[klibc] Add pread and pwrite 32bit syscall wrappers for parisc

On the hppa arch (32bit userspace and 32 or 64bit kernel), the fstype
program fails to detect the filesystem.  The reason for this failure
is, that fstype calls the pread() syscall, which has on some
architectures with 32bit userspace a different calling syntax.  I
noticed this bug on hppa, but I assume s390 (32bit) and others might
run into similiar issues.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>

5 files changed, 69 insertions, 2 deletions

diff --git a/usr/include/endian.h b/usr/include/endian.h
index a6cd6d9bcde478..61cda3a5315127 100644
--- a/usr/include/endian.h
+++ b/usr/include/endian.h
@@ -12,4 +12,10 @@
 #define PDP_ENDIAN	__PDP_ENDIAN
 #define BYTE_ORDER	__BYTE_ORDER
 
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+# define __LONG_LONG_PAIR(HI, LO) LO, HI
+#elif __BYTE_ORDER == __BIG_ENDIAN
+# define __LONG_LONG_PAIR(HI, LO) HI, LO
+#endif
+
 #endif				/* _ENDIAN_H */
diff --git a/usr/klibc/Kbuild b/usr/klibc/Kbuild
index 40d43c7889e55c..d3e2b9fbc99b15 100644
--- a/usr/klibc/Kbuild
+++ b/usr/klibc/Kbuild
@@ -35,6 +35,7 @@ klib-y += vsnprintf.o snprintf.o vsprintf.o sprintf.o \
 	  siglongjmp.o \
 	  sigaction.o sigpending.o sigprocmask.o sigsuspend.o \
 	  pselect.o ppoll.o \
+	  pread.o pwrite.o \
 	  brk.o sbrk.o malloc.o realloc.o zalloc.o calloc.o \
 	  mmap.o shm_open.o shm_unlink.o \
 	  memcpy.o memcmp.o memset.o memccpy.o memmem.o memswap.o \
diff --git a/usr/klibc/SYSCALLS.def b/usr/klibc/SYSCALLS.def
index 41cfa171b0e416..c56e8f99783814 100644
--- a/usr/klibc/SYSCALLS.def
+++ b/usr/klibc/SYSCALLS.def
@@ -189,8 +189,10 @@ int fdatasync,fsync::fdatasync(int);
 int readv(int, const struct iovec *, int);
 int writev(int, const struct iovec *, int);
 int ftruncate64,ftruncate::ftruncate(int, off_t);
-ssize_t pread64,pread::pread(int, void *, size_t, off_t);
-ssize_t pwrite64,pwrite::pwrite(int, void *, size_t, off_t);
+<parisc> ssize_t pread64,pread::__pread(int, void *, size_t, off_t);
+<parisc> ssize_t pwrite64,pwrite::__pwrite(int, void *, size_t, off_t);
+<!parisc> ssize_t pread64,pread::pread(int, void *, size_t, off_t);
+<!parisc> ssize_t pwrite64,pwrite::pwrite(int, void *, size_t, off_t);
 int sync_file_range,fdatasync,fsync::sync_file_range(int, off_t, off_t, unsigned int);
 <?> int splice(int, off_t *, int, off_t *, size_t, unsigned int);
 <?> int tee(int, int, size_t, unsigned int);
diff --git a/usr/klibc/pread.c b/usr/klibc/pread.c
new file mode 100644
index 00000000000000..0d8c3b13f4fc87
--- /dev/null
+++ b/usr/klibc/pread.c
@@ -0,0 +1,29 @@
+/*
+ * pread.c
+ *
+ * Some architectures need to wrap the system call
+ */
+
+#include <endian.h>
+#include <sys/syscall.h>
+
+#if defined(__hppa__)
+
+#if _BITSIZE == 32
+extern size_t __pread(int, void *, size_t, unsigned int, unsigned int);
+#else
+extern size_t __pread(int, void *, size_t, off_t);
+#endif
+
+size_t pread(int fd, void *buf, size_t count, off_t offset)
+{
+#if _BITSIZE == 32
+	unsigned int hi = offset >> 32;
+	unsigned int lo = (unsigned int) offset;
+	return __pread(fd, buf, count, __LONG_LONG_PAIR(hi, lo));
+#else
+	return __pread(fd, buf, count, offset);
+#endif
+}
+
+#endif
diff --git a/usr/klibc/pwrite.c b/usr/klibc/pwrite.c
new file mode 100644
index 00000000000000..691d0e4a1a74cf
--- /dev/null
+++ b/usr/klibc/pwrite.c
@@ -0,0 +1,29 @@
+/*
+ * pwrite.c
+ *
+ * Some architectures need to wrap the system call
+ */
+
+#include <endian.h>
+#include <sys/syscall.h>
+
+#if defined(__hppa__)
+
+#if _BITSIZE == 32
+extern ssize_t __pwrite(int, const void *, size_t, unsigned int, unsigned int);
+#else
+extern ssize_t __pwrite(int, const void *, size_t, off_t);
+#endif
+
+size_t pwrite(int fd, void *buf, size_t count, off_t offset)
+{
+#if _BITSIZE == 32
+	unsigned int hi = offset >> 32;
+	unsigned int lo = (unsigned int) offset;
+	return __pwrite(fd, buf, count, __LONG_LONG_PAIR(hi, lo));
+#else
+	return __pwrite(fd, buf, count, offset);
+#endif
+}
+
+#endif