8346059: [ASAN] awt_LoadLibrary.c reported compile warning ignoring return value of function by clang17 #22701

sendaoYan · 2024-12-12T04:32:14Z

Hi all,
This PR fix file src/java.desktop/unix/native/libawt/awt/awt_LoadLibrary.c reported compile warning "ignoring return value of function" by clang17, which add check the return value of realpath function. Risk is low.

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JDK-8346059: [ASAN] awt_LoadLibrary.c reported compile warning ignoring return value of function by clang17 (Bug - P4)

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Magnus Ihse Bursie (@magicus - Reviewer)

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$ git checkout pull/22701
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…eturn value of function by clang17

bridgekeeper · 2024-12-12T04:33:05Z

👋 Welcome back syan! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

openjdk · 2024-12-12T04:33:54Z

@sendaoYan This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8346059: [ASAN] awt_LoadLibrary.c reported compile warning ignoring return value of function by clang17

Reviewed-by: ihse

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 16 new commits pushed to the master branch:

db9eab3: 8311542: Consolidate the native stack printing code
18e0b34: 8344137: Update XML Security for Java to 3.0.5
e9ad27f: 8339313: 32-bit build broken
ff85865: 8346008: Fix recent NULL usage backsliding in Shenandoah
11cd639: 8345573: Module dependencies not resolved from run-time image when --limit-module is being used
22845a7: 8337995: ZUtils::fill uses std::fill_n
f71d515: 8345777: Improve sections for inherited members
b8bb51e: 8345908: Class links should be properly spaced
ef6e987: 8346040: Zero interpreter build on Linux Aarch64 is broken
f7f07b9: 8345804: Update copyright year to 2024 for langtools in files where it was missed
... and 6 more: https://git.openjdk.org/jdk/compare/72c59de615b216c1729de4f4251652488f6f74ef...master

As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

openjdk · 2024-12-12T04:34:26Z

@sendaoYan The following label will be automatically applied to this pull request:

client

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing list. If you would like to change these labels, use the /label pull request command.

mlbridge · 2024-12-12T04:38:09Z

Webrevs

00: Full (f746b57e)

magicus · 2024-12-12T10:28:57Z

src/java.desktop/unix/native/libawt/awt/awt_LoadLibrary.c

        dladdr((void *)AWT_OnLoad, &dlinfo);
-        realpath((char *)dlinfo.dli_fname, buf);
+        if (realpath((char *)dlinfo.dli_fname, buf) == NULL) {
+            perror((char *)dlinfo.dli_fname);


Having error handling is better than no error handling, but is perror the best we can do?

OTOH, maybe it doesn't matter as much. Something would be very, very broken if this were to fail.

I saw this in another bug report too from the same submitter.
I don't know that I want to encourage this as a pattern, except in debug builds. better might be to just copy dlinfo.dli_fname into buf ..

perror will print the given message accrording the previous errno info to stderr, so this change will not change the original behaviour.

Hi @prrace,

I saw this in another bug report too from the same submitter.

I did create 3 clang17 compile waring issues, the compile warings occur in different files, and maybe use should different solutions to solve the issue, so I create the separate issues.

better might be to just copy dlinfo.dli_fname into buf

"Something would be very, very broken if this were to fail.", So I think perror maybe better, it will print which file and the reason get realpath fail.

Should I combine 3 similar issues(JDK-8346104/JDK-8346103/JDK-8346059) to 1 issue

I personally would probably have started out by making a single issue for these, since they all try to address the same new warning in clang, and are all in client code, and only split it up later if reviewers had requested it. But since you have created separate issues, I suggest you do not change things now. Also, the other two I believe need a more serious response; a write to a pipe has a somewhat more realistic chance at failure than this filename lookup.

Sorry for the confuse. I mean this PR change nothing except it will print a message to stderr when realpath return NULL. Thanks magicus.

Why did you integrate this ?
It did not yet have my approval even though I was clearly reviewing it.
Nor did it have the required 2nd reviewer, in fact did it not have ANY reviewer from the client team which is responsible for this code.

Hi @prrace , sorry for the rash integrated. I can backout or redo this change quickly if it's necessary. If I should redo or backport this PR, please let me known.

I will pay more attention for the future PRs.

Apologize for the rash integrated again.

@prrace I don't think it is reasonable for you to blame @sendaoYan for integrating. He had a review from a Reviewer, and he waited 24 hours after that before integrating. The general JDK rule is that one review is enough; Hotspot as a special case requires two. Your comment did not say that you wanted to review it further, nor did you clearly request any changes, just a vague idea of replacing realpath with a strcpy (which seems like much more risky, and potentially incorrect, change!)

