/* Native-dependent code for GNU/Linux on MIPS processors.
- Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
+ Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
Free Software Foundation, Inc.
This file is part of GDB.
along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
+#include "command.h"
+#include "gdbcmd.h"
+#include "gdb_assert.h"
#include "inferior.h"
#include "mips-tdep.h"
#include "target.h"
we'll clear this and use PTRACE_PEEKUSER instead. */
static int have_ptrace_regsets = 1;
+/* Whether or not to print the mirrored debug registers. */
+
+static int maint_show_dr;
+
/* Saved function pointers to fetch and store a single register using
PTRACE_PEEKUSER and PTRACE_POKEUSER. */
-void (*super_fetch_registers) (struct regcache *, int);
-void (*super_store_registers) (struct regcache *, int);
+static void (*super_fetch_registers) (struct target_ops *,
+ struct regcache *, int);
+static void (*super_store_registers) (struct target_ops *,
+ struct regcache *, int);
+
+static void (*super_close) (int);
/* Map gdb internal register number to ptrace ``address''.
These ``addresses'' are normally defined in <asm/ptrace.h>.
using any working method. */
static void
-mips64_linux_fetch_registers (struct regcache *regcache, int regnum)
+mips64_linux_fetch_registers (struct target_ops *ops,
+ struct regcache *regcache, int regnum)
{
/* Unless we already know that PTRACE_GETREGS does not work, try it. */
if (have_ptrace_regsets)
/* If we know, or just found out, that PTRACE_GETREGS does not work, fall
back to PTRACE_PEEKUSER. */
if (!have_ptrace_regsets)
- super_fetch_registers (regcache, regnum);
+ super_fetch_registers (ops, regcache, regnum);
}
/* Store REGNO (or all registers if REGNO == -1) to the target
using any working method. */
static void
-mips64_linux_store_registers (struct regcache *regcache, int regnum)
+mips64_linux_store_registers (struct target_ops *ops,
+ struct regcache *regcache, int regnum)
{
/* Unless we already know that PTRACE_GETREGS does not work, try it. */
if (have_ptrace_regsets)
/* If we know, or just found out, that PTRACE_GETREGS does not work, fall
back to PTRACE_PEEKUSER. */
if (!have_ptrace_regsets)
- super_store_registers (regcache, regnum);
+ super_store_registers (ops, regcache, regnum);
}
/* Return the address in the core dump or inferior of register
return tdesc_mips64_linux;
}
+#ifndef PTRACE_GET_WATCH_REGS
+# define PTRACE_GET_WATCH_REGS 0xd0
+#endif
+
+#ifndef PTRACE_SET_WATCH_REGS
+# define PTRACE_SET_WATCH_REGS 0xd1
+#endif
+
+#define W_BIT 0
+#define R_BIT 1
+#define I_BIT 2
+
+#define W_MASK (1 << W_BIT)
+#define R_MASK (1 << R_BIT)
+#define I_MASK (1 << I_BIT)
+
+#define IRW_MASK (I_MASK | R_MASK | W_MASK)
+
+enum pt_watch_style {
+ pt_watch_style_mips32,
+ pt_watch_style_mips64
+};
+
+#define MAX_DEBUG_REGISTER 8
+
+/* A value of zero in a watchlo indicates that it is available. */
+
+struct mips32_watch_regs
+{
+ uint32_t watchlo[MAX_DEBUG_REGISTER];
+ /* Lower 16 bits of watchhi. */
+ uint16_t watchhi[MAX_DEBUG_REGISTER];
+ /* Valid mask and I R W bits.
+ * bit 0 -- 1 if W bit is usable.
+ * bit 1 -- 1 if R bit is usable.
+ * bit 2 -- 1 if I bit is usable.
+ * bits 3 - 11 -- Valid watchhi mask bits.
