/* Native-dependent code for the i386.
- Copyright 2001, 2004 Free Software Foundation, Inc.
+ Copyright (C) 2001-2014 Free Software Foundation, Inc.
This file is part of GDB.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
+ the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA. */
+ along with this program. If not, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
-#include "breakpoint.h"
-#include "command.h"
+#include "i386-nat.h"
#include "gdbcmd.h"
+#include "inferior.h"
/* Support for hardware watchpoints and breakpoints using the i386
debug registers.
more of the watchpoints triggered and at what address, checking
whether a given region can be watched, etc.
- A target which wants to use these functions should define several
- macros, such as `target_insert_watchpoint' and
- `target_stopped_data_address', listed in target.h, to call the
- appropriate functions below. It should also define
- I386_USE_GENERIC_WATCHPOINTS in its tm.h file.
+ The functions below implement debug registers sharing by reference
+ counts, and allow to watch regions up to 16 bytes long. */
- In addition, each target should provide several low-level macros
- that will be called to insert watchpoints and hardware breakpoints
- into the inferior, remove them, and check their status. These
- macros are:
+/* Whether or not to print the mirrored debug registers. */
+int debug_hw_points;
- I386_DR_LOW_SET_CONTROL -- set the debug control (DR7)
- register to a given value
+/* Low-level function vector. */
+struct i386_dr_low_type i386_dr_low;
- I386_DR_LOW_SET_ADDR -- put an address into one debug
- register
+/* Per-process data. We don't bind this to a per-inferior registry
+ because of targets like x86 GNU/Linux that need to keep track of
+ processes that aren't bound to any inferior (e.g., fork children,
+ checkpoints). */
- I386_DR_LOW_RESET_ADDR -- reset the address stored in
- one debug register
+struct i386_process_info
+{
+ /* Linked list. */
+ struct i386_process_info *next;
- I386_DR_LOW_GET_STATUS -- return the value of the debug
- status (DR6) register.
+ /* The process identifier. */
+ pid_t pid;
- The functions below implement debug registers sharing by reference
- counts, and allow to watch regions up to 16 bytes long. */
+ /* Copy of i386 hardware debug registers. */
+ struct i386_debug_reg_state state;
+};
-#ifdef I386_USE_GENERIC_WATCHPOINTS
-
-/* Support for 8-byte wide hw watchpoints. */
-#ifndef TARGET_HAS_DR_LEN_8
-#define TARGET_HAS_DR_LEN_8 0
-#endif
-
-/* Debug registers' indices. */
-#define DR_NADDR 4 /* The number of debug address registers. */
-#define DR_STATUS 6 /* Index of debug status register (DR6). */
-#define DR_CONTROL 7 /* Index of debug control register (DR7). */
-
-/* DR7 Debug Control register fields. */
-
-/* How many bits to skip in DR7 to get to R/W and LEN fields. */
-#define DR_CONTROL_SHIFT 16
-/* How many bits in DR7 per R/W and LEN field for each watchpoint. */
-#define DR_CONTROL_SIZE 4
-
-/* Watchpoint/breakpoint read/write fields in DR7. */
-#define DR_RW_EXECUTE (0x0) /* Break on instruction execution. */
-#define DR_RW_WRITE (0x1) /* Break on data writes. */
-#define DR_RW_READ (0x3) /* Break on data reads or writes. */
-
-/* This is here for completeness. No platform supports this
- functionality yet (as of March 2001). Note that the DE flag in the
- CR4 register needs to be set to support this. */
-#ifndef DR_RW_IORW
-#define DR_RW_IORW (0x2) /* Break on I/O reads or writes. */
-#endif
-
-/* Watchpoint/breakpoint length fields in DR7. The 2-bit left shift
- is so we could OR this with the read/write field defined above. */
-#define DR_LEN_1 (0x0 << 2) /* 1-byte region watch or breakpoint. */
-#define DR_LEN_2 (0x1 << 2) /* 2-byte region watch. */
-#define DR_LEN_4 (0x3 << 2) /* 4-byte region watch. */
-#define DR_LEN_8 (0x2 << 2) /* 8-byte region watch (AMD64). */
-
-/* Local and Global Enable flags in DR7.
