How can I detect a suppressed error in Valgrind?

Question

I have a valgrind output:

==28099== ==28099== HEAP SUMMARY: ==28099== in use at exit: 0 bytes in 0 blocks ==28099== total heap usage: 131 allocs, 131 frees, 3,472 bytes allocated ==28099== ==28099== All heap blocks were freed -- no leaks are possible ==28099== ==28099== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 4 from 4) --28099-- --28099-- used_suppression: 2 dl-hack3-cond-1 --28099-- used_suppression: 2 glibc-2.5.x-on-SUSE-10.2-(PPC)-2a ==28099== ==28099== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 4 from 4) 

There are 4 suppressed errors. Although there is no leak, there is a problem when transferring to another system.

[EDIT]

I repeat with the option valgrind -v . But I do not see any errors there.

  == 30287 == Memcheck, a memory error detector  
  == 30287 == Copyright (C) 2002-2010, and GNU GPL'd, by Julian Seward et al.
  == 30287 == Using Valgrind-3.6.0.SVN-Debian and LibVEX;  rerun with -h for copyright info
  == 30287 == Command: ./EXECUTABLE1 test_input.txt 
  == 30287 == 
  --30287-- Valgrind options:
  --30287-- --suppressions = / usr / lib / valgrind / debian-libc6-dbg.supp
  --30287-- -v
  --30287-- --gen-suppressions = all
  --30287-- --error-limit = no
  --30287-- Contents of / proc / version:
  --30287-- Linux version 2.6.38.3.2.amd64-smp (gcc version 4.4.5 (Debian 4.4.5-8)) # 1 SMP Wed Apr 20 17:36:19 CEST 2011
  --30287-- Arch and hwcaps: AMD64, amd64-sse3-cx16
  --30287-- Page sizes: currently 4096, max supported 4096
  --30287-- Valgrind library directory: / usr / lib / valgrind
  --30287-- Reading syms from / home / path / to / file (0x400000)
  --30287-- Reading syms from /lib/ld-2.11.2.so (0x4000000)
  --30287-- Considering /lib/ld-2.11.2.so ..
  --30287-- .. CRC mismatch (computed cd91cee9 wanted 11b4673c)
  --30287-- Considering /usr/lib/debug/lib/ld-2.11.2.so ..
  --30287-- .. CRC is valid
  --30287-- Reading syms from / usr / lib / valgrind / memcheck-amd64-linux (0x38000000)
  --30287-- object doesn't have a dynamic symbol table
  --30287-- Reading suppressions file: /usr/lib/valgrind/debian-libc6-dbg.supp
  --30287-- Reading suppressions file: /usr/lib/valgrind/default.supp
   --30287-- REDIR: 0x4016230 (strlen) redirected to 0x380408a7 (vgPlain_amd64_linux_REDIR_FOR_strlen)
  --30287-- Reading syms from /usr/lib/valgrind/vgpreload_core-amd64-linux.so (0x4a20000)
   --30287-- Reading syms from /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so (0x4c21000)
   == 30287 == WARNING: new redirection conflicts with existing - ignoring it 
   --30287-- new: 0x04016230 (strlen) R-> 0x04c25850 strlen
   --30287-- REDIR: 0x40160a0 (index) redirected to 0x4c25460 (index)
   --30287-- REDIR: 0x4016120 (strcmp) redirected to 0x4c25e30 (strcmp)
   --30287-- Reading syms from /lib/libm-2.11.2.so (0x4e29000)
   --30287-- Considering /lib/libm-2.11.2.so ..
   --30287-- .. CRC mismatch (computed dd5c85df wanted ccd85fcf)
   --30287-- Considering /usr/lib/debug/lib/libm-2.11.2.so ..
   --30287-- .. CRC is valid
   --30287-- Reading syms from /lib/libc-2.11.2.so (0x50ab000)
   --30287-- Considering /lib/libc-2.11.2.so ..
   --30287-- .. CRC mismatch (computed 7d8e8f4f wanted 9b015f2c)
   --30287-- Considering /usr/lib/debug/lib/libc-2.11.2.so ..
   --30287-- .. CRC is valid
   --30287-- REDIR: 0x5128600 (__GI_strrchr) redirected to 0x4c25280 (__GI_strrchr)
   --30287-- REDIR: 0x51218c0 (malloc) redirected to 0x4c24466 (malloc)
   --30287-- REDIR: 0x5128d00 (memchr) redirected to 0x4c25ed0 (memchr)
   --30287-- REDIR: 0x512a750 (memcpy) redirected to 0x4c25f00 (memcpy)
   --30287-- REDIR: 0x5126b10 (strlen) redirected to 0x4a205ac (_vgnU_ifunc_wrapper)
    == 30287 == WARNING: new redirection conflicts with existing - ignoring it
   --30287-- new: 0x05126b40 (__GI_strlen) R-> 0x04c257f0 strlen
   --30287-- REDIR: 0x5126b40 (__GI_strlen) redirected to 0x4c25810 (__GI_strlen)
   --30287-- REDIR: 0x512baf0 (__GI___rawmemchr) redirected to 0x4c26ba0 (__GI___rawmemchr)
   --30287-- REDIR: 0x51217e0 (free) redirected to 0x4c24076 (free)
    Following are the keys and their corresponding value present
   --30287-- REDIR: 0x512bb40 (strchrnul) redirected to 0x4c26b50 (strchrnul)

Answer 1

You can view / modify suppressed errors in /usr/lib/valgrind/default.supp .

Answer 2

Suppressed errors are simply errors that are system-specific, known problems with your libraries. Therefore, they are not the correct suspects of portability problems in another system.

Answer 3

On x86 hosts, valgrind displays the following line: For counts of detected and suppressed errors, rerun with: -v So run your program: valgrind -v ./myprog .