/* GNU/Linux/MIPS specific low level interface, for the remote server for GDB.
- Copyright (C) 1995-2013 Free Software Foundation, Inc.
+ Copyright (C) 1995-2015 Free Software Foundation, Inc.
This file is part of GDB.
#include "server.h"
#include "linux-low.h"
-#include <sys/ptrace.h>
+#include "nat/gdb_ptrace.h"
#include <endian.h>
+#include "nat/mips-linux-watch.h"
#include "gdb_proc_service.h"
/* Defined in auto-generated file mips-linux.c. */
{
if (have_dsp < 0)
{
- int pid = lwpid_of (get_thread_lwp (current_inferior));
+ int pid = lwpid_of (current_thread);
+ errno = 0;
ptrace (PTRACE_PEEKUSER, pid, DSP_CONTROL, 0);
switch (errno)
{
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
static CORE_ADDR
mips_reinsert_addr (void)
{
- struct regcache *regcache = get_thread_regcache (current_inferior, 1);
+ struct regcache *regcache = get_thread_regcache (current_thread, 1);
union mips_register ra;
collect_register_by_name (regcache, "r31", ra.buf);
return register_size (regcache->tdesc, 0) == 4 ? ra.reg32 : ra.reg64;
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 thread_info *thread = (struct thread_info *) entry;
+ struct lwp_info *lwp = get_thread_lwp (thread);
+ int pid = *(int *) pid_p;
+
+ /* Only update the threads of this process. */
+ if (pid_of (thread) == 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 void
+mips_linux_new_thread (struct lwp_info *lwp)
+{
+ struct arch_lwp_info *info = xcalloc (1, sizeof (*info));
+
+ info->watch_registers_changed = 1;
+
+ lwp->arch_private = info;
+}
+
+/* Create a new mips_watchpoint and add it to the list. */
+
+static void
+mips_add_watchpoint (struct arch_process_info *private, CORE_ADDR addr,
+ int len, int watch_type)
+{
+ struct mips_watchpoint *new_watch;
+ struct mips_watchpoint **pw;
+
+ 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;
+}
+
+/* Hook to call when a new fork is attached. */
+
+static void
+mips_linux_new_fork (struct process_info *parent,
+ struct process_info *child)
+{
+ struct arch_process_info *parent_private;
+ struct arch_process_info *child_private;
+ struct mips_watchpoint *wp;
+
+ /* These are allocated by linux_add_process. */
+ gdb_assert (parent->priv != NULL
+ && parent->priv->arch_private != NULL);
+ gdb_assert (child->priv != NULL
+ && child->priv->arch_private != NULL);
+
+ /* Linux kernel before 2.6.33 commit
+ 72f674d203cd230426437cdcf7dd6f681dad8b0d
+ will inherit hardware debug registers from parent
+ on fork/vfork/clone. Newer Linux kernels create such tasks with
+ zeroed debug registers.
+
+ GDB core assumes the child inherits the watchpoints/hw
+ breakpoints of the parent, and will remove them all from the
+ forked off process. Copy the debug registers mirrors into the
+ new process so that all breakpoints and watchpoints can be
+ removed together. The debug registers mirror will become zeroed
+ in the end before detaching the forked off process, thus making
+ this compatible with older Linux kernels too. */
+
+ parent_private = parent->priv->arch_private;
+ child_private = child->priv->arch_private;
+
+ child_private->watch_readback_valid = parent_private->watch_readback_valid;
+ child_private->watch_readback = parent_private->watch_readback;
+
+ for (wp = parent_private->current_watches; wp != NULL; wp = wp->next)
+ mips_add_watchpoint (child_private, wp->addr, wp->len, wp->type);
+
+ child_private->watch_mirror = parent_private->watch_mirror;
+}
+/* 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 (get_lwp_thread (lwp));
+ struct process_info *proc = find_process_pid (ptid_get_pid (ptid));
+ struct arch_process_info *priv = proc->priv->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 (&priv->watch_mirror) > 0)
+ {
+ /* Write the mirrored watch register values. */
+ int tid = ptid_get_lwp (ptid);
+
+ if (-1 == ptrace (PTRACE_SET_WATCH_REGS, tid,
