diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-07-02 12:08:10 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-07-02 12:08:10 -0700 |
commit | 71bd9341011f626d692aabe024f099820f02c497 (patch) | |
tree | a1c27fd8f17daff36e380800c5b69769d0d9cc99 /ipc | |
parent | 3dbdb38e286903ec220aaf1fb29a8d94297da246 (diff) | |
parent | b869d5be0acf0e125e69adcffdca04000dc5b17c (diff) |
Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:
"190 patches.
Subsystems affected by this patch series: mm (hugetlb, userfaultfd,
vmscan, kconfig, proc, z3fold, zbud, ras, mempolicy, memblock,
migration, thp, nommu, kconfig, madvise, memory-hotplug, zswap,
zsmalloc, zram, cleanups, kfence, and hmm), procfs, sysctl, misc,
core-kernel, lib, lz4, checkpatch, init, kprobes, nilfs2, hfs,
signals, exec, kcov, selftests, compress/decompress, and ipc"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (190 commits)
ipc/util.c: use binary search for max_idx
ipc/sem.c: use READ_ONCE()/WRITE_ONCE() for use_global_lock
ipc: use kmalloc for msg_queue and shmid_kernel
ipc sem: use kvmalloc for sem_undo allocation
lib/decompressors: remove set but not used variabled 'level'
selftests/vm/pkeys: exercise x86 XSAVE init state
selftests/vm/pkeys: refill shadow register after implicit kernel write
selftests/vm/pkeys: handle negative sys_pkey_alloc() return code
selftests/vm/pkeys: fix alloc_random_pkey() to make it really, really random
kcov: add __no_sanitize_coverage to fix noinstr for all architectures
exec: remove checks in __register_bimfmt()
x86: signal: don't do sas_ss_reset() until we are certain that sigframe won't be abandoned
hfsplus: report create_date to kstat.btime
hfsplus: remove unnecessary oom message
nilfs2: remove redundant continue statement in a while-loop
kprobes: remove duplicated strong free_insn_page in x86 and s390
init: print out unknown kernel parameters
checkpatch: do not complain about positive return values starting with EPOLL
checkpatch: improve the indented label test
checkpatch: scripts/spdxcheck.py now requires python3
...
Diffstat (limited to 'ipc')
-rw-r--r-- | ipc/msg.c | 6 | ||||
-rw-r--r-- | ipc/sem.c | 25 | ||||
-rw-r--r-- | ipc/shm.c | 6 | ||||
-rw-r--r-- | ipc/util.c | 44 | ||||
-rw-r--r-- | ipc/util.h | 3 |
5 files changed, 63 insertions, 21 deletions
diff --git a/ipc/msg.c b/ipc/msg.c index 6e6c8e0c9380..6810276d6bb9 100644 --- a/ipc/msg.c +++ b/ipc/msg.c @@ -130,7 +130,7 @@ static void msg_rcu_free(struct rcu_head *head) struct msg_queue *msq = container_of(p, struct msg_queue, q_perm); security_msg_queue_free(&msq->q_perm); - kvfree(msq); + kfree(msq); } /** @@ -147,7 +147,7 @@ static int newque(struct ipc_namespace *ns, struct ipc_params *params) key_t key = params->key; int msgflg = params->flg; - msq = kvmalloc(sizeof(*msq), GFP_KERNEL); + msq = kmalloc(sizeof(*msq), GFP_KERNEL); if (unlikely(!msq)) return -ENOMEM; @@ -157,7 +157,7 @@ static int newque(struct ipc_namespace *ns, struct ipc_params *params) msq->q_perm.security = NULL; retval = security_msg_queue_alloc(&msq->q_perm); if (retval) { - kvfree(msq); + kfree(msq); return retval; } diff --git a/ipc/sem.c b/ipc/sem.c index bf534c74293e..971e75d28364 100644 --- a/ipc/sem.c +++ b/ipc/sem.c @@ -217,6 +217,8 @@ static int sysvipc_sem_proc_show(struct seq_file *s, void *it); * this smp_load_acquire(), this is guaranteed because the smp_load_acquire() * is inside a spin_lock() and after a write from 0 to non-zero a * spin_lock()+spin_unlock() is done. + * To prevent the compiler/cpu temporarily writing 0 to use_global_lock, + * READ_ONCE()/WRITE_ONCE() is used. * * 2) queue.status: (SEM_BARRIER_2) * Initialization is done while holding sem_lock(), so no further barrier is @@ -342,10 +344,10 @@ static void complexmode_enter(struct sem_array *sma) * Nothing to do, just reset the * counter until we return to simple mode. */ - sma->use_global_lock = USE_GLOBAL_LOCK_HYSTERESIS; + WRITE_ONCE(sma->use_global_lock, USE_GLOBAL_LOCK_HYSTERESIS); return; } - sma->use_global_lock = USE_GLOBAL_LOCK_HYSTERESIS; + WRITE_ONCE(sma->use_global_lock, USE_GLOBAL_LOCK_HYSTERESIS); for (i = 0; i < sma->sem_nsems; i++) { sem = &sma->sems[i]; @@ -371,7 +373,8 @@ static void complexmode_tryleave(struct sem_array *sma) /* See SEM_BARRIER_1 for purpose/pairing */ smp_store_release(&sma->use_global_lock, 0); } else { - sma->use_global_lock--; + WRITE_ONCE(sma->use_global_lock, + sma->use_global_lock-1); } } @@ -412,7 +415,7 @@ static inline int sem_lock(struct sem_array *sma, struct sembuf *sops, * Initial check for use_global_lock. Just an optimization, * no locking, no memory barrier. */ - if (!sma->use_global_lock) { + if (!READ_ONCE(sma->use_global_lock)) { /* * It appears that no complex operation is around. * Acquire the per-semaphore lock. @@ -1154,7 +1157,7 @@ static void freeary(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp) un->semid = -1; list_del_rcu(&un->list_proc); spin_unlock(&un->ulp->lock); - kfree_rcu(un, rcu); + kvfree_rcu(un, rcu); } /* Wake up all pending processes and let them fail with EIDRM. */ @@ -1937,7 +1940,8 @@ static struct sem_undo *find_alloc_undo(struct ipc_namespace *ns, int semid) rcu_read_unlock(); /* step 2: allocate new undo structure */ - new = kzalloc(sizeof(struct sem_undo) + sizeof(short)*nsems, GFP_KERNEL); + new = kvzalloc(sizeof(struct sem_undo) + sizeof(short)*nsems, + GFP_KERNEL); if (!new) { ipc_rcu_putref(&sma->sem_perm, sem_rcu_free); return ERR_PTR(-ENOMEM); @@ -1949,7 +1953,7 @@ static struct sem_undo *find_alloc_undo(struct ipc_namespace *ns, int semid) if (!ipc_valid_object(&sma->sem_perm)) { sem_unlock(sma, -1); rcu_read_unlock(); - kfree(new); + kvfree(new); un = ERR_PTR(-EIDRM); goto out; } @@ -1960,7 +1964,7 @@ static struct sem_undo *find_alloc_undo(struct ipc_namespace *ns, int semid) */ un = lookup_undