[Valgrind-users] Endless loop happen when using lackey with --trace-mem=yes on ARM

[jianan hu <huj...@gm...>]

Hi everyone,

I tried to use lackey to record every memory access made by program. I
wrote very simple Hello Word program and used lackey to trace.
Unfortunately, lackey couldn't finish this job and I got very huge log file
(>100M) so I had to stop it.

After checked log file, lackey recorded a lot of following repeat
information:
I  04853198,2
I  0485319a,2
I  0485319c,4
 S 0490c0bc,4
I  048531a0,4
I  048531a4,2
I  04853194,4
 L 0490c0bc,4
I  04853198,2
I  0485319a,2
I  0485319c,4
 S 0490c0bc,4
I  048531a0,4
I  048531a4,2
I  04853194,4
 L 0490c0bc,4

My environment:
uname -r : 3.9.0-1-linaro-omap
Pandaboard ES, I also checked on OMAP 5432 Evm Board.


Steps to Reproduce:
Setp 1. Write test.c
#include <stdio.h>
int main()
{
    printf("Hello\n");
    return 0;
}

Step 2. Compile program.
    arm-linux-gnueabihf-gcc ./test.c

Step 3. valgrind --log-file="log.txt" --tool=lackey --trace-mem=yes ./a.out



After checked the code (lk_main.c), I found that the problem may be dirty
helper. I only call addStmtToIRSB when "ev->addr->tag" is "Iex_RdTmp",
Endless loop never happens.

I modified the "addStmtToIRSB( sb, IRStmt_Dirty(di) );" (in flushEvents
function) code into following codes:

      switch (ev->addr->tag) {
      case Iex_Const:
           VG_(printf)("L %08lx\n", ev->addr->Iex.Const.con->Ico.U32);
           break;
      case Iex_RdTmp:
           addStmtToIRSB( sb, IRStmt_Dirty(di) );
           VG_(printf)("Iex_RdTmp %lu\n", ev->addr->Iex.RdTmp.tmp);
           break;
      }


Does anyone can help me? Thanks!

Best Regards.