From b5914469f9dd6b332ed51eea9b5954bd12375cd7 Mon Sep 17 00:00:00 2001 From: Jan Kratochvil Date: Mon, 2 Jan 2012 02:52:20 +0000 Subject: [PATCH] gdb/ Fix regression for gdb.cp/gdb2495.exp with gcc-4.7. * arch-utils.c (displaced_step_at_entry_point): Incrase BP_LEN skip to 3 times. * infcall.c (call_function_by_hand) : Move it upwards and fall through into AT_ENTRY_POINT. (call_function_by_hand) : New variable bp_len. Adjust DUMMY_ADDR with it. * ppc-linux-tdep.c (ppc_linux_displaced_step_location): Increase PPC_INSN_SIZE skip to 3 times. --- gdb/ChangeLog | 13 ++++++++++++ gdb/arch-utils.c | 2 +- gdb/infcall.c | 47 ++++++++++++++++++++++++++++++-------------- gdb/ppc-linux-tdep.c | 2 +- 4 files changed, 47 insertions(+), 17 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 3a5f1875eeb..db26777db31 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,16 @@ +2012-01-02 Jan Kratochvil + Joel Brobecker + + Fix regression for gdb.cp/gdb2495.exp with gcc-4.7. + * arch-utils.c (displaced_step_at_entry_point): Incrase BP_LEN skip to + 3 times. + * infcall.c (call_function_by_hand) : Move it upwards and + fall through into AT_ENTRY_POINT. + (call_function_by_hand) : New variable bp_len. Adjust + DUMMY_ADDR with it. + * ppc-linux-tdep.c (ppc_linux_displaced_step_location): Increase + PPC_INSN_SIZE skip to 3 times. + 2012-01-02 Jan Kratochvil * amd64-linux-nat.c (update_debug_registers_callback): New comment on diff --git a/gdb/arch-utils.c b/gdb/arch-utils.c index 2cedb38f92c..92e310172b9 100644 --- a/gdb/arch-utils.c +++ b/gdb/arch-utils.c @@ -86,7 +86,7 @@ displaced_step_at_entry_point (struct gdbarch *gdbarch) We don't want displaced stepping to interfere with those breakpoints, so leave space. */ gdbarch_breakpoint_from_pc (gdbarch, &addr, &bp_len); - addr += bp_len * 2; + addr += bp_len * 3; return addr; } diff --git a/gdb/infcall.c b/gdb/infcall.c index b8b7ff5d328..e3171d7051f 100644 --- a/gdb/infcall.c +++ b/gdb/infcall.c @@ -631,17 +631,6 @@ call_function_by_hand (struct value *function, int nargs, struct value **args) args, nargs, target_values_type, &real_pc, &bp_addr, get_current_regcache ()); break; - case AT_ENTRY_POINT: - { - CORE_ADDR dummy_addr; - - real_pc = funaddr; - dummy_addr = entry_point_address (); - /* A call dummy always consists of just a single breakpoint, so - its address is the same as the address of the dummy. */ - bp_addr = dummy_addr; - break; - } case AT_SYMBOL: /* Some executables define a symbol __CALL_DUMMY_ADDRESS whose address is the location where the breakpoint should be @@ -661,11 +650,39 @@ call_function_by_hand (struct value *function, int nargs, struct value **args) dummy_addr = gdbarch_convert_from_func_ptr_addr (gdbarch, dummy_addr, ¤t_target); + /* A call dummy always consists of just a single breakpoint, + so its address is the same as the address of the dummy. */ + bp_addr = dummy_addr; + break; } - else - dummy_addr = entry_point_address (); - /* A call dummy always consists of just a single breakpoint, - so it's address is the same as the address of the dummy. */ + } + /* FALLTHROUGH */ + case AT_ENTRY_POINT: + { + CORE_ADDR dummy_addr; + int bp_len; + + real_pc = funaddr; + dummy_addr = entry_point_address (); + + /* If the inferior call throws an uncaught C++ exception, + the inferior unwinder tries to unwind all frames, including + our dummy frame. The unwinder determines the address of + the calling instruction by subtracting 1 to the return + address. So, using the entry point's address as the return + address would lead the unwinder to use the unwinding + information of the code immediately preceding the entry + point. This information, if found, is invalid for the dummy + frame, and can potentially crash the inferior's unwinder. + Therefore, we adjust the return address by the length of + a breakpoint, guaranteeing that the unwinder finds the + correct function as the caller. */ + + gdbarch_breakpoint_from_pc (gdbarch, &dummy_addr, &bp_len); + dummy_addr += bp_len; + + /* A call dummy always consists of just a single breakpoint, so + its address is the same as the address of the dummy. */ bp_addr = dummy_addr; break; } diff --git a/gdb/ppc-linux-tdep.c b/gdb/ppc-linux-tdep.c index 9968621e0dc..07dd990a982 100644 --- a/gdb/ppc-linux-tdep.c +++ b/gdb/ppc-linux-tdep.c @@ -1075,7 +1075,7 @@ ppc_linux_displaced_step_location (struct gdbarch *gdbarch) /* Inferior calls also use the entry point as a breakpoint location. We don't want displaced stepping to interfere with those breakpoints, so leave space. */ - ppc_linux_entry_point_addr = addr + 2 * PPC_INSN_SIZE; + ppc_linux_entry_point_addr = addr + 3 * PPC_INSN_SIZE; } return ppc_linux_entry_point_addr; -- 2.30.2