[Bug translator/18936] New: script cache will fail if $jiffies is referenced

["dsmith at redhat dot com" <sourceware-bugzilla at sourceware dot org>]

https://sourceware.org/bugzilla/show_bug.cgi?id=18936

            Bug ID: 18936
           Summary: script cache will fail if $jiffies is referenced
           Product: systemtap
           Version: unspecified
            Status: NEW
          Severity: normal
          Priority: P2
         Component: translator
          Assignee: systemtap at sourceware dot org
          Reporter: dsmith at redhat dot com
  Target Milestone: ---

I saw this on a RHEL7 x86_64 system:

====
# # start with a clean cache
# rm -rf ~/.systemtap.cache
# # compile a script (same as testsuite/buildok/pr13284.stp)
# stap -vp4 -e 'probe kernel.function("schedule_timeout") { println($jiffies)
}'
Pass 1: parsed user script and 113 library script(s) using
219172virt/32280res/3112shr/29500data kb, in 620usr/50sys/662real ms.
Pass 2: analyzed script: 1 probe(s), 1 function(s), 0 embed(s), 0 global(s)
using 253912virt/67892res/3960shr/64240data kb, in 1170usr/130sys/1304real ms.
Pass 3: translated to C into
"/tmp/stapcC0UrM/stap_48e8457a3acdccca58a072ce28c0dcc9_1925_src.c" using
253912virt/68240res/4308shr/64240data kb, in 20usr/80sys/101real ms.
/home/dsmith/.systemtap/cache/48/stap_48e8457a3acdccca58a072ce28c0dcc9_1925.ko
Pass 4: compiled C into "stap_48e8457a3acdccca58a072ce28c0dcc9_1925.ko" in
11290usr/2230sys/13840real ms.
# # compile the script again
# stap -vp4 -e 'probe kernel.function("schedule_timeout") { println($jiffies)
}'
Pass 1: parsed user script and 113 library script(s) using
219172virt/32280res/3112shr/29500data kb, in 650usr/30sys/688real ms.
Pass 2: analyzed script: 1 probe(s), 1 function(s), 0 embed(s), 0 global(s)
using 253912virt/67892res/3960shr/64240data kb, in 1190usr/150sys/1331real ms.
Pass 3: translated to C into
"/tmp/stapKnmi7U/stap_3763a751bb95c90049e7dcbf9a949d14_1925_src.c" using
253912virt/68240res/4308shr/64240data kb, in 10usr/90sys/778real ms.
/home/dsmith/.systemtap/cache/37/stap_3763a751bb95c90049e7dcbf9a949d14_1925.ko
Pass 4: compiled C into "stap_3763a751bb95c90049e7dcbf9a949d14_1925.ko" in
2610usr/630sys/3051real ms.
# diff -u
/home/dsmith/.systemtap/cache/48/stap_48e8457a3acdccca58a072ce28c0dcc9_1925.c
/home/dsmith/.systemtap/cache/37/stap_3763a751bb95c90049e7dcbf9a949d14_1925.c
---
/home/dsmith/.systemtap/cache/48/stap_48e8457a3acdccca58a072ce28c0dcc9_1925.c  
    2015-09-08 14:45:31.050480484 -0500
+++
/home/dsmith/.systemtap/cache/37/stap_3763a751bb95c90049e7dcbf9a949d14_1925.c  
    2015-09-08 14:45:42.426228745 -0500
@@ -161,7 +161,7 @@
 {
   {
     uintptr_t addr;
-    { // DWARF expression: 0xd1(57956440,61661464)
+    { // DWARF expression: 0xd1(56842328,60547352)
       {
         uintptr_t s0;
         s0 = ({ static unsigned long addr = 0; if (addr==0) addr =
_stp_kmodule_relocate ("kernel","_stext",0xa70e38); addr; });
====

So, this comment is causing the script to have 2 different hash values.

-- 
You are receiving this mail because:
You are the assignee for the bug.