RFR: 8376269: Mixed jstack cannot find function in vDSO

[Yasumasa Suenaga]

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.

-------------

Commit messages:
 - 8376269: Mixed jstack cannot find function in vDSO

Changes: https://git.openjdk.org/jdk/pull/29400/files
  Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=29400&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8376269
  Stats: 129 lines in 5 files changed: 115 ins; 1 del; 13 mod
  Patch: https://git.openjdk.org/jdk/pull/29400.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/29400/head:pull/29400

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