Fix repeated rwatch output.
* amd64-linux-nat.c (amd64_linux_dr_set, amd64_linux_dr_set_control)
(amd64_linux_dr_set_addr, amd64_linux_dr_reset_addr)
(amd64_linux_dr_get_status): New comments.
(amd64_linux_dr_unset_status): New function.
(_initialize_amd64_linux_nat): Install it.
* i386-linux-nat.c (i386_linux_dr_get, i386_linux_dr_set)
(i386_linux_dr_set_control, i386_linux_dr_set_addr)
(i386_linux_dr_reset_addr, i386_linux_dr_get_status): New comments.
(i386_linux_dr_unset_status): New function.
(_initialize_i386_linux_nat): Install it.
* i386-nat.c (I386_DR_WATCH_MASK): New macro.
(I386_DR_WATCH_HIT): Use I386_DR_WATCH_MASK.
(i386_insert_aligned_watchpoint): Call i386_dr_low.unset_status.
* i386-nat.h (struct i386_dr_low_type): Extend comments for
set_control, set_addr, reset_addr and get_status. New unset_status.
* breakpoint.c (update_watchpoint): Extend the comment.
gdb/testsuite/
* gdb.base/watchpoint-hw-hit-once.exp,
gdb.base/watchpoint-hw-hit-once.c: New.
+2009-11-20 Jan Kratochvil <jan.kratochvil@redhat.com>
+
+ Fix repeated rwatch output.
+ * amd64-linux-nat.c (amd64_linux_dr_set, amd64_linux_dr_set_control)
+ (amd64_linux_dr_set_addr, amd64_linux_dr_reset_addr)
+ (amd64_linux_dr_get_status): New comments.
+ (amd64_linux_dr_unset_status): New function.
+ (_initialize_amd64_linux_nat): Install it.
+ * i386-linux-nat.c (i386_linux_dr_get, i386_linux_dr_set)
+ (i386_linux_dr_set_control, i386_linux_dr_set_addr)
+ (i386_linux_dr_reset_addr, i386_linux_dr_get_status): New comments.
+ (i386_linux_dr_unset_status): New function.
+ (_initialize_i386_linux_nat): Install it.
+ * i386-nat.c (I386_DR_WATCH_MASK): New macro.
+ (I386_DR_WATCH_HIT): Use I386_DR_WATCH_MASK.
+ (i386_insert_aligned_watchpoint): Call i386_dr_low.unset_status.
+ * i386-nat.h (struct i386_dr_low_type): Extend comments for
+ set_control, set_addr, reset_addr and get_status. New unset_status.
+ * breakpoint.c (update_watchpoint): Extend the comment.
+
2009-11-20 Jan Kratochvil <jan.kratochvil@redhat.com>
Pedro Alves <pedro@codesourcery.com>
return value;
}
+/* Set debug register REGNUM to VALUE in only the one LWP of PTID. */
+
static void
amd64_linux_dr_set (ptid_t ptid, int regnum, unsigned long value)
{
perror_with_name (_("Couldn't write debug register"));
}
+/* Set DR_CONTROL to ADDR in all LWPs of LWP_LIST. */
+
static void
amd64_linux_dr_set_control (unsigned long control)
{
amd64_linux_dr_set (ptid, DR_CONTROL, control);
}
+/* Set address REGNUM (zero based) to ADDR in all LWPs of LWP_LIST. */
+
static void
amd64_linux_dr_set_addr (int regnum, CORE_ADDR addr)
{
amd64_linux_dr_set (ptid, DR_FIRSTADDR + regnum, addr);
}
+/* Set address REGNUM (zero based) to zero in all LWPs of LWP_LIST. */
+
static void
amd64_linux_dr_reset_addr (int regnum)
{
amd64_linux_dr_set_addr (regnum, 0);
}
+/* 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);
}
+/* Unset MASK bits in DR_STATUS in all LWPs of LWP_LIST. */
+
+static void
+amd64_linux_dr_unset_status (unsigned long mask)
+{
+ struct lwp_info *lp;
+ ptid_t ptid;
+
+ ALL_LWPS (lp, ptid)
+ {
+ unsigned long value;
+
+ value = amd64_linux_dr_get (ptid, DR_STATUS);
+ value &= ~mask;
+ amd64_linux_dr_set (ptid, DR_STATUS, value);
+ }
+}
+
+
static void
amd64_linux_new_thread (ptid_t ptid)
{
i386_dr_low.set_addr = amd64_linux_dr_set_addr;
i386_dr_low.reset_addr = amd64_linux_dr_reset_addr;
i386_dr_low.get_status = amd64_linux_dr_get_status;
+ i386_dr_low.unset_status = amd64_linux_dr_unset_status;
i386_set_debug_register_length (8);
/* Override the GNU/Linux inferior startup hook. */
- Update the list of values that must be watched in B->loc.
