Perf doesn't display kernel symbols anymore (bisected commit 659ad3492b91 ("perf maps: Switch from rbtree to lazily sorted array for addresses"))

[Christophe Leroy <christophe.leroy@csgroup.eu>]

Hi,

I noticed with 6.12 LTS Kernel that perf top and perf record/report 
don't display kernel symbols anymore, instead it displays the raw 
address with [unknown] as object.

After bisect I see that the problem appears with commit 659ad3492b91 
("perf maps: Switch from rbtree to lazily sorted array for addresses"). 
Previous commit 39d14c0dd650 ("Merge branch 'perf-tools' into 
perf-tools-next") doesn't exbibit the problem.

Now:

# Overhead  Command     Shared Object  Symbol 

# ........  ..........  ............. 
......................................
#
     80.49%  Coeur main  [unknown]      [k] 0xc005f0f8
      3.91%  Coeur main  gau            [.] engine_loop.constprop.0.isra.0
      1.72%  Coeur main  [unknown]      [k] 0xc005f11c
      1.09%  Coeur main  [unknown]      [k] 0xc01f82c8
      0.44%  Coeur main  libc.so.6      [.] epoll_wait
      0.38%  Coeur main  [unknown]      [k] 0xc0011718
      0.36%  Coeur main  [unknown]      [k] 0xc01f45c0
      0.22%  Coeur main  libc.so.6      [.] 
__GI___pthread_enable_asynccancel
      0.19%  Coeur main  libc.so.6      [.] 
__GI___pthread_disable_asynccancel
      0.19%  Coeur main  [unknown]      [k] 0xc0011170
      0.19%  Coeur main  [unknown]      [k] 0xc019ac64
      0.19%  Coeur main  [unknown]      [k] 0xc01f54bc
      0.16%  Coeur main  libc.so.6      [.] read

Before commit 659ad3492b91 ("perf maps: Switch from rbtree to lazily 
sorted array for addresses"):

# Overhead  Command     Shared Object      Symbol 

# ........  ..........  ................. 
......................................
#
     76.65%  Coeur main  [kernel.kallsyms]  [k] finish_task_switch.isra.0
      4.26%  Coeur main  gau                [.] 
engine_loop.constprop.0.isra.0
      3.69%  Coeur main  [kernel.kallsyms]  [k] do_epoll_wait
      2.00%  Coeur main  [kernel.kallsyms]  [k] timerfd_read_iter
      0.96%  Coeur main  [kernel.kallsyms]  [k] ep_start_scan
      0.87%  Coeur main  [kernel.kallsyms]  [k] __rseq_handle_notify_resume
      0.79%  Coeur main  [kernel.kallsyms]  [k] system_call_exception
      0.71%  Coeur main  [kernel.kallsyms]  [k] do_notify_resume
      0.66%  Coeur main  [kernel.kallsyms]  [k] timerfd_poll
      0.63%  Coeur main  [kernel.kallsyms]  [k] __copy_tofrom_user
      0.57%  Coeur main  libc.so.6          [.] read
      0.52%  Coeur main  [kernel.kallsyms]  [k] ep_item_poll.isra.0
      0.52%  Coeur main  [kernel.kallsyms]  [k] 
schedule_hrtimeout_range_clock
      0.49%  Coeur main  [kernel.kallsyms]  [k] ep_done_scan
      0.46%  Coeur main  [kernel.kallsyms]  [k] schedule
      0.46%  Coeur main  libc.so.6          [.] 
__GI___pthread_disable_asynccancel

Can you help fixing that ?

Christophe