+ */
+ uint16_t watch_masks[MAX_DEBUG_REGISTER];
+ /* The number of valid watch register pairs. */
+ uint32_t num_valid;
+ /* There is confusion across gcc versions about structure alignment,
+ so we force 8 byte alignment for these structures so they match
+ the kernel even if it was build with a different gcc version. */
+} __attribute__ ((aligned (8)));
+
+struct mips64_watch_regs
+{
+ uint64_t watchlo[MAX_DEBUG_REGISTER];
+ uint16_t watchhi[MAX_DEBUG_REGISTER];
+ uint16_t watch_masks[MAX_DEBUG_REGISTER];
+ uint32_t num_valid;
+} __attribute__ ((aligned (8)));
+
+struct pt_watch_regs
+{
+ enum pt_watch_style style;
+ union
+ {
+ struct mips32_watch_regs mips32;
+ struct mips64_watch_regs mips64;
+ };
+};
+
+/* -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. */
+
+static int watch_readback_valid;
+
+/* Cached watch register read values. */
+
+static struct pt_watch_regs watch_readback;
+
+/* We keep list of all watchpoints we should install and calculate the
+ watch register values each time the list changes. This allows for
+ easy sharing of watch registers for more than one watchpoint. */
+
+struct mips_watchpoint
+{
+ CORE_ADDR addr;
+ int len;
+ int type;
+ struct mips_watchpoint *next;
+};
+
+static struct mips_watchpoint *current_watches;
+
+/* The current set of watch register values for writing the
+ registers. */
+
+static struct pt_watch_regs watch_mirror;
+
+/* Assuming usable watch registers, return the irw_mask. */
+
+static uint32_t
+get_irw_mask (struct pt_watch_regs *regs, int set)
+{
+ switch (regs->style)
+ {
+ case pt_watch_style_mips32:
+ return regs->mips32.watch_masks[set] & IRW_MASK;
+ case pt_watch_style_mips64:
+ return regs->mips64.watch_masks[set] & IRW_MASK;
+ default:
+ internal_error (__FILE__, __LINE__,
+ _("Unrecognized watch register style"));
+ }
+}
+
+/* Assuming usable watch registers, return the reg_mask. */
+
+static uint32_t
+get_reg_mask (struct pt_watch_regs *regs, int set)
+{
+ switch (regs->style)
+ {
+ case pt_watch_style_mips32:
+ return regs->mips32.watch_masks[set] & ~IRW_MASK;
+ case pt_watch_style_mips64:
+ return regs->mips64.watch_masks[set] & ~IRW_MASK;
+ default:
+ internal_error (__FILE__, __LINE__,
+ _("Unrecognized watch register style"));
+ }
+}
+
+/* Assuming usable watch registers, return the num_valid. */
+
+static uint32_t
+get_num_valid (struct pt_watch_regs *regs)
+{
+ switch (regs->style)
+ {
+ case pt_watch_style_mips32:
+ return regs->mips32.num_valid;
+ case pt_watch_style_mips64:
+ return regs->mips64.num_valid;
+ default:
+ internal_error (__FILE__, __LINE__,
+ _("Unrecognized watch register style"));
+ }
+}
+
+/* Assuming usable watch registers, return the watchlo. */
+
+static CORE_ADDR
+get_watchlo (struct pt_watch_regs *regs, int set)
+{
+ switch (regs->style)
+ {
+ case pt_watch_style_mips32:
+ return regs->mips32.watchlo[set];
+ case pt_watch_style_mips64:
+ return regs->mips64.watchlo[set];
+ default:
+ internal_error (__FILE__, __LINE__,
+ _("Unrecognized watch register style"));
+ }
+}
+
+/* Assuming usable watch registers, set a watchlo value. */
+
+static void
+set_watchlo (struct pt_watch_regs *regs, int set, CORE_ADDR value)
+{
+ switch (regs->style)
+ {
+ case pt_watch_style_mips32:
+ /* The cast will never throw away bits as 64 bit addresses can