If the watchpoint disposition is disp_del_at_next_stop, then do nothing.
- If this is local watchpoint that is out of scope, delete it. */
+ If this is local watchpoint that is out of scope, delete it.
+
+ Even with `set breakpoint always-inserted on' the watchpoints are removed
+ + inserted on each stop here. Normal breakpoints must never be removed
+ because they might be missed by a running thread when debugging in non-stop
+ mode. On the other hand, hardware watchpoints (is_hardware_watchpoint;
+ processed here) are specific to each LWP since they are stored in each LWP's
+ hardware debug registers. Therefore, such LWP must be stopped first in
+ order to be able to modify its hardware watchpoints.
+
+ Hardware watchpoints must be reset exactly once after being presented to the
+ user. It cannot be done sooner, because it would reset the data used to
+ present the watchpoint hit to the user. And it must not be done later
+ because it could display the same single watchpoint hit during multiple GDB
+ stops. Note that the latter is relevant only to the hardware watchpoint
+ types bp_read_watchpoint and bp_access_watchpoint. False hit by
+ bp_hardware_watchpoint is not user-visible - its hit is suppressed if the
+ memory content has not changed.
+
+ The following constraints influence the location where we can reset hardware
+ watchpoints:
+
+ * target_stopped_by_watchpoint and target_stopped_data_address are called
+ several times when GDB stops.
+
+ [linux]
+ * Multiple hardware watchpoints can be hit at the same time, causing GDB to
+ stop. GDB only presents one hardware watchpoint hit at a time as the
+ reason for stopping, and all the other hits are presented later, one after
+ the other, each time the user requests the execution to be resumed.
+ Execution is not resumed for the threads still having pending hit event
+ stored in LWP_INFO->STATUS. While the watchpoint is already removed from
+ the inferior on the first stop the thread hit event is kept being reported
+ from its cached value by linux_nat_stopped_data_address until the real
+ thread resume happens after the watchpoint gets presented and thus its
+ LWP_INFO->STATUS gets reset.
+
+ Therefore the hardware watchpoint hit can get safely reset on the watchpoint
+ removal from inferior. */
+
static void
update_watchpoint (struct breakpoint *b, int reparse)
{
static unsigned long i386_linux_dr[DR_CONTROL + 1];
+/* Get debug register REGNUM value from only the one LWP of PTID. */
+
static unsigned long
i386_linux_dr_get (ptid_t ptid, int regnum)
{
return value;
}
+/* Set debug register REGNUM to VALUE in only the one LWP of PTID. */
+
static void
i386_linux_dr_set (ptid_t ptid, int regnum, unsigned long value)
{
perror_with_name (_("Couldn't write debug register"));
}
+/* Set DR_CONTROL to ADDR in all LWPs of LWP_LIST. */
+
static void
i386_linux_dr_set_control (unsigned long control)
{
i386_linux_dr_set (ptid, DR_CONTROL, control);
}
+/* Set address REGNUM (zero based) to ADDR in all LWPs of LWP_LIST. */
+
static void
i386_linux_dr_set_addr (int regnum, CORE_ADDR addr)
{
i386_linux_dr_set (ptid, DR_FIRSTADDR + regnum, addr);
}
+/* Set address REGNUM (zero based) to zero in all LWPs of LWP_LIST. */
+
static void
i386_linux_dr_reset_addr (int regnum)
{
i386_linux_dr_set_addr (regnum, 0);
}
+/* Get DR_STATUS from only the one LWP of INFERIOR_PTID. */
+
static unsigned long
i386_linux_dr_get_status (void)
{
return i386_linux_dr_get (inferior_ptid, DR_STATUS);
}
+/* Unset MASK bits in DR_STATUS in all LWPs of LWP_LIST. */
+
+static void
+i386_linux_dr_unset_status (unsigned long mask)
+{
+ struct lwp_info *lp;
+ ptid_t ptid;
+
+ ALL_LWPS (lp, ptid)
+ {
+ unsigned long value;
+
+ value = i386_linux_dr_get (ptid, DR_STATUS);
+ value &= ~mask;
+ i386_linux_dr_set (ptid, DR_STATUS, value);
+ }
+}
+
static void
i386_linux_new_thread (ptid_t ptid)
{
i386_dr_low.set_addr = i386_linux_dr_set_addr;
i386_dr_low.reset_addr = i386_linux_dr_reset_addr;
i386_dr_low.get_status = i386_linux_dr_get_status;