-
- When the Local Enable flag is set, the breakpoint/watchpoint is
- enabled only for the current task; the processor automatically
- clears this flag on every task switch. When the Global Enable flag
- is set, the breakpoint/watchpoint is enabled for all tasks; the
- processor never clears this flag.
-
- Currently, all watchpoint are locally enabled. If you need to
- enable them globally, read the comment which pertains to this in
- i386_insert_aligned_watchpoint below. */
-#define DR_LOCAL_ENABLE_SHIFT 0 /* Extra shift to the local enable bit. */
-#define DR_GLOBAL_ENABLE_SHIFT 1 /* Extra shift to the global enable bit. */
-#define DR_ENABLE_SIZE 2 /* Two enable bits per debug register. */
-
-/* Local and global exact breakpoint enable flags (a.k.a. slowdown
- flags). These are only required on i386, to allow detection of the
- exact instruction which caused a watchpoint to break; i486 and
- later processors do that automatically. We set these flags for
- backwards compatibility. */
-#define DR_LOCAL_SLOWDOWN (0x100)
-#define DR_GLOBAL_SLOWDOWN (0x200)
-
-/* Fields reserved by Intel. This includes the GD (General Detect
- Enable) flag, which causes a debug exception to be generated when a
- MOV instruction accesses one of the debug registers.
-
- FIXME: My Intel manual says we should use 0xF800, not 0xFC00. */
-#define DR_CONTROL_RESERVED (0xFC00)
-
-/* Auxiliary helper macros. */
-
-/* A value that masks all fields in DR7 that are reserved by Intel. */
-#define I386_DR_CONTROL_MASK (~DR_CONTROL_RESERVED)
-
-/* The I'th debug register is vacant if its Local and Global Enable
- bits are reset in the Debug Control register. */
-#define I386_DR_VACANT(i) \
- ((dr_control_mirror & (3 << (DR_ENABLE_SIZE * (i)))) == 0)
-
-/* Locally enable the break/watchpoint in the I'th debug register. */
-#define I386_DR_LOCAL_ENABLE(i) \
- dr_control_mirror |= (1 << (DR_LOCAL_ENABLE_SHIFT + DR_ENABLE_SIZE * (i)))
-
-/* Globally enable the break/watchpoint in the I'th debug register. */
-#define I386_DR_GLOBAL_ENABLE(i) \
- dr_control_mirror |= (1 << (DR_GLOBAL_ENABLE_SHIFT + DR_ENABLE_SIZE * (i)))
-
-/* Disable the break/watchpoint in the I'th debug register. */
-#define I386_DR_DISABLE(i) \
- dr_control_mirror &= ~(3 << (DR_ENABLE_SIZE * (i)))
-
-/* Set in DR7 the RW and LEN fields for the I'th debug register. */
-#define I386_DR_SET_RW_LEN(i,rwlen) \
- do { \
- dr_control_mirror &= ~(0x0f << (DR_CONTROL_SHIFT+DR_CONTROL_SIZE*(i))); \
- dr_control_mirror |= ((rwlen) << (DR_CONTROL_SHIFT+DR_CONTROL_SIZE*(i))); \
- } while (0)
-
-/* Get from DR7 the RW and LEN fields for the I'th debug register. */
-#define I386_DR_GET_RW_LEN(i) \
- ((dr_control_mirror >> (DR_CONTROL_SHIFT + DR_CONTROL_SIZE * (i))) & 0x0f)
-
-/* Did the watchpoint whose address is in the I'th register break? */
-#define I386_DR_WATCH_HIT(i) (dr_status_mirror & (1 << (i)))
-
-/* A macro to loop over all debug registers. */
-#define ALL_DEBUG_REGISTERS(i) for (i = 0; i < DR_NADDR; i++)
-
-/* Mirror the inferior's DRi registers. We keep the status and
- control registers separated because they don't hold addresses. */
-static CORE_ADDR dr_mirror[DR_NADDR];
-static unsigned dr_status_mirror, dr_control_mirror;
-
-/* Reference counts for each debug register. */
-static int dr_ref_count[DR_NADDR];
+static struct i386_process_info *i386_process_list = NULL;
-/* Whether or not to print the mirrored debug registers. */
-static int maint_show_dr;
-
-/* Types of operations supported by i386_handle_nonaligned_watchpoint. */
-typedef enum { WP_INSERT, WP_REMOVE, WP_COUNT } i386_wp_op_t;
-
-/* Internal functions. */
-
-/* Return the value of a 4-bit field for DR7 suitable for watching a
- region of LEN bytes for accesses of type TYPE. LEN is assumed to
- have the value of 1, 2, or 4. */
-static unsigned i386_length_and_rw_bits (int len, enum target_hw_bp_type type);
-
-/* Insert a watchpoint at address ADDR, which is assumed to be aligned
- according to the length of the region to watch. LEN_RW_BITS is the
- value of the bit-field from DR7 which describes the length and
- access type of the region to be watched by this watchpoint. Return
- 0 on success, -1 on failure. */
-static int i386_insert_aligned_watchpoint (CORE_ADDR addr,
- unsigned len_rw_bits);
-
-/* Remove a watchpoint at address ADDR, which is assumed to be aligned
- according to the length of the region to watch. LEN_RW_BITS is the
- value of the bits from DR7 which describes the length and access
- type of the region watched by this watchpoint. Return 0 on
- success, -1 on failure. */
-static int i386_remove_aligned_watchpoint (CORE_ADDR addr,
- unsigned len_rw_bits);
-
-/* Insert or remove a (possibly non-aligned) watchpoint, or count the
- number of debug registers required to watch a region at address
- ADDR whose length is LEN for accesses of type TYPE. Return 0 on
- successful insertion or removal, a positive number when queried
- about the number of registers, or -1 on failure. If WHAT is not a
- valid value, bombs through internal_error. */
-static int i386_handle_nonaligned_watchpoint (i386_wp_op_t what,
- CORE_ADDR addr, int len,
- enum target_hw_bp_type type);
-
-/* Implementation. */
+/* Find process data for process PID. */
-/* Clear the reference counts and forget everything we knew about the
- debug registers. */
-
-void
-i386_cleanup_dregs (void)
+static struct i386_process_info *
+i386_find_process_pid (pid_t pid)
{
- int i;
+ struct i386_process_info *proc;
- ALL_DEBUG_REGISTERS(i)
- {
- dr_mirror[i] = 0;
- dr_ref_count[i] = 0;
- }
- dr_control_mirror = 0;
- dr_status_mirror = 0;
-}
+ for (proc = i386_process_list; proc; proc = proc->next)
+ if (proc->pid == pid)
+ return proc;
-#ifndef LINUX_CHILD_POST_STARTUP_INFERIOR
+ return NULL;
+}
-/* Reset all debug registers at each new startup to avoid missing
- watchpoints after restart. */
+/* Add process data for process PID. Returns newly allocated info
+ object. */
-void
-child_post_startup_inferior (ptid_t ptid)
+static struct i386_process_info *
+i386_add_process (pid_t pid)
{
- i386_cleanup_dregs ();
-}
+ struct i386_process_info *proc;
-#endif /* LINUX_CHILD_POST_STARTUP_INFERIOR */
+ proc = xcalloc (1, sizeof (*proc));
+ proc->pid = pid;
-/* Print the values of the mirrored debug registers. This is called
- when maint_show_dr is non-zero. To set that up, type "maint
- show-debug-regs" at GDB's prompt. */
+ proc->next = i386_process_list;
+ i386_process_list = proc;
-static void
-i386_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=%lx, len=%d, type=%s)",
- /* This code is for ia32, so casting CORE_ADDR
- to unsigned long should be okay. */
- (unsigned long)addr, len,
- type == hw_write ? "data-write"
- : (type == hw_read ? "data-read"
- : (type == hw_access ? "data-read/write"
- : (type == hw_execute ? "instruction-execute"
- /* FIXME: if/when I/O read/write
- watchpoints are supported, add them
- here. */
- : "??unknown??"))));
- puts_unfiltered (":\n");
- printf_unfiltered ("\tCONTROL (DR7): %08x STATUS (DR6): %08x\n",
- dr_control_mirror, dr_status_mirror);
- ALL_DEBUG_REGISTERS(i)
- {
- printf_unfiltered ("\
-\tDR%d: addr=0x%s, ref.count=%d DR%d: addr=0x%s, ref.count=%d\n",
- i, paddr(dr_mirror[i]), dr_ref_count[i],
- i+1, paddr(dr_mirror[i+1]), dr_ref_count[i+1]);
- i++;
- }
+ return proc;
}
-/* Return the value of a 4-bit field for DR7 suitable for watching a
- region of LEN bytes for accesses of type TYPE. LEN is assumed to
- have the value of 1, 2, or 4. */
+/* Get data specific info for process PID, creating it if necessary.
+ Never returns NULL. */
-static unsigned
-i386_length_and_rw_bits (int len, enum target_hw_bp_type type)
+static struct i386_process_info *
+i386_process_info_get (pid_t pid)
{
- unsigned rw;
+ struct i386_process_info *proc;
- switch (type)
- {
- case hw_execute:
- rw = DR_RW_EXECUTE;
- break;
- case hw_write:
- rw = DR_RW_WRITE;
- break;
- case hw_read:
- /* The i386 doesn't support data-read watchpoints. */
- case hw_access:
- rw = DR_RW_READ;
- break;
-#if 0
- /* Not yet supported. */
- case hw_io_access:
- rw = DR_RW_IORW;
- break;
-#endif
- default:
- internal_error (__FILE__, __LINE__, "\
-Invalid hardware breakpoint type %d in i386_length_and_rw_bits.\n",
- (int) type);
- }
+ proc = i386_find_process_pid (pid);
+ if (proc == NULL)
+ proc = i386_add_process (pid);
- switch (len)
- {
- case 1:
- return (DR_LEN_1 | rw);
- case 2:
- return (DR_LEN_2 | rw);
- case 4:
- return (DR_LEN_4 | rw);
- case 8:
- if (TARGET_HAS_DR_LEN_8)
- return (DR_LEN_8 | rw);
- default:
- internal_error (__FILE__, __LINE__, "\
-Invalid hardware breakpoint length %d in i386_length_and_rw_bits.\n", len);
- }
+ return proc;
}
-/* Insert a watchpoint at address ADDR, which is assumed to be aligned
- according to the length of the region to watch. LEN_RW_BITS is the
- value of the bits from DR7 which describes the length and access
- type of the region to be watched by this watchpoint. Return 0 on
- success, -1 on failure. */
+/* Get debug registers state for process PID. */
-static int
-i386_insert_aligned_watchpoint (CORE_ADDR addr, unsigned len_rw_bits)
+struct i386_debug_reg_state *
+i386_debug_reg_state (pid_t pid)
{
- int i;
-
- /* First, look for an occupied debug register with the same address
- and the same RW and LEN definitions. If we find one, we can
- reuse it for this watchpoint as well (and save a register). */
- ALL_DEBUG_REGISTERS(i)
- {
- if (!I386_DR_VACANT (i)
- && dr_mirror[i] == addr
- && I386_DR_GET_RW_LEN (i) == len_rw_bits)
- {
- dr_ref_count[i]++;
- return 0;
- }
- }
-
- /* Next, look for a vacant debug register. */
- ALL_DEBUG_REGISTERS(i)
- {
- if (I386_DR_VACANT (i))
- break;
- }
-
- /* No more debug registers! */
- if (i >= DR_NADDR)
- return -1;
-
- /* Now set up the register I to watch our region. */
-
- /* Record the info in our local mirrored array. */
- dr_mirror[i] = addr;
- dr_ref_count[i] = 1;
- I386_DR_SET_RW_LEN (i, len_rw_bits);
- /* Note: we only enable the watchpoint locally, i.e. in the current
- task. Currently, no i386 target allows or supports global
- watchpoints; however, if any target would want that in the
- future, GDB should probably provide a command to control whether
- to enable watchpoints globally or locally, and the code below
- should use global or local enable and slow-down flags as
- appropriate. */
- I386_DR_LOCAL_ENABLE (i);
- dr_control_mirror |= DR_LOCAL_SLOWDOWN;
- dr_control_mirror &= I386_DR_CONTROL_MASK;
-
- /* Finally, actually pass the info to the inferior. */
