[Bug tapsets/3423] New: src/testsuite/systemtap.base/probefunc.exp fails on IA64

[Bug tapsets/3423] New: src/testsuite/systemtap.base/probefunc.exp fails on IA64

[thang dot p dot nguyen at intel dot com]

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The probefunc.exp fails on printing the probe name for a statement probe. 

The probe below is supposed to print the probe name “scheduler_tick” on IA64
(2.6.17-1.2519.4.21.el5, ia64 GNU/Linux), but an empty string is printed 
instead.

probe kernel.statement(0xa000000100068e40){
   printf("%s\n", probefunc())
}

There seems to be a bug in probefunc() in tapset/context.stp.  The comparison 
(REG_IP(CONTEXT->regs) >= PAGE_OFFSET) is not valid in this particular case 
since the values below were observed:

REG_IP(CONTEXT->regs)  = 0xa000000100068e40   
PAGE_OFFSET=0xe000000000000000

-- 
           Summary: src/testsuite/systemtap.base/probefunc.exp fails on IA64
           Product: systemtap
           Version: unspecified
            Status: NEW
          Severity: normal
          Priority: P2
         Component: tapsets
        AssignedTo: systemtap at sources dot redhat dot com
        ReportedBy: thang dot p dot nguyen at intel dot com
                CC: bibo dot mao at intel dot com


http://sourceware.org/bugzilla/show_bug.cgi?id=3423

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[Bug tapsets/3423] src/testsuite/systemtap.base/probefunc.exp fails on IA64

[fche at redhat dot com]

------- Additional Comments From fche at redhat dot com  2006-10-25 03:48 -------
Actually, the comparison appears to be sound, except that the
pointers need to be compared in an *unsigned* manner.

-- 


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[Bug tapsets/3423] src/testsuite/systemtap.base/probefunc.exp fails on IA64

[bibo dot mao at intel dot com]

------- Additional Comments From bibo dot mao at intel dot com  2006-10-25 03:53 -------
The main aim of the comparison is to judge whether REG_IP(CONTEXT->regs) is 
within kernel space, I will check all architecture to watch whether PAGE_OFFSET 
is limit of user space vs kernel space.

-- 


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[Bug tapsets/3423] src/testsuite/systemtap.base/probefunc.exp fails on IA64

[bibo dot mao at intel dot com]

------- Additional Comments From bibo dot mao at intel dot com  2006-10-25 06:54 -------
I do not know whether it is possible to use user_mode macro to judge whether it
is in kernel space or userspace, change tapset/context.stp as follows:
-----------------------------------------------
       } else if (CONTEXT->regs &&
                (!user_mode(CONTEXT->regs))) {
-----------------------------------------------


-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
         AssignedTo|systemtap at sources dot    |thang dot p dot nguyen at
                   |redhat dot com              |intel dot com
             Status|NEW                         |ASSIGNED


http://sourceware.org/bugzilla/show_bug.cgi?id=3423

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