* linux-arm-low.c: Include <signal.h>.

(PTRACE_GETHBPREGS, PTRACE_SETHBPREGS): Define if necessary.
	(struct arm_linux_hwbp_cap): New data type.
	(arm_hwbp_type, arm_hwbp_control_t): New typedefs.
	(struct arm_linux_hw_breakpoint): New data type.
	(MAX_BPTS, MAX_WPTS): Define.
	(struct arch_process_info, struct arch_lwp_info): New data types.
	(arm_linux_get_hwbp_cap): New function.
	(arm_linux_get_hw_breakpoint_count): Likewise.
	(arm_linux_get_hw_watchpoint_count): Likewise.
	(arm_linux_get_hw_watchpoint_max_length): Likewise.
	(arm_hwbp_control_initialize): Likewise.
	(arm_hwbp_control_is_enabled): Likewise.
	(arm_hwbp_control_is_initialized): Likewise.
	(arm_hwbp_control_disable): Likewise.
	(arm_linux_hw_breakpoint_equal): Likewise.
	(arm_linux_hw_point_initialize): Likewise.
	(struct update_registers_data): New data structure.
	(update_registers_callback: New function.
	(arm_insert_point): Likewise.
	(arm_remove_point): Likewise.
	(arm_stopped_by_watchpoint): Likewise.
	(arm_stopped_data_address): Likewise.
	(arm_new_process): Likewise.
	(arm_new_thread): Likewise.
	(arm_prepare_to_resume): Likewise.
	(the_low_target): Register arm_insert_point, arm_remove_point,
	arm_stopped_by_watchpoint, arm_stopped_data_address, arm_new_process,
	arm_new_thread, and arm_prepare_to_resume.
This commit is contained in:
Ulrich Weigand 2011-09-21 12:39:50 +00:00
parent 7ba695a99c
commit 09b4ad9fcb
2 changed files with 527 additions and 0 deletions

View File

@ -1,3 +1,35 @@
2011-11-15 Ulrich Weigand <ulrich.weigand@linaro.org>
* linux-arm-low.c: Include <signal.h>.
(PTRACE_GETHBPREGS, PTRACE_SETHBPREGS): Define if necessary.
(struct arm_linux_hwbp_cap): New data type.
(arm_hwbp_type, arm_hwbp_control_t): New typedefs.
(struct arm_linux_hw_breakpoint): New data type.
(MAX_BPTS, MAX_WPTS): Define.
(struct arch_process_info, struct arch_lwp_info): New data types.
(arm_linux_get_hwbp_cap): New function.
(arm_linux_get_hw_breakpoint_count): Likewise.
(arm_linux_get_hw_watchpoint_count): Likewise.
(arm_linux_get_hw_watchpoint_max_length): Likewise.
(arm_hwbp_control_initialize): Likewise.
(arm_hwbp_control_is_enabled): Likewise.
(arm_hwbp_control_is_initialized): Likewise.
(arm_hwbp_control_disable): Likewise.
(arm_linux_hw_breakpoint_equal): Likewise.
(arm_linux_hw_point_initialize): Likewise.
(struct update_registers_data): New data structure.
(update_registers_callback: New function.
(arm_insert_point): Likewise.
(arm_remove_point): Likewise.
(arm_stopped_by_watchpoint): Likewise.
(arm_stopped_data_address): Likewise.
(arm_new_process): Likewise.
(arm_new_thread): Likewise.
(arm_prepare_to_resume): Likewise.
(the_low_target): Register arm_insert_point, arm_remove_point,
arm_stopped_by_watchpoint, arm_stopped_data_address, arm_new_process,
arm_new_thread, and arm_prepare_to_resume.
2011-09-15 Stan Shebs <stan@codesourcery.com>
* server.h (struct emit_ops): Add compare-goto fields.