- I386_DR_LOW_SET_ADDR (i, addr);
- I386_DR_LOW_SET_CONTROL (dr_control_mirror);
-
- return 0;
+ return &i386_process_info_get (pid)->state;
}
-/* Remove a watchpoint at address ADDR, which is assumed to be aligned
- according to the length of the region to watch. LEN_RW_BITS is the
- value of the bits from DR7 which describes the length and access
- type of the region watched by this watchpoint. Return 0 on
- success, -1 on failure. */
+/* See declaration in i386-nat.h. */
-static int
-i386_remove_aligned_watchpoint (CORE_ADDR addr, unsigned len_rw_bits)
+void
+i386_forget_process (pid_t pid)
{
- int i, retval = -1;
+ struct i386_process_info *proc, **proc_link;
- ALL_DEBUG_REGISTERS(i)
+ proc = i386_process_list;
+ proc_link = &i386_process_list;
+
+ while (proc != NULL)
{
- if (!I386_DR_VACANT (i)
- && dr_mirror[i] == addr
- && I386_DR_GET_RW_LEN (i) == len_rw_bits)
+ if (proc->pid == pid)
{
- if (--dr_ref_count[i] == 0) /* no longer in use? */
- {
- /* Reset our mirror. */
- dr_mirror[i] = 0;
- I386_DR_DISABLE (i);
- /* Reset it in the inferior. */
- I386_DR_LOW_SET_CONTROL (dr_control_mirror);
- I386_DR_LOW_RESET_ADDR (i);
- }
- retval = 0;
+ *proc_link = proc->next;
+
+ xfree (proc);
+ return;
}
- }
- return retval;
+ proc_link = &proc->next;
+ proc = *proc_link;
+ }
}
-/* Insert or remove a (possibly non-aligned) watchpoint, or count the
- number of debug registers required to watch a region at address
- ADDR whose length is LEN for accesses of type TYPE. Return 0 on
- successful insertion or removal, a positive number when queried
- about the number of registers, or -1 on failure. If WHAT is not a
- valid value, bombs through internal_error. */
+/* Clear the reference counts and forget everything we knew about the
+ debug registers. */
-static int
-i386_handle_nonaligned_watchpoint (i386_wp_op_t what, CORE_ADDR addr, int len,
- enum target_hw_bp_type type)
+void
+i386_cleanup_dregs (void)
{
- int retval = 0, status = 0;
- int max_wp_len = TARGET_HAS_DR_LEN_8 ? 8 : 4;
-
- static int size_try_array[8][8] =
- {
- {1, 1, 1, 1, 1, 1, 1, 1}, /* Trying size one. */
- {2, 1, 2, 1, 2, 1, 2, 1}, /* Trying size two. */
- {2, 1, 2, 1, 2, 1, 2, 1}, /* Trying size three. */
- {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size four. */
- {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size five. */
- {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size six. */
- {4, 1, 2, 1, 4, 1, 2, 1}, /* Trying size seven. */
- {8, 1, 2, 1, 4, 1, 2, 1}, /* Trying size eight. */
- };
-
- while (len > 0)
- {
- int align = addr % max_wp_len;
- /* Four (eigth on AMD64) is the maximum length a debug register
- can watch. */
- int try = (len > max_wp_len ? (max_wp_len - 1) : len - 1);
- int size = size_try_array[try][align];
-
- if (what == WP_COUNT)
- {
- /* size_try_array[] is defined such that each iteration
- through the loop is guaranteed to produce an address and a
- size that can be watched with a single debug register.
