-/* Intel x86 (a.k.a. ia32) native-dependent code.
- Copyright (C) 2001 Free Software Foundation, Inc.
+/* Native-dependent code for the i386.
+
+ Copyright 2001, 2004 Free Software Foundation, Inc.
This file is part of GDB.
#include "command.h"
#include "gdbcmd.h"
-/* Support for hardware watchpoints and breakpoints using the x86
+/* Support for hardware watchpoints and breakpoints using the i386
debug registers.
This provides several functions for inserting and removing
- hardware-assisted breakpoints and watchpoints, testing if
- one or 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
+ hardware-assisted breakpoints and watchpoints, testing if one or
+ 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.
- 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:
+ 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:
I386_DR_LOW_SET_CONTROL -- set the debug control (DR7)
register to a given value
I386_DR_LOW_GET_STATUS -- return the value of the debug
status (DR6) register.
- The functions below implement debug registers sharing by
- reference counts, and allow to watch regions up to 16 bytes
- long. */
+ The functions below implement debug registers sharing by reference
+ counts, and allow to watch regions up to 16 bytes long. */
#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
+#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) */
+#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. */
#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 */
+#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 Mar-2001). Note that the DE flag in the
+ 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 */
+#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 breakpt */
-#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 (x86-64) */
+#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.
+ 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 /* 2 enable bits per debug register */
+#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
- back compatibility. */
+ backwards compatibility. */
#define DR_LOCAL_SLOWDOWN (0x100)
-#define DR_GLOBAL_SLOWDOWN (0x200)
+#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
/* Auxiliary helper macros. */
/* A value that masks all fields in DR7 that are reserved by Intel. */
-#define I386_DR_CONTROL_MASK (~DR_CONTROL_RESERVED)
+#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. */
/* 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;
+static unsigned dr_status_mirror, dr_control_mirror;
/* Reference counts for each debug register. */
-static int dr_ref_count[DR_NADDR];
+static int dr_ref_count[DR_NADDR];
/* Whether or not to print the mirrored debug registers. */
-static int maint_show_dr;
+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. */
+ 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
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. */
+ 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. */
-/* Clear the reference counts and forget everything we knew about
- the debug registers. */
+/* Clear the reference counts and forget everything we knew about the
+ debug registers. */
+
void
i386_cleanup_dregs (void)
{
}
#ifndef LINUX_CHILD_POST_STARTUP_INFERIOR
-/* Reset all debug registers at each new startup
- to avoid missing watchpoints after restart. */
+
+/* Reset all debug registers at each new startup to avoid missing
+ watchpoints after restart. */
+
void
child_post_startup_inferior (ptid_t ptid)
{
i386_cleanup_dregs ();
}
+
#endif /* LINUX_CHILD_POST_STARTUP_INFERIOR */
-/* 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. */
+/* 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. */
+
static void
i386_show_dr (const char *func, CORE_ADDR addr,
int len, enum target_hw_bp_type type)
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",
+ 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 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. */
+ 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)
{
case hw_write:
rw = DR_RW_WRITE;
break;
- case hw_read: /* x86 doesn't support data-read watchpoints */
+ case hw_read:
+ /* The i386 doesn't support data-read watchpoints. */
case hw_access:
rw = DR_RW_READ;
break;
#if 0
- case hw_io_access: /* not yet supported */
+ /* Not yet supported. */
+ case hw_io_access:
rw = DR_RW_IORW;
break;
#endif
default:
internal_error (__FILE__, __LINE__, "\
-Invalid hw breakpoint type %d in i386_length_and_rw_bits.\n", (int)type);
+Invalid hardware breakpoint type %d in i386_length_and_rw_bits.\n",
+ (int) type);
}
switch (len)
return (DR_LEN_8 | rw);
default:
internal_error (__FILE__, __LINE__, "\
-Invalid hw breakpoint length %d in i386_length_and_rw_bits.\n", len);
+Invalid hardware breakpoint length %d in i386_length_and_rw_bits.\n", len);
}
}
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. */
+
static int
i386_insert_aligned_watchpoint (CORE_ADDR addr, unsigned len_rw_bits)
{
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 x86 target allows or supports global
+ 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
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)
{
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. */
+ 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)
{
- int align;
- int size;
- int rv = 0, status = 0;
+ 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 */
+ {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)
{
- align = addr % max_wp_len;
- /* Four(eigth on x86_64) is the maximum length an x86 debug register
+ int align = addr % max_wp_len;
+ /* Four (eigth on AMD64) is the maximum length a debug register
can watch. */
- size = size_try_array[len > max_wp_len ? (max_wp_len - 1) : len - 1][align];
+ 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 so 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. */
- rv++;
+ {
+ /* 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);
to our failure to insert this watchpoint and tries to
remove it. */
if (status)
- rv = status;
+ retval = status;
}
+
addr += size;
len -= size;
}
- return rv;
+
+ return retval;
}
/* 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)
{
/* 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)
{
+ int nregs;
+
/* Compute how many aligned watchpoints we would need to cover this
region. */
- int nregs = i386_handle_nonaligned_watchpoint (WP_COUNT, addr, len,
- hw_write);
-
+ nregs = i386_handle_nonaligned_watchpoint (WP_COUNT, addr, len, hw_write);
return nregs <= DR_NADDR ? 1 : 0;
}
/* If the inferior has some watchpoint that triggered, return the
- address associated with that watchpoint. Otherwise, return
- zero. */
+ address associated with that watchpoint. Otherwise, return zero. */
+
CORE_ADDR
i386_stopped_data_address (void)
{
+ CORE_ADDR addr = 0;
int i;
- CORE_ADDR ret = 0;
dr_status_mirror = I386_DR_LOW_GET_STATUS ();
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. */
+ being paranoid. */
&& I386_DR_GET_RW_LEN (i) != 0)
{
- ret = dr_mirror[i];
+ addr = dr_mirror[i];
if (maint_show_dr)
- i386_show_dr ("watchpoint_hit", ret, -1, hw_write);
+ i386_show_dr ("watchpoint_hit", addr, -1, hw_write);
}
}
- if (maint_show_dr && ret == 0)
+ if (maint_show_dr && addr == 0)
i386_show_dr ("stopped_data_addr", 0, 0, hw_write);
- return ret;
+ return addr;
}
/* Return non-zero if the inferior has some break/watchpoint that
triggered. */
+
int
i386_stopped_by_hwbp (void)
{
/* Remove a hardware-assisted breakpoint at address ADDR. SHADOW is
unused. Return 0 on success, -1 on failure. */
+
int
i386_remove_hw_breakpoint (CORE_ADDR addr, void *shadow)
{
}
#endif /* I386_USE_GENERIC_WATCHPOINTS */
-
\f
+
+/* Provide a prototype to silence -Wmissing-prototypes. */
+void _initialize_i386_nat (void);
+
void
_initialize_i386_nat (void)
{
projects / binutils-gdb.git / commitdiff