Testing valgrind in rawhide (separate valgrind-debuginfo package)

[Jan Kratochvil]

On Wed, 06 Mar 2013 15:38:54 +0100, Richard W.M. Jones wrote:
> ==11843== 56 bytes in 1 blocks are definitely lost in loss record 6 of 6
> ==11843==    at 0x4A06409: malloc (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so)
> ==11843==    by 0x38EAC861F9: strdup (strdup.c:42)
> ==11843==    by 0x38EC8097C9: setprocattrcon_raw.constprop.3 (procattr.c:241)
> ==11843==    by 0x38EC8099B7: setprocattrcon.constprop.2 (procattr.c:274)
> ==11843==    by 0x400955: main (in /tmp/test)
> 
> The symbol we're actually calling is 'setsockcreatecon'.  It's not a
> macro.  There is no public function called 'setprocattrcon'
[...]
On Thu, 07 Mar 2013 10:10:56 +0100, Mark Wielaard wrote:
> Though note that the name we were really looking for was
> setsockcreatecon, since that is what was called from main. I think that
> one is doing a tail-call to setprocattrcon.constprop.2 so might not
> easily be available in the backtrace. If you compile and run Richard's
> reproducer from https://bugzilla.redhat.com/show_bug.cgi?id=918572 and
> break at the strdup call, can you get a backtrace from gdb with
> setsockcreatecon in it?

Yes:

(gdb) bt
#0  __GI___strdup (s=0x6021e0 "unconfined_u:unconfined_r:svirt_socket_t:s0-s0:c0.c1023") at strdup.c:40
#1  0x00007ffff7bc27ca in setprocattrcon_raw (context=0x6021e0 "unconfined_u:unconfined_r:svirt_socket_t:s0-s0:c0.c1023", 
    attr=attr at entry=0x7ffff7bd11f6 "sockcreate", pid=0) at procattr.c:241
#2  0x00007ffff7bc29b8 in setprocattrcon (context=<optimized out>, attr=attr at entry=0x7ffff7bd11f6 "sockcreate", pid=0) at procattr.c:274
#3  0x00007ffff7bc2ddc in setsockcreatecon (c=<optimized out>) at procattr.c:320
#4  0x0000000000400818 in main () at constprop.c:33
(gdb) info frame 3
Stack frame at 0x7fffffffe130:
 rip = 0x7ffff7bc2ddc in setsockcreatecon (procattr.c:320); saved rip 0x7ffff781ab75
 tail call frame, caller of frame at 0x7fffffffe130
 ^^^^^^^^^^^^^^^
 source language c.
 Arglist at unknown address.
 Locals at unknown address, Previous frame's sp is 0x7fffffffe130

But one has to compile the main program with -O2 -g so that it has the needed
call site debug information:
	gcc -Wall constprop.c -o constprop -lselinux -g -O2

 <2><37e>: Abbrev Number: 21 (DW_TAG_GNU_call_site)
    <37f>   DW_AT_low_pc      : 0x400818
    <387>   DW_AT_abstract_origin: <0x515>
 <1><515>: Abbrev Number: 24 (DW_TAG_subprogram)
    <516>   DW_AT_name        : (indirect string, offset: 0x11): setsockcreatecon
    <520>   DW_AT_declaration : 1


Jan