From fa5308bdcc4967861d1277b45205c2623b154a64 Mon Sep 17 00:00:00 2001 From: Antoine Tremblay Date: Fri, 18 Dec 2015 11:33:58 -0500 Subject: [PATCH] Replace breakpoint_reinsert_addr by get_next_pcs operation in GDBServer This patch in preparation for software single step support on ARM. It refactors breakpoint_reinsert_addr into get_next_pcs so that multiple location can be returned. When software single stepping there can be multiple possible next addresses because we're stepping over a conditional branch instruction, for example. The operation get_next_pcs handles that by returning a vector of all the possible next addresses. Software breakpoints are installed at each location returned. No regressions, tested on ubuntu 14.04 ARMv7 and x86. With gdbserver-{native,extended} / { -marm -mthumb } gdb/gdbserver/ChangeLog: * linux-aarch64-low.c (the_low_targets): Rename breakpoint_reinsert_addr to get_next_pcs. * linux-arm-low.c (the_low_targets): Likewise. * linux-bfin-low.c (the_low_targets): Likewise. * linux-cris-low.c (the_low_targets): Likewise. * linux-crisv32-low.c (the_low_targets): Likewise. * linux-low.c (can_software_single_step): Likewise. (install_software_single_step_breakpoints): New function. (start_step_over): Use install_software_single_step_breakpoints. * linux-low.h: New CORE_ADDR vector. (struct linux_target_ops) Rename breakpoint_reinsert_addr to get_next_pcs. * linux-mips-low.c (the_low_targets): Likewise. * linux-nios2-low.c (the_low_targets): Likewise. * linux-sparc-low.c (the_low_targets): Likewise. --- gdb/gdbserver/ChangeLog | 18 ++++++++++++++++++ gdb/gdbserver/linux-aarch64-low.c | 2 +- gdb/gdbserver/linux-arm-low.c | 2 +- gdb/gdbserver/linux-bfin-low.c | 2 +- gdb/gdbserver/linux-cris-low.c | 2 +- gdb/gdbserver/linux-crisv32-low.c | 2 +- gdb/gdbserver/linux-low.c | 27 +++++++++++++++++++++++---- gdb/gdbserver/linux-low.h | 5 ++++- gdb/gdbserver/linux-mips-low.c | 2 +- gdb/gdbserver/linux-nios2-low.c | 2 +- gdb/gdbserver/linux-sparc-low.c | 2 +- 11 files changed, 53 insertions(+), 13 deletions(-) diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog index 44a94f05782..eebc12e251f 100644 --- a/gdb/gdbserver/ChangeLog +++ b/gdb/gdbserver/ChangeLog @@ -1,3 +1,21 @@ +2015-12-18 Antoine Tremblay + + * linux-aarch64-low.c (the_low_targets): Rename + breakpoint_reinsert_addr to get_next_pcs. + * linux-arm-low.c (the_low_targets): Likewise. + * linux-bfin-low.c (the_low_targets): Likewise. + * linux-cris-low.c (the_low_targets): Likewise. + * linux-crisv32-low.c (the_low_targets): Likewise. + * linux-low.c (can_software_single_step): Likewise. + (install_software_single_step_breakpoints): New function. + (start_step_over): Use install_software_single_step_breakpoints. + * linux-low.h: New CORE_ADDR vector. + (struct linux_target_ops) Rename breakpoint_reinsert_addr to + get_next_pcs. + * linux-mips-low.c (the_low_targets): Likewise. + * linux-nios2-low.c (the_low_targets): Likewise. + * linux-sparc-low.c (the_low_targets): Likewise. + 2015-12-17 Pedro Alves * linux-low.c (linux_kill_one_lwp): Remove references to diff --git a/gdb/gdbserver/linux-aarch64-low.c b/gdb/gdbserver/linux-aarch64-low.c index b4eb36be2cd..2acadddea93 100644 --- a/gdb/gdbserver/linux-aarch64-low.c +++ b/gdb/gdbserver/linux-aarch64-low.c @@ -2980,7 +2980,7 @@ struct linux_target_ops the_low_target = aarch64_set_pc, aarch64_breakpoint_kind_from_pc, aarch64_sw_breakpoint_from_kind, - NULL, /* breakpoint_reinsert_addr */ + NULL, /* get_next_pcs */ 0, /* decr_pc_after_break */ aarch64_breakpoint_at, aarch64_supports_z_point_type, diff --git a/gdb/gdbserver/linux-arm-low.c b/gdb/gdbserver/linux-arm-low.c index d4d58a8c982..2e8cd6d924d 100644 --- a/gdb/gdbserver/linux-arm-low.c +++ b/gdb/gdbserver/linux-arm-low.c @@ -871,7 +871,7 @@ struct linux_target_ops the_low_target = { arm_set_pc, arm_breakpoint_kind_from_pc, arm_sw_breakpoint_from_kind, - NULL, /* breakpoint_reinsert_addr */ + NULL, /* get_next_pcs */ 0, arm_breakpoint_at, arm_supports_z_point_type, diff --git a/gdb/gdbserver/linux-bfin-low.c b/gdb/gdbserver/linux-bfin-low.c index 912d253342c..1de2f78a624 100644 --- a/gdb/gdbserver/linux-bfin-low.c +++ b/gdb/gdbserver/linux-bfin-low.c @@ -141,7 +141,7 @@ struct linux_target_ops the_low_target = { bfin_set_pc, NULL, /* breakpoint_kind_from_pc */ bfin_sw_breakpoint_from_kind, - NULL, /* breakpoint_reinsert_addr */ + NULL, /* get_next_pcs */ 2, bfin_breakpoint_at, NULL, /* supports_z_point_type */ diff --git a/gdb/gdbserver/linux-cris-low.c b/gdb/gdbserver/linux-cris-low.c index 9f4519c1953..6902a45bc05 100644 --- a/gdb/gdbserver/linux-cris-low.c +++ b/gdb/gdbserver/linux-cris-low.c @@ -139,7 +139,7 @@ struct linux_target_ops the_low_target = { cris_set_pc, NULL, /* breakpoint_kind_from_pc */ cris_sw_breakpoint_from_kind, - NULL, /* breakpoint_reinsert_addr */ + NULL, /* get_next_pcs */ 0, cris_breakpoint_at, }; diff --git a/gdb/gdbserver/linux-crisv32-low.c b/gdb/gdbserver/linux-crisv32-low.c index 2404d0e1f04..28c1981e02d 100644 --- a/gdb/gdbserver/linux-crisv32-low.c +++ b/gdb/gdbserver/linux-crisv32-low.c @@ -422,7 +422,7 @@ struct linux_target_ops the_low_target = { cris_set_pc, NULL, /* breakpoint_kind_from_pc */ cris_sw_breakpoint_from_kind, - NULL, /* breakpoint_reinsert_addr */ + NULL, /* get_next_pcs */ 0, cris_breakpoint_at, cris_supports_z_point_type, diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c index edff9165e48..d48fdbf73a0 100644 --- a/gdb/gdbserver/linux-low.c +++ b/gdb/gdbserver/linux-low.c @@ -282,12 +282,12 @@ can_hardware_single_step (void) } /* True if the low target can software single-step. Such targets - implement the BREAKPOINT_REINSERT_ADDR callback. */ + implement the GET_NEXT_PCS callback. */ static int can_software_single_step (void) { - return (the_low_target.breakpoint_reinsert_addr != NULL); + return (the_low_target.get_next_pcs != NULL); } /* True if the low target supports memory breakpoints. If so, we'll @@ -3960,6 +3960,26 @@ enqueue_pending_signal (struct lwp_info *lwp, int signal, siginfo_t *info) lwp->pending_signals = p_sig; } +/* Install breakpoints for software single stepping. */ + +static void +install_software_single_step_breakpoints (struct lwp_info *lwp) +{ + int i; + CORE_ADDR pc; + struct regcache *regcache = get_thread_regcache (current_thread, 1); + VEC (CORE_ADDR) *next_pcs = NULL; + struct cleanup *old_chain = make_cleanup (VEC_cleanup (CORE_ADDR), &next_pcs); + + pc = get_pc (lwp); + next_pcs = (*the_low_target.get_next_pcs) (pc, regcache); + + for (i = 0; VEC_iterate (CORE_ADDR, next_pcs, i, pc); ++i) + set_reinsert_breakpoint (pc); + + do_cleanups (old_chain); +} + /* Resume execution of LWP. If STEP is nonzero, single-step it. If SIGNAL is nonzero, give it that signal. */ @@ -4525,8 +4545,7 @@ start_step_over (struct lwp_info *lwp) } else if (can_software_single_step ()) { - CORE_ADDR raddr = (*the_low_target.breakpoint_reinsert_addr) (); - set_reinsert_breakpoint (raddr); + install_software_single_step_breakpoints (lwp); step = 0; } else diff --git a/gdb/gdbserver/linux-low.h b/gdb/gdbserver/linux-low.h index c211a37d280..cd455a879b2 100644 --- a/gdb/gdbserver/linux-low.h +++ b/gdb/gdbserver/linux-low.h @@ -124,6 +124,8 @@ struct process_info_private struct lwp_info; +DEF_VEC_I (CORE_ADDR); + struct linux_target_ops { /* Architecture-specific setup. */ @@ -153,7 +155,8 @@ struct linux_target_ops /* See target.h for details. */ const gdb_byte *(*sw_breakpoint_from_kind) (int kind, int *size); - CORE_ADDR (*breakpoint_reinsert_addr) (void); + /* Find the next possible PCs after the current instruction executes. */ + VEC (CORE_ADDR) *(*get_next_pcs) (CORE_ADDR pc, struct regcache *regcache); int decr_pc_after_break; int (*breakpoint_at) (CORE_ADDR pc); diff --git a/gdb/gdbserver/linux-mips-low.c b/gdb/gdbserver/linux-mips-low.c index b8f8805cbaa..9da4610edf4 100644 --- a/gdb/gdbserver/linux-mips-low.c +++ b/gdb/gdbserver/linux-mips-low.c @@ -880,7 +880,7 @@ struct linux_target_ops the_low_target = { mips_set_pc, NULL, /* breakpoint_kind_from_pc */ mips_sw_breakpoint_from_kind, - NULL, /* breakpoint_reinsert_addr */ + NULL, /* get_next_pcs */ 0, mips_breakpoint_at, mips_supports_z_point_type, diff --git a/gdb/gdbserver/linux-nios2-low.c b/gdb/gdbserver/linux-nios2-low.c index 9380c3b211d..1accc034120 100644 --- a/gdb/gdbserver/linux-nios2-low.c +++ b/gdb/gdbserver/linux-nios2-low.c @@ -267,7 +267,7 @@ struct linux_target_ops the_low_target = nios2_set_pc, NULL, /* breakpoint_kind_from_pc */ nios2_sw_breakpoint_from_kind, - NULL, /* breakpoint_reinsert_addr */ + NULL, /* get_next_pcs */ 0, nios2_breakpoint_at, }; diff --git a/gdb/gdbserver/linux-sparc-low.c b/gdb/gdbserver/linux-sparc-low.c index 54a849c61ae..bfdd8c181b9 100644 --- a/gdb/gdbserver/linux-sparc-low.c +++ b/gdb/gdbserver/linux-sparc-low.c @@ -320,7 +320,7 @@ struct linux_target_ops the_low_target = { NULL, NULL, /* breakpoint_kind_from_pc */ sparc_sw_breakpoint_from_kind, - NULL, /* breakpoint_reinsert_addr */ + NULL, /* get_next_pcs */ 0, sparc_breakpoint_at, NULL, /* supports_z_point_type */ -- 2.30.2