On Wed, Sep 01, 2021 at 07:51:06PM +0200, Marco Elver wrote: > On Wed, 1 Sept 2021 at 16:06, Vasily Gorbik <gor@xxxxxxxxxxxxx> wrote: > > current_stack_pointer() simply returns current value of %r15. If > > current_stack_pointer() caller allocates stack (which is the case in > > unwind code) %r15 points to a stack frame allocated for callees, meaning > > current_stack_pointer() caller (e.g. stack_trace_save) will end up in > > the stacktrace. This is not expected by stack_trace_save*() callers and > > causes problems. > > > > current_frame_address() on the other hand returns function stack frame > > address, which matches %r15 upon function invocation. Using it in > > get_stack_pointer() makes it more aligned with x86 implementation > > (according to BACKTRACE_SELF_TEST output) and meets stack_trace_save*() > > caller's expectations, notably KCSAN. > > > > Also make sure unwind_start is always inlined. > > > > Reported-by: Nathan Chancellor <nathan@xxxxxxxxxx> > > Suggested-by: Marco Elver <elver@xxxxxxxxxx> > > Signed-off-by: Vasily Gorbik <gor@xxxxxxxxxxxxx> > > Tested-by: Marco Elver <elver@xxxxxxxxxx> > > Thanks! > > > --- > > arch/s390/include/asm/stacktrace.h | 20 ++++++++++---------- > > arch/s390/include/asm/unwind.h | 8 ++++---- > > 2 files changed, 14 insertions(+), 14 deletions(-) Applied, thanks!
