From: Janosch Frank <frankja@xxxxxxxxxxxxx> When setting the first stack frame to 0, we can check for a 0 backchain pointer when doing backtraces to know when to stop. Signed-off-by: Janosch Frank <frankja@xxxxxxxxxxxxx> Reviewed-by: Nico Boehr <nrb@xxxxxxxxxxxxx> Reviewed-by: Claudio Imbrenda <imbrenda@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20230112154548.163021-7-frankja@xxxxxxxxxxxxx Message-Id: <20230112154548.163021-7-frankja@xxxxxxxxxxxxx> --- lib/s390x/stack.c | 2 ++ s390x/cstart64.S | 2 ++ 2 files changed, 4 insertions(+) diff --git a/lib/s390x/stack.c b/lib/s390x/stack.c index e714e07c..9f234a12 100644 --- a/lib/s390x/stack.c +++ b/lib/s390x/stack.c @@ -22,6 +22,8 @@ int backtrace_frame(const void *frame, const void **return_addrs, int max_depth) for (depth = 0; stack && depth < max_depth; depth++) { return_addrs[depth] = (void *)stack->grs[8]; stack = stack->back_chain; + if (!stack) + break; } return depth; diff --git a/s390x/cstart64.S b/s390x/cstart64.S index 666a9567..6f83da2a 100644 --- a/s390x/cstart64.S +++ b/s390x/cstart64.S @@ -37,6 +37,8 @@ start: sam64 # Set addressing mode to 64 bit /* setup stack */ larl %r15, stackptr + /* Clear first stack frame */ + xc 0(160,%r15), 0(%r15) /* setup initial PSW mask + control registers*/ larl %r1, initial_psw lpswe 0(%r1) -- 2.39.1
