x86/debug: Remove aout_dump_debugregs()

Unused remnants for the bit-bucket.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Daniel Thompson <daniel.thompson@linaro.org>
Link: https://lore.kernel.org/r/20200902133201.233022474@infradead.org

Author: Peter Zijlstra

arch/x86/include/asm/debugreg.h

@@ -90,8 +90,6 @@ static __always_inline bool hw_breakpoint_active(void)
 	return __this_cpu_read(cpu_dr7) & DR_GLOBAL_ENABLE_MASK;
 }
 
-extern void aout_dump_debugregs(struct user *dump);
-
 extern void hw_breakpoint_restore(void);
 
 static __always_inline unsigned long local_db_save(void)

arch/x86/kernel/hw_breakpoint.c

@@ -441,42 +441,6 @@ int hw_breakpoint_arch_parse(struct perf_event *bp,
 	return 0;
 }
 
-/*
- * 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;
-}
-EXPORT_SYMBOL_GPL(aout_dump_debugregs);
-
 /*
  * Release the user breakpoints used by ptrace
  */