The responsibility for this PR is mine. I had reviewed and approved the PR. I did consider if I should increase the number of reviewers and state that a client team reviewer was also needed, but decided against it. That was my decision as a reviewer. The PR was clearly unproblematic. It added some extra logging in case something gets terribly wrong. Without this fix, AWT would just break without any indication whatsoever if something did go wrong with realpath. With this fix, this unlikely problem will at least get some indication. I did not think this needed confirmation from the client team as well.

magicus

Looks good to me.

prrace · 2024-12-12T19:57:13Z

jtreg tests(include tier1/2/3) on linux-x64 with release build
jtreg tests(include tier1/2/3) on linux-x64 with fastdebug build
jtreg tests(include tier1/2/3) on linux-aarch64 with release build
jtreg tests(include tier1/2/3) on linux-aarch64 with fastdebug build

That was entirely a waste of time and hasn't proved anything.

If you examine the content of those tiers you will not find even a single test that loads AWT !

Try running the jdk_desktop group instead.

sendaoYan · 2024-12-13T03:55:09Z

Try running the jdk_desktop group instead.

Thanks your advice. Mine meaning was verify this change will not cause new failures, since it will not change behaviour in theory.

I have run all the jtreg tests except test/hotspot/jtreg/vmTestbase/ and test/hotspot/jtreg/applications/, which has include jdk_desktop.

sendaoYan · 2024-12-13T07:52:52Z

Compile warning of JDK-8346059 was introduced recently, Compile warnings of JDK-8346104/JDK-8346103 has exists for several years. So I want to deal with JDK-8346059 separately make other issues can be backported to jdk21u-dev or jdk17u-dev cleanly.

magicus · 2024-12-13T08:06:06Z

Thanks your advice. Mine meaning was verify this change will not cause new failures, since it will not change behaviour in theory.

Well, yes, but to prove that you do need to run tests that actually exercise the code.

sendaoYan · 2024-12-13T08:33:43Z

Thanks all for the reviews.

/integrate

openjdk · 2024-12-13T08:34:12Z

Going to push as commit 367c304.
Since your change was applied there have been 19 commits pushed to the master branch:

31ceec7: 8346055: javax/swing/text/StyledEditorKit/4506788/bug4506788.java fails in ubuntu22.04
09c29d1: 8346069: Add missing Classpath exception statements
28e49e9: 8345505: Fix -Wzero-as-null-pointer-constant warnings in zero code
db9eab3: 8311542: Consolidate the native stack printing code
18e0b34: 8344137: Update XML Security for Java to 3.0.5
e9ad27f: 8339313: 32-bit build broken
ff85865: 8346008: Fix recent NULL usage backsliding in Shenandoah
11cd639: 8345573: Module dependencies not resolved from run-time image when --limit-module is being used
22845a7: 8337995: ZUtils::fill uses std::fill_n
f71d515: 8345777: Improve sections for inherited members
... and 9 more: https://git.openjdk.org/jdk/compare/72c59de615b216c1729de4f4251652488f6f74ef...master

Your commit was automatically rebased without conflicts.

openjdk · 2024-12-13T08:34:19Z

@sendaoYan Pushed as commit 367c304.

💡 You may see a message that your pull request was closed with unmerged commits. This can be safely ignored.

tstuefe · 2024-12-18T09:50:26Z

Drive-By comment:

I think we should avoid perror, since its error message is localized. I would prefer these messages in English, not in whatever language the customer set up. If you really want to print a message, at least also print out the numerical value of errno.

See https://pubs.opengroup.org/onlinepubs/007904875/functions/perror.html

"The perror() function shall map the error number accessed through the symbol errno to a language-dependent error message"

8346059: [ASAN] awt_LoadLibrary.c reported compile warning ignoring r…

f746b57

…eturn value of function by clang17

openjdk bot added the rfr Pull request is ready for review label Dec 12, 2024

openjdk bot added the client client-libs-dev@openjdk.org label Dec 12, 2024

magicus reviewed Dec 12, 2024

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openjdk bot added the ready Pull request is ready to be integrated label Dec 12, 2024

openjdk bot added the integrated Pull request has been integrated label Dec 13, 2024

openjdk bot closed this Dec 13, 2024

openjdk bot removed ready Pull request is ready to be integrated rfr Pull request is ready for review labels Dec 13, 2024

sendaoYan deleted the jbs8346059 branch December 13, 2024 08:35

8346059: [ASAN] awt_LoadLibrary.c reported compile warning ignoring return value of function by clang17 #22701

8346059: [ASAN] awt_LoadLibrary.c reported compile warning ignoring return value of function by clang17 #22701

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