View File

@ -26,6 +26,7 @@
#include <elf.h>
#endif
#include <sys/ptrace.h>
#include <signal.h>
/* Defined in auto-generated files. */
void init_registers_arm (void);
@ -48,6 +49,65 @@ void init_registers_arm_with_neon (void);
# define PTRACE_SETVFPREGS 28
#endif
#ifndef PTRACE_GETHBPREGS
#define PTRACE_GETHBPREGS 29
#define PTRACE_SETHBPREGS 30
#endif
/* Information describing the hardware breakpoint capabilities. */
struct arm_linux_hwbp_cap
{
unsigned char arch;
unsigned char max_wp_length;
unsigned char wp_count;
unsigned char bp_count;
};
/* Enum describing the different types of ARM hardware break-/watch-points. */
typedef enum
{
arm_hwbp_break = 0,
arm_hwbp_load = 1,
arm_hwbp_store = 2,
arm_hwbp_access = 3
} arm_hwbp_type;
/* Type describing an ARM Hardware Breakpoint Control register value. */
typedef unsigned int arm_hwbp_control_t;
/* Structure used to keep track of hardware break-/watch-points. */
struct arm_linux_hw_breakpoint
{
/* Address to break on, or being watched. */
unsigned int address;
/* Control register for break-/watch- point. */
arm_hwbp_control_t control;
};
/* Since we cannot dynamically allocate subfields of arch_process_info,
assume a maximum number of supported break-/watchpoints. */
#define MAX_BPTS 32
#define MAX_WPTS 32
/* Per-process arch-specific data we want to keep. */
struct arch_process_info
{
/* Hardware breakpoints for this process. */
struct arm_linux_hw_breakpoint bpts[MAX_BPTS];
/* Hardware watchpoints for this process. */
struct arm_linux_hw_breakpoint wpts[MAX_WPTS];
};
/* Per-thread arch-specific data we want to keep. */
struct arch_lwp_info
{
/* Non-zero if our copy differs from what's recorded in the thread. */
char bpts_changed[MAX_BPTS];
char wpts_changed[MAX_WPTS];
/* Cached stopped data address. */
CORE_ADDR stopped_data_address;
};
static unsigned long arm_hwcap;
/* These are in <asm/elf.h> in current kernels. */
@ -280,6 +340,431 @@ ps_get_thread_area (const struct ps_prochandle *ph,
return PS_OK;
}
/* Get hold of the Hardware Breakpoint information for the target we are
attached to. Returns NULL if the kernel doesn't support Hardware
breakpoints at all, or a pointer to the information structure. */
static const struct arm_linux_hwbp_cap *
arm_linux_get_hwbp_cap (void)
{
/* The info structure we return. */
static struct arm_linux_hwbp_cap info;
/* Is INFO in a good state? -1 means that no attempt has been made to
initialize INFO; 0 means an attempt has been made, but it failed; 1
means INFO is in an initialized state. */
static int available = -1;
if (available == -1)
{
int pid = lwpid_of (get_thread_lwp (current_inferior));
unsigned int val;
if (ptrace (PTRACE_GETHBPREGS, pid, 0, &val) < 0)
available = 0;
else
{
info.arch = (unsigned char)((val >> 24) & 0xff);
info.max_wp_length = (unsigned char)((val >> 16) & 0xff);
info.wp_count = (unsigned char)((val >> 8) & 0xff);
info.bp_count = (unsigned char)(val & 0xff);
available = (info.arch != 0);
}
if (available)
{
if (info.wp_count > MAX_WPTS)
internal_error (__FILE__, __LINE__,
"Unsupported number of watchpoints");
if (info.bp_count > MAX_BPTS)
internal_error (__FILE__, __LINE__,
"Unsupported number of breakpoints");
}
}
return available == 1 ? &info : NULL;
}
/* How many hardware breakpoints are available? */
static int
arm_linux_get_hw_breakpoint_count (void)
{
const struct arm_linux_hwbp_cap *cap = arm_linux_get_hwbp_cap ();
return cap != NULL ? cap->bp_count : 0;
}
/* How many hardware watchpoints are available? */
static int
arm_linux_get_hw_watchpoint_count (void)
{
const struct arm_linux_hwbp_cap *cap = arm_linux_get_hwbp_cap ();
return cap != NULL ? cap->wp_count : 0;
}
/* Maximum length of area watched by hardware watchpoint. */
static int
arm_linux_get_hw_watchpoint_max_length (void)
{
const struct arm_linux_hwbp_cap *cap = arm_linux_get_hwbp_cap ();
return cap != NULL ? cap->max_wp_length : 0;
}
/* Initialize an ARM hardware break-/watch-point control register value.