+ never be used on a 32 bit kernel. */
+ regs->mips32.watchlo[set] = (uint32_t)value;
+ break;
+ case pt_watch_style_mips64:
+ regs->mips64.watchlo[set] = value;
+ break;
+ default:
+ internal_error (__FILE__, __LINE__,
+ _("Unrecognized watch register style"));
+ }
+}
+
+/* Assuming usable watch registers, return the watchhi. */
+
+static uint32_t
+get_watchhi (struct pt_watch_regs *regs, int n)
+{
+ switch (regs->style)
+ {
+ case pt_watch_style_mips32:
+ return regs->mips32.watchhi[n];
+ case pt_watch_style_mips64:
+ return regs->mips64.watchhi[n];
+ default:
+ internal_error (__FILE__, __LINE__,
+ _("Unrecognized watch register style"));
+ }
+}
+
+/* Assuming usable watch registers, set a watchhi value. */
+
+static void
+set_watchhi (struct pt_watch_regs *regs, int n, uint16_t value)
+{
+ switch (regs->style)
+ {
+ case pt_watch_style_mips32:
+ regs->mips32.watchhi[n] = value;
+ break;
+ case pt_watch_style_mips64:
+ regs->mips64.watchhi[n] = value;
+ break;
+ default:
+ internal_error (__FILE__, __LINE__,
+ _("Unrecognized watch register style"));
+ }
+}
+
+static void
+mips_show_dr (const char *func, CORE_ADDR addr,
+ int len, enum target_hw_bp_type type)
+{
+ int i;
+
+ puts_unfiltered (func);
+ if (addr || len)
+ printf_unfiltered (" (addr=%s, len=%d, type=%s)",
+ paddress (target_gdbarch, addr), len,
+ type == hw_write ? "data-write"
+ : (type == hw_read ? "data-read"
+ : (type == hw_access ? "data-read/write"
+ : (type == hw_execute ? "instruction-execute"
+ : "??unknown??"))));
+ puts_unfiltered (":\n");
+
+ for (i = 0; i < MAX_DEBUG_REGISTER; i++)
+ printf_unfiltered ("\tDR%d: lo=%s, hi=%s\n", i,
+ paddress (target_gdbarch,
+ get_watchlo (&watch_mirror, i)),
+ paddress (target_gdbarch,
+ get_watchhi (&watch_mirror, i)));
+}
+
+/* Return 1 if watch registers are usable. Cached information is used
+ unless force is true. */
+
+static int
+mips_linux_read_watch_registers (int force)
+{
+ int tid;
+
+ if (force || watch_readback_valid == 0)
+ {
+ tid = ptid_get_lwp (inferior_ptid);
+ if (ptrace (PTRACE_GET_WATCH_REGS, tid, &watch_readback) == -1)
+ {
+ watch_readback_valid = -1;
+ return 0;
+ }
+ switch (watch_readback.style)
+ {
+ case pt_watch_style_mips32:
+ if (watch_readback.mips32.num_valid == 0)
+ {
+ watch_readback_valid = -1;
+ return 0;
+ }
+ break;
+ case pt_watch_style_mips64:
+ if (watch_readback.mips64.num_valid == 0)
+ {
+ watch_readback_valid = -1;
+ return 0;
+ }
+ break;
+ default:
+ watch_readback_valid = -1;
+ return 0;
+ }
+ /* Watch registers appear to be usable. */
+ watch_readback_valid = 1;
+ }
+ return (watch_readback_valid == 1) ? 1 : 0;
+}
+
+/* Convert GDB's type to an IRW mask. */
+
+static unsigned
+type_to_irw (int type)
+{
+ switch (type)
+ {
+ case hw_write:
+ return W_MASK;
+ case hw_read:
+ return R_MASK;
+ case hw_access:
+ return (W_MASK | R_MASK);
+ default:
+ return 0;
+ }
+}
+
+/* Target to_can_use_hw_breakpoint implementation. Return 1 if we can
+ handle the specified watch type. */
+
+static int
+mips_linux_can_use_hw_breakpoint (int type, int cnt, int ot)
+{
+ int i;
+ uint32_t wanted_mask, irw_mask;
+
+ if (!mips_linux_read_watch_registers (0))
+ return 0;
+
+ switch (type)
+ {
+ case bp_hardware_watchpoint:
+ wanted_mask = W_MASK;
+ break;
+ case bp_read_watchpoint:
+ wanted_mask = R_MASK;
+ break;
+ case bp_access_watchpoint:
+ wanted_mask = R_MASK | W_MASK;
+ break;
+ default:
+ return 0;
+ }
+
+ for (i = 0; i < get_num_valid (&watch_readback) && cnt; i++)
+ {
+ irw_mask = get_irw_mask (&watch_readback, i);
+ if ((irw_mask & wanted_mask) == wanted_mask)
+ cnt--;
+ }
+ return (cnt == 0) ? 1 : 0;
+}
+
+/* Target to_stopped_by_watchpoint implementation. Return 1 if
+ stopped by watchpoint. The watchhi R and W bits indicate the watch
+ register triggered. */
+
+static int
+mips_linux_stopped_by_watchpoint (void)
+{
+ int n;
+ int num_valid;
+
+ if (!mips_linux_read_watch_registers (1))
+ return 0;
+
+ num_valid = get_num_valid (&watch_readback);
+
+ for (n = 0; n < MAX_DEBUG_REGISTER && n < num_valid; n++)
+ if (get_watchhi (&watch_readback, n) & (R_MASK | W_MASK))
+ return 1;
+
+ return 0;
+}
+
+/* Target to_stopped_data_address implementation. Set the address
+ where the watch triggered (if known). Return 1 if the address was
+ known. */
+
+static int
+mips_linux_stopped_data_address (struct target_ops *t, CORE_ADDR *paddr)
+{
+ /* On mips we don't know the low order 3 bits of the data address,
+ so we must return false. */
+ return 0;
+}
+
+/* Set any low order bits in mask that are not set. */
+
+static CORE_ADDR
+fill_mask (CORE_ADDR mask)
+{
+ CORE_ADDR f = 1;
+ while (f && f < mask)
+ {
+ mask |= f;
+ f <<= 1;
+ }
+ return mask;
+}
+
+/* Try to add a single watch to the specified registers. Return 1 on
+ success, 0 on failure. */
+
+static int
+try_one_watch (struct pt_watch_regs *regs, CORE_ADDR addr,
+ int len, unsigned irw)
+{
+ CORE_ADDR base_addr, last_byte, break_addr, segment_len;
+ CORE_ADDR mask_bits, t_low, t_low_end;
+ uint16_t t_hi;
+ int i, free_watches;
+ struct pt_watch_regs regs_copy;
+
+ if (len <= 0)
+ return 0;
+
+ last_byte = addr + len - 1;
+ mask_bits = fill_mask (addr ^ last_byte) | IRW_MASK;
+ base_addr = addr & ~mask_bits;
+
+ /* Check to see if it is covered by current registers. */
+ for (i = 0; i < get_num_valid (regs); i++)
+ {
+ t_low = get_watchlo (regs, i);
+ if (t_low != 0 && irw == ((unsigned)t_low & irw))
+ {
+ t_hi = get_watchhi (regs, i) | IRW_MASK;
+ t_low &= ~(CORE_ADDR)t_hi;
+ if (addr >= t_low && last_byte <= (t_low + t_hi))
+ return 1;
+ }
+ }
+ /* Try to find an empty register. */
+ free_watches = 0;
+ for (i = 0; i < get_num_valid (regs); i++)
+ {
+ t_low = get_watchlo (regs, i);
+ if (t_low == 0 && irw == (get_irw_mask (regs, i) & irw))
+ {
+ if (mask_bits <= (get_reg_mask (regs, i) | IRW_MASK))
+ {
+ /* It fits, we'll take it. */
+ set_watchlo (regs, i, base_addr | irw);
+ set_watchhi (regs, i, mask_bits & ~IRW_MASK);
+ return 1;
+ }
+ else
+ {
+ /* It doesn't fit, but has the proper IRW capabilities. */
+ free_watches++;
+ }
+ }
+ }
+ if (free_watches > 1)
+ {
+ /* Try to split it across several registers. */
+ regs_copy = *regs;
+ for (i = 0; i < get_num_valid (®s_copy); i++)
+ {
+ t_low = get_watchlo (®s_copy, i);
+ t_hi = get_reg_mask (®s_copy, i) | IRW_MASK;
+ if (t_low == 0 && irw == (t_hi & irw))
+ {
+ t_low = addr & ~(CORE_ADDR)t_hi;
+ break_addr = t_low + t_hi + 1;
+ if (break_addr >= addr + len)
+ segment_len = len;
+ else
+ segment_len = break_addr - addr;
+ mask_bits = fill_mask (addr ^ (addr + segment_len - 1));
