From 7a60ad401761a2fc7d95ba164b90e4b58052ca86 Mon Sep 17 00:00:00 2001 From: Yao Qi Date: Sat, 27 Jul 2013 07:59:49 +0000 Subject: [PATCH] gdb/gdbserver/ * Makefile.in (SFILES): Add common/mips-linux-watch.c. (mips-linux-watch.o): New rule. (mips_linux_watch_h): New variable. * configure.srv : Add mips-linux-watch.o to srv_tgtobj. * linux-mips-low.c: Include mips-linux-watch.h. (struct arch_process_info, struct arch_lwp_info): New. (update_watch_registers_callback): New function. (mips_linux_new_process, mips_linux_new_thread) New functions. (mips_linux_prepare_to_resume, mips_insert_point): New functions. (mips_remove_point, mips_stopped_by_watchpoint): New functions. (rsp_bp_type_to_target_hw_bp_type): New function. (mips_stopped_data_address): New function. (the_low_target): Add watchpoint support functions. gdb/ * NEWS: Mention that GDBserver now supports hardware watchpoints on the MIPS GNU/Linux target. --- gdb/ChangeLog | 5 + gdb/NEWS | 3 + gdb/gdbserver/ChangeLog | 21 ++ gdb/gdbserver/Makefile.in | 8 +- gdb/gdbserver/configure.srv | 1 + gdb/gdbserver/linux-mips-low.c | 365 +++++++++++++++++++++++++++++++++ 6 files changed, 402 insertions(+), 1 deletion(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 2d953fbd33f..519e4886469 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,8 @@ +2013-07-27 Yao Qi + + * NEWS: Mention that GDBserver now supports hardware + watchpoints on the MIPS GNU/Linux target. + 2013-07-27 Yao Qi * Makefile.in (HFILES_NO_SRCDIR): Add diff --git a/gdb/NEWS b/gdb/NEWS index 6ee8ad7ed56..6ee82f7b631 100644 --- a/gdb/NEWS +++ b/gdb/NEWS @@ -128,6 +128,9 @@ qXfer:libraries-svr4:read's annex 'qXfer:traceframe-info:read'. It has the id of the collected trace state variables. + ** GDBserver now supports hardware watchpoints on the MIPS GNU/Linux + target. + * New 'z' formatter for printing and examining memory, this displays the value as hexadecimal zero padded on the left to the size of the type. diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog index 426e2ba6d65..6a5d1be539b 100644 --- a/gdb/gdbserver/ChangeLog +++ b/gdb/gdbserver/ChangeLog @@ -1,3 +1,24 @@ +2013-07-27 Jie Zhang + Daniel Jacobowitz + Yao Qi + + * Makefile.in (SFILES): Add common/mips-linux-watch.c. + (mips-linux-watch.o): New rule. + (mips_linux_watch_h): New variable. + * configure.srv : Add mips-linux-watch.o to + srv_tgtobj. + * linux-mips-low.c: Include mips-linux-watch.h. + (struct arch_process_info, struct arch_lwp_info): New. + (update_watch_registers_callback): New function. + (mips_linux_new_process, mips_linux_new_thread) New functions. + (mips_linux_prepare_to_resume, mips_insert_point): New + functions. + (mips_remove_point, mips_stopped_by_watchpoint): New + functions. + (rsp_bp_type_to_target_hw_bp_type): New function. + (mips_stopped_data_address): New function. + (the_low_target): Add watchpoint support functions. + 2013-07-27 Yao Qi * i386-low.c: Include break-common.h. diff --git a/gdb/gdbserver/Makefile.in b/gdb/gdbserver/Makefile.in index b28f743209d..e541497938b 100644 --- a/gdb/gdbserver/Makefile.in +++ b/gdb/gdbserver/Makefile.in @@ -157,7 +157,8 @@ SFILES= $(srcdir)/gdbreplay.c $(srcdir)/inferiors.c $(srcdir)/dll.c \ $(srcdir)/common/common-utils.c $(srcdir)/common/xml-utils.c \ $(srcdir)/common/linux-osdata.c $(srcdir)/common/ptid.c \ $(srcdir)/common/buffer.c $(srcdir)/common/linux-btrace.c \ - $(srcdir)/common/filestuff.c $(srcdir)/common/target-common.c + $(srcdir)/common/filestuff.c $(srcdir)/common/target-common.c \ + $(srcdir)/common/mips-linux-watch.c DEPFILES = @GDBSERVER_DEPFILES@ @@ -456,6 +457,8 @@ lynx_low_h = $(srcdir)/lynx-low.h $(srcdir)/server.h nto_low_h = $(srcdir)/nto-low.h +mips_linux_watch_h = $(srcdir)/../common/mips-linux-watch.h + UST_CFLAGS = $(ustinc) -DCONFIG_UST_GDB_INTEGRATION # Note, we only build the IPA if -fvisibility=hidden is supported in @@ -554,6 +557,9 @@ target-common.o: ../common/target-common.c linux-btrace.o: ../common/linux-btrace.c $(linux_btrace_h) $(server_h) $(CC) -c $(CPPFLAGS) $(INTERNAL_CFLAGS) $< +mips-linux-watch.o: ../common/mips-linux-watch.c $(mips_linux_watch_h) $(server_h) + $(CC) -c $(CPPFLAGS) $(INTERNAL_CFLAGS) $< + # We build vasprintf with -DHAVE_CONFIG_H because we want that unit to # include our config.h file. Otherwise, some system headers do not get # included, and the compiler emits a warning about implicitly defined diff --git a/gdb/gdbserver/configure.srv b/gdb/gdbserver/configure.srv index 879d0de5362..b9dfd6c6cb6 100644 --- a/gdb/gdbserver/configure.srv +++ b/gdb/gdbserver/configure.srv @@ -184,6 +184,7 @@ case "${target}" in srv_regobj="${srv_regobj} mips64-dsp-linux.o" srv_tgtobj="linux-low.o linux-osdata.o linux-mips-low.o linux-procfs.o" srv_tgtobj="${srv_tgtobj} linux-ptrace.o" + srv_tgtobj="${srv_tgtobj} mips-linux-watch.o" srv_xmlfiles="mips-linux.xml" srv_xmlfiles="${srv_xmlfiles} mips-dsp-linux.xml" srv_xmlfiles="${srv_xmlfiles} mips-cpu.xml" diff --git a/gdb/gdbserver/linux-mips-low.c b/gdb/gdbserver/linux-mips-low.c index 1010528524b..8ba1096aec4 100644 --- a/gdb/gdbserver/linux-mips-low.c +++ b/gdb/gdbserver/linux-mips-low.c @@ -22,6 +22,7 @@ #include #include +#include "mips-linux-watch.h" #include "gdb_proc_service.h" /* Defined in auto-generated file mips-linux.c. */ @@ -159,6 +160,39 @@ get_usrregs_info (void) return regs_info->usrregs; } +/* Per-process arch-specific data we want to keep. */ + +struct arch_process_info +{ + /* -1 if the kernel and/or CPU do not support watch registers. + 1 if watch_readback is valid and we can read style, num_valid + and the masks. + 0 if we need to read the watch_readback. */ + + int watch_readback_valid; + + /* Cached watch register read values. */ + + struct pt_watch_regs watch_readback; + + /* Current watchpoint requests for this process. */ + + struct mips_watchpoint *current_watches; + + /* The current set of watch register values for writing the + registers. */ + + struct pt_watch_regs watch_mirror; +}; + +/* Per-thread arch-specific data we want to keep. */ + +struct arch_lwp_info +{ + /* Non-zero if our copy differs from what's recorded in the thread. */ + int watch_registers_changed; +}; + /* From mips-linux-nat.c. */ /* Pseudo registers can not be read. ptrace does not provide a way to @@ -257,6 +291,327 @@ mips_breakpoint_at (CORE_ADDR where) return 0; } +/* Mark the watch registers of lwp, represented by ENTRY, as changed, + if the lwp's process id is *PID_P. */ + +static int +update_watch_registers_callback (struct inferior_list_entry *entry, + void *pid_p) +{ + struct lwp_info *lwp = (struct lwp_info *) entry; + int pid = *(int *) pid_p; + + /* Only update the threads of this process. */ + if (pid_of (lwp) == pid) + { + /* The actual update is done later just before resuming the lwp, + we just mark that the registers need updating. */ + lwp->arch_private->watch_registers_changed = 1; + + /* If the lwp isn't stopped, force it to momentarily pause, so + we can update its watch registers. */ + if (!lwp->stopped) + linux_stop_lwp (lwp); + } + + return 0; +} + +/* This is the implementation of linux_target_ops method + new_process. */ + +static struct arch_process_info * +mips_linux_new_process (void) +{ + struct arch_process_info *info = xcalloc (1, sizeof (*info)); + + return info; +} + +/* This is the implementation of linux_target_ops method new_thread. + Mark the watch registers as changed, so the threads' copies will + be updated. */ + +static struct arch_lwp_info * +mips_linux_new_thread (void) +{ + struct arch_lwp_info *info = xcalloc (1, sizeof (*info)); + + info->watch_registers_changed = 1; + + return