commit 9f6b3c2c30cfbb1166ce7e74a8f9fd93ae19d2de
author Frederic Weisbecker <fweisbec@gmail.com> Mon Nov 09 21:03:43 2009 +0100
committer Frederic Weisbecker <fweisbec@gmail.com> Tue Nov 10 11:23:05 2009 +0100
tree 1144b1c516327765c7daacc6f4b23cc606a0c013
parent 676c0dbe6e514fdd8e434a9e623c781aa9b40b15

hw-breakpoints: Fix broken a.out format dump

Fix the broken a.out format dump. For now we only dump the ptrace
breakpoints.

TODO: Dump every perf breakpoints for the current thread, not only
ptrace based ones.

Reported-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: "K. Prasad" <prasad@linux.vnet.ibm.com>

arch/x86/kernel/hw_breakpoint.c

diff --git a/arch/x86/kernel/hw_breakpoint.c b/arch/x86/kernel/hw_breakpoint.c
index e622620..57dcee5 100644
--- a/arch/x86/kernel/hw_breakpoint.c
+++ b/arch/x86/kernel/hw_breakpoint.c
@@ -376,6 +376,41 @@
 }
 
 /*
+ * Dump the debug register contents to the user.
+ * We can't dump our per cpu values because it
+ * may contain cpu wide breakpoint, something that
+ * doesn't belong to the current task.
+ *
+ * TODO: include non-ptrace user breakpoints (perf)
+ */
+void aout_dump_debugregs(struct user *dump)
+{
+	int i;
+	int dr7 = 0;
+	struct perf_event *bp;
+	struct arch_hw_breakpoint *info;
+	struct thread_struct *thread = &current->thread;
+
+	for (i = 0; i < HBP_NUM; i++) {
+		bp = thread->ptrace_bps[i];
+
+		if (bp && !bp->attr.disabled) {
+			dump->u_debugreg[i] = bp->attr.bp_addr;
+			info = counter_arch_bp(bp);
+			dr7 |= encode_dr7(i, info->len, info->type);
+		} else {
+			dump->u_debugreg[i] = 0;
+		}
+	}
+
+	dump->u_debugreg[4] = 0;
+	dump->u_debugreg[5] = 0;
+	dump->u_debugreg[6] = current->thread.debugreg6;
+
+	dump->u_debugreg[7] = dr7;
+}
+
+/*
  * Release the user breakpoints used by ptrace
  */
 void flush_ptrace_hw_breakpoint(struct task_struct *tsk)