From 99b76233803beab302123d243eea9e41149804f3 Mon Sep 17 00:00:00 2001 From: Alexey Dobriyan Date: Wed, 25 Mar 2009 22:48:06 +0300 Subject: 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 --- arch/alpha/kernel/srm_env.c | 5 ----- arch/blackfin/mm/sram-alloc.c | 1 - arch/ia64/kernel/palinfo.c | 2 -- arch/ia64/sn/kernel/sn2/prominfo_proc.c | 9 ++------- arch/powerpc/kernel/rtas_flash.c | 1 - arch/sparc/kernel/led.c | 1 - arch/x86/kernel/cpu/mtrr/if.c | 10 +--------- 7 files changed, 3 insertions(+), 26 deletions(-) (limited to 'arch') diff --git a/arch/alpha/kernel/srm_env.c b/arch/alpha/kernel/srm_env.c index 78ad7cd..d12af47 100644 --- a/arch/alpha/kernel/srm_env.c +++ b/arch/alpha/kernel/srm_env.c @@ -218,7 +218,6 @@ srm_env_init(void) BASE_DIR); goto cleanup; } - base_dir->owner = THIS_MODULE; /* * Create per-name subdirectory @@ -229,7 +228,6 @@ srm_env_init(void) BASE_DIR, NAMED_DIR); goto cleanup; } - named_dir->owner = THIS_MODULE; /* * Create per-number subdirectory @@ -241,7 +239,6 @@ srm_env_init(void) goto cleanup; } - numbered_dir->owner = THIS_MODULE; /* * Create all named nodes @@ -254,7 +251,6 @@ srm_env_init(void) goto cleanup; entry->proc_entry->data = (void *) entry; - entry->proc_entry->owner = THIS_MODULE; entry->proc_entry->read_proc = srm_env_read; entry->proc_entry->write_proc = srm_env_write; @@ -275,7 +271,6 @@ srm_env_init(void) entry->id = var_num; entry->proc_entry->data = (void *) entry; - entry->proc_entry->owner = THIS_MODULE; entry->proc_entry->read_proc = srm_env_read; entry->proc_entry->write_proc = srm_env_write; } diff --git a/arch/blackfin/mm/sram-alloc.c b/arch/blackfin/mm/sram-alloc.c index 834cab7..530d139 100644 --- a/arch/blackfin/mm/sram-alloc.c +++ b/arch/blackfin/mm/sram-alloc.c @@ -854,7 +854,6 @@ static int __init sram_proc_init(void) printk(KERN_WARNING "unable to create /proc/sram\n"); return -1; } - ptr->owner = THIS_MODULE; ptr->read_proc = sram_proc_read; return 0; } 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++; } diff --git a/arch/powerpc/kernel/rtas_flash.c b/arch/powerpc/kernel/rtas_flash.c index 149cb11..13011a9 100644 --- a/arch/powerpc/kernel/rtas_flash.c +++ b/arch/powerpc/kernel/rtas_flash.c @@ -669,7 +669,6 @@ static void remove_flash_pde(struct proc_dir_entry *dp) { if (dp) { kfree(dp->data); - dp->owner = NULL; remove_proc_entry(dp->name, dp->parent); } } diff --git a/arch/sparc/kernel/led.c b/arch/sparc/kernel/led.c index adaaed4..00d034e 100644 --- a/arch/sparc/kernel/led.c +++ b/arch/sparc/kernel/led.c @@ -126,7 +126,6 @@ static int __init led_init(void) led = proc_create("led", 0, NULL, &led_proc_fops); if (!led) return -ENOMEM; - led->owner = THIS_MODULE; printk(KERN_INFO "led: version %s, Lars Kotthoff \n", diff --git a/arch/x86/kernel/cpu/mtrr/if.c b/arch/x86/kernel/cpu/mtrr/if.c index 4c42146..fb73a52 100644 --- a/arch/x86/kernel/cpu/mtrr/if.c +++ b/arch/x86/kernel/cpu/mtrr/if.c @@ -377,10 +377,6 @@ static const struct file_operations mtrr_fops = { .release = mtrr_close, }; - -static struct proc_dir_entry *proc_root_mtrr; - - static int mtrr_seq_show(struct seq_file *seq, void *offset) { char factor; @@ -423,11 +419,7 @@ static int __init mtrr_if_init(void) (!cpu_has(c, X86_FEATURE_CENTAUR_MCR))) return -ENODEV; - proc_root_mtrr = - proc_create("mtrr", S_IWUSR | S_IRUGO, NULL, &mtrr_fops); - - if (proc_root_mtrr) - proc_root_mtrr->owner = THIS_MODULE; + proc_create("mtrr", S_IWUSR | S_IRUGO, NULL, &mtrr_fops); return 0; } -- cgit v1.1