From 87a7c0317e0abe487ad06ab326f71536a6545f26 Mon Sep 17 00:00:00 2001
From: "Nakamura, Yuuichi" <Yuuichi.A.Nakamura@sony.com>
Date: Thu, 23 Jul 2020 22:18:14 +0900
Subject: [PATCH] Add note_syscall args support

---
 include/nuttx/sched_note.h | 14 ++++++++++--
 sched/Kconfig              |  3 ++-
 sched/sched/sched_note.c   | 45 +++++++++++++++++++++++++++++++++++---
 3 files changed, 56 insertions(+), 6 deletions(-)

diff --git a/include/nuttx/sched_note.h b/include/nuttx/sched_note.h
index 51011631b9a..90baedfa2a3 100644
--- a/include/nuttx/sched_note.h
+++ b/include/nuttx/sched_note.h
@@ -69,6 +69,9 @@
 #ifdef CONFIG_SCHED_INSTRUMENTATION_IRQHANDLER
 #define NOTE_FILTER_MODE_FLAG_IRQ          (1 << 2) /* Enable IRQ instrumentaiton */
 #endif
+#ifdef CONFIG_SCHED_INSTRUMENTATION_SYSCALL
+#define NOTE_FILTER_MODE_FLAG_SYSCALL_ARGS (1 << 3) /* Enable collecting syscall arguments */
+#endif
 
 /* Helper macros for syscall instrumentation filter */
 
@@ -278,10 +281,17 @@ struct note_spinlock_s
 #ifdef CONFIG_SCHED_INSTRUMENTATION_SYSCALL
 /* This is the specific form of the NOTE_SYSCALL_ENTER/LEAVE notes */
 
+#define MAX_SYSCALL_ARGS  6
+#define SIZEOF_NOTE_SYSCALL_ENTER(n) (sizeof(struct note_common_s) + \
+                                      sizeof(uint8_t) + sizeof(uint8_t) + \
+                                      (sizeof(uintptr_t) * (n)))
+
 struct note_syscall_enter_s
 {
-  struct note_common_s nsc_cmn; /* Common note parameters */
-  uint8_t nsc_nr;               /* System call number */
+  struct note_common_s nsc_cmn;                           /* Common note parameters */
+  uint8_t nsc_nr;                                         /* System call number */
+  uint8_t nsc_argc;                                       /* Number of system call arguments */
+  uint8_t nsc_args[sizeof(uintptr_t) * MAX_SYSCALL_ARGS]; /* System call arguments */
 };
 
 struct note_syscall_leave_s
diff --git a/sched/Kconfig b/sched/Kconfig
index 840f5897999..6ebfcf9eb7b 100644
--- a/sched/Kconfig
+++ b/sched/Kconfig
@@ -1003,12 +1003,13 @@ config SCHED_INSTRUMENTATION_FILTER
 config SCHED_INSTRUMENTATION_FILTER_DEFAULT_MODE
 	hex "Default instrumentation filter mode"
 	depends on SCHED_INSTRUMENTATION_FILTER
-	default 0x7
+	default 0xf
 	---help---
 		Default mode of the instrumentation filter logic.
 			Bit 0 = Enable instrumentation
 			Bit 1 = Enable syscall instrumentation
 			Bit 2 = Enable IRQ instrumentation
+			Bit 3 = Enable collecting syscall arguments
 
 endif # SCHED_INSTRUMENTATION
 endmenu # Performance Monitoring
diff --git a/sched/sched/sched_note.c b/sched/sched/sched_note.c
index bf8d22fc8aa..02f5b244eb2 100644
--- a/sched/sched/sched_note.c
+++ b/sched/sched/sched_note.c
@@ -25,6 +25,7 @@
 #include <nuttx/config.h>
 
 #include <stdint.h>
+#include <stdarg.h>
 #include <string.h>
 #include <assert.h>
 #include <errno.h>
@@ -651,22 +652,60 @@ void sched_note_syscall_enter(int nr, int argc, ...)
 {
   struct note_syscall_enter_s note;
   FAR struct tcb_s *tcb = this_task();
+  unsigned int length;
+  va_list ap;
+  uintptr_t arg;
+  int i;
+  uint8_t *args;
 
   if (!note_isenabled_syscall(nr))
     {
       return;
     }
 
+#ifdef CONFIG_SCHED_INSTRUMENTATION_FILTER
+  if (!(g_note_filter.mode.flag & NOTE_FILTER_MODE_FLAG_SYSCALL_ARGS))
+    {
+      argc = 0;
+    }
+#endif
+
   /* Format the note */
 
-  note_common(tcb, &note.nsc_cmn, sizeof(struct note_syscall_enter_s),
-              NOTE_SYSCALL_ENTER);
+  length = SIZEOF_NOTE_SYSCALL_ENTER(argc);
+  note_common(tcb, &note.nsc_cmn, length, NOTE_SYSCALL_ENTER);
   DEBUGASSERT(nr <= UCHAR_MAX);
   note.nsc_nr = nr;
+  DEBUGASSERT(argc <= MAX_SYSCALL_ARGS);
+  note.nsc_argc = argc;
+
+  /* If needed, retrieve the given syscall arguments */
+
+  va_start(ap, argc);
+
+  args = note.nsc_args;
+  for (i = 0; i < argc; i++)
+    {
+      arg = (uintptr_t)va_arg(ap, uintptr_t);
+      *args++ = (uint8_t)(arg & 0xff);
+      *args++ = (uint8_t)((arg >> 8)  & 0xff);
+#if UINTPTR_MAX > UINT16_MAX
+      *args++ = (uint8_t)((arg >> 16) & 0xff);
+      *args++ = (uint8_t)((arg >> 24) & 0xff);
+#if UINTPTR_MAX > UINT32_MAX
+      *args++ = (uint8_t)((arg >> 32) & 0xff);
+      *args++ = (uint8_t)((arg >> 40) & 0xff);
+      *args++ = (uint8_t)((arg >> 48) & 0xff);
+      *args++ = (uint8_t)((arg >> 56) & 0xff);
+#endif
+#endif
+    }
+
+  va_end(ap);
 
   /* Add the note to circular buffer */
 
-  sched_note_add(&note, sizeof(struct note_syscall_enter_s));
+  sched_note_add((FAR const uint8_t *)&note, length);
 }
 
 void sched_note_syscall_leave(int nr, uintptr_t result)