53ea\u8bfb\u65b9\u5f0f\u6253\u5f00\u6587\u4ef6test.c\uff0c\u518d\u901a\u8fc7\u8be5\u6587\u4ef6\u8fd4\u56de\u5230\u6587\u4ef6\u63cf\u8ff0\u7b26\u548cmmap\u51fd\u6570\u5c06test.c\u6587\u4ef6\u6620\u5c04\u5230\u5f53\u524d\u8fdb\u7a0b\u5230\u7528\u6237\u5730\u5740\u7a7a\u95f4\u4e2d\u3002\u6210\u529f\u6267\u884cmmap\u51fd\u6570\u540e\uff0cbuf\u88ab\u8d4b\u503c\u4e3a\u6240\u6620\u5c04\u7684\u865a\u5b58\u533a\u7684\u9996\u5730\u5740\u3002\u6ce8\u610f\uff0cmmap\u51fd\u6570\u8fd4\u56de\u7684\u662fvoid\u578b\u6307\u9488\uff0c\u800cbuf\u662fchar\u578b\u6307\u9488\u3002\u5c06mmap\u8fd4\u56de\u503c\u8d4b\u503c\u7ed9buf\u53d8\u91cf\u65f6\uff0c\u81ea\u52a8\u5c06void*\u8f6c\u5316\u4e3achar*\u578b\u3002<\/p>\n
\u6700\u540e\uff0c\u5c31\u50cf\u5e73\u5e38\u6211\u4eec\u4f7f\u7528\u4e00\u4e2achar\u578b\u6307\u9488\u53d8\u91cf\u90a3\u6837\uff0c\u4f9d\u6b21\u6253\u5370\u51fabuf\u4e2d\u5230\u6570\u636e\u3002<\/p>\n
#include < stdio.h >\r\n#include < sys\/mman.h >\r\n#include < fcntl.h >\r\nint main()\r\n{\r\n\tint i,fd;\r\n\tchar *buf = NULL;\r\n\r\n\tfd = open(\".\/test.c\", O_RDONLY);\r\n\tif(fd < 0)\r\n\t{\r\n\t\tprintf(\"open error\\n\");\r\n\t\treturn -1;\r\n\t}\r\n\r\n\tbuf = mmap(NULL, 12, PROT_READ, MAP_PRIVATE ,fd, 0);\r\n\tfor(i = 0;i < 12;i++)\r\n\t{\r\n\t\tprintf(\"%c\",buf[i]);\r\n\t}\r\n\tprintf(\"\\n\");\r\n\r\n\treturn 0;\r\n}<\/pre>\ntry\u4e00\u4e0b\uff01<\/p>\n","protected":false},"excerpt":{"rendered":"
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