Re: malloc() call somehow calling the rtld malloc() implementaion

Hi,

Are you being affected by this rtld behaviour:

https://lists.freebsd.org/pipermail/freebsd-hackers/2016-July/049769.html <https://lists.freebsd.org/pipermail/freebsd-hackers/2016-July/049769.html>

https://lists.freebsd.org/pipermail/freebsd-stable/2015-July/082751.html <https://lists.freebsd.org/pipermail/freebsd-stable/2015-July/082751.html>

(I still find this a bit scary.)

Regards,

Jan.


> On 27 Jan 2017, at 19:31, Don Lewis <truckman_at_FreeBSD.org> wrote:
> 
> I've been attempting to get OpenOffice to build properly in a
> clang400-import poudriere jail and have run into a mystery.  The build
> procedure creates a c++ executable "idlc", which is used to build other
> stuff.  The new operator has been overrriden to call a custom memory
> allocator, which I have configured to call the system version of
> malloc().
> 
> At some point idlc crashes because it has allocated a 16 byte structure
> and the compiler is using "movaps %xmm0,(%rax)" to initialize it, which
> requires 16 byte alignment.  Unfortunately this structure is only 8 byte
> aligned, causing a bus error.  This shouldn't be happening because our
> system malloc() always seems to do the proper alignment.  It appears
> that intead of calling the version of malloc() in libc, the simple
> version of malloc() built into rtld is being called instead.
> 
> GNU gdb 6.1.1 [FreeBSD]
> Copyright 2004 Free Software Foundation, Inc.
> GDB is free software, covered by the GNU General Public License, and you are
> welcome to change it and/or distribute copies of it under certain conditions.
> Type "show copying" to see the conditions.
> There is absolutely no warranty for GDB.  Type "show warranty" for details.
> This GDB was configured as "amd64-marcel-freebsd"...
> (gdb) break main
> Breakpoint 1 at 0x43b1f6: file idlcmain.cxx, line 34.
> (gdb) run _at_/tmp/r
> Starting program: /wrkdirs/usr/ports/editors/openoffice-devel/work/aoo-4.2.0/main/solver/420/unxfbsdx.pro/bin/idlc _at_/tmp/r
> [New LWP 101304]
> [New Thread 802616000 (LWP 101304/idlc)]
> [Switching to Thread 802616000 (LWP 101304/idlc)]
> 
> Breakpoint 1, main (argc=2, argv=0x7fffffffb278) at idlcmain.cxx:34
> 34	SAL_IMPLEMENT_MAIN_WITH_ARGS(argc, argv)
> (gdb) break malloc
> Breakpoint 2 at 0x8006a5f01: file /var/poudriere/jails/clang400amd64/usr/src/libexec/rtld-elf/malloc.c, line 163.
> (gdb) cont
> Continuing.
> Trace 12474/1: "Min Prioriy for policy '2' == '0'
> "
> Trace 12474/1: "Max Prioriy for policy '2' == '103'
> "
> /wrkdirs/usr/ports/editors/openoffice-devel/work/aoo-4.2.0/main/solver/420/unxfbsdx.pro/bin/idlc: compiling 1 source files ... 
> Compiling: /wrkdirs/usr/ports/editors/openoffice-devel/work/aoo-4.2.0/main/offapi/com/sun/star/i18n/KParseTokens.idl
> 
> Breakpoint 2, malloc (nbytes=343)
>    at /var/poudriere/jails/clang400amd64/usr/src/libexec/rtld-elf/malloc.c:163
> 163	/var/poudriere/jails/clang400amd64/usr/src/libexec/rtld-elf/malloc.c: No such file or directory.
> 	in /var/poudriere/jails/clang400amd64/usr/src/libexec/rtld-elf/malloc.c
> Current language:  auto; currently minimal
> (gdb) cont
> Continuing.
> 
> Breakpoint 2, malloc (nbytes=32)
>    at /var/poudriere/jails/clang400amd64/usr/src/libexec/rtld-elf/malloc.c:163
