src: readlink("/proc/self/exe") -> uv_exename()

bnoordhuis · Trott · commit 54ae5309513b · 2019-07-30T06:21:06.000-07:00
This commit also adds error handling. A THP-enabled build terminated with an out-of-memory error on a system without /proc because it cast the -1 from readlink() to size_t (i.e. ULONG_MAX) and then tried to allocate a string of that size. PR-URL: nodejs#28333 Reviewed-By: Rich Trott <rtrott@gmail.com> Reviewed-By: Colin Ihrig <cjihrig@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Anna Henningsen <anna@addaleax.net>
diff --git a/src/large_pages/node_large_page.cc b/src/large_pages/node_large_page.cc
@@ -115,8 +115,12 @@ static struct text_region FindNodeTextRegion() {
   std::string exename;
   {
       char selfexe[PATH_MAX];
-      ssize_t count = readlink("/proc/self/exe", selfexe, PATH_MAX);
-      exename = std::string(selfexe, count);
+
+      size_t size = sizeof(selfexe);
+      if (uv_exepath(selfexe, &size))
+        return nregion;
+
+      exename = std::string(selfexe, size);
   }
 
   while (std::getline(ifs, map_line)) {

Original file line number	Diff line number	Diff line change
`@@ -115,8 +115,12 @@ static struct text_region FindNodeTextRegion() {`
`115`	`115`	`std::string exename;`
`116`	`116`	`{`
`117`	`117`	`char selfexe[PATH_MAX];`
`118`		`- ssize_t count = readlink("/proc/self/exe", selfexe, PATH_MAX);`
`119`		`- exename = std::string(selfexe, count);`
	`118`	`+`
	`119`	`+ size_t size = sizeof(selfexe);`
	`120`	`+ if (uv_exepath(selfexe, &size))`
	`121`	`+ return nregion;`
	`122`	`+`
	`123`	`+ exename = std::string(selfexe, size);`
`120`	`124`	`}`
`121`	`125`
`122`	`126`	`while (std::getline(ifs, map_line)) {`