- Thus, for counting the registers required to watch a
- region, we simply need to increment the count on each
- iteration. */
- retval++;
- }
- else
- {
- unsigned len_rw = i386_length_and_rw_bits (size, type);
-
- if (what == WP_INSERT)
- status = i386_insert_aligned_watchpoint (addr, len_rw);
- else if (what == WP_REMOVE)
- status = i386_remove_aligned_watchpoint (addr, len_rw);
- else
- internal_error (__FILE__, __LINE__, "\
-Invalid value %d of operation in i386_handle_nonaligned_watchpoint.\n",
- (int)what);
- /* We keep the loop going even after a failure, because some
- of the other aligned watchpoints might still succeed
- (e.g. if they watch addresses that are already watched,
- in which case we just increment the reference counts of
- occupied debug registers). If we break out of the loop
- too early, we could cause those addresses watched by
- other watchpoints to be disabled when breakpoint.c reacts
- to our failure to insert this watchpoint and tries to
- remove it. */
- if (status)
- retval = status;
- }
-
- addr += size;
- len -= size;
- }
-
- return retval;
+ /* Starting from scratch has the same effect. */
+ i386_forget_process (ptid_get_pid (inferior_ptid));
}
/* Insert a watchpoint to watch a memory region which starts at
address ADDR and whose length is LEN bytes. Watch memory accesses
of the type TYPE. Return 0 on success, -1 on failure. */
-int
-i386_insert_watchpoint (CORE_ADDR addr, int len, int type)
+static int
+i386_insert_watchpoint (struct target_ops *self,
+ CORE_ADDR addr, int len, int type,
+ struct expression *cond)
{
- int retval;
+ struct i386_debug_reg_state *state
+ = i386_debug_reg_state (ptid_get_pid (inferior_ptid));
- if (((len != 1 && len !=2 && len !=4) && !(TARGET_HAS_DR_LEN_8 && len == 8))
- || addr % len != 0)
- retval = i386_handle_nonaligned_watchpoint (WP_INSERT, addr, len, type);
- else
- {
- unsigned len_rw = i386_length_and_rw_bits (len, type);
-
- retval = i386_insert_aligned_watchpoint (addr, len_rw);
- }
-
- if (maint_show_dr)
- i386_show_dr ("insert_watchpoint", addr, len, type);
-
- return retval;
+ return i386_dr_insert_watchpoint (state, type, addr, len);
}
/* Remove a watchpoint that watched the memory region which starts at
address ADDR, whose length is LEN bytes, and for accesses of the
type TYPE. Return 0 on success, -1 on failure. */
-int
-i386_remove_watchpoint (CORE_ADDR addr, int len, int type)
+static int
+i386_remove_watchpoint (struct target_ops *self,
+ CORE_ADDR addr, int len, int type,
+ struct expression *cond)
{
- int retval;
+ struct i386_debug_reg_state *state
+ = i386_debug_reg_state (ptid_get_pid (inferior_ptid));
- if (((len != 1 && len !=2 && len !=4) && !(TARGET_HAS_DR_LEN_8 && len == 8))
- || addr % len != 0)
- retval = i386_handle_nonaligned_watchpoint (WP_REMOVE, addr, len, type);
- else
- {
- unsigned len_rw = i386_length_and_rw_bits (len, type);
-
- retval = i386_remove_aligned_watchpoint (addr, len_rw);
- }
-
- if (maint_show_dr)
- i386_show_dr ("remove_watchpoint", addr, len, type);
-
- return retval;
+ return i386_dr_remove_watchpoint (state, type, addr, len);
}
/* Return non-zero if we can watch a memory region that starts at
address ADDR and whose length is LEN bytes. */
-int
-i386_region_ok_for_watchpoint (CORE_ADDR addr, int len)
+static int
+i386_region_ok_for_watchpoint (struct target_ops *self,
+ CORE_ADDR addr, int len)
{
- int nregs;
+ struct i386_debug_reg_state *state
+ = i386_debug_reg_state (ptid_get_pid (inferior_ptid));
- /* Compute how many aligned watchpoints we would need to cover this
- region. */
- nregs = i386_handle_nonaligned_watchpoint (WP_COUNT, addr, len, hw_write);
- return nregs <= DR_NADDR ? 1 : 0;
+ return i386_dr_region_ok_for_watchpoint (state, addr, len);
}
-/* If the inferior has some watchpoint that triggered, return the
- address associated with that watchpoint. Otherwise, return zero. */
+/* If the inferior has some break/watchpoint that triggered, set the
+ address associated with that break/watchpoint and return non-zero.
