#include <elf.h>
#endif
#include <sys/ptrace.h>
+#include <signal.h>
/* Defined in auto-generated files. */
void init_registers_arm (void);
# define PTRACE_SETVFPREGS 28
#endif
+#ifndef PTRACE_GETHBPREGS
+#define PTRACE_GETHBPREGS 29
+#define PTRACE_SETHBPREGS 30
+#endif
+
+/* Information describing the hardware breakpoint capabilities. */
+struct arm_linux_hwbp_cap
+{
+ unsigned char arch;
+ unsigned char max_wp_length;
+ unsigned char wp_count;
+ unsigned char bp_count;
+};
+
+/* Enum describing the different types of ARM hardware break-/watch-points. */
+typedef enum
+{
+ arm_hwbp_break = 0,
+ arm_hwbp_load = 1,
+ arm_hwbp_store = 2,
+ arm_hwbp_access = 3
+} arm_hwbp_type;
+
+/* Type describing an ARM Hardware Breakpoint Control register value. */
+typedef unsigned int arm_hwbp_control_t;
+
+/* Structure used to keep track of hardware break-/watch-points. */
+struct arm_linux_hw_breakpoint
+{
+ /* Address to break on, or being watched. */
+ unsigned int address;
+ /* Control register for break-/watch- point. */
+ arm_hwbp_control_t control;
+};
+
+/* Since we cannot dynamically allocate subfields of arch_process_info,
+ assume a maximum number of supported break-/watchpoints. */
+#define MAX_BPTS 32
+#define MAX_WPTS 32
+
+/* Per-process arch-specific data we want to keep. */
+struct arch_process_info
+{
+ /* Hardware breakpoints for this process. */
+ struct arm_linux_hw_breakpoint bpts[MAX_BPTS];
+ /* Hardware watchpoints for this process. */
+ struct arm_linux_hw_breakpoint wpts[MAX_WPTS];
+};
+
+/* 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. */
+ char bpts_changed[MAX_BPTS];
+ char wpts_changed[MAX_WPTS];
+ /* Cached stopped data address. */
+ CORE_ADDR stopped_data_address;
+};
+
static unsigned long arm_hwcap;
/* These are in <asm/elf.h> in current kernels. */
return PS_OK;
}
+
+/* Get hold of the Hardware Breakpoint information for the target we are
+ attached to. Returns NULL if the kernel doesn't support Hardware
+ breakpoints at all, or a pointer to the information structure. */
+static const struct arm_linux_hwbp_cap *
+arm_linux_get_hwbp_cap (void)
+{
+ /* The info structure we return. */
+ static struct arm_linux_hwbp_cap info;
+
+ /* Is INFO in a good state? -1 means that no attempt has been made to
+ initialize INFO; 0 means an attempt has been made, but it failed; 1
+ means INFO is in an initialized state. */
+ static int available = -1;
+
+ if (available == -1)
+ {
+ int pid = lwpid_of (get_thread_lwp (current_inferior));
+ unsigned int val;
+
+ if (ptrace (PTRACE_GETHBPREGS, pid, 0, &val) < 0)
+ available = 0;
+ else
+ {
+ info.arch = (unsigned char)((val >> 24) & 0xff);
+ info.max_wp_length = (unsigned char)((val >> 16) & 0xff);
+ info.wp_count = (unsigned char)((val >> 8) & 0xff);
+ info.bp_count = (unsigned char)(val & 0xff);
+ available = (info.arch != 0);
+ }
+
+ if (available)
+ {
+ if (info.wp_count > MAX_WPTS)
+ internal_error (__FILE__, __LINE__,
+ "Unsupported number of watchpoints");
+ if (info.bp_count > MAX_BPTS)
+ internal_error (__FILE__, __LINE__,
+ "Unsupported number of breakpoints");
+ }
+ }
+
+ return available == 1 ? &info : NULL;
+}
+
+/* How many hardware breakpoints are available? */
+static int
+arm_linux_get_hw_breakpoint_count (void)
+{
+ const struct arm_linux_hwbp_cap *cap = arm_linux_get_hwbp_cap ();
+ return cap != NULL ? cap->bp_count : 0;
+}
+
+/* How many hardware watchpoints are available? */
+static int
+arm_linux_get_hw_watchpoint_count (void)
+{
+ const struct arm_linux_hwbp_cap *cap = arm_linux_get_hwbp_cap ();
+ return cap != NULL ? cap->wp_count : 0;
+}
+
+/* Maximum length of area watched by hardware watchpoint. */
+static int
+arm_linux_get_hw_watchpoint_max_length (void)
+{
+ const struct arm_linux_hwbp_cap *cap = arm_linux_get_hwbp_cap ();
+ return cap != NULL ? cap->max_wp_length : 0;
+}
+
+/* Initialize an ARM hardware break-/watch-point control register value.
