From 2ae28aa91e6ac03b623e098900ea377ba47d9920 Mon Sep 17 00:00:00 2001 From: Yao Qi Date: Wed, 14 Nov 2012 03:49:12 +0000 Subject: [PATCH] gdb/ 2012-11-14 Daniel Jacobowitz Yao Qi * arm-tdep.c (arm_addr_bits_remove): Do not adjust the low bit of EXC_RETURN. (arm_m_exception_cache, arm_m_exception_this_id) (arm_m_exception_prev_register, arm_m_exception_unwind_sniffer) (arm_m_exception_unwind): New. (arm_gdbarch_init): Register arm_m_exception_unwind. --- gdb/ChangeLog | 10 ++++ gdb/arm-tdep.c | 129 +++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 139 insertions(+) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index a098310a45..4344f13cde 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,13 @@ +2012-11-14 Daniel Jacobowitz + Yao Qi + + * arm-tdep.c (arm_addr_bits_remove): Do not adjust the low + bit of EXC_RETURN. + (arm_m_exception_cache, arm_m_exception_this_id) + (arm_m_exception_prev_register, arm_m_exception_unwind_sniffer) + (arm_m_exception_unwind): New. + (arm_gdbarch_init): Register arm_m_exception_unwind. + 2012-11-13 Giuseppe Montalto * mi/mi-main.c (mi_cmd_data_write_memory): Handle additional diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c index 1a6736642e..a221fd6767 100644 --- a/gdb/arm-tdep.c +++ b/gdb/arm-tdep.c @@ -448,6 +448,12 @@ arm_pc_is_thumb (struct gdbarch *gdbarch, CORE_ADDR memaddr) static CORE_ADDR arm_addr_bits_remove (struct gdbarch *gdbarch, CORE_ADDR val) { + /* On M-profile devices, do not strip the low bit from EXC_RETURN + (the magic exception return address). */ + if (gdbarch_tdep (gdbarch)->is_m + && (val & 0xfffffff0) == 0xfffffff0) + return val; + if (arm_apcs_32) return UNMAKE_THUMB_ADDR (val); else @@ -2926,6 +2932,127 @@ struct frame_unwind arm_stub_unwind = { arm_stub_unwind_sniffer }; +/* Put here the code to store, into CACHE->saved_regs, the addresses + of the saved registers of frame described by THIS_FRAME. CACHE is + returned. */ + +static struct arm_prologue_cache * +arm_m_exception_cache (struct frame_info *this_frame) +{ + struct gdbarch *gdbarch = get_frame_arch (this_frame); + enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); + struct arm_prologue_cache *cache; + CORE_ADDR unwound_sp; + LONGEST xpsr; + + cache = FRAME_OBSTACK_ZALLOC (struct arm_prologue_cache); + cache->saved_regs = trad_frame_alloc_saved_regs (this_frame); + + unwound_sp = get_frame_register_unsigned (this_frame, + ARM_SP_REGNUM); + + /* The hardware saves eight 32-bit words, comprising xPSR, + ReturnAddress, LR (R14), R12, R3, R2, R1, R0. See details in + "B1.5.6 Exception entry behavior" in + "ARMv7-M Architecture Reference Manual". */ + cache->saved_regs[0].addr = unwound_sp; + cache->saved_regs[1].addr = unwound_sp + 4; + cache->saved_regs[2].addr = unwound_sp + 8; + cache->saved_regs[3].addr = unwound_sp + 12; + cache->saved_regs[12].addr = unwound_sp + 16; + cache->saved_regs[14].addr = unwound_sp + 20; + cache->saved_regs[15].addr = unwound_sp + 24; + cache->saved_regs[ARM_PS_REGNUM].addr = unwound_sp + 28; + + /* If bit 9 of the saved xPSR is set, then there is a four-byte + aligner between the top of the 32-byte stack frame and the + previous context's stack pointer. */ + cache->prev_sp = unwound_sp + 32; + if (safe_read_memory_integer (unwound_sp + 28, 4, byte_order, &xpsr) + && (xpsr & (1 << 9)) != 0) + cache->prev_sp += 4; + + return cache; +} + +/* Implementation of function hook 'this_id' in + 'struct frame_uwnind'. */ + +static void +arm_m_exception_this_id (struct frame_info *this_frame, + void **this_cache, + struct frame_id *this_id) +{ + struct arm_prologue_cache *cache; + + if (*this_cache == NULL) + *this_cache = arm_m_exception_cache (this_frame); + cache = *this_cache; + + /* Our frame ID for a stub frame is the current SP and LR. */ + *this_id = frame_id_build (cache->prev_sp, + get_frame_pc (this_frame)); +} + +/* Implementation of function hook 'prev_register' in + 'struct frame_uwnind'. */ + +static struct value * +arm_m_exception_prev_register (struct frame_info *this_frame, + void **this_cache, + int prev_regnum) +{ + struct gdbarch *gdbarch = get_frame_arch (this_frame); + struct arm_prologue_cache *cache; + + if (*this_cache == NULL) + *this_cache = arm_m_exception_cache (this_frame); + cache = *this_cache; + + /* The value was already reconstructed into PREV_SP. */ + if (prev_regnum == ARM_SP_REGNUM) + return frame_unwind_got_constant (this_frame, prev_regnum, + cache->prev_sp); + + return trad_frame_get_prev_register (this_frame, cache->saved_regs, + prev_regnum); +} + +/* Implementation of function hook 'sniffer' in + 'struct frame_uwnind'. */ + +static int +arm_m_exception_unwind_sniffer (const struct frame_unwind *self, + struct frame_info *this_frame, + void **this_prologue_cache) +{ + CORE_ADDR this_pc = get_frame_pc (this_frame); + + /* No need to check is_m; this sniffer is only registered for + M-profile architectures. */ + + /* Exception frames return to one of these magic PCs. Other values + are not defined as of v7-M. See details in "B1.5.8 Exception + return behavior" in "ARMv7-M Architecture Reference Manual". */ + if (this_pc == 0xfffffff1 || this_pc == 0xfffffff9 + || this_pc == 0xfffffffd) + return 1; + + return 0; +} + +/* Frame unwinder for M-profile exceptions. */ + +struct frame_unwind arm_m_exception_unwind = +{ + SIGTRAMP_FRAME, + default_frame_unwind_stop_reason, + arm_m_exception_this_id, + arm_m_exception_prev_register, + NULL, + arm_m_exception_unwind_sniffer +}; + static CORE_ADDR arm_normal_frame_base (struct frame_info *this_frame, void **this_cache) { @@ -10218,6 +10345,8 @@ arm_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) dwarf2_frame_set_init_reg (gdbarch, arm_dwarf2_frame_init_reg); /* Add some default predicates. */ + if (is_m) + frame_unwind_append_unwinder (gdbarch, &arm_m_exception_unwind); frame_unwind_append_unwinder (gdbarch, &arm_stub_unwind); dwarf2_append_unwinders (gdbarch); frame_unwind_append_unwinder (gdbarch, &arm_exidx_unwind);