Change the C wrappers for mmap/lseek/pread/pwrite/truncate/ftruncate to

call the pad-less versions of the corresponding syscalls if the running
kernel supports it.  Check kern.osreldate once per program and cache the
result to select the appropriate syscall.  This maintains userland
compatability with kernel.old's from quite a while back.

Approved by:  re (kensmith)

6 files changed, 33 insertions, 8 deletions

diff --git a/lib/libc/sys/ftruncate.c b/lib/libc/sys/ftruncate.c
index fcd2ef8..78b5a36 100644
--- a/lib/libc/sys/ftruncate.c
+++ b/lib/libc/sys/ftruncate.c
@@ -36,6 +36,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/types.h>
 #include <sys/syscall.h>
 #include <unistd.h>
+#include "libc_private.h"
 
 /*
  * This function provides 64-bit offset padding that
@@ -47,5 +48,8 @@ ftruncate(fd, length)
 	off_t	length;
 {
 
-	return(__syscall((quad_t)SYS_ftruncate, fd, 0, length));
+	if (__getosreldate() >= 700051)
+		return(__sys_ftruncate(fd, length));
+	else
+		return(__sys_freebsd6_ftruncate(fd, 0, length));
 }
diff --git a/lib/libc/sys/lseek.c b/lib/libc/sys/lseek.c
index 8613678..a086be1 100644
--- a/lib/libc/sys/lseek.c
+++ b/lib/libc/sys/lseek.c
@@ -36,6 +36,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/types.h>
 #include <sys/syscall.h>
 #include <unistd.h>
+#include "libc_private.h"
 
 /*
  * This function provides 64-bit offset padding that
@@ -47,5 +48,9 @@ lseek(fd, offset, whence)
 	off_t	offset;
 	int	whence;
 {
-	return(__syscall((quad_t)SYS_lseek, fd, 0, offset, whence));
+
+	if (__getosreldate() >= 700051)
+		return(__sys_lseek(fd, offset, whence));
+	else
+		return(__sys_freebsd6_lseek(fd, 0, offset, whence));
 }
diff --git a/lib/libc/sys/mmap.c b/lib/libc/sys/mmap.c
index 8b22147..cfdb944 100644
--- a/lib/libc/sys/mmap.c
+++ b/lib/libc/sys/mmap.c
@@ -37,6 +37,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/mman.h>
 #include <sys/syscall.h>
 #include <unistd.h>
+#include "libc_private.h"
 
 /*
  * This function provides 64-bit offset padding that
@@ -52,6 +53,9 @@ mmap(addr, len, prot, flags, fd, offset)
 	off_t	offset;
 {
 
-	return ((void *)(intptr_t)__syscall((quad_t)SYS_mmap, addr, len, prot,
-	    flags, fd, 0, offset));
+	if (__getosreldate() >= 700051)
+		return (__sys_mmap(addr, len, prot, flags, fd, offset));
+	else
+
+		return (__sys_freebsd6_mmap(addr, len, prot, flags, fd, 0, offset));
 }
diff --git a/lib/libc/sys/pread.c b/lib/libc/sys/pread.c
index 1d2fee6..7566566 100644
--- a/lib/libc/sys/pread.c
+++ b/lib/libc/sys/pread.c
@@ -36,6 +36,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/types.h>
 #include <sys/syscall.h>
 #include <unistd.h>
+#include "libc_private.h"
 
 /*
  * This function provides 64-bit offset padding that
@@ -48,5 +49,9 @@ pread(fd, buf, nbyte, offset)
 	size_t	nbyte;
 	off_t	offset;
 {
-	return ((ssize_t)__syscall((quad_t)SYS_pread, fd, buf, nbyte, 0, offset));
+
+	if (__getosreldate() >= 700051)
+		return (__sys_pread(fd, buf, nbyte, offset));
+	else
+		return (__sys_freebsd6_pread(fd, buf, nbyte, 0, offset));
 }
diff --git a/lib/libc/sys/pwrite.c b/lib/libc/sys/pwrite.c
index ebbb1ec..d17ed29 100644
--- a/lib/libc/sys/pwrite.c
+++ b/lib/libc/sys/pwrite.c
@@ -36,6 +36,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/types.h>
 #include <sys/syscall.h>
 #include <unistd.h>
+#include "libc_private.h"
 
 /*
  * This function provides 64-bit offset padding that
@@ -48,5 +49,8 @@ pwrite(fd, buf, nbyte, offset)
 	size_t	nbyte;
 	off_t	offset;
 {
-	return ((ssize_t)__syscall((quad_t)SYS_pwrite, fd, buf, nbyte, 0, offset));
+	if (__getosreldate() >= 700051)
+		return (__sys_pwrite(fd, buf, nbyte, offset));
+	else
+		return (__sys_freebsd6_pwrite(fd, buf, nbyte, 0, offset));
 }
diff --git a/lib/libc/sys/truncate.c b/lib/libc/sys/truncate.c
index e26f3f5..375c9d9 100644
--- a/lib/libc/sys/truncate.c
+++ b/lib/libc/sys/truncate.c
@@ -35,8 +35,8 @@ __FBSDID("$FreeBSD$");
 
 #include <sys/types.h>
 #include <sys/syscall.h>
-
 #include <unistd.h>
+#include "libc_private.h"
 
 /*
  * This function provides 64-bit offset padding that
@@ -48,5 +48,8 @@ truncate(path, length)
 	off_t	length;
 {
 
-	return(__syscall((quad_t)SYS_truncate, path, 0, length));
+	if (__getosreldate() >= 700051)
+		return(__sys_truncate(path, length));
+	else
+		return(__sys_freebsd6_truncate(path, 0, length));
 }