Implement intelligent backtracing by searching for stack frame creation,
and emitting only return addresses. Use print_hex_dump() to display the
entire binary kernel stack.
Limitation: MMU kernels are not currently able to trace beyond a system trap
(interrupt, syscall, etc.). It is the intent of this patch to provide
infrastructure that can be extended to add this capability later.
Changes from V1:
* Removed checks in find_frame_creation() that prevented location of the frame
creation instruction in heavily optimized code
* Various formatting/commenting/file location tweaks per review comments
* Dropped Kconfig option to enable STACKTRACE as something logically separate
Signed-off-by: Steven J. Magnani <steve@digidescorp.com>
sys_clone syscall ignored args which this patch mapped to args
which are passing from glibc.
Here is the origin problem description.
"I ran the static libgcc tests (very few of them are there, they are
mostly dynamically linked) and some of them fail with an assertion in
fork() system call (tid != pid), I looked at the microblaze/entry.S
file and it looks suspicious (ignores arguments 3-5)"
Arg mapping should be:
glibc ARCH_FORK(...) -> do_fork(...)
r5 -> r5 (clone_flags)
r6 -> r6 (stack_start, use parent->stack if NULL)
pt_regs -> r7 (pt_regs)
r7 -> r8 (stack_size)
r8 -> r9 (parent_tidptr)
r9 -> r10 (child_tidptr)
Signed-off-by: John Williams <john.williams@petalogix.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>
There is possible to save r3/r4 at the beggining of user part
before calling handlers and at the end restore it.
Signed-off-by: Michal Simek <monstr@monstr.eu>
This patch add core PREEMPT support for Microblaze.
I tried to trace it via tracers and I was able to see any output.
I also added low level debug functions to see if that code is called.
Signed-off-by: Michal Simek <monstr@monstr.eu>
Saving is done in SAVE_STATE macros that's why another save discard
previous saved value.
This change has no effect to normal programs because they ends in any exception
and they are killed. On the other side has effect on debugging.
Signed-off-by: Michal Simek <monstr@monstr.eu>
Previous patch d63678d607d0e37ec7abe5ceb545d7e8aab956a4 clear
it for noMMU kernel. This one do it for MMU.
Correct noMMU version
Signed-off-by: Michal Simek <monstr@monstr.eu>
The prototypes in syscalls.h all make sense for
microblaze, but for some of them, the actual implementation
in sys_microblaze.c needs to be adapted.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michal Simek <monstr@monstr.eu>
When legacy signal handling is disabled, the
arch/microblaze/kernel/signal.c implementation can
be much simpler, as most of it is handled generically
from kernel/signal.c.
This is also a prerequisite for using the generic
asm/unistd.h, which does not provide __NR_sigreturn,
because this macro is referenced by the current signal.c
implementation.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michal Simek <monstr@monstr.eu>
