linux-kernel - Profiling of vdso_test

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <30e9575c-a53e-4e17-bbbd-7127798efb05@csgroup.eu>
Date: Wed, 4 Sep 2024 13:41:19 +0200
From: Christophe Leroy <christophe.leroy@...roup.eu>
To: "Jason A. Donenfeld" <Jason@...c4.com>,
 Adhemerval Zanella <adhemerval.zanella@...aro.org>,
 Xi Ruoyao <xry111@...111.site>
Cc: "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
 "linuxppc-dev@...ts.ozlabs.org" <linuxppc-dev@...ts.ozlabs.org>
Subject: Profiling of vdso_test_random

Hi,

I'm done a 'perf record' on vdso_test_random reduced to vdso test only, 
and I get the following function usage profile.

Do you see the same type of percentage on your platforms ?

I would have expected most of the time to be spent in 
__arch_chacha20_blocks_nostack() but that's in fact not the case.

# Samples: 61K of event 'task-clock:ppp'
# Event count (approx.): 15463500000
#
# Overhead  Command          Shared Object        Symbol 

# ........  ...............  ................... 
....................................
#
     57.74%  vdso_test_getra  [vdso]               [.] __c_kernel_getrandom
     22.49%  vdso_test_getra  [vdso]               [.] 
__arch_chacha20_blocks_nostack
     10.80%  vdso_test_getra  vdso_test_getrandom  [.] test_vdso_getrandom
      8.89%  vdso_test_getra  [vdso]               [.] __kernel_getrandom
      0.01%  vdso_test_getra  [kernel.kallsyms]    [k] 
finish_task_switch.isra.0

Christophe