> 163	in /var/poudriere/jails/clang400amd64/usr/src/libexec/rtld-elf/malloc.c
> (gdb) cont
> Continuing.
> Trace 13112/2: "ChildStatusProc : starting '/wrkdirs/usr/ports/editors/openoffice-devel/work/aoo-4.2.0/main/solver/420/unxfbsdx.pro/bin/ucpp'"
> [New Thread 802616500 (LWP 100249/idlc)]
> [Switching to Thread 802616500 (LWP 100249/idlc)]
> 
> Breakpoint 2, malloc (nbytes=19)
>    at /var/poudriere/jails/clang400amd64/usr/src/libexec/rtld-elf/malloc.c:163
> 163	in /var/poudriere/jails/clang400amd64/usr/src/libexec/rtld-elf/malloc.c
> (gdb) cont
> Continuing.
> 
> Breakpoint 2, malloc (nbytes=34)
>    at /var/poudriere/jails/clang400amd64/usr/src/libexec/rtld-elf/malloc.c:163
> 163	in /var/poudriere/jails/clang400amd64/usr/src/libexec/rtld-elf/malloc.c
> (gdb) cont
> Continuing.
> 
> Breakpoint 2, malloc (nbytes=16)
>    at /var/poudriere/jails/clang400amd64/usr/src/libexec/rtld-elf/malloc.c:163
> 163	in /var/poudriere/jails/clang400amd64/usr/src/libexec/rtld-elf/malloc.c
> (gdb) cont
> Continuing.
> 
> Breakpoint 2, malloc (nbytes=16)
>    at /var/poudriere/jails/clang400amd64/usr/src/libexec/rtld-elf/malloc.c:163
> 163	in /var/poudriere/jails/clang400amd64/usr/src/libexec/rtld-elf/malloc.c
> (gdb) cont
> Continuing.
> 
> Breakpoint 2, malloc (nbytes=16)
>    at /var/poudriere/jails/clang400amd64/usr/src/libexec/rtld-elf/malloc.c:163
> 163	in /var/poudriere/jails/clang400amd64/usr/src/libexec/rtld-elf/malloc.c
> (gdb) cont
> Continuing.
> 
> Breakpoint 2, malloc (nbytes=16)
>    at /var/poudriere/jails/clang400amd64/usr/src/libexec/rtld-elf/malloc.c:163
> 163	in /var/poudriere/jails/clang400amd64/usr/src/libexec/rtld-elf/malloc.c
> (gdb) cont
> Continuing.
> sizeof(AstExprValue)=16
> 
> Program received signal SIGBUS, Bus error.
> [Switching to Thread 802616000 (LWP 101304/idlc)]
> 0x0000000000478cc2 in AstExpression::eval_bit_op (this=0x802633dc8, 
>    ek=EK_const) at astexpression.cxx:1001
> 1001	    std::auto_ptr< AstExprValue	> retval(new AstExprValue());
> 
> 
> idlc is linked to libc.so:
> 
> /wrkdirs/usr/ports/editors/openoffice-devel/work/aoo-4.2.0/main/solver/420/unxfbsdx.pro/bin/idlc:
> 	libreg.so.3 => /wrkdirs/usr/ports/editors/openoffice-devel/work/aoo-4.2.0/main/solver/420/unxfbsdx.pro/lib/libreg.so.3 (0x8008b9000)
> 	libuno_sal.so.3 => /wrkdirs/usr/ports/editors/openoffice-devel/work/aoo-4.2.0/main/solver/420/unxfbsdx.pro/lib/libuno_sal.so.3 (0x800c00000)
> 	libuno_salhelpergcc3.so.3 => /wrkdirs/usr/ports/editors/openoffice-devel/work/aoo-4.2.0/main/solver/420/unxfbsdx.pro/lib/libuno_salhelpergcc3.so.3 (0x801040000)
> 	libm.so.5 => /lib/libm.so.5 (0x801244000)
> 	libc++.so.1 => /usr/lib/libc++.so.1 (0x80146e000)
> 	libcxxrt.so.1 => /lib/libcxxrt.so.1 (0x801735000)
> 	libgcc_s.so.1 => /lib/libgcc_s.so.1 (0x801953000)
> 	libthr.so.3 => /lib/libthr.so.3 (0x801b69000)
> 	libc.so.7 => /lib/libc.so.7 (0x801d91000)
> 	libstore.so.3 => /wrkdirs/usr/ports/editors/openoffice-devel/work/aoo-4.2.0/main/solver/420/unxfbsdx.pro/lib/libstore.so.3 (0x802152000)
> 
> 
> If I create a simple test program that calls malloc() and set a
> breakpoint in malloc(), the breakpoint gets set in the rtld version, but
> the the libc version of malloc is what gets called.
> 
> What the heck is going on here, and how can I fix it?
> 
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