+ BYTE_ADDRESS_SELECT is the mask of bytes to trigger on; HWBP_TYPE is the
+ type of break-/watch-point; ENABLE indicates whether the point is enabled.
+ */
+static arm_hwbp_control_t
+arm_hwbp_control_initialize (unsigned byte_address_select,
+ arm_hwbp_type hwbp_type,
+ int enable)
+{
+ gdb_assert ((byte_address_select & ~0xffU) == 0);
+ gdb_assert (hwbp_type != arm_hwbp_break
+ || ((byte_address_select & 0xfU) != 0));
+
+ return (byte_address_select << 5) | (hwbp_type << 3) | (3 << 1) | enable;
+}
+
+/* Does the breakpoint control value CONTROL have the enable bit set? */
+static int
+arm_hwbp_control_is_enabled (arm_hwbp_control_t control)
+{
+ return control & 0x1;
+}
+
+/* Is the breakpoint control value CONTROL initialized? */
+static int
+arm_hwbp_control_is_initialized (arm_hwbp_control_t control)
+{
+ return control != 0;
+}
+
+/* Change a breakpoint control word so that it is in the disabled state. */
+static arm_hwbp_control_t
+arm_hwbp_control_disable (arm_hwbp_control_t control)
+{
+ return control & ~0x1;
+}
+
+/* Are two break-/watch-points equal? */
+static int
+arm_linux_hw_breakpoint_equal (const struct arm_linux_hw_breakpoint *p1,
+ const struct arm_linux_hw_breakpoint *p2)
+{
+ return p1->address == p2->address && p1->control == p2->control;
+}
+
+/* Initialize the hardware breakpoint structure P for a breakpoint or
+ watchpoint at ADDR to LEN. The type of watchpoint is given in TYPE.
+ Returns -1 if TYPE is unsupported, 0 if TYPE represents a breakpoint,
+ and 1 if type represents a watchpoint. */
+static int
+arm_linux_hw_point_initialize (char type, CORE_ADDR addr, int len,
+ struct arm_linux_hw_breakpoint *p)
+{
+ arm_hwbp_type hwbp_type;
+ unsigned mask;
+
+ /* Breakpoint/watchpoint types (GDB terminology):
+ 0 = memory breakpoint for instructions
+ (not supported; done via memory write instead)
+ 1 = hardware breakpoint for instructions (supported)
+ 2 = write watchpoint (supported)
+ 3 = read watchpoint (supported)
+ 4 = access watchpoint (supported). */
+ switch (type)
+ {
+ case '1':
+ hwbp_type = arm_hwbp_break;
+ break;
+ case '2':
+ hwbp_type = arm_hwbp_store;
+ break;
+ case '3':
+ hwbp_type = arm_hwbp_load;
+ break;
+ case '4':
+ hwbp_type = arm_hwbp_access;
+ break;
+ default:
+ /* Unsupported. */
+ return -1;
+ }
+
+ if (hwbp_type == arm_hwbp_break)
+ {
+ /* For breakpoints, the length field encodes the mode. */
+ switch (len)
+ {
+ case 2: /* 16-bit Thumb mode breakpoint */
+ case 3: /* 32-bit Thumb mode breakpoint */
+ mask = 0x3 << (addr & 2);
+ break;
+ case 4: /* 32-bit ARM mode breakpoint */
+ mask = 0xf;
+ break;
+ default:
+ /* Unsupported. */
+ return -1;
+ }
+
+ addr &= ~3;
+ }
+ else
+ {
+ CORE_ADDR max_wp_length = arm_linux_get_hw_watchpoint_max_length ();
+ CORE_ADDR aligned_addr;
+
+ /* Can not set watchpoints for zero or negative lengths. */
+ if (len <= 0)
+ return -1;
+ /* The current ptrace interface can only handle watchpoints that are a
+ power of 2. */
+ if ((len & (len - 1)) != 0)
+ return -1;
+
+ /* Test that the range [ADDR, ADDR + LEN) fits into the largest address
+ range covered by a watchpoint. */
+ aligned_addr = addr & ~(max_wp_length - 1);
+ if (aligned_addr + max_wp_length < addr + len)
+ return -1;
+
+ mask = (1 << len) - 1;
+ }
+
