svn commit: r296060 - in head/sys: compat/freebsd32 kern sys

[Mark Johnston]

Author: markj
Date: Thu Feb 25 19:58:23 2016
New Revision: 296060
URL: https://svnweb.freebsd.org/changeset/base/296060

Log:
  Improve error handling for posix_fallocate(2) and posix_fadvise(2).
  
  - Set td_errno so that ktrace and dtrace can obtain the syscall error
    number in the usual way.
  - Pass negative error numbers directly to the syscall layer, as they're
    not intended to be returned to userland.
  
  Reviewed by:	kib
  Sponsored by:	EMC / Isilon Storage Division
  Differential Revision: https://reviews.freebsd.org/D5425

Modified:
  head/sys/compat/freebsd32/freebsd32_misc.c
  head/sys/kern/sys_generic.c
  head/sys/kern/vfs_syscalls.c
  head/sys/sys/syscallsubr.h

Modified: head/sys/compat/freebsd32/freebsd32_misc.c
==============================================================================
--- head/sys/compat/freebsd32/freebsd32_misc.c	Thu Feb 25 19:29:55 2016	(r296059)
+++ head/sys/compat/freebsd32/freebsd32_misc.c	Thu Feb 25 19:58:23 2016	(r296060)
@@ -2965,21 +2965,22 @@ int
 freebsd32_posix_fallocate(struct thread *td,
     struct freebsd32_posix_fallocate_args *uap)
 {
+	int error;
 
-	td->td_retval[0] = kern_posix_fallocate(td, uap->fd,
+	error = kern_posix_fallocate(td, uap->fd,
 	    PAIR32TO64(off_t, uap->offset), PAIR32TO64(off_t, uap->len));
-	return (0);
+	return (kern_posix_error(td, error));
 }
 
 int
 freebsd32_posix_fadvise(struct thread *td,
     struct freebsd32_posix_fadvise_args *uap)
 {
+	int error;
 
-	td->td_retval[0] = kern_posix_fadvise(td, uap->fd,
-	    PAIR32TO64(off_t, uap->offset), PAIR32TO64(off_t, uap->len),
-	    uap->advice);
-	return (0);
+	error = kern_posix_fadvise(td, uap->fd, PAIR32TO64(off_t, uap->offset),
+	    PAIR32TO64(off_t, uap->len), uap->advice);
+	return (kern_posix_error(td, error));
 }
 
 int

Modified: head/sys/kern/sys_generic.c
==============================================================================
--- head/sys/kern/sys_generic.c	Thu Feb 25 19:29:55 2016	(r296059)
+++ head/sys/kern/sys_generic.c	Thu Feb 25 19:58:23 2016	(r296060)
@@ -1910,3 +1910,19 @@ selectinit(void *dummy __unused)
 	    NULL, NULL, UMA_ALIGN_PTR, 0);
 	mtxpool_select = mtx_pool_create("select mtxpool", 128, MTX_DEF);
 }
+
+/*
+ * Set up a syscall return value that follows the convention specified for
+ * posix_* functions.
+ */
+int
+kern_posix_error(struct thread *td, int error)
+{
+
+	if (error <= 0)
+		return (error);
+	td->td_errno = error;
+	td->td_pflags |= TDP_NERRNO;
+	td->td_retval[0] = error;
+	return (0);
+}

Modified: head/sys/kern/vfs_syscalls.c
==============================================================================
--- head/sys/kern/vfs_syscalls.c	Thu Feb 25 19:29:55 2016	(r296059)
+++ head/sys/kern/vfs_syscalls.c	Thu Feb 25 19:58:23 2016	(r296060)
@@ -4533,10 +4533,10 @@ kern_posix_fallocate(struct thread *td, 
 int
 sys_posix_fallocate(struct thread *td, struct posix_fallocate_args *uap)
 {
+	int error;
 
-	td->td_retval[0] = kern_posix_fallocate(td, uap->fd, uap->offset,
-	    uap->len);
-	return (0);
+	error = kern_posix_fallocate(td, uap->fd, uap->offset, uap->len);
+	return (kern_posix_error(td, error));
 }
 
 /*
@@ -4668,8 +4668,9 @@ out:
 int
 sys_posix_fadvise(struct thread *td, struct posix_fadvise_args *uap)
 {
+	int error;
 
-	td->td_retval[0] = kern_posix_fadvise(td, uap->fd, uap->offset,
-	    uap->len, uap->advice);
-	return (0);
+	error = kern_posix_fadvise(td, uap->fd, uap->offset, uap->len,
+	    uap->advice);
+	return (kern_posix_error(td, error));
 }

Modified: head/sys/sys/syscallsubr.h
==============================================================================
--- head/sys/sys/syscallsubr.h	Thu Feb 25 19:29:55 2016	(r296059)
+++ head/sys/sys/syscallsubr.h	Thu Feb 25 19:58:23 2016	(r296060)
@@ -158,6 +158,7 @@ int	kern_pipe(struct thread *td, int fil
 	    struct filecaps *fcaps1, struct filecaps *fcaps2);
 int	kern_poll(struct thread *td, struct pollfd *fds, u_int nfds,
 	    struct timespec *tsp, sigset_t *uset);
+int	kern_posix_error(struct thread *td, int error);
 int	kern_posix_fadvise(struct thread *td, int fd, off_t offset, off_t len,
 	    int advice);
 int	kern_posix_fallocate(struct thread *td, int fd, off_t offset,