/* Native-dependent code for GNU/Linux x86-64.
- Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010,
- 2011 Free Software Foundation, Inc.
+ Copyright (C) 2001-2012 Free Software Foundation, Inc.
Contributed by Jiri Smid, SuSE Labs.
This file is part of GDB.
<asm/ptrace.h> because the latter redefines FS and GS for no apparent
reason, and those definitions don't match the ones that libpthread_db
uses, which come from <sys/reg.h>. */
-/* ezannoni-2003-07-09: I think this is fixed. The extraneous defs have
+/* ezannoni-2003-07-09: I think this is fixed. The extraneous defs have
been removed from ptrace.h in the kernel. However, better safe than
sorry. */
#include <asm/ptrace.h>
#define PTRACE_SETREGSET 0x4205
#endif
+/* 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. */
+ int debug_registers_changed;
+};
+
/* Does the current host support PTRACE_GETREGSET? */
static int have_ptrace_getregset = -1;
\f
/* Support for debug registers. */
-static unsigned long amd64_linux_dr[DR_CONTROL + 1];
-
static unsigned long
amd64_linux_dr_get (ptid_t ptid, int regnum)
{
if (tid == 0)
tid = PIDGET (ptid);
- /* FIXME: kettenis/2001-03-27: Calling perror_with_name if the
- ptrace call fails breaks debugging remote targets. The correct
- way to fix this is to add the hardware breakpoint and watchpoint
- stuff to the target vector. For now, just return zero if the
- ptrace call fails. */
errno = 0;
value = ptrace (PTRACE_PEEKUSER, tid,
offsetof (struct user, u_debugreg[regnum]), 0);
if (errno != 0)
-#if 0
perror_with_name (_("Couldn't read debug register"));
-#else
- return 0;
-#endif
return value;
}
perror_with_name (_("Couldn't write debug register"));
}
-/* Set DR_CONTROL to ADDR in all LWPs of LWP_LIST. */
+/* Return the inferior's debug register REGNUM. */
-static void
-amd64_linux_dr_set_control (unsigned long control)
+static CORE_ADDR
+amd64_linux_dr_get_addr (int regnum)
{
- struct lwp_info *lp;
- ptid_t ptid;
+ /* DR6 and DR7 are retrieved with some other way. */
+ gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR);
- amd64_linux_dr[DR_CONTROL] = control;
- ALL_LWPS (lp, ptid)
- amd64_linux_dr_set (ptid, DR_CONTROL, control);
+ return amd64_linux_dr_get (inferior_ptid, regnum);
}
-/* Set address REGNUM (zero based) to ADDR in all LWPs of LWP_LIST. */
+/* Return the inferior's DR7 debug control register. */
-static void
-amd64_linux_dr_set_addr (int regnum, CORE_ADDR addr)
+static unsigned long
+amd64_linux_dr_get_control (void)
{
- struct lwp_info *lp;
- ptid_t ptid;
+ return amd64_linux_dr_get (inferior_ptid, DR_CONTROL);
+}
- gdb_assert (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR);
+/* Get DR_STATUS from only the one LWP of INFERIOR_PTID. */
+
+static unsigned long
+amd64_linux_dr_get_status (void)
+{
+ return amd64_linux_dr_get (inferior_ptid, DR_STATUS);
+}
+
+/* Callback for linux_nat_iterate_watchpoint_lwps. Update the debug registers
+ of LWP. */
+
+static int
+update_debug_registers_callback (struct lwp_info *lwp, void *arg)
+{
+ if (lwp->arch_private == NULL)
+ lwp->arch_private = XCNEW (struct arch_lwp_info);
+
+ /* The actual update is done later just before resuming the lwp, we
+ just mark that the registers need updating. */
+ lwp->arch_private->debug_registers_changed = 1;
- amd64_linux_dr[DR_FIRSTADDR + regnum] = addr;
- ALL_LWPS (lp, ptid)
- amd64_linux_dr_set (ptid, DR_FIRSTADDR + regnum, addr);
+ /* If the lwp isn't stopped, force it to momentarily pause, so we
+ can update its debug registers. */
+ if (!lwp->stopped)
+ linux_stop_lwp (lwp);
+
+ /* Continue the iteration. */
+ return 0;
}
-/* Set address REGNUM (zero based) to zero in all LWPs of LWP_LIST. */
+/* Set DR_CONTROL to CONTROL in all LWPs of the current inferior. */
static void
-amd64_linux_dr_reset_addr (int regnum)
+amd64_linux_dr_set_control (unsigned long control)
{
- amd64_linux_dr_set_addr (regnum, 0);
+ linux_nat_iterate_watchpoint_lwps (update_debug_registers_callback, NULL);
}
-/* Get DR_STATUS from only the one LWP of INFERIOR_PTID. */
+/* Set address REGNUM (zero based) to ADDR in all LWPs of the current
+ inferior. */
-static unsigned long
-amd64_linux_dr_get_status (void)
+static void
+amd64_linux_dr_set_addr (int regnum, CORE_ADDR addr)
{
- return amd64_linux_dr_get (inferior_ptid, DR_STATUS);
+ gdb_assert (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR);
+
+ linux_nat_iterate_watchpoint_lwps (update_debug_registers_callback, NULL);
}
-/* Unset MASK bits in DR_STATUS in all LWPs of LWP_LIST. */
+/* Called when resuming a thread.
+ If the debug regs have changed, update the thread's copies. */
static void
-amd64_linux_dr_unset_status (unsigned long mask)
+amd64_linux_prepare_to_resume (struct lwp_info *lwp)
{
- struct lwp_info *lp;
- ptid_t ptid;
+ int clear_status = 0;
+
+ /* NULL means this is the main thread still going through the shell,
+ or, no watchpoint has been set yet. In that case, there's
+ nothing to do. */
+ if (lwp->arch_private == NULL)
+ return;
- ALL_LWPS (lp, ptid)
+ if (lwp->arch_private->debug_registers_changed)
{
- unsigned long value;
-
- value = amd64_linux_dr_get (ptid, DR_STATUS);
- value &= ~mask;
- amd64_linux_dr_set (ptid, DR_STATUS, value);
+ struct i386_debug_reg_state *state = i386_debug_reg_state ();
+ int i;
+
+ /* On Linux kernel before 2.6.33 commit
+ 72f674d203cd230426437cdcf7dd6f681dad8b0d
+ if you enable a breakpoint by the DR_CONTROL bits you need to have
+ already written the corresponding DR_FIRSTADDR...DR_LASTADDR registers.
+
+ Ensure DR_CONTROL gets written as the very last register here. */
+
+ for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
+ if (state->dr_ref_count[i] > 0)
+ {
+ amd64_linux_dr_set (lwp->ptid, i, state->dr_mirror[i]);
+
+ /* If we're setting a watchpoint, any change the inferior
+ had done itself to the debug registers needs to be
+ discarded, otherwise, i386_stopped_data_address can get
+ confused. */
+ clear_status = 1;
+ }
+
+ amd64_linux_dr_set (lwp->ptid, DR_CONTROL, state->dr_control_mirror);
+
+ lwp->arch_private->debug_registers_changed = 0;
}
-}
+ if (clear_status || lwp->stopped_by_watchpoint)
+ amd64_linux_dr_set (lwp->ptid, DR_STATUS, 0);
+}
static void
-amd64_linux_new_thread (ptid_t ptid)
+amd64_linux_new_thread (struct lwp_info *lp)
{
- int i;
+ struct arch_lwp_info *info = XCNEW (struct arch_lwp_info);
- for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
- amd64_linux_dr_set (ptid, i, amd64_linux_dr[i]);
+ info->debug_registers_changed = 1;
- amd64_linux_dr_set (ptid, DR_CONTROL, amd64_linux_dr[DR_CONTROL]);
+ lp->arch_private = info;
}
\f
i386_dr_low.set_control = amd64_linux_dr_set_control;
i386_dr_low.set_addr = amd64_linux_dr_set_addr;
- i386_dr_low.reset_addr = amd64_linux_dr_reset_addr;
+ i386_dr_low.get_addr = amd64_linux_dr_get_addr;
i386_dr_low.get_status = amd64_linux_dr_get_status;
- i386_dr_low.unset_status = amd64_linux_dr_unset_status;
+ i386_dr_low.get_control = amd64_linux_dr_get_control;
i386_set_debug_register_length (8);
/* Override the GNU/Linux inferior startup hook. */
linux_nat_add_target (t);
linux_nat_set_new_thread (t, amd64_linux_new_thread);
linux_nat_set_siginfo_fixup (t, amd64_linux_siginfo_fixup);
+ linux_nat_set_prepare_to_resume (t, amd64_linux_prepare_to_resume);
}
projects / deliverable / binutils-gdb.git / blobdiff