Sorry, the patch and test is below: diff -r 777356696811 src/java.base/unix/classes/java/io/UnixFileSystem.java --- a/src/java.base/unix/classes/java/io/UnixFileSystem.java    Fri Sep 08 18:24:17 2017 +0000 +++ b/src/java.base/unix/classes/java/io/UnixFileSystem.java    Mon Dec 25 16:48:36 2017 +0800 @@ -100,10 +100,10 @@          if (child.equals("")) return parent;          if (child.charAt(0) == '/') {              if (parent.equals("/")) return child; -            return parent + child; +            return normalize(parent + child);          }          if (parent.equals("/")) return parent + child; -        return parent + '/' + child; +        return normalize(parent + '/' + child);      }        public String getDefaultParent() { diff -r 777356696811 test/java/io/File/GetCanonicalPath.java --- a/test/java/io/File/GetCanonicalPath.java   Fri Sep 08 18:24:17 2017 +0000 +++ b/test/java/io/File/GetCanonicalPath.java   Mon Dec 25 16:48:36 2017 +0800 @@ -23,20 +23,35 @@    /* @test     @bug 4899022 +   @library /lib/testlibrary +   @run main/othervm GetCanonicalPath      @summary Look for erroneous representation of drive letter   */    import java.io.*; +import java.lang.reflect.Field; +import java.util.Properties;    public class GetCanonicalPath {      public static void main(String[] args) throws Exception {          if (File.separatorChar == '\\') {              testDriveLetter();          } +        String osName = System.getProperty("os.name"); +        if (osName.startsWith("Linux")) { +            testDuplicateSeparators(); +        }      }      private static void testDriveLetter() throws Exception {          String path = new File("c:/").getCanonicalPath();          if (path.length() > 3)              throw new RuntimeException("Drive letter incorrectly represented");      } +    private static void testDuplicateSeparators() throws Exception { +        Field f = System.class.getDeclaredField("props"); +        f.setAccessible(true); +        Properties p = (Properties) f.get(null); +        p.setProperty("user.dir", "/home/a/b/c/"); +        System.out.println(new File("./a").getCanonicalPath()); +   }  }  ps: only test on Linux :) ------------------------------------------------------------------发件人：David Holmes <david.holmes@oracle.com>发送时间：2017年12月27日(星期三) 14:14收件人：裴文谦(右席) <wenqian.peiwq@alibaba-inc.com>; core-libs-dev <core-libs-dev@openjdk.java.net>抄　送：陆传胜(传胜) <chuansheng.lcs@alipay.com>; 李三红(三红) <sanhong.lsh@alibaba-inc.com>主　题：Re: RFR: 8194154 patch for crash at File.getCanonicalPath() Hi, Attachments get stripped (usually). You'll need to include it inline. Cheers, David On 25/12/2017 7:40 PM, Wenqian Pei wrote:

   Hi:    Bug: https://bugs.openjdk.java.net/browse/JDK-8194154    We found that if user defines -Duser.dir like "/home/a/b/c/", jvm will crash at File.getCanonicalPath() in java process bootstrap (before invoking user's java code). The native implematation of canonicalize_md.c:collapsible(char *names) has problem in processing double '/', parameter 'names' need normalized before JNI_CALL.    This patch normalize parameters before call canonicalize0() in this call path    Patch and test are in mailbox attachments.    Can I please have a review for this patch?      Thanks      Wenqian Pei  

Alan, In fact, if property "user.dir" is cached, the problem will go away without any changes to native or UnixFileSystem.java, since it won't canonicalize the string supplied from user. The output will be getProperty("user.dir") + "/" + file. (The result is not as expected, user can not change the property, means user has to work around the problem to reach their targeted directory to do things like loading classes) Any change to "user.dir" in java program does not have any effect. For Windows: --- a/src/java.base/windows/classes/java/io/WinNTFileSystem.java Fri Feb 02 10:32:59 2018 -0800 +++ b/src/java.base/windows/classes/java/io/WinNTFileSystem.java Tue Feb 13 23:40:21 2018 +0000 @@ -43,12 +43,14 @@ private final char slash; private final char altSlash; private final char semicolon; + private final String userDir; public WinNTFileSystem() { Properties props = GetPropertyAction.privilegedGetProperties(); slash = props.getProperty("file.separator").charAt(0); semicolon = props.getProperty("path.separator").charAt(0); altSlash = (this.slash == '\\') ? '/' : '\\'; + userDir = props.getProperty("user.dir"); } private boolean isSlash(char c) { @@ -347,7 +349,7 @@ private String getUserPath() { /* For both compatibility and security, we must look this up every time */ - return normalize(System.getProperty("user.dir")); + return normalize(userDir); } private String getDrive(String path) { Does it need normalize(userDir) in getUserPath()? I think we need here. I will update the webrev and send for another round of review: the change in native will be reverted, and made changes to UnixFileSystem.java. Thanks Yumin On Mon, Feb 12, 2018 at 3:09 AM, Alan Bateman <Alan.Bateman@oracle.com> wrote:

On 09/02/2018 18:01, Alan Bateman wrote:

...

:

I'll study the patch you have but I think we also need to create issues to get us to the point where changing this system property in a running VM doesn't impact running code.

Looking at it again, I think we should change java.io.UnixFileSystem (and the Windows equivalent) to cache the value of user.dir to avoid difficult to diagnose issues with bad code changing the value of this property in a running VM. This should reduce the issue down to cases where user.dir is changed on the command line (never supported either of course) to a value that is not "/" but has trailing or duplicate slashes.

When reduced down then the alternatives are to change the native canonicalize method as you have done or alternatively do it once at UnixFileSystem initialization time so that canonicalize does not have to deal with this case. The former would require changing the description of the function (it currently reads "The input path is assumed to contain no duplicate slashes"), the latter avoids any changes to the native implementation.

-Alan

diff -r 0937e5f799df src/java.base/unix/classes/jav a/io/UnixFileSystem.java --- a/src/java.base/unix/classes/java/io/UnixFileSystem.java Sat Feb 10 07:06:16 2018 -0500 +++ b/src/java.base/unix/classes/java/io/UnixFileSystem.java Mon Feb 12 10:49:40 2018 +0000 @@ -34,12 +34,14 @@ private final char slash; private final char colon; private final String javaHome; + private final String userDir;

public UnixFileSystem() { Properties props = GetPropertyAction.privilegedGetProperties(); slash = props.getProperty("file.separator").charAt(0); colon = props.getProperty("path.separator").charAt(0); javaHome = props.getProperty("java.home"); + userDir = props.getProperty("user.dir"); }

@@ -128,7 +130,11 @@

public String resolve(File f) { if (isAbsolute(f)) return f.getPath(); - return resolve(System.getProperty("user.dir"), f.getPath()); + SecurityManager sm = System.getSecurityManager(); + if (sm != null) { + sm.checkPropertyAccess("user.dir"); + } + return resolve(userDir, f.getPath()); }

// Caches for canonicalization results to improve startup performance.

HI, Roger and Brian Updated again in same link. I could not run jtreg so please have a look if the options are good for @run Thanks Yumin On Wed, Feb 14, 2018 at 11:13 AM, Roger Riggs <Roger.Riggs@oracle.com> wrote:

Hi,

In the test, the message can be improved; though the exception should never occur it will be misleading if it does. Instead: "Changing property user.dir should have no effect on the getCanonicalPath"

It is cleaner to throw AssertionError for the test failure. Throwing FileSystemException makes it look like it came from inside the file system implementation.

Regards, Roger

On 2/13/2018 6:45 PM, yumin qi wrote:

...

Alan,

In fact, if property "user.dir" is cached, the problem will go away without any changes to native or UnixFileSystem.java, since it won't canonicalize the string supplied from user. The output will be getProperty("user.dir") + "/" + file. (The result is not as expected, user can not change the property, means user has to work around the problem to reach their targeted directory to do things like loading classes)

Any change to "user.dir" in java program does not have any effect. For Windows:

--- a/src/java.base/windows/classes/java/io/WinNTFileSystem.java Fri Feb 02 10:32:59 2018 -0800 +++ b/src/java.base/windows/classes/java/io/WinNTFileSystem.java Tue Feb 13 23:40:21 2018 +0000 @@ -43,12 +43,14 @@ private final char slash; private final char altSlash; private final char semicolon; + private final String userDir;

public WinNTFileSystem() { Properties props = GetPropertyAction.privilegedGetProperties(); slash = props.getProperty("file.separator").charAt(0); semicolon = props.getProperty("path.separator").charAt(0); altSlash = (this.slash == '\\') ? '/' : '\\'; + userDir = props.getProperty("user.dir"); }

private boolean isSlash(char c) { @@ -347,7 +349,7 @@ private String getUserPath() { /* For both compatibility and security, we must look this up every time */ - return normalize(System.getProperty("user.dir")); + return normalize(userDir); }

private String getDrive(String path) {

Does it need normalize(userDir) in getUserPath()? I think we need here.

I will update the webrev and send for another round of review: the change in native will be reverted, and made changes to UnixFileSystem.java.

Thanks Yumin

On Mon, Feb 12, 2018 at 3:09 AM, Alan Bateman <Alan.Bateman@oracle.com> wrote:

On 09/02/2018 18:01, Alan Bateman wrote:

...

:

...

I'll study the patch you have but I think we also need to create issues to get us to the point where changing this system property in a running VM doesn't impact running code.

Looking at it again, I think we should change java.io.UnixFileSystem

(and the Windows equivalent) to cache the value of user.dir to avoid difficult to diagnose issues with bad code changing the value of this property in a running VM. This should reduce the issue down to cases where user.dir is changed on the command line (never supported either of course) to a value that is not "/" but has trailing or duplicate slashes.

When reduced down then the alternatives are to change the native canonicalize method as you have done or alternatively do it once at UnixFileSystem initialization time so that canonicalize does not have to deal with this case. The former would require changing the description of the function (it currently reads "The input path is assumed to contain no duplicate slashes"), the latter avoids any changes to the native implementation.

-Alan

diff -r 0937e5f799df src/java.base/unix/classes/jav a/io/UnixFileSystem.java --- a/src/java.base/unix/classes/java/io/UnixFileSystem.java Sat Feb 10 07:06:16 2018 -0500 +++ b/src/java.base/unix/classes/java/io/UnixFileSystem.java Mon Feb 12 10:49:40 2018 +0000 @@ -34,12 +34,14 @@ private final char slash; private final char colon; private final String javaHome; + private final String userDir;

public UnixFileSystem() { Properties props = GetPropertyAction.privilegedGe tProperties(); slash = props.getProperty("file.separator").charAt(0); colon = props.getProperty("path.separator").charAt(0); javaHome = props.getProperty("java.home"); + userDir = props.getProperty("user.dir"); }

@@ -128,7 +130,11 @@

public String resolve(File f) { if (isAbsolute(f)) return f.getPath(); - return resolve(System.getProperty("user.dir"), f.getPath()); + SecurityManager sm = System.getSecurityManager(); + if (sm != null) { + sm.checkPropertyAccess("user.dir"); + } + return resolve(userDir, f.getPath()); }

// Caches for canonicalization results to improve startup performance.