+ p->address = (unsigned int) addr;
+ p->control = arm_hwbp_control_initialize (mask, hwbp_type, 1);
+
+ return hwbp_type != arm_hwbp_break;
+}
+
+/* Callback to mark a watch-/breakpoint to be updated in all threads of
+ the current process. */
+
+struct update_registers_data
+{
+ int watch;
+ int i;
+};
+
+static int
+update_registers_callback (struct inferior_list_entry *entry, void *arg)
+{
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+ struct update_registers_data *data = (struct update_registers_data *) arg;
+
+ /* Only update the threads of the current process. */
+ if (pid_of (lwp) == pid_of (get_thread_lwp (current_inferior)))
+ {
+ /* The actual update is done later just before resuming the lwp,
+ we just mark that the registers need updating. */
+ if (data->watch)
+ lwp->arch_private->wpts_changed[data->i] = 1;
+ else
+ lwp->arch_private->bpts_changed[data->i] = 1;
+
+ /* If the lwp isn't stopped, force it to momentarily pause, so
+ we can update its breakpoint registers. */
+ if (!lwp->stopped)
+ linux_stop_lwp (lwp);
+ }
+
+ return 0;
+}
+
+/* Insert hardware break-/watchpoint. */
+static int
+arm_insert_point (char type, CORE_ADDR addr, int len)
+{
+ struct process_info *proc = current_process ();
+ struct arm_linux_hw_breakpoint p, *pts;
+ int watch, i, count;
+
+ watch = arm_linux_hw_point_initialize (type, addr, len, &p);
+ if (watch < 0)
+ {
+ /* Unsupported. */
+ return 1;
+ }
+
+ if (watch)
+ {
+ count = arm_linux_get_hw_watchpoint_count ();
+ pts = proc->private->arch_private->wpts;
+ }
+ else
+ {
+ count = arm_linux_get_hw_breakpoint_count ();
+ pts = proc->private->arch_private->bpts;
+ }
+
+ for (i = 0; i < count; i++)
+ if (!arm_hwbp_control_is_enabled (pts[i].control))
+ {
+ struct update_registers_data data = { watch, i };
+ pts[i] = p;
+ find_inferior (&all_lwps, update_registers_callback, &data);
+ return 0;
+ }
+
+ /* We're out of watchpoints. */
+ return -1;
+}
+
+/* Remove hardware break-/watchpoint. */
+static int
+arm_remove_point (char type, CORE_ADDR addr, int len)
+{
+ struct process_info *proc = current_process ();
+ struct arm_linux_hw_breakpoint p, *pts;
+ int watch, i, count;
+
+ watch = arm_linux_hw_point_initialize (type, addr, len, &p);
+ if (watch < 0)
+ {
+ /* Unsupported. */
+ return -1;
+ }
+
+ if (watch)
+ {
+ count = arm_linux_get_hw_watchpoint_count ();
+ pts = proc->private->arch_private->wpts;
+ }
+ else
+ {
+ count = arm_linux_get_hw_breakpoint_count ();
+ pts = proc->private->arch_private->bpts;
+ }
+
+ for (i = 0; i < count; i++)
+ if (arm_linux_hw_breakpoint_equal (&p, pts + i))
+ {
+ struct update_registers_data data = { watch, i };
+ pts[i].control = arm_hwbp_control_disable (pts[i].control);
+ find_inferior (&all_lwps, update_registers_callback, &data);
+ return 0;
+ }
+
+ /* No watchpoint matched. */
+ return -1;
+}
+
+/* Return whether current thread is stopped due to a watchpoint. */
+static int
+arm_stopped_by_watchpoint (void)
+{
+ struct lwp_info *lwp = get_thread_lwp (current_inferior);
+ struct siginfo siginfo;
+
+ /* We must be able to set hardware watchpoints. */
+ if (arm_linux_get_hw_watchpoint_count () == 0)
+ return 0;
+
+ /* Retrieve siginfo. */
+ errno = 0;
+ ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &siginfo);
+ if (errno != 0)
+ return 0;
+
+ /* This must be a hardware breakpoint. */
+ if (siginfo.si_signo != SIGTRAP
+ || (siginfo.si_code & 0xffff) != 0x0004 /* TRAP_HWBKPT */)
+ return 0;
+
+ /* If we are in a positive slot then we're looking at a breakpoint and not
+ a watchpoint. */
+ if (siginfo.si_errno >= 0)
+ return 0;
+
+ /* Cache stopped data address for use by arm_stopped_data_address. */
+ lwp->arch_private->stopped_data_address
+ = (CORE_ADDR) (uintptr_t) siginfo.si_addr;
+
+ return 1;
+}
+
+/* Return data address that triggered watchpoint. Called only if
+ arm_stopped_by_watchpoint returned true. */
+static CORE_ADDR
+arm_stopped_data_address (void)
+{
+ struct lwp_info *lwp = get_thread_lwp (current_inferior);
+ return lwp->arch_private->stopped_data_address;
+}
+
+/* Called when a new process is created. */
+static struct arch_process_info *
+arm_new_process (void)
+{
+ struct arch_process_info *info = xcalloc (1, sizeof (*info));
+ return info;
+}
+
+/* Called when a new thread is detected. */
+static struct arch_lwp_info *
+arm_new_thread (void)
+{
+ struct arch_lwp_info *info = xcalloc (1, sizeof (*info));
+ int i;
+
+ for (i = 0; i < MAX_BPTS; i++)
+ info->bpts_changed[i] = 1;
+ for (i = 0; i < MAX_WPTS; i++)
+ info->wpts_changed[i] = 1;
+
+ return info;
+}
+
+/* Called when resuming a thread.
+ If the debug regs have changed, update the thread's copies. */
+static void
+arm_prepare_to_resume (struct lwp_info *lwp)
+{
+ int pid = lwpid_of (lwp);
+ struct process_info *proc = find_process_pid (pid_of (lwp));
+ struct arch_process_info *proc_info = proc->private->arch_private;
+ struct arch_lwp_info *lwp_info = lwp->arch_private;
+ int i;
+
+ for (i = 0; i < arm_linux_get_hw_breakpoint_count (); i++)
+ if (lwp_info->bpts_changed[i])
+ {
+ errno = 0;
+
+ if (arm_hwbp_control_is_enabled (proc_info->bpts[i].control))
+ if (ptrace (PTRACE_SETHBPREGS, pid, ((i << 1) + 1),
+ &proc_info->bpts[i].address) < 0)
+ error (_("Unexpected error setting breakpoint address"));
+
+ if (arm_hwbp_control_is_initialized (proc_info->bpts[i].control))
+ if (ptrace (PTRACE_SETHBPREGS, pid, ((i << 1) + 2),
+ &proc_info->bpts[i].control) < 0)
+ error (_("Unexpected error setting breakpoint"));
+
+ lwp_info->bpts_changed[i] = 0;
+ }
+
+ for (i = 0; i < arm_linux_get_hw_watchpoint_count (); i++)
+ if (lwp_info->wpts_changed[i])
+ {
+ errno = 0;
+
+ if (arm_hwbp_control_is_enabled (proc_info->wpts[i].control))
+ if (ptrace (PTRACE_SETHBPREGS, pid, -((i << 1) + 1),
+ &proc_info->wpts[i].address) < 0)
+ error (_("Unexpected error setting watchpoint address"));
+
+ if (arm_hwbp_control_is_initialized (proc_info->wpts[i].control))
+ if (ptrace (PTRACE_SETHBPREGS, pid, -((i << 1) + 2),
+ &proc_info->wpts[i].control) < 0)
+ error (_("Unexpected error setting watchpoint"));
+
+ lwp_info->wpts_changed[i] = 0;
+ }
+}
+
+
static int
arm_get_hwcap (unsigned long *valp)
{
arm_reinsert_addr,
0,
arm_breakpoint_at,
+ arm_insert_point,
+ arm_remove_point,
+ arm_stopped_by_watchpoint,
+ arm_stopped_data_address,
+ NULL, /* collect_ptrace_register */
+ NULL, /* supply_ptrace_register */
+ NULL, /* siginfo_fixup */
+ arm_new_process,
+ arm_new_thread,
+ arm_prepare_to_resume,
};
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