BYTE_ADDRESS_SELECT is the mask of bytes to trigger on; HWBP_TYPE is the
type of break-/watch-point; ENABLE indicates whether the point is enabled.
*/
static arm_hwbp_control_t
arm_hwbp_control_initialize (unsigned byte_address_select,
arm_hwbp_type hwbp_type,
int enable)
{
gdb_assert ((byte_address_select & ~0xffU) == 0);
gdb_assert (hwbp_type != arm_hwbp_break
|| ((byte_address_select & 0xfU) != 0));
return (byte_address_select << 5) | (hwbp_type << 3) | (3 << 1) | enable;
}
/* Does the breakpoint control value CONTROL have the enable bit set? */
static int
arm_hwbp_control_is_enabled (arm_hwbp_control_t control)
{
return control & 0x1;
}
/* Is the breakpoint control value CONTROL initialized? */
static int
arm_hwbp_control_is_initialized (arm_hwbp_control_t control)
{
return control != 0;
}
/* Change a breakpoint control word so that it is in the disabled state. */
static arm_hwbp_control_t
arm_hwbp_control_disable (arm_hwbp_control_t control)
{
return control & ~0x1;
}
/* Are two break-/watch-points equal? */
static int
arm_linux_hw_breakpoint_equal (const struct arm_linux_hw_breakpoint *p1,
const struct arm_linux_hw_breakpoint *p2)
{
return p1->address == p2->address && p1->control == p2->control;
}
/* Initialize the hardware breakpoint structure P for a breakpoint or
watchpoint at ADDR to LEN. The type of watchpoint is given in TYPE.
Returns -1 if TYPE is unsupported, 0 if TYPE represents a breakpoint,
and 1 if type represents a watchpoint. */
static int
arm_linux_hw_point_initialize (char type, CORE_ADDR addr, int len,
struct arm_linux_hw_breakpoint *p)
{
arm_hwbp_type hwbp_type;
unsigned mask;
/* Breakpoint/watchpoint types (GDB terminology):
0 = memory breakpoint for instructions
(not supported; done via memory write instead)
1 = hardware breakpoint for instructions (supported)
2 = write watchpoint (supported)
3 = read watchpoint (supported)
4 = access watchpoint (supported). */
switch (type)
{
case '1':
hwbp_type = arm_hwbp_break;
break;
case '2':
hwbp_type = arm_hwbp_store;
break;
case '3':
hwbp_type = arm_hwbp_load;
break;
case '4':
hwbp_type = arm_hwbp_access;
break;
default:
/* Unsupported. */
return -1;
}
if (hwbp_type == arm_hwbp_break)
{
/* For breakpoints, the length field encodes the mode. */
switch (len)
{
case 2: /* 16-bit Thumb mode breakpoint */
case 3: /* 32-bit Thumb mode breakpoint */
mask = 0x3 << (addr & 2);
break;
case 4: /* 32-bit ARM mode breakpoint */
mask = 0xf;
break;
default:
/* Unsupported. */
return -1;
}
addr &= ~3;
}
else
{
CORE_ADDR max_wp_length = arm_linux_get_hw_watchpoint_max_length ();
CORE_ADDR aligned_addr;
/* Can not set watchpoints for zero or negative lengths. */
if (len <= 0)
return -1;
/* The current ptrace interface can only handle watchpoints that are a
power of 2. */
if ((len & (len - 1)) != 0)
return -1;
/* Test that the range [ADDR, ADDR + LEN) fits into the largest address
range covered by a watchpoint. */
aligned_addr = addr & ~(max_wp_length - 1);
if (aligned_addr + max_wp_length < addr + len)
return -1;
mask = (1 << len) - 1;
