/* Native-dependent code for the i386.
- Copyright (C) 2001, 2004, 2005, 2007 Free Software Foundation, Inc.
+ Copyright (C) 2001-2014 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 "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;
+
+ 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;
-/* 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 = xcalloc (1, sizeof (*proc));
+ proc->pid = pid;
-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++;
- }
+ proc->next = i386_process_list;
+ i386_process_list = proc;
+
+ 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;
+
+ proc = i386_process_list;
+ proc_link = &i386_process_list;
- ALL_DEBUG_REGISTERS(i)
+ 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 (eight 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;
-
- 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);
+ struct i386_debug_reg_state *state
+ = i386_debug_reg_state (ptid_get_pid (inferior_ptid));
- 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;
-
- 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);
+ struct i386_debug_reg_state *state
+ = i386_debug_reg_state (ptid_get_pid (inferior_ptid));
- 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, set the
- address associated with that watchpoint and return non-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. */
-int
-i386_stopped_data_address (CORE_ADDR *addr_p)
+static int
+i386_stopped_data_address (struct target_ops *ops, CORE_ADDR *addr_p)
{
- CORE_ADDR addr = 0;
- int i;
- int rc = 0;
-
- dr_status_mirror = I386_DR_LOW_GET_STATUS ();
+ struct i386_debug_reg_state *state
+ = i386_debug_reg_state (ptid_get_pid (inferior_ptid));
- 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 paranoiac. */
- && I386_DR_GET_RW_LEN (i) != 0)
- {
- addr = dr_mirror[i];
- rc = 1;
- 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);
-
- if (rc)
- *addr_p = addr;
- return rc;
+ return i386_dr_stopped_data_address (state, addr_p);
}
-int
-i386_stopped_by_watchpoint (void)
-{
- CORE_ADDR addr = 0;
- return i386_stopped_data_address (&addr);
-}
+/* Return non-zero if the inferior has some watchpoint that triggered.
+ Otherwise return zero. */
-/* Return non-zero if the inferior has some break/watchpoint that
- triggered. */
-
-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 BP_TGT->placed_address.
Return 0 on success, EBUSY on failure. */
-int
-i386_insert_hw_breakpoint (struct bp_target_info *bp_tgt)
-{
- unsigned len_rw = i386_length_and_rw_bits (1, hw_execute);
- CORE_ADDR addr = bp_tgt->placed_address;
- int retval = i386_insert_aligned_watchpoint (addr, len_rw) ? EBUSY : 0;
- 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 BP_TGT->placed_address.
Return 0 on success, -1 on failure. */
-int
-i386_remove_hw_breakpoint (struct bp_target_info *bp_tgt)
+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);
- CORE_ADDR addr = bp_tgt->placed_address;
- 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. */
- deprecated_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
+ 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