+ set_watchlo (®s_copy, i, (addr & ~mask_bits) | irw);
+ set_watchhi (®s_copy, i, mask_bits & ~IRW_MASK);
+ if (break_addr >= addr + len)
+ {
+ *regs = regs_copy;
+ return 1;
+ }
+ len = addr + len - break_addr;
+ addr = break_addr;
+ }
+ }
+ }
+ /* It didn't fit anywhere, we failed. */
+ return 0;
+}
+
+/* Target to_region_ok_for_hw_watchpoint implementation. Return 1 if
+ the specified region can be covered by the watch registers. */
+
+static int
+mips_linux_region_ok_for_hw_watchpoint (CORE_ADDR addr, int len)
+{
+ struct pt_watch_regs dummy_regs;
+ int i;
+
+ if (!mips_linux_read_watch_registers (0))
+ return 0;
+
+ dummy_regs = watch_readback;
+ /* Clear them out. */
+ for (i = 0; i < get_num_valid (&dummy_regs); i++)
+ set_watchlo (&dummy_regs, i, 0);
+ return try_one_watch (&dummy_regs, addr, len, 0);
+}
+
+
+/* Write the mirrored watch register values for each thread. */
+
+static int
+write_watchpoint_regs (void)
+{
+ struct lwp_info *lp;
+ ptid_t ptid;
+ int tid;
+
+ ALL_LWPS (lp, ptid)
+ {
+ tid = ptid_get_lwp (ptid);
+ if (ptrace (PTRACE_SET_WATCH_REGS, tid, &watch_mirror) == -1)
+ perror_with_name (_("Couldn't write debug register"));
+ }
+ return 0;
+}
+
+/* linux_nat new_thread implementation. Write the mirrored watch
+ register values for the new thread. */
+
+static void
+mips_linux_new_thread (ptid_t ptid)
+{
+ int tid;
+
+ if (!mips_linux_read_watch_registers (0))
+ return;
+
+ tid = ptid_get_lwp (ptid);
+ if (ptrace (PTRACE_SET_WATCH_REGS, tid, &watch_mirror) == -1)
+ perror_with_name (_("Couldn't write debug register"));
+}
+
+/* Fill in the watch registers with the currently cached watches. */
+
+static void
+populate_regs_from_watches (struct pt_watch_regs *regs)
+{
+ struct mips_watchpoint *w;
+ int i;
+
+ /* Clear them out. */
+ for (i = 0; i < get_num_valid (regs); i++)
+ {
+ set_watchlo (regs, i, 0);
+ set_watchhi (regs, i, 0);
+ }
+
+ w = current_watches;
+ while (w)
+ {
+ i = try_one_watch (regs, w->addr, w->len, type_to_irw (w->type));
+ /* They must all fit, because we previously calculated that they
+ would. */
+ gdb_assert (i);
+ w = w->next;
+ }
+}
+
+/* Target to_insert_watchpoint implementation. Try to insert a new
+ watch. Return zero on success. */
+
+static int
+mips_linux_insert_watchpoint (CORE_ADDR addr, int len, int type)
+{
+ struct pt_watch_regs regs;
+ struct mips_watchpoint *new_watch;
+ struct mips_watchpoint **pw;
+
+ int i;
+ int retval;
+
+ if (!mips_linux_read_watch_registers (0))
+ return -1;
+
+ if (len <= 0)
+ return -1;
+
+ regs = watch_readback;
+ /* Add the current watches. */
+ populate_regs_from_watches (®s);
+
+ /* Now try to add the new watch. */
+ if (!try_one_watch (®s, addr, len, type_to_irw (type)))
+ return -1;
+
+ /* It fit. Stick it on the end of the list. */
+ new_watch = (struct mips_watchpoint *)
+ xmalloc (sizeof (struct mips_watchpoint));
+ new_watch->addr = addr;
+ new_watch->len = len;
+ new_watch->type = type;
+ new_watch->next = NULL;
+
+ pw = ¤t_watches;
+ while (*pw != NULL)
+ pw = &(*pw)->next;
+ *pw = new_watch;
+
+ watch_mirror = regs;
+ retval = write_watchpoint_regs ();
+
+ if (maint_show_dr)
+ mips_show_dr ("insert_watchpoint", addr, len, type);
+
+ return retval;
+}
+
+/* Target to_remove_watchpoint implementation. Try to remove a watch.
