Differential D14148 Diff 40118 devel/gdb/files/commit-12279366d7

Changeset View

Standalone View

devel/gdb/files/commit-12279366d7

This file was added.

Property	Old Value	New Value
fbsd:nokeywords	null	yes \ No newline at end of property
svn:eol-style	null	native \ No newline at end of property
svn:mime-type	null	text/plain \ No newline at end of property

				commit 12279366d71627bfbdd74d1a6675dca825d8feca
				Author: John Baldwin <jhb@FreeBSD.org>
				Date: Sat Mar 3 21:25:33 2018 -0800

				Implement "to_stopped_by_hw_breakpoint" for x86 debug registers.

				Report that a thread is stopped by a hardware breakpoint if a non-data
				watchpoint is set in DR6. This change should be a no-op since a target
				still needs to implement the "to_supports_stopped_by_hw_breakpoint"
				method before this function is used.

				gdb/ChangeLog:

				* nat/x86-dregs.c (x86_dr_stopped_by_hw_breakpoint): New function.
				* nat/x86-dregs.h (x86_dr_stopped_by_hw_breakpoint): New
				prototype.
				* x86-nat.c (x86_stopped_by_hw_breakpoint): New function.
				(x86_use_watchpoints): Set "stopped_by_hw_breakpoint" target
				method.

				diff --git gdb/nat/x86-dregs.c gdb/nat/x86-dregs.c
				index c816473628..f11a708e27 100644
				--- gdb/nat/x86-dregs.c
				+++ gdb/nat/x86-dregs.c
				@@ -649,3 +649,48 @@ x86_dr_stopped_by_watchpoint (struct x86_debug_reg_state *state)
				CORE_ADDR addr = 0;
				return x86_dr_stopped_data_address (state, &addr);
				}
				+
				+/* Return non-zero if the inferior has some hardware breakpoint that
				+ triggered. Otherwise return zero. */
				+
				+int
				+x86_dr_stopped_by_hw_breakpoint (struct x86_debug_reg_state *state)
				+{
				+ CORE_ADDR addr = 0;
				+ int i;
				+ int rc = 0;
				+ /* The current thread's DR_STATUS. We always need to read this to
				+ check whether some watchpoint caused the trap. */
				+ unsigned status;
				+ /* We need DR_CONTROL as well, but only iff DR_STATUS indicates a
				+ breakpoint trap. Only fetch it when necessary, to avoid an
				+ unnecessary extra syscall when no watchpoint triggered. */
				+ int control_p = 0;
				+ unsigned control = 0;
				+
				+ /* As above, always read the current thread's debug registers rather
				+ than trusting dr_mirror. */
				+ status = x86_dr_low_get_status ();
				+
				+ ALL_DEBUG_ADDRESS_REGISTERS (i)
				+ {
				+ if (!X86_DR_WATCH_HIT (status, i))
				+ continue;
				+
				+ if (!control_p)
				+ {
				+ control = x86_dr_low_get_control ();
				+ control_p = 1;
				+ }
				+
				+ if (X86_DR_GET_RW_LEN (control, i) == 0)
				+ {
				+ addr = x86_dr_low_get_addr (i);
				+ rc = 1;
				+ if (show_debug_regs)
				+ x86_show_dr (state, "watchpoint_hit", addr, -1, hw_execute);
				+ }
				+ }
				+
				+ return rc;
				+}
				diff --git gdb/nat/x86-dregs.h gdb/nat/x86-dregs.h
				index dd6242eda9..e86e83aea0 100644
				--- gdb/nat/x86-dregs.h
				+++ gdb/nat/x86-dregs.h
				@@ -128,4 +128,8 @@ extern int x86_dr_stopped_data_address (struct x86_debug_reg_state *state,
				Otherwise return false. */
				extern int x86_dr_stopped_by_watchpoint (struct x86_debug_reg_state *state);

				+/* Return true if the inferior has some hardware breakpoint that
				+ triggered. Otherwise return false. */
				+extern int x86_dr_stopped_by_hw_breakpoint (struct x86_debug_reg_state *state);
				+
				#endif /* X86_DREGS_H */
				diff --git gdb/x86-nat.c gdb/x86-nat.c
				index b126c47c94..bec51373a6 100644
				--- gdb/x86-nat.c
				+++ gdb/x86-nat.c
				@@ -260,6 +260,18 @@ x86_can_use_hw_breakpoint (struct target_ops *self,
				return 1;
				}

				+/* Return non-zero if the inferior has some breakpoint that triggered.
				+ Otherwise return zero. */
				+
				+static int
				+x86_stopped_by_hw_breakpoint (struct target_ops *ops)
				+{
				+ struct x86_debug_reg_state *state
				+ = x86_debug_reg_state (ptid_get_pid (inferior_ptid));
				+
				+ return x86_dr_stopped_by_hw_breakpoint (state);
				+}
				+
				static void
				add_show_debug_regs_command (void)
				{
				@@ -297,6 +309,11 @@ x86_use_watchpoints (struct target_ops *t)
				t->to_remove_watchpoint = x86_remove_watchpoint;
				t->to_insert_hw_breakpoint = x86_insert_hw_breakpoint;
				t->to_remove_hw_breakpoint = x86_remove_hw_breakpoint;
				+
				+ /* A target must provide an implementation of the
				+ "to_supports_stopped_by_hw_breakpoint" target method before this
				+ callback will be used. */
				+ t->to_stopped_by_hw_breakpoint = x86_stopped_by_hw_breakpoint;
				}

				void