}
p->address = (unsigned int) addr;
p->control = arm_hwbp_control_initialize (mask, hwbp_type, 1);
return hwbp_type != arm_hwbp_break;
}
/* Callback to mark a watch-/breakpoint to be updated in all threads of
the current process. */
struct update_registers_data
{
int watch;
int i;
};
static int
update_registers_callback (struct inferior_list_entry *entry, void *arg)
{
struct lwp_info *lwp = (struct lwp_info *) entry;
struct update_registers_data *data = (struct update_registers_data *) arg;
/* Only update the threads of the current process. */
if (pid_of (lwp) == pid_of (get_thread_lwp (current_inferior)))
{
/* The actual update is done later just before resuming the lwp,
we just mark that the registers need updating. */
if (data->watch)
lwp->arch_private->wpts_changed[data->i] = 1;
else
lwp->arch_private->bpts_changed[data->i] = 1;
/* If the lwp isn't stopped, force it to momentarily pause, so
we can update its breakpoint registers. */
if (!lwp->stopped)
linux_stop_lwp (lwp);
}
return 0;
}
/* Insert hardware break-/watchpoint. */
static int
arm_insert_point (char type, CORE_ADDR addr, int len)
{
struct process_info *proc = current_process ();
struct arm_linux_hw_breakpoint p, *pts;
int watch, i, count;
watch = arm_linux_hw_point_initialize (type, addr, len, &p);
if (watch < 0)
{
/* Unsupported. */
return 1;
}
if (watch)
{
count = arm_linux_get_hw_watchpoint_count ();
pts = proc->private->arch_private->wpts;
}
else
{
count = arm_linux_get_hw_breakpoint_count ();
pts = proc->private->arch_private->bpts;
}
for (i = 0; i < count; i++)
if (!arm_hwbp_control_is_enabled (pts[i].control))
{
struct update_registers_data data = { watch, i };
pts[i] = p;
find_inferior (&all_lwps, update_registers_callback, &data);
return 0;
}
/* We're out of watchpoints. */
return -1;
}
/* Remove hardware break-/watchpoint. */
static int
arm_remove_point (char type, CORE_ADDR addr, int len)
{
struct process_info *proc = current_process ();
struct arm_linux_hw_breakpoint p, *pts;
int watch, i, count;
watch = arm_linux_hw_point_initialize (type, addr, len, &p);
if (watch < 0)
{
/* Unsupported. */
return -1;
}
if (watch)
{
count = arm_linux_get_hw_watchpoint_count ();
pts = proc->private->arch_private->wpts;
}
else
{
count = arm_linux_get_hw_breakpoint_count ();
pts = proc->private->arch_private->bpts;
}
for (i = 0; i < count; i++)
if (arm_linux_hw_breakpoint_equal (&p, pts + i))
{
struct update_registers_data data = { watch, i };
pts[i].control = arm_hwbp_control_disable (pts[i].control);
find_inferior (&all_lwps, update_registers_callback, &data);
return 0;
}
/* No watchpoint matched. */
return -1;
}
/* Return whether current thread is stopped due to a watchpoint. */
static int
arm_stopped_by_watchpoint (void)
{
struct lwp_info *lwp = get_thread_lwp (current_inferior);
struct siginfo siginfo;
/* We must be able to set hardware watchpoints. */
if (arm_linux_get_hw_watchpoint_count () == 0)
return 0;
/* Retrieve siginfo. */
errno = 0;
ptrace (PTRACE_GETSIGINFO, lwpid_of (lwp), 0, &siginfo);
if (errno != 0)
return 0;
