From: Philippe Gerum <rpm at xenomai.org>
set_fs() is on its way out, so we cannot open code a file read
operation by calling the VFS handler directly anymore, faking a user
address space.
We do have kernel interfaces for loading files though, particularly
kernel_read_file(). So let's use that one for loading the
configuration file contents. Unfortunately, the signature of this
service changed during the 5.9-rc cycle, so we have to resort to an
ugly wrapper to cope with all supported kernels once again. Sigh.
Signed-off-by: Philippe Gerum <rpm at xenomai.org>
---
.../include/asm-generic/xenomai/wrappers.h | 15 ++++
kernel/drivers/net/stack/rtcfg/rtcfg_ioctl.c | 74 +++++++++----------
2 files changed, 52 insertions(+), 37 deletions(-)
diff --git a/kernel/cobalt/include/asm-generic/xenomai/wrappers.h b/kernel/cobalt/include/asm-generic/xenomai/wrappers.h
index 652a04759f..54fdc8b05e 100644
--- a/kernel/cobalt/include/asm-generic/xenomai/wrappers.h
+++ b/kernel/cobalt/include/asm-generic/xenomai/wrappers.h
@@ -216,4 +216,19 @@ devm_hwmon_device_register_with_groups(struct device *dev, const char *name,
#define vmalloc_kernel(__size, __flags) __vmalloc(__size, GFP_KERNEL|__flags)
#endif
+#if LINUX_VERSION_CODE < KERNEL_VERSION(5,9,0)
+#define read_file_from_kernel(__file, __buf, __buf_size, __file_size, __id) \
+ ({ \
+ loff_t ___file_size; \
+ int __ret; \
+ __ret = kernel_read_file(__file, __buf, &___file_size, \
+ __buf_size, __id); \
+ (*__file_size) = ___file_size; \
+ __ret; \
+ })
+#else
+#define read_file_from_kernel(__file, __buf, __buf_size, __file_size, __id) \
+ kernel_read_file(__file, 0, __buf, __buf_size, __file_size, __id)
+#endif
+
#endif /* _COBALT_ASM_GENERIC_WRAPPERS_H */
diff --git a/kernel/drivers/net/stack/rtcfg/rtcfg_ioctl.c b/kernel/drivers/net/stack/rtcfg/rtcfg_ioctl.c
index 769b4e143c..158d7118f2 100644
--- a/kernel/drivers/net/stack/rtcfg/rtcfg_ioctl.c
+++ b/kernel/drivers/net/stack/rtcfg/rtcfg_ioctl.c
@@ -22,6 +22,7 @@
*
*/
+#include <linux/fs.h>
#include <linux/file.h>
#include <linux/vmalloc.h>
@@ -196,6 +197,40 @@ void cleanup_cmd_detach(void *priv_data)
kfree_rtskb(cmd->args.detach.stage2_chain);
}
+static int load_cfg_file(struct rtcfg_file *cfgfile, struct rtcfg_cmd *cmd)
+{
+ size_t file_size = 0;
+ struct file *filp;
+ loff_t i_size;
+ int ret;
+
+ filp = filp_open(cfgfile->name, O_RDONLY, 0);
+ if (IS_ERR(filp))
+ return PTR_ERR(filp);
+
+ i_size = i_size_read(file_inode(filp));
+ if (i_size <= 0) {
+ /* allocate buffer even for empty files */
+ cfgfile->buffer = vmalloc(1);
+ } else {
+ cfgfile->buffer = NULL; /* Leave allocation to the kernel. */
+ ret = read_file_from_kernel(filp, &cfgfile->buffer,
+ i_size_read(file_inode(filp)),
+ &file_size, READING_UNKNOWN);
+ if (ret < 0) {
+ fput(filp);
+ return ret;
+ }
+ }
+
+ fput(filp);
+ cfgfile->size = file_size;
+
+ /* dispatch again, this time with new file attached */
+ return rtpc_dispatch_call(rtcfg_event_handler, 0, cmd,
+ sizeof(*cmd), NULL, cleanup_cmd_add);
+}
+
int rtcfg_ioctl_add(struct rtnet_device *rtdev, struct rtcfg_cmd *cmd)
{
struct rtcfg_connection *conn_buf;
@@ -264,46 +299,11 @@ int rtcfg_ioctl_add(struct rtnet_device *rtdev, struct rtcfg_cmd *cmd)
/* load file if missing */
if (ret > 0) {
- struct file *filp;
- mm_segment_t oldfs;
-
- filp = filp_open(file->name, O_RDONLY, 0);
- if (IS_ERR(filp)) {
+ ret = load_cfg_file(file, cmd);
+ if (ret) {
rtcfg_unlockwr_proc(cmd->internal.data.ifindex);
- ret = PTR_ERR(filp);
goto err;
}
-
- file->size = filp->f_path.dentry->d_inode->i_size;
-
- /* allocate buffer even for empty files */
- file->buffer = vmalloc((file->size) ? file->size : 1);
- if (file->buffer == NULL) {
- rtcfg_unlockwr_proc(cmd->internal.data.ifindex);
- fput(filp);
- ret = -ENOMEM;
- goto err;
- }
-
- oldfs = get_fs();
- set_fs(KERNEL_DS);
- filp->f_pos = 0;
-
- ret = filp->f_op->read(filp, file->buffer, file->size,
- &filp->f_pos);
-
- set_fs(oldfs);
- fput(filp);
-
- if (ret != (int)file->size) {
- rtcfg_unlockwr_proc(cmd->internal.data.ifindex);
- ret = -EIO;
- goto err;
- }
-
- /* dispatch again, this time with new file attached */
- ret = rtpc_dispatch_call(rtcfg_event_handler, 0, cmd,
- sizeof(*cmd), NULL, cleanup_cmd_add);
}
return ret;
--
2.26.2