8378603: libfontmanager FFM path needs to use FFM to locate both malloc and free

[prrace]

We need to use FFM to locate free() because we use malloc() as located by FFM.
If these two don't match, then it can cause problems and confusion.

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 ⚠️ Found leading lowercase letter in issue title for 8378603: libfontmanager FFM path needs to use FFM to locate both malloc and free

Issue

• JDK-8378603: libfontmanager FFM path needs to use FFM to locate both malloc and free (Bug - P4)

Reviewers

• Alexander Zuev (@azuev-java - Reviewer)
• Alexander Zvegintsev (@azvegint - Reviewer)
• Jayathirth D V (@jayathirthrao - Reviewer)

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8378603: libfontmanager FFM path needs to use FFM to locate both malloc and free

Reviewed-by: kizune, azvegint, jdv

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• 90d2142: 8332632: Redundant assert "compiler should always document failure: %s" with possible UB
• 3444dad: 8381739: Comma-separated declaration with type-use annotations causes compiler crash
• 0ba115c: 8382635: G1: TAMSes overwritten by G1ConcurrentMark::fully_initialize() cause verification errors
• ... and 149 more: https://git.openjdk.org/jdk/compare/10e23dd5823258cfbf500175dde23be12cdd99bf...master

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[mrserb]

I wonder why this is not considered ffm bug. Since free/malloc/ and other methods used via ffm bindings use different functions than the same jni libraries, it is unclear why LD_PRELOAD does not affect ffm?

[prrace]

I wonder why this is not considered ffm bug. Since free/malloc/ and other methods used via ffm bindings use different functions than the same jni libraries, it is unclear why LD_PRELOAD does not affect ffm?

This was already raised with FFM devs. It is behaving as designed. Docs on Linker were referenced to support this.

I think it is this text.

"In addition, a linker provides a way to look up foreign functions in libraries that conform to the ABI. Each linker chooses a set of libraries that are commonly used on the OS and processor combination associated with the ABI. For example, a linker for Linux/x64 might choose two libraries: libc and libm. The functions in these libraries are exposed via a symbol lookup."

Hence this PR.

[prrace]

@jayathirthrao @prsadhuk please review

[azuev-java]

Looks good.

[mrserb]

"In addition, a linker provides a way to look up foreign functions in libraries that conform to the ABI. Each linker chooses a set of libraries that are commonly used on the OS and processor combination associated with the ABI. For example, a linker for Linux/x64 might choose two libraries: libc and libm. The functions in these libraries are exposed via a symbol lookup."

Is there any public information about that discussion? From the description above it is unclear why LD_PRELOAD is not supported it sounds like a regression. For such bugs we will always need to check the whole third party libraries that uses malloc/free/calloc/etc and make sure it is not mixed with similar methods loaded by FFM?

[prrace]

"In addition, a linker provides a way to look up foreign functions in libraries that conform to the ABI. Each linker chooses a set of libraries that are commonly used on the OS and processor combination associated with the ABI. For example, a linker for Linux/x64 might choose two libraries: libc and libm. The functions in these libraries are exposed via a symbol lookup."

Is there any public information about that discussion? From the description above it is unclear why LD_PRELOAD is not supported it sounds like a regression. For such bugs we will always need to check the whole third party libraries that uses malloc/free/calloc/etc and make sure it is not mixed with similar methods loaded by FFM?

It was an internal discussion, but nonetheless the outcome is the same and the FFM team have no plans to make changes.

[prrace]

/integrate

[openjdk]

Going to push as commit 704efcb.
Since your change was applied there have been 161 commits pushed to the master branch:

• e29ffd1: 8381840: Lots of /tmp/8173970- folders on test machines
• 0b9548b: 8382933: Improve Shenandoah clone barrier tests
• 5ddb0fd: 8383168: jpackage: enhance capabilities of the test lib for testing jpackage console output
• ... and 158 more: https://git.openjdk.org/jdk/compare/10e23dd5823258cfbf500175dde23be12cdd99bf...master

Your commit was automatically rebased without conflicts.

[openjdk]

@prrace Pushed as commit 704efcb.

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