See <http://gcc.gnu.org/ml/gcc/2009-12/msg00183.html>.
To sum up: the question is whether the CFA needs to be adjusted after push
{lr}, and before calling __gnu_mcount_nc. Currently it is not valid until
__gnu_mcount_nc returns.
--
Summary: CFI statements vs. -pg
Product: gcc
Version: 4.5.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: debug
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: tschwinge at gcc dot gnu dot org
GCC target triplet: arm-none-linux-gnueabi
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42380