+ &priv->watch_mirror))
+ perror_with_name ("Couldn't write watch register");
+ }
+
+ lwp->arch_private->watch_registers_changed = 0;
+ }
+}
+
+static int
+mips_supports_z_point_type (char z_type)
+{
+ switch (z_type)
+ {
+ case Z_PACKET_WRITE_WP:
+ case Z_PACKET_READ_WP:
+ case Z_PACKET_ACCESS_WP:
+ return 1;
+ default:
+ return 0;
+ }
+}
+
+/* This is the implementation of linux_target_ops method
+ insert_point. */
+
+static int
+mips_insert_point (enum raw_bkpt_type type, CORE_ADDR addr,
+ int len, struct raw_breakpoint *bp)
+{
+ struct process_info *proc = current_process ();
+ struct arch_process_info *priv = proc->priv->arch_private;
+ struct pt_watch_regs regs;
+ int pid;
+ long lwpid;
+ enum target_hw_bp_type watch_type;
+ uint32_t irw;
+
+ lwpid = lwpid_of (current_thread);
+ if (!mips_linux_read_watch_registers (lwpid,
+ &priv->watch_readback,
+ &priv->watch_readback_valid,
+ 0))
+ return -1;
+
+ if (len <= 0)
+ return -1;
+
+ regs = priv->watch_readback;
+ /* Add the current watches. */
+ mips_linux_watch_populate_regs (priv->current_watches, ®s);
+
+ /* Now try to add the new watch. */
+ watch_type = raw_bkpt_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. */
+ mips_add_watchpoint (priv, addr, len, watch_type);
+
+ priv->watch_mirror = regs;
+
+ /* Only update the threads of this process. */
+ pid = pid_of (proc);
+ find_inferior (&all_threads, update_watch_registers_callback, &pid);
+
+ return 0;
+}
+
+/* This is the implementation of linux_target_ops method
+ remove_point. */
+
+static int
+mips_remove_point (enum raw_bkpt_type type, CORE_ADDR addr,
+ int len, struct raw_breakpoint *bp)
+{
+ struct process_info *proc = current_process ();
+ struct arch_process_info *priv = proc->priv->arch_private;
+
+ int deleted_one;
+ int pid;
+ enum target_hw_bp_type watch_type;
+
+ struct mips_watchpoint **pw;
+ struct mips_watchpoint *w;
+
+ /* Search for a known watch that matches. Then unlink and free it. */
+ watch_type = raw_bkpt_type_to_target_hw_bp_type (type);
+ deleted_one = 0;
+ pw = &priv->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 (priv->watch_readback_valid == 1);
+
+ priv->watch_mirror = priv->watch_readback;
+ mips_linux_watch_populate_regs (priv->current_watches,
+ &priv->watch_mirror);
+
+ /* Only update the threads of this process. */
+ pid = pid_of (proc);
+ find_inferior (&all_threads, 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 *priv = proc->priv->arch_private;
+ int n;
+ int num_valid;
+ long lwpid = lwpid_of (current_thread);
+
+ if (!mips_linux_read_watch_registers (lwpid,
+ &priv->watch_readback,
+ &priv->watch_readback_valid,
+ 1))
+ return 0;
+
+ num_valid = mips_linux_watch_get_num_valid (&priv->watch_readback);
+
+ for (n = 0; n < MAX_DEBUG_REGISTER && n < num_valid; n++)
+ if (mips_linux_watch_get_watchhi (&priv->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 *priv = proc->priv->arch_private;
+ int n;
+ int num_valid;
+ long lwpid = lwpid_of (current_thread);
+
+ /* 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,
+ &priv->watch_readback,
+ &priv->watch_readback_valid,
+ 0))
+ return 0;
+
+ num_valid = mips_linux_watch_get_num_valid (&priv->watch_readback);
+
+ for (n = 0; n < MAX_DEBUG_REGISTER && n < num_valid; n++)
+ if (mips_linux_watch_get_watchhi (&priv->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 (&priv->watch_readback, n);
+ t_irw = t_low & IRW_MASK;
+ t_hi = (mips_linux_watch_get_watchhi (&priv->watch_readback, n)
+ | IRW_MASK);
+ t_low &= ~(CORE_ADDR)t_hi;
+
+ for (watch = priv->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
mips_reinsert_addr,
0,
mips_breakpoint_at,
+ mips_supports_z_point_type,
+ 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_new_fork,
+ mips_linux_prepare_to_resume
};
void
projects / binutils-gdb.git / blobdiff