Re: [PATCH v2] Support regular file type in _swistat for ARM

From 967c45d40709f873f84860f43700f1d2d25c0551 Mon Sep 17 00:00:00 2001
From: Joe Ramsay <[email protected]>
Date: Tue, 18 Aug 2020 13:04:24 +0000
Subject: [PATCH] Support regular file type in _swistat

Previously, the implementation of _swistat() for ARM assumed all files
to be of type character device. This change adds support for stat-ing
regular files
---
 libgloss/arm/syscalls.c        | 44 +++++++++++++++++++-----------
 newlib/libc/sys/arm/syscalls.c | 61 ++++++++++++++++++++++++++++++++++++------
 2 files changed, 82 insertions(+), 23 deletions(-)

diff --git a/libgloss/arm/syscalls.c b/libgloss/arm/syscalls.c
index fc394f94bda37dfb2dfc2d12a5dd923391b9e025..652301cef67489d4b85bd009c14713df29d77d5e 100644
--- a/libgloss/arm/syscalls.c
+++ b/libgloss/arm/syscalls.c
@@ -59,6 +59,7 @@ struct fdent
 };
 
 #define MAX_OPEN_FILES 20
+#define DEFAULT_BLOCK_SIZE 1024
 
 /* User file descriptors (fd) are integer indexes into 
    the openfiles[] array. Error checking is done by using
@@ -728,33 +729,46 @@ _sbrk (ptrdiff_t incr)
 int 
 _swistat (int fd, struct stat * st)
 {
-  struct fdent *pfd;
-  int res;
-
-  pfd = findslot (fd);
+  struct fdent *pfd = findslot (fd);
   if (pfd == NULL)
     {
       errno = EBADF;
       return -1;
     }
 
-  /* Always assume a character device,
-     with 1024 byte blocks. */
-  st->st_mode |= S_IFCHR;
-  st->st_blksize = 1024;
+  int isCharDevice;
 #ifdef ARM_RDI_MONITOR
-  res = checkerror (do_AngelSWI (AngelSWI_Reason_FLen, &pfd->handle));
+  isCharDevice = checkerror (do_AngelSWI (AngelSWI_Reason_IsTTY, &pfd->handle));
 #else
   asm ("mov r0, %2; swi %a1; mov %0, r0"
-       : "=r" (res)
+       : "=r" (isCharDevice)
+       : "i" (SWI_IsTTY), "r" (pfd->handle)
+       : "r0");
+  checkerror(isCharDevice);
+#endif
+
+  int flen;
+#ifdef ARM_RDI_MONITOR
+  flen = checkerror (do_AngelSWI (AngelSWI_Reason_FLen, &pfd->handle));
+#else
+  asm ("mov r0, %2; swi %a1; mov %0, r0"
+       : "=r" (flen)
        : "i" (SWI_Flen), "r" (pfd->handle)
        : "r0");
-  checkerror (res);
+  checkerror(flen);
 #endif
-  if (res == -1)
-    return -1;
-  /* Return the file size. */
-  st->st_size = res;
+
+  st->st_size = flen;
+  st->st_blksize = DEFAULT_BLOCK_SIZE;
+
+  if (isCharDevice)
+    st->st_mode |= S_IFCHR;
+  else
+    {
+      st->st_mode |= S_IFREG;
+      st->st_blocks = (flen + DEFAULT_BLOCK_SIZE - 1) / DEFAULT_BLOCK_SIZE;
+    }
+
   return 0;
 }
 
diff --git a/newlib/libc/sys/arm/syscalls.c b/newlib/libc/sys/arm/syscalls.c
index 1f722298024885d04691a1af1ff509318b36b7a6..5156f1ac81663fffa9b8286133f43181d6f16852 100644
--- a/newlib/libc/sys/arm/syscalls.c
+++ b/newlib/libc/sys/arm/syscalls.c
@@ -28,6 +28,7 @@ int	_unlink		(const char *);
 int	_link		(const char *, const char *);
 int	_stat		(const char *, struct stat *);
 int	_fstat		(int, struct stat *);
+int     _swistat        (int fd, struct stat * st);
 void *	_sbrk		(ptrdiff_t);
 pid_t	_getpid		(void);
 int	_kill		(int, int);
@@ -84,6 +85,8 @@ poslog;
 #define MAX_OPEN_FILES 20
 static poslog openfiles [MAX_OPEN_FILES];
 
+#define DEFAULT_BLOCK_SIZE 1024
+
 static int
 findslot (int fh)
 {
@@ -543,33 +546,75 @@ _sbrk (ptrdiff_t incr)
   return (void *) prev_heap_end;
 }
 
+int 
+_swistat (int fd, struct stat * st)
+{
+  struct fdent *pfd = findslot (fd);
+  if (pfd == NULL)
+    {
+      errno = EBADF;
+      return -1;
+    }
+
+  int isCharDevice;
+#ifdef ARM_RDI_MONITOR
+  isCharDevice = checkerror (do_AngelSWI (AngelSWI_Reason_IsTTY, &pfd->handle));
+#else
+  asm ("mov r0, %2; swi %a1; mov %0, r0"
+       : "=r" (isCharDevice)
+       : "i" (SWI_IsTTY), "r" (pfd->handle)
+       : "r0");
+  checkerror(isCharDevice);
+#endif
+
+  int flen;
+#ifdef ARM_RDI_MONITOR
+  flen = checkerror (do_AngelSWI (AngelSWI_Reason_FLen, &pfd->handle));
+#else
+  asm ("mov r0, %2; swi %a1; mov %0, r0"
+       : "=r" (flen)
+       : "i" (SWI_Flen), "r" (pfd->handle)
+       : "r0");
+  checkerror(flen);
+#endif
+
+  st->st_size = flen;
+  st->st_blksize = DEFAULT_BLOCK_SIZE;
+
+  if (isCharDevice)
+    st->st_mode |= S_IFCHR;
+  else
+    {
+      st->st_mode |= S_IFREG;
+      st->st_blocks = (flen + DEFAULT_BLOCK_SIZE - 1) / DEFAULT_BLOCK_SIZE;
+    }
+
+  return 0;
+}
+
 extern void memset (struct stat *, int, unsigned int);
 
 int __attribute__((weak))
 _fstat (int file, struct stat * st)
 {
   memset (st, 0, sizeof (* st));
-  st->st_mode = S_IFCHR;
-  st->st_blksize = 1024;
-  return 0;
-  file = file;
+  return _swistat (file, st);
 }
 
 int __attribute__((weak))
 _stat (const char *fname, struct stat *st)
 {
   int file;
-
+  memset (st, 0, sizeof (* st));
   /* The best we can do is try to open the file readonly.  If it exists,
      then we can guess a few things about it.  */
   if ((file = _open (fname, O_RDONLY)) < 0)
     return -1;
 
-  memset (st, 0, sizeof (* st));
   st->st_mode = S_IFREG | S_IREAD;
-  st->st_blksize = 1024;
+  res = _swistat (file, st);
   _swiclose (file); /* Not interested in the error.  */
-  return 0;
+  return res;
 }
 
 int __attribute__((weak))
-- 
2.7.4