+ Return zero on success. */
+
+static int
+mips_linux_remove_watchpoint (CORE_ADDR addr, int len, int type)
+{
+ int retval;
+ int deleted_one;
+
+ struct mips_watchpoint **pw;
+ struct mips_watchpoint *w;
+
+ /* Search for a known watch that matches. Then unlink and free
+ it. */
+ deleted_one = 0;
+ pw = ¤t_watches;
+ while ((w = *pw))
+ {
+ if (w->addr == addr && w->len == len && w->type == type)
+ {
+ *pw = w->next;
+ xfree (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 (watch_readback_valid == 1);
+
+ watch_mirror = watch_readback;
+ populate_regs_from_watches (&watch_mirror);
+
+ retval = write_watchpoint_regs ();
+
+ if (maint_show_dr)
+ mips_show_dr ("remove_watchpoint", addr, len, type);
+
+ return retval;
+}
+
+/* Target to_close implementation. Free any watches and call the
+ super implementation. */
+
+static void
+mips_linux_close (int quitting)
+{
+ struct mips_watchpoint *w;
+ struct mips_watchpoint *nw;
+
+ /* Clean out the current_watches list. */
+ w = current_watches;
+ while (w)
+ {
+ nw = w->next;
+ xfree (w);
+ w = nw;
+ }
+ current_watches = NULL;
+
+ if (super_close)
+ super_close (quitting);
+}
+
void _initialize_mips_linux_nat (void);
void
_initialize_mips_linux_nat (void)
{
- struct target_ops *t = linux_trad_target (mips_linux_register_u_offset);
+ struct target_ops *t;
+
+ add_setshow_boolean_cmd ("show-debug-regs", class_maintenance,
+ &maint_show_dr, _("\
+Set whether to show variables that mirror the mips debug registers."), _("\
+Show whether to show variables that mirror the mips debug registers."), _("\
+Use \"on\" to enable, \"off\" to disable.\n\
+If enabled, the debug registers values are shown when GDB inserts\n\
+or removes a hardware breakpoint or watchpoint, and when the inferior\n\
+triggers a breakpoint or watchpoint."),
+ NULL,
+ NULL,
+ &maintenance_set_cmdlist,
+ &maintenance_show_cmdlist);
+
+ t = linux_trad_target (mips_linux_register_u_offset);
+
+ super_close = t->to_close;
+ t->to_close = mips_linux_close;
super_fetch_registers = t->to_fetch_registers;
super_store_registers = t->to_store_registers;
t->to_fetch_registers = mips64_linux_fetch_registers;
t->to_store_registers = mips64_linux_store_registers;
+ t->to_can_use_hw_breakpoint = mips_linux_can_use_hw_breakpoint;
+ t->to_remove_watchpoint = mips_linux_remove_watchpoint;
+ t->to_insert_watchpoint = mips_linux_insert_watchpoint;
+ t->to_stopped_by_watchpoint = mips_linux_stopped_by_watchpoint;
+ t->to_stopped_data_address = mips_linux_stopped_data_address;
+ t->to_region_ok_for_hw_watchpoint = mips_linux_region_ok_for_hw_watchpoint;
+
t->to_read_description = mips_linux_read_description;
linux_nat_add_target (t);
+ linux_nat_set_new_thread (t, mips_linux_new_thread);
/* Initialize the standard target descriptions. */
initialize_tdesc_mips_linux ();
projects / external / binutils.git / blobdiff