/* This must be a hardware breakpoint. */
if (siginfo.si_signo != SIGTRAP
|| (siginfo.si_code & 0xffff) != 0x0004 /* TRAP_HWBKPT */)
return 0;
/* If we are in a positive slot then we're looking at a breakpoint and not
a watchpoint. */
if (siginfo.si_errno >= 0)
return 0;
/* Cache stopped data address for use by arm_stopped_data_address. */
lwp->arch_private->stopped_data_address
= (CORE_ADDR) (uintptr_t) siginfo.si_addr;
return 1;
}
/* Return data address that triggered watchpoint. Called only if
arm_stopped_by_watchpoint returned true. */
static CORE_ADDR
arm_stopped_data_address (void)
{
struct lwp_info *lwp = get_thread_lwp (current_inferior);
return lwp->arch_private->stopped_data_address;
}
/* Called when a new process is created. */
static struct arch_process_info *
arm_new_process (void)
{
struct arch_process_info *info = xcalloc (1, sizeof (*info));
return info;
}
/* Called when a new thread is detected. */
static struct arch_lwp_info *
arm_new_thread (void)
{
struct arch_lwp_info *info = xcalloc (1, sizeof (*info));
int i;
for (i = 0; i < MAX_BPTS; i++)
info->bpts_changed[i] = 1;
for (i = 0; i < MAX_WPTS; i++)
info->wpts_changed[i] = 1;
return info;
}
/* Called when resuming a thread.
If the debug regs have changed, update the thread's copies. */
static void
arm_prepare_to_resume (struct lwp_info *lwp)
{
int pid = lwpid_of (lwp);
struct process_info *proc = find_process_pid (pid_of (lwp));
struct arch_process_info *proc_info = proc->private->arch_private;
struct arch_lwp_info *lwp_info = lwp->arch_private;
int i;
for (i = 0; i < arm_linux_get_hw_breakpoint_count (); i++)
if (lwp_info->bpts_changed[i])
{
errno = 0;
if (arm_hwbp_control_is_enabled (proc_info->bpts[i].control))
if (ptrace (PTRACE_SETHBPREGS, pid, ((i << 1) + 1),
&proc_info->bpts[i].address) < 0)
error (_("Unexpected error setting breakpoint address"));
if (arm_hwbp_control_is_initialized (proc_info->bpts[i].control))
if (ptrace (PTRACE_SETHBPREGS, pid, ((i << 1) + 2),
&proc_info->bpts[i].control) < 0)
error (_("Unexpected error setting breakpoint"));
lwp_info->bpts_changed[i] = 0;
}
for (i = 0; i < arm_linux_get_hw_watchpoint_count (); i++)
if (lwp_info->wpts_changed[i])
{
errno = 0;
if (arm_hwbp_control_is_enabled (proc_info->wpts[i].control))
if (ptrace (PTRACE_SETHBPREGS, pid, -((i << 1) + 1),
&proc_info->wpts[i].address) < 0)
error (_("Unexpected error setting watchpoint address"));
if (arm_hwbp_control_is_initialized (proc_info->wpts[i].control))
if (ptrace (PTRACE_SETHBPREGS, pid, -((i << 1) + 2),
&proc_info->wpts[i].control) < 0)
error (_("Unexpected error setting watchpoint"));
lwp_info->wpts_changed[i] = 0;
}
}
static int
arm_get_hwcap (unsigned long *valp)
{
@ -389,4 +874,14 @@ struct linux_target_ops the_low_target = {
arm_reinsert_addr,
0,
arm_breakpoint_at,
arm_insert_point,
arm_remove_point,
arm_stopped_by_watchpoint,
arm_stopped_data_address,
NULL, /* collect_ptrace_register */
NULL, /* supply_ptrace_register */
NULL, /* siginfo_fixup */
arm_new_process,
arm_new_thread,
arm_prepare_to_resume,
};