strace failure on ARM Linux 2.6.31-rc7 running on TI OMAP3 hardware

[Konstantin Malolin]

I believe this must be a kernel bug.
Attached are two strace binaries :

strace_arm and strace_t2

The difference between them is that strace_arm is compiled as an original ARM ISA,
strace_t2 is compiled for Thumb2 (-mthumb -mcpu=cortex-a8 -mfpu=neon -mfloat-abi=softfp).

I tried these compilers :

gcc version 4.2.1 (CodeSourcery Sourcery G++ Lite 2007q3-51)
gcc version 4.3.3 (Sourcery G++ 4.3-234)
gcc version 4.4.1 (Sourcery G++ 4.4-71)

The bug shows up with all of them, most easily reproduces with an strace binary built with 2007q3-51.

If run by this way on an OMAP3 system, 2.6.31-rc7 plain vanilla kernel :

./strace_arm ./strace_t2 echo "abc" 2> /dev/null

the strace_arm fails randomly with either signal 11 or 4
The PC locations point to some junk areas in functions padding.
Please note that the only scheme when the failure occures is this : ARM binary traces Thumb2 binary.
When ARM traces ARM, Thumb2 traces Thumb2, Thumb2 traces ARM, the failure doesn't show up.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: strace_arm
Type: application/octet-stream
Size: 205669 bytes
Desc: strace_arm
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20091130/bf8d952e/attachment-0002.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: strace_t2
Type: application/octet-stream
Size: 191476 bytes
Desc: strace_t2
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20091130/bf8d952e/attachment-0003.obj>