info; +} + +/* This is the implementation of linux_target_ops method + prepare_to_resume. If the watch regs have changed, update the + thread's copies. */ + +static void +mips_linux_prepare_to_resume (struct lwp_info *lwp) +{ + ptid_t ptid = ptid_of (lwp); + struct process_info *proc = find_process_pid (ptid_get_pid (ptid)); + struct arch_process_info *private = proc->private->arch_private; + + if (lwp->arch_private->watch_registers_changed) + { + /* Only update the watch registers if we have set or unset a + watchpoint already. */ + if (mips_linux_watch_get_num_valid (&private->watch_mirror) > 0) + { + /* Write the mirrored watch register values. */ + int tid = ptid_get_lwp (ptid); + + if (-1 == ptrace (PTRACE_SET_WATCH_REGS, tid, + &private->watch_mirror)) + perror_with_name ("Couldn't write watch register"); + } + + lwp->arch_private->watch_registers_changed = 0; + } +} + +/* Translate breakpoint type TYPE in rsp to 'enum target_hw_bp_type'. */ + +static enum target_hw_bp_type +rsp_bp_type_to_target_hw_bp_type (char type) +{ + switch (type) + { + case '2': + return hw_write; + case '3': + return hw_read; + case '4': + return hw_access; + } + + gdb_assert_not_reached ("unhandled RSP breakpoint type"); +} + +/* This is the implementation of linux_target_ops method + insert_point. */ + +static int +mips_insert_point (char type, CORE_ADDR addr, int len) +{ + struct process_info *proc = current_process (); + struct arch_process_info *private = proc->private->arch_private; + struct pt_watch_regs regs; + struct mips_watchpoint *new_watch; + struct mips_watchpoint **pw; + int pid; + long lwpid; + enum target_hw_bp_type watch_type; + uint32_t irw; + + /* Breakpoint/watchpoint types: + '0' - software-breakpoint (not supported) + '1' - hardware-breakpoint (not supported) + '2' - write watchpoint (supported) + '3' - read watchpoint (supported) + '4' - access watchpoint (supported). */ + + if (type < '2' || type > '4') + { + /* Unsupported. */ + return 1; + } + + lwpid = lwpid_of (get_thread_lwp (current_inferior)); + if (!mips_linux_read_watch_registers (lwpid, + &private->watch_readback, + &private->watch_readback_valid, + 0)) + return -1; + + if (len <= 0) + return -1; + + regs = private->watch_readback; + /* Add the current watches. */ + mips_linux_watch_populate_regs (private->current_watches, ®s); + + /* Now try to add the new watch. */ + watch_type = rsp_bp_type_to_target_hw_bp_type (type); + irw = mips_linux_watch_type_to_irw (watch_type); + if (!mips_linux_watch_try_one_watch (®s, addr, len, irw)) + return -1; + + /* It fit. Stick it on the end of the list. */ + new_watch = xmalloc (sizeof (struct mips_watchpoint)); + new_watch->addr = addr; + new_watch->len = len; + new_watch->type = watch_type; + new_watch->next = NULL; + + pw = &private->current_watches; + while (*pw != NULL) + pw = &(*pw)->next; + *pw = new_watch; + + private->watch_mirror = regs; + + /* Only update the threads of this process. */ + pid = pid_of (proc); + find_inferior (&all_lwps, update_watch_registers_callback, &pid); + + return 0; +} + +/* This is the implementation of linux_target_ops method + remove_point. */ + +static int +mips_remove_point (char type, CORE_ADDR addr, int len) +{ + struct process_info *proc = current_process (); + struct arch_process_info *private = proc->private->arch_private; + + int deleted_one; + int pid; + enum target_hw_bp_type watch_type; + + struct mips_watchpoint **pw; + struct mips_watchpoint *w; + + /* Breakpoint/watchpoint types: + '0' - software-breakpoint (not supported) + '1' - hardware-breakpoint (not supported) + '2' - write watchpoint (supported) + '3' - read watchpoint (supported) + '4' - access watchpoint (supported). */ + + if (type < '2' || type > '4') + { + /* Unsupported. */ + return 1; + } + + /* Search for a known watch