create_proc_entry and !CONFIG_PROC_FS
Hi,
I've observed a possible problem with create_proc_entry and !CONFIG_PROC_FS.
If !CONFIG_PROC_FS include/linux/proc_fs.h includes a dummy create_proc_entry that simply returns NULL.
Unfortunately, many callers of this function do things like e.g.
static int __init br2684_init(void)
{
struct proc_dir_entry *p;
if ((p = create_proc_entry("br2684", 0, atm_proc_root)) == NULL)
return -ENOMEM;
p->proc_fops = &br2684_proc_operations;
br2684_ioctl_set(br2684_ioctl);
return 0;
}IOW, the dummy create_proc_entry fixes the compilation but the init function always returns -ENOMEM if !CONFIG_PROC_FS.
Is there any better solution than removing the dummy create_proc_entry and #ifdef'ing all places where it's used?
cu
Adrian
Signature · 4 lines
"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon SeedQuoted 22 lines · Adrian Bunk
Hi,
I've observed a possible problem with
create_proc_entryand !CONFIG_PROC_FS.If !CONFIG_PROC_FS
include/linux/proc_fs.hincludes a dummycreate_proc_entrythat simply returns NULL.Unfortunately, many callers of this function do things like e.g.
static int
__initbr2684_init(void){ struct proc_dir_entry *p; if ((p = create_proc_entry("br2684", 0, atm_proc_root)) == NULL) return -ENOMEM; p->proc_fops = &br2684_proc_operations; br2684_ioctl_set(br2684_ioctl); return 0; }
Quoted 5 lines
IOW, the dummy
create_proc_entryfixes the compilation but the init function always returns-ENOMEMif !CONFIG_PROC_FS.Is there any better solution than removing the dummy
create_proc_entryand #ifdef'ing all places where it's used?
The normal fix would be to sprinkle ifdefs throughout the driver itself.
You need to lok at the driver and ask yourself "is anyone ever going to want to use this in a no-procfs system". Probably, the answer is always "no". In which case appropriate fixes would be to ignore the problem, or disable the driver in config if !CONFIG_PROC_FS.
Quoted 23 lines · Andrew Morton
Quoted 22 lines · Adrian Bunk
Hi,
I've observed a possible problem with
create_proc_entryand !CONFIG_PROC_FS.If !CONFIG_PROC_FS
include/linux/proc_fs.hincludes a dummycreate_proc_entrythat simply returns NULL.Unfortunately, many callers of this function do things like e.g.
static int
__initbr2684_init(void){ struct proc_dir_entry *p; if ((p = create_proc_entry("br2684", 0, atm_proc_root)) == NULL) return -ENOMEM; p->proc_fops = &br2684_proc_operations; br2684_ioctl_set(br2684_ioctl); return 0; }
Quoted 7 lines
Quoted 5 lines
IOW, the dummy
create_proc_entryfixes the compilation but the init function always returns-ENOMEMif !CONFIG_PROC_FS.Is there any better solution than removing the dummy
create_proc_entryand #ifdef'ing all places where it's used?The normal fix would be to sprinkle ifdefs throughout the driver itself.
That's what I was thinking of when I wrote "#ifdef'ing all places where it's used"...
Quoted 4 lines
You need to lok at the driver and ask yourself "is anyone ever going to want to use this in a no-procfs system". Probably, the answer is always "no". In which case appropriate fixes would be to ignore the problem, or disable the driver in config if !CONFIG_PROC_FS.
The latter is IMHO the better solution, a driver that compiles but doesn't work (#if !CONFIG_PROC_FS) is simply useless.
cu
Adrian
Signature · 4 lines
"Is there not promise of rain?" Ling Tan asked suddenly out
of the darkness. There had been need of rain for many days.
"Only a promise," Lao Er said.
Pearl S. Buck - Dragon Seed