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author | Alexey Dobriyan <adobriyan@gmail.com> | 2009-03-25 19:48:06 (GMT) |
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committer | Alexey Dobriyan <adobriyan@gmail.com> | 2009-03-30 21:14:44 (GMT) |
commit | 99b76233803beab302123d243eea9e41149804f3 (patch) | |
tree | 398178210fe66845ccd6fa4258ba762a87e023ad /arch/ia64 | |
parent | 3dec7f59c370c7b58184d63293c3dc984d475840 (diff) | |
download | linux-99b76233803beab302123d243eea9e41149804f3.tar.xz |
proc 2/2: remove struct proc_dir_entry::owner
Setting ->owner as done currently (pde->owner = THIS_MODULE) is racy
as correctly noted at bug #12454. Someone can lookup entry with NULL
->owner, thus not pinning enything, and release it later resulting
in module refcount underflow.
We can keep ->owner and supply it at registration time like ->proc_fops
and ->data.
But this leaves ->owner as easy-manipulative field (just one C assignment)
and somebody will forget to unpin previous/pin current module when
switching ->owner. ->proc_fops is declared as "const" which should give
some thoughts.
->read_proc/->write_proc were just fixed to not require ->owner for
protection.
rmmod'ed directories will be empty and return "." and ".." -- no harm.
And directories with tricky enough readdir and lookup shouldn't be modular.
We definitely don't want such modular code.
Removing ->owner will also make PDE smaller.
So, let's nuke it.
Kudos to Jeff Layton for reminding about this, let's say, oversight.
http://bugzilla.kernel.org/show_bug.cgi?id=12454
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Diffstat (limited to 'arch/ia64')
-rw-r--r-- | arch/ia64/kernel/palinfo.c | 2 | ||||
-rw-r--r-- | arch/ia64/sn/kernel/sn2/prominfo_proc.c | 9 |
2 files changed, 2 insertions, 9 deletions
diff --git a/arch/ia64/kernel/palinfo.c b/arch/ia64/kernel/palinfo.c index e5c57f4..a4f19c7 100644 --- a/arch/ia64/kernel/palinfo.c +++ b/arch/ia64/kernel/palinfo.c @@ -1002,8 +1002,6 @@ create_palinfo_proc_entries(unsigned int cpu) *pdir = create_proc_read_entry( palinfo_entries[j].name, 0, cpu_dir, palinfo_read_entry, (void *)f.value); - if (*pdir) - (*pdir)->owner = THIS_MODULE; pdir++; } } diff --git a/arch/ia64/sn/kernel/sn2/prominfo_proc.c b/arch/ia64/sn/kernel/sn2/prominfo_proc.c index 4dcce3d..e633288 100644 --- a/arch/ia64/sn/kernel/sn2/prominfo_proc.c +++ b/arch/ia64/sn/kernel/sn2/prominfo_proc.c @@ -225,7 +225,6 @@ static struct proc_dir_entry *sgi_prominfo_entry; int __init prominfo_init(void) { struct proc_dir_entry **entp; - struct proc_dir_entry *p; cnodeid_t cnodeid; unsigned long nasid; int size; @@ -246,14 +245,10 @@ int __init prominfo_init(void) sprintf(name, "node%d", cnodeid); *entp = proc_mkdir(name, sgi_prominfo_entry); nasid = cnodeid_to_nasid(cnodeid); - p = create_proc_read_entry("fit", 0, *entp, read_fit_entry, + create_proc_read_entry("fit", 0, *entp, read_fit_entry, (void *)nasid); - if (p) - p->owner = THIS_MODULE; - p = create_proc_read_entry("version", 0, *entp, + create_proc_read_entry("version", 0, *entp, read_version_entry, (void *)nasid); - if (p) - p->owner = THIS_MODULE; entp++; } |