+ Otherwise, return zero. */
-CORE_ADDR
-i386_stopped_data_address (void)
+static int
+i386_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p)
{
- CORE_ADDR addr = 0;
- int i;
-
- dr_status_mirror = I386_DR_LOW_GET_STATUS ();
-
- ALL_DEBUG_REGISTERS(i)
- {
- if (I386_DR_WATCH_HIT (i)
- /* This second condition makes sure DRi is set up for a data
- watchpoint, not a hardware breakpoint. The reason is
- that GDB doesn't call the target_stopped_data_address
- method except for data watchpoints. In other words, I'm
- being paranoid. */
- && I386_DR_GET_RW_LEN (i) != 0)
- {
- addr = dr_mirror[i];
- if (maint_show_dr)
- i386_show_dr ("watchpoint_hit", addr, -1, hw_write);
- }
- }
- if (maint_show_dr && addr == 0)
- i386_show_dr ("stopped_data_addr", 0, 0, hw_write);
+ struct i386_debug_reg_state *state
+ = i386_debug_reg_state (ptid_get_pid (inferior_ptid));
- return addr;
+ return i386_dr_stopped_data_address (state, addr_p);
}
-/* Return non-zero if the inferior has some break/watchpoint that
- triggered. */
+/* Return non-zero if the inferior has some watchpoint that triggered.
+ Otherwise return zero. */
-int
-i386_stopped_by_hwbp (void)
+static int
+i386_stopped_by_watchpoint (struct target_ops *ops)
{
- int i;
+ struct i386_debug_reg_state *state
+ = i386_debug_reg_state (ptid_get_pid (inferior_ptid));
- dr_status_mirror = I386_DR_LOW_GET_STATUS ();
- if (maint_show_dr)
- i386_show_dr ("stopped_by_hwbp", 0, 0, hw_execute);
-
- ALL_DEBUG_REGISTERS(i)
- {
- if (I386_DR_WATCH_HIT (i))
- return 1;
- }
-
- return 0;
+ return i386_dr_stopped_by_watchpoint (state);
}
-/* Insert a hardware-assisted breakpoint at address ADDR. SHADOW is
- unused. Return 0 on success, EBUSY on failure. */
-int
-i386_insert_hw_breakpoint (CORE_ADDR addr, void *shadow)
-{
- unsigned len_rw = i386_length_and_rw_bits (1, hw_execute);
- int retval = i386_insert_aligned_watchpoint (addr, len_rw) ? EBUSY : 0;
+/* Insert a hardware-assisted breakpoint at BP_TGT->placed_address.
+ Return 0 on success, EBUSY on failure. */
- if (maint_show_dr)
- i386_show_dr ("insert_hwbp", addr, 1, hw_execute);
+static int
+i386_insert_hw_breakpoint (struct target_ops *self, struct gdbarch *gdbarch,
+ struct bp_target_info *bp_tgt)
+{
+ struct i386_debug_reg_state *state
+ = i386_debug_reg_state (ptid_get_pid (inferior_ptid));
- return retval;
+ return i386_dr_insert_watchpoint (state, hw_execute,
+ bp_tgt->placed_address, 1) ? EBUSY : 0;
}
-/* Remove a hardware-assisted breakpoint at address ADDR. SHADOW is
- unused. Return 0 on success, -1 on failure. */
+/* Remove a hardware-assisted breakpoint at BP_TGT->placed_address.
