From 148ca9dd5cf96049c0db17c1230e4b96c0ac054a Mon Sep 17 00:00:00 2001 From: Yvan Roux Date: Thu, 9 Jun 2022 16:31:40 +0200 Subject: [PATCH] gdb/arm: Terminate unwinding when LR is 0xffffffff MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit ARMv7-M Architecture Reference "A2.3.1 Arm core registers" states that LR is set to 0xffffffff on reset. ARMv8-M Architecture Reference "B3.3 Registers" states that LR is set to 0xffffffff on warm reset if Main Extension is implemented, otherwise the value is unknown. Signed-off-by: Torbjörn SVENSSON Signed-off-by: Yvan Roux --- gdb/arm-tdep.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c index 591a2da99f2..09670b69a1d 100644 --- a/gdb/arm-tdep.c +++ b/gdb/arm-tdep.c @@ -3330,6 +3330,17 @@ arm_m_exception_cache (struct frame_info *this_frame) lr = get_frame_register_unsigned (this_frame, ARM_LR_REGNUM); sp = get_frame_register_unsigned (this_frame, ARM_SP_REGNUM); + /* ARMv7-M Architecture Reference "A2.3.1 Arm core registers" + states that LR is set to 0xffffffff on reset. ARMv8-M Architecture + Reference "B3.3 Registers" states that LR is set to 0xffffffff on warm + reset if Main Extension is implemented, otherwise the value is unknown. */ + if (lr == 0xffffffff) + { + /* Terminate any further stack unwinding by referring to self. */ + arm_cache_set_active_sp_value (cache, tdep, sp); + return cache; + } + fnc_return = ((lr & 0xfffffffe) == 0xfefffffe); if (tdep->have_sec_ext && fnc_return) { -- 2.30.2