From 8d57ad9bc4497963420f60765ee6b99eec65d9df Mon Sep 17 00:00:00 2001
From: Masamichi Takagi <masamichi.takagi@riken.jp>
Date: Tue, 11 Jul 2017 18:59:19 +0900
Subject: [PATCH] pmc_start, pmc_stop: Error check on counter number

---
 arch/x86/kernel/perfctr.c | 36 ++++++++++++++++++++++++++++++++----
 1 file changed, 32 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/perfctr.c b/arch/x86/kernel/perfctr.c
index 1b1ab99d..962a4ace 100644
--- a/arch/x86/kernel/perfctr.c
+++ b/arch/x86/kernel/perfctr.c
@@ -17,8 +17,26 @@
 extern unsigned int *x86_march_perfmap;
 extern int running_on_kvm(void);
 
+//#define PERFCTR_DEBUG
+#ifdef PERFCTR_DEBUG
+#define	dkprintf(...)	do { kprintf(__VA_ARGS__); } while (0)
+#define	ekprintf(...)	do { kprintf(__VA_ARGS__); } while (0)
+#else
+#define	dkprintf(...)	do { } while (0)
+#define	ekprintf(...)	do { kprintf(__VA_ARGS__); } while (0)
+#endif
+
 #define X86_CR4_PCE     0x00000100
 
+#define PERFCTR_CHKANDJUMP(cond, msg, err)								\
+    do {																\
+		if(cond) {														\
+			ekprintf("%s,"msg"\n", __FUNCTION__);						\
+			ret = err;                                                  \
+			goto fn_fail;                                               \
+		}                                                               \
+    } while(0)
+
 int perf_counters_discovered = 0;
 int X86_IA32_NUM_PERF_COUNTERS = 0;
 unsigned long X86_IA32_PERF_COUNTERS_MASK = 0;
@@ -203,9 +221,12 @@ extern void x86_march_perfctr_start(unsigned long counter_mask);
 
 int ihk_mc_perfctr_start(unsigned long counter_mask)
 {
+	int ret = 0;
 	unsigned long value = 0;
 	unsigned long mask = X86_IA32_PERF_COUNTERS_MASK | X86_IA32_FIXED_PERF_COUNTERS_MASK;
 
+	PERFCTR_CHKANDJUMP(counter_mask & ~mask, "counter_mask out of range", -EINVAL);
+
 #ifdef HAVE_MARCH_PERFCTR_START
 	x86_march_perfctr_start(counter_mask);
 #endif
@@ -213,15 +234,20 @@ int ihk_mc_perfctr_start(unsigned long counter_mask)
 	value = rdmsr(MSR_PERF_GLOBAL_CTRL);
 	value |= counter_mask;
 	wrmsr(MSR_PERF_GLOBAL_CTRL, value);
-
-	return 0;
+ fn_exit:
+	return ret;
+ fn_fail:
+	goto fn_exit;
 }
 
 int ihk_mc_perfctr_stop(unsigned long counter_mask)
 {
+	int ret = 0;
 	unsigned long value;
 	unsigned long mask = X86_IA32_PERF_COUNTERS_MASK | X86_IA32_FIXED_PERF_COUNTERS_MASK;
 
+	PERFCTR_CHKANDJUMP(counter_mask & ~mask, "counter_mask out of range", -EINVAL);
+
 	counter_mask &= mask;
 	value = rdmsr(MSR_PERF_GLOBAL_CTRL);
 	value &= ~counter_mask;
@@ -244,8 +270,10 @@ int ihk_mc_perfctr_stop(unsigned long counter_mask)
 		value &= ~(0xf << 8);
 		wrmsr(MSR_PERF_FIXED_CTRL, value);
 	}
-
-	return 0;
+ fn_exit:
+	return ret;
+ fn_fail:
+	goto fn_exit;
 }
 
 // init for fixed counter