that matches. Then unlink and free it. */ + watch_type = rsp_bp_type_to_target_hw_bp_type (type); + deleted_one = 0; + pw = &private->current_watches; + while ((w = *pw)) + { + if (w->addr == addr && w->len == len && w->type == watch_type) + { + *pw = w->next; + free (w); + deleted_one = 1; + break; + } + pw = &(w->next); + } + + if (!deleted_one) + return -1; /* We don't know about it, fail doing nothing. */ + + /* At this point watch_readback is known to be valid because we + could not have added the watch without reading it. */ + gdb_assert (private->watch_readback_valid == 1); + + private->watch_mirror = private->watch_readback; + mips_linux_watch_populate_regs (private->current_watches, + &private->watch_mirror); + + /* Only update the threads of this process. */ + pid = pid_of (proc); + find_inferior (&all_lwps, update_watch_registers_callback, &pid); + return 0; +} + +/* This is the implementation of linux_target_ops method + stopped_by_watchpoint. The watchhi R and W bits indicate + the watch register triggered. */ + +static int +mips_stopped_by_watchpoint (void) +{ + struct process_info *proc = current_process (); + struct arch_process_info *private = proc->private->arch_private; + int n; + int num_valid; + long lwpid = lwpid_of (get_thread_lwp (current_inferior)); + + if (!mips_linux_read_watch_registers (lwpid, + &private->watch_readback, + &private->watch_readback_valid, + 1)) + return 0; + + num_valid = mips_linux_watch_get_num_valid (&private->watch_readback); + + for (n = 0; n < MAX_DEBUG_REGISTER && n < num_valid; n++) + if (mips_linux_watch_get_watchhi (&private->watch_readback, n) + & (R_MASK | W_MASK)) + return 1; + + return 0; +} + +/* This is the implementation of linux_target_ops method + stopped_data_address. */ + +static CORE_ADDR +mips_stopped_data_address (void) +{ + struct process_info *proc = current_process (); + struct arch_process_info *private = proc->private->arch_private; + int n; + int num_valid; + long lwpid = lwpid_of (get_thread_lwp (current_inferior)); + + /* On MIPS we don't know the low order 3 bits of the data address. + GDB does not support remote targets that can't report the + watchpoint address. So, make our best guess; return the starting + address of a watchpoint request which overlaps the one that + triggered. */ + + if (!mips_linux_read_watch_registers (lwpid, + &private->watch_readback, + &private->watch_readback_valid, + 0)) + return 0; + + num_valid = mips_linux_watch_get_num_valid (&private->watch_readback); + + for (n = 0; n < MAX_DEBUG_REGISTER && n < num_valid; n++) + if (mips_linux_watch_get_watchhi (&private->watch_readback, n) + & (R_MASK | W_MASK)) + { + CORE_ADDR t_low, t_hi; + int t_irw; + struct mips_watchpoint *watch; + + t_low = mips_linux_watch_get_watchlo (&private->watch_readback, n); + t_irw = t_low & IRW_MASK; + t_hi = (mips_linux_watch_get_watchhi (&private->watch_readback, n) + | IRW_MASK); + t_low &= ~(CORE_ADDR)t_hi; + + for (watch = private->current_watches; + watch != NULL; + watch = watch->next) + { + CORE_ADDR addr = watch->addr; + CORE_ADDR last_byte = addr + watch->len - 1; + + if ((t_irw & mips_linux_watch_type_to_irw (watch->type)) == 0) + { + /* Different type. */ + continue; + } + /* Check for overlap of even a single byte. */ + if (last_byte >= t_low && addr <= t_low + t_hi) + return addr; + } + } + + /* Shouldn't happen. */ + return 0; +} + /* Fetch the thread-local storage pointer for libthread_db. */ ps_err_e @@ -506,6 +861,16 @@ struct linux_target_ops the_low_target = { mips_reinsert_addr, 0, mips_breakpoint_at, + mips_insert_point, + mips_remove_point, + mips_stopped_by_watchpoint, + mips_stopped_data_address, + NULL, + NULL, + NULL, /* siginfo_fixup */ + mips_linux_new_process, + mips_linux_new_thread, + mips_linux_prepare_to_resume }; void -- 2.30.2