Integrated: 8376269: Mixed jstack cannot find function in vDSO

[Yasumasa Suenaga]

On Sun, 25 Jan 2026 03:55:13 GMT, Yasumasa Suenaga <ysuenaga at openjdk.org> wrote:

> Some functions / signal trampoline would be provided by vDSO in Linux. However SA cannot find symbols in it because it is not a regular ELF, it is on the memory only.
> For example, mixed jstack could not decode the symbol in the coredump crashed in gettimeofday(2) as following:
> 
> 
> 0x00007faae3dd0818      VMError::report_and_die(Thread*, unsigned int, unsigned char*, void const*, void const*) + 0x58
> 0x00007faae3aff1ba      JVM_handle_linux_signal + 0x42a
> 0x00007faae4ad9290      <signal handler called>
> 0x00007faae4cd8e69              ????????
> 0x00007faaca78ffa1      <nep_invoker_blob>
> 0x00007faaca73fd48      * java.lang.invoke.LambdaForm$MH+0x0000000028156c00.invoke(java.lang.Object, long, long, long) bci:12 (Interpreted frame)
> 
> 
> It should be:
> 
> 
> 0x00007fb5841d0818      VMError::report_and_die(Thread*, unsigned int, unsigned char*, void const*, void const*) + 0x58
> 0x00007fb583eff1ba      JVM_handle_linux_signal + 0x42a
> 0x00007fb584fd9290      <signal handler called>
> 0x00007fb5851d8e69      __cvdso_gettimeofday_data.constprop.0 + 0x99
> 0x00007fb56a78f321      <nep_invoker_blob>
> 0x00007fb56a73fd48      * java.lang.invoke.LambdaForm$MH+0x000000000e156c00.invoke(java.lang.Object, long, long, long) bci:12 (Interpreted frame)
> 
> 
> Some platforms (Ubuntu 24.04 and Fedora 43 at least) provide vDSO binary in `/lib/modules/<kernel version>/vdso`. This patch attempts to load it if we can refer it because we want to use debuginfo of vDSO if possible. Otherwise load vDSO memory.

This pull request has now been integrated.

Changeset: 77e680b1
Author:    Yasumasa Suenaga <ysuenaga at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/77e680b11efea0eb707b72f4f3bb9e3422e170fd
Stats:     225 lines in 5 files changed: 217 ins; 0 del; 8 mod

8376269: Mixed jstack cannot find function in vDSO

Reviewed-by: kevinw, cjplummer

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PR: https://git.openjdk.org/jdk/pull/29400