On 05/28/2018 10:01 AM, Matthew Wilcox wrote: > > ping? > > I have this queued up in my XArray tree. If I don't hear from you before > -rc1, I'll be submitting it as part of the XArray conversion. > hey Mathew,
I've pulled this into apparmor-next and done the retuning of AA_SECID_INVALID a follow on patch. The reworking of the api to return the specific error type can wait for another cycle. > On Tue, May 22, 2018 at 02:32:59AM -0700, Matthew Wilcox wrote: >> Replace the custom usage of the radix tree to store a list of free IDs >> with the IDR. >> >> Signed-off-by: Matthew Wilcox <mawil...@microsoft.com> >> >> security/apparmor/secid.c | 114 >> ++++------------------------------------------ >> 1 file changed, 11 insertions(+), 103 deletions(-) >> >> diff --git a/security/apparmor/secid.c b/security/apparmor/secid.c >> index c2f0c1571156..3ad94b2ffbb2 100644 >> --- a/security/apparmor/secid.c >> +++ b/security/apparmor/secid.c >> @@ -18,6 +18,7 @@ >> #include <linux/errno.h> >> #include <linux/err.h> >> #include <linux/gfp.h> >> +#include <linux/idr.h> >> #include <linux/slab.h> >> #include <linux/spinlock.h> >> >> @@ -30,18 +31,10 @@ >> /* >> * secids - do not pin labels with a refcount. They rely on the label >> * properly updating/freeing them >> - * >> - * A singly linked free list is used to track secids that have been >> - * freed and reuse them before allocating new ones >> */ >> >> -#define FREE_LIST_HEAD 1 >> - >> -static RADIX_TREE(aa_secids_map, GFP_ATOMIC); >> +static DEFINE_IDR(aa_secids); >> static DEFINE_SPINLOCK(secid_lock); >> -static u32 alloced_secid = FREE_LIST_HEAD; >> -static u32 free_list = FREE_LIST_HEAD; >> -static unsigned long free_count; >> >> /* >> * TODO: allow policy to reserve a secid range? >> @@ -49,65 +42,6 @@ static unsigned long free_count; >> * TODO: use secid_update in label replace >> */ >> >> -#define SECID_MAX U32_MAX >> - >> -/* TODO: mark free list as exceptional */ >> -static void *to_ptr(u32 secid) >> -{ >> - return (void *) >> - ((((unsigned long) secid) << RADIX_TREE_EXCEPTIONAL_SHIFT)); >> -} >> - >> -static u32 to_secid(void *ptr) >> -{ >> - return (u32) (((unsigned long) ptr) >> RADIX_TREE_EXCEPTIONAL_SHIFT); >> -} >> - >> - >> -/* TODO: tag free_list entries to mark them as different */ >> -static u32 __pop(struct aa_label *label) >> -{ >> - u32 secid = free_list; >> - void __rcu **slot; >> - void *entry; >> - >> - if (free_list == FREE_LIST_HEAD) >> - return AA_SECID_INVALID; >> - >> - slot = radix_tree_lookup_slot(&aa_secids_map, secid); >> - AA_BUG(!slot); >> - entry = radix_tree_deref_slot_protected(slot, &secid_lock); >> - free_list = to_secid(entry); >> - radix_tree_replace_slot(&aa_secids_map, slot, label); >> - free_count--; >> - >> - return secid; >> -} >> - >> -static void __push(u32 secid) >> -{ >> - void __rcu **slot; >> - >> - slot = radix_tree_lookup_slot(&aa_secids_map, secid); >> - AA_BUG(!slot); >> - radix_tree_replace_slot(&aa_secids_map, slot, to_ptr(free_list)); >> - free_list = secid; >> - free_count++; >> -} >> - >> -static struct aa_label * __secid_update(u32 secid, struct aa_label *label) >> -{ >> - struct aa_label *old; >> - void __rcu **slot; >> - >> - slot = radix_tree_lookup_slot(&aa_secids_map, secid); >> - AA_BUG(!slot); >> - old = radix_tree_deref_slot_protected(slot, &secid_lock); >> - radix_tree_replace_slot(&aa_secids_map, slot, label); >> - >> - return old; >> -} >> - >> /** >> * aa_secid_update - update a secid mapping to a new label >> * @secid: secid to update >> @@ -115,11 +49,10 @@ static struct aa_label * __secid_update(u32 secid, >> struct aa_label *label) >> */ >> void aa_secid_update(u32 secid, struct aa_label *label) >> { >> - struct aa_label *old; >> unsigned long flags; >> >> spin_lock_irqsave(&secid_lock, flags); >> - old = __secid_update(secid, label); >> + idr_replace(&aa_secids, label, secid); >> spin_unlock_irqrestore(&secid_lock, flags); >> } >> >> @@ -132,7 +65,7 @@ struct aa_label *aa_secid_to_label(u32 secid) >> struct aa_label *label; >> >> rcu_read_lock(); >> - label = radix_tree_lookup(&aa_secids_map, secid); >> + label = idr_find(&aa_secids, secid); >> rcu_read_unlock(); >> >> return label; >> @@ -167,7 +100,6 @@ int apparmor_secid_to_secctx(u32 secid, char **secdata, >> u32 *seclen) >> return 0; >> } >> >> - >> int apparmor_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid) >> { >> struct aa_label *label; >> @@ -186,7 +118,6 @@ void apparmor_release_secctx(char *secdata, u32 seclen) >> kfree(secdata); >> } >> >> - >> /** >> * aa_alloc_secid - allocate a new secid for a profile >> */ >> @@ -195,35 +126,12 @@ u32 aa_alloc_secid(struct aa_label *label, gfp_t gfp) >> unsigned long flags; >> u32 secid; >> >> - /* racey, but at worst causes new allocation instead of reuse */ >> - if (free_list == FREE_LIST_HEAD) { >> - bool preload = 0; >> - int res; >> - >> -retry: >> - if (gfpflags_allow_blocking(gfp) && !radix_tree_preload(gfp)) >> - preload = 1; >> - spin_lock_irqsave(&secid_lock, flags); >> - if (alloced_secid != SECID_MAX) { >> - secid = ++alloced_secid; >> - res = radix_tree_insert(&aa_secids_map, secid, label); >> - AA_BUG(res == -EEXIST); >> - } else { >> - secid = AA_SECID_INVALID; >> - } >> - spin_unlock_irqrestore(&secid_lock, flags); >> - if (preload) >> - radix_tree_preload_end(); >> - } else { >> - spin_lock_irqsave(&secid_lock, flags); >> - /* remove entry from free list */ >> - secid = __pop(label); >> - if (secid == AA_SECID_INVALID) { >> - spin_unlock_irqrestore(&secid_lock, flags); >> - goto retry; >> - } >> - spin_unlock_irqrestore(&secid_lock, flags); >> - } >> + idr_preload(gfp); >> + spin_lock_irqsave(&secid_lock, flags); >> + secid = idr_alloc(&aa_secids, label, 0, 0, GFP_ATOMIC); >> + /* XXX: Can return -ENOMEM */ >> + spin_unlock_irqrestore(&secid_lock, flags); >> + idr_preload_end(); >> >> return secid; >> } >> @@ -237,6 +145,6 @@ void aa_free_secid(u32 secid) >> unsigned long flags; >> >> spin_lock_irqsave(&secid_lock, flags); >> - __push(secid); >> + idr_remove(&aa_secids, secid); >> spin_unlock_irqrestore(&secid_lock, flags); >> } >>