+ Return 0 on success, -1 on failure. */
-int
-i386_remove_hw_breakpoint (CORE_ADDR addr, void *shadow)
+static int
+i386_remove_hw_breakpoint (struct target_ops *self, struct gdbarch *gdbarch,
+ struct bp_target_info *bp_tgt)
{
- unsigned len_rw = i386_length_and_rw_bits (1, hw_execute);
- int retval = i386_remove_aligned_watchpoint (addr, len_rw);
+ struct i386_debug_reg_state *state
+ = i386_debug_reg_state (ptid_get_pid (inferior_ptid));
- if (maint_show_dr)
- i386_show_dr ("remove_hwbp", addr, 1, hw_execute);
-
- return retval;
+ return i386_dr_remove_watchpoint (state, hw_execute,
+ bp_tgt->placed_address, 1);
}
-#endif /* I386_USE_GENERIC_WATCHPOINTS */
-\f
+/* Returns the number of hardware watchpoints of type TYPE that we can
+ set. Value is positive if we can set CNT watchpoints, zero if
+ setting watchpoints of type TYPE is not supported, and negative if
+ CNT is more than the maximum number of watchpoints of type TYPE
+ that we can support. TYPE is one of bp_hardware_watchpoint,
+ bp_read_watchpoint, bp_write_watchpoint, or bp_hardware_breakpoint.
+ CNT is the number of such watchpoints used so far (including this
+ one). OTHERTYPE is non-zero if other types of watchpoints are
+ currently enabled.
+
+ We always return 1 here because we don't have enough information
+ about possible overlap of addresses that they want to watch. As an
+ extreme example, consider the case where all the watchpoints watch
+ the same address and the same region length: then we can handle a
+ virtually unlimited number of watchpoints, due to debug register
+ sharing implemented via reference counts in i386-nat.c. */
-/* Provide a prototype to silence -Wmissing-prototypes. */
-void _initialize_i386_nat (void);
+static int
+i386_can_use_hw_breakpoint (struct target_ops *self,
+ int type, int cnt, int othertype)
+{
+ return 1;
+}
-void
-_initialize_i386_nat (void)
+static void
+add_show_debug_regs_command (void)
{
-#ifdef I386_USE_GENERIC_WATCHPOINTS
/* A maintenance command to enable printing the internal DRi mirror
variables. */
- add_set_cmd ("show-debug-regs", class_maintenance,
- var_boolean, (char *) &maint_show_dr,
- "\
-Set whether to show variables that mirror the x86 debug registers.\n\
+ add_setshow_boolean_cmd ("show-debug-regs", class_maintenance,
+ &debug_hw_points, _("\
+Set whether to show variables that mirror the x86 debug registers."), _("\
+Show whether to show variables that mirror the x86 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.", &maintenancelist);
-#endif
+triggers a breakpoint or watchpoint."),
+ NULL,
+ NULL,
+ &maintenance_set_cmdlist,
+ &maintenance_show_cmdlist);
+}
+
+/* There are only two global functions left. */
+
+void
+i386_use_watchpoints (struct target_ops *t)
+{
+ /* After a watchpoint trap, the PC points to the instruction after the
+ one that caused the trap. Therefore we don't need to step over it.
+ But we do need to reset the status register to avoid another trap. */
+ t->to_have_continuable_watchpoint = 1;
+
+ t->to_can_use_hw_breakpoint = i386_can_use_hw_breakpoint;
+ t->to_region_ok_for_hw_watchpoint = i386_region_ok_for_watchpoint;
+ t->to_stopped_by_watchpoint = i386_stopped_by_watchpoint;
+ t->to_stopped_data_address = i386_stopped_data_address;
+ t->to_insert_watchpoint = i386_insert_watchpoint;
+ t->to_remove_watchpoint = i386_remove_watchpoint;
+ t->to_insert_hw_breakpoint = i386_insert_hw_breakpoint;
+ t->to_remove_hw_breakpoint = i386_remove_hw_breakpoint;
+}
+
+void
+i386_set_debug_register_length (int len)
+{
+ /* This function should be called only once for each native target. */
+ gdb_assert (i386_dr_low.debug_register_length == 0);
+ gdb_assert (len == 4 || len == 8);
+ i386_dr_low.debug_register_length = len;
+ add_show_debug_regs_command ();
}
projects / deliverable / binutils-gdb.git / blobdiff