svn commit: r283905 - stable/10/usr.sbin/pmcstat
Hiren Panchasara
hiren at FreeBSD.org
Tue Jun 2 08:03:29 UTC 2015
Author: hiren
Date: Tue Jun 2 08:03:28 2015
New Revision: 283905
URL: https://svnweb.freebsd.org/changeset/base/283905
Log:
MFC: r282866
Fix pmcstat symbol resolution for userland processes.
When examining existing processes pmcstat fails to
correctly determine the locations of executable sections
of the process due to a miscalculated virtual load address.
This does not affect the newly launched processes as the
same value passed as a "start address" to the pmcstat_image_link()
thus nullifying the effect of it. The issue manifests itself
in processes not being reported in the pmcstat(8) output and
"dubious frames" being reported.
Fix it for now by ignoring all the sections except the executable
one. This won't fix the issue for objects with multiple
executable sections but helps in majority of real world usecases.
The real solution would be to modify the MAP-IN event to include
the appropriate load address so pmcstat(8) won't have to manually
parse object files to try to determine it.
PR: 198147, 198148
Submitted by: stas
Modified:
stable/10/usr.sbin/pmcstat/pmcstat_log.c
Directory Properties:
stable/10/ (props changed)
Modified: stable/10/usr.sbin/pmcstat/pmcstat_log.c
==============================================================================
--- stable/10/usr.sbin/pmcstat/pmcstat_log.c Tue Jun 2 07:26:26 2015 (r283904)
+++ stable/10/usr.sbin/pmcstat/pmcstat_log.c Tue Jun 2 08:03:28 2015 (r283905)
@@ -716,7 +716,8 @@ pmcstat_image_get_elf_params(struct pmcs
ph.p_offset);
break;
case PT_LOAD:
- if ((ph.p_offset & (-ph.p_align)) == 0)
+ if ((ph.p_flags & PF_X) != 0 &&
+ (ph.p_offset & (-ph.p_align)) == 0)
image->pi_vaddr = ph.p_vaddr & (-ph.p_align);
break;
}
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