+ i386_dr_low.unset_status = i386_linux_dr_unset_status;
i386_set_debug_register_length (4);
/* Override the default ptrace resume method. */
#define I386_DR_GET_RW_LEN(i) \
((dr_control_mirror >> (DR_CONTROL_SHIFT + DR_CONTROL_SIZE * (i))) & 0x0f)
+/* Mask that this I'th watchpoint has triggered. */
+#define I386_DR_WATCH_MASK(i) (1 << (i))
+
/* Did the watchpoint whose address is in the I'th register break? */
-#define I386_DR_WATCH_HIT(i) (dr_status_mirror & (1 << (i)))
+#define I386_DR_WATCH_HIT(i) (dr_status_mirror & I386_DR_WATCH_MASK (i))
/* A macro to loop over all debug registers. */
#define ALL_DEBUG_REGISTERS(i) for (i = 0; i < DR_NADDR; i++)
i386_dr_low.set_addr (i, addr);
i386_dr_low.set_control (dr_control_mirror);
+ /* Only a sanity check for leftover bits (set possibly only by inferior). */
+ if (i386_dr_low.unset_status)
+ i386_dr_low.unset_status (I386_DR_WATCH_MASK (i));
+
return 0;
}
functions are:
set_control -- set the debug control (DR7)
- register to a given value
+ register to a given value for all LWPs
set_addr -- put an address into one debug
- register
+ register for all LWPs
reset_addr -- reset the address stored in
- one debug register
+ one debug register for all LWPs
get_status -- return the value of the debug
- status (DR6) register.
+ status (DR6) register for current LWP
+
+ unset_status -- unset the specified bits of the debug
+ status (DR6) register for all LWPs
Additionally, the native file should set the debug_register_length
field to 4 or 8 depending on the number of bytes used for
void (*set_addr) (int, CORE_ADDR);
void (*reset_addr) (int);
unsigned long (*get_status) (void);
+ void (*unset_status) (unsigned long);
int debug_register_length;
};
2009-11-20 Jan Kratochvil <jan.kratochvil@redhat.com>
- * gdb.base/watchthreads-reorder.exp,
- gdb.base/watchthreads-reorder.c: New.
+ * gdb.base/watchpoint-hw-hit-once.exp,
+ gdb.base/watchpoint-hw-hit-once.c: New.
+
+2009-11-20 Jan Kratochvil <jan.kratochvil@redhat.com>
+
+ * gdb.threads/watchthreads-reorder.exp,
+ gdb.threads/watchthreads-reorder.c: New.
2009-11-17 Nathan Sidwell <nathan@codesourcery.com>
--- /dev/null
+/* This testcase is part of GDB, the GNU debugger.
+
+ Copyright 2009 Free Software Foundation, Inc.
+
+ 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 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ 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, see <http://www.gnu.org/licenses/>. */
+
+static int watchee;
+
+int
+main (void)
+{
+ volatile int dummy;
+
+ /* Stub lines are present as no breakpoints/watchpoint gets hit if current PC
+ already stays on the line PC while entering "step"/"continue". */
+
+ dummy = 0; /* Stub to catch WATCHEE access after runto_main. */
+ dummy = watchee;
+ dummy = 1; /* Stub to catch break-at-exit after WATCHEE has been hit. */
+ dummy = 2; /* break-at-exit */
+
+ return 0;
+}
--- /dev/null
+# Copyright 2009 Free Software Foundation, Inc.
+
+# 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 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# 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, see <http://www.gnu.org/licenses/>.
+
+# Arch not supporting hw watchpoints does not imply no_hardware_watchpoints set.
+if {(![istarget "i?86-*-*"] && ![istarget "x86_64-*-*"]
+ && ![istarget "ia64-*-*"] && ![istarget "s390*-*-*"])
+ || [target_info exists gdb,no_hardware_watchpoints]} then {
+ verbose "Skipping watchpoint-hw-hit-once test."
+ return
+}
+
+set test watchpoint-hw-hit-once
+set srcfile ${test}.c
+if { [prepare_for_testing ${test}.exp ${test} ${srcfile}] } {
+ return -1
+}
+
+if ![runto_main] {
+ return -1
+}
+
+gdb_test "rwatch watchee"
+
+gdb_breakpoint [gdb_get_line_number "break-at-exit"]
+
+gdb_test "continue" "Continuing.\r\nHardware read watchpoint \[0-9\]+: watchee\r\n\r\nValue = 0\r\n.*"
+
+# Here should be no repeated notification of the read watchpoint.
+gdb_test "continue" \
+ "Continuing\\.\[ \r\n\]+Breakpoint \[0-9\]+, .*break-at-exit.*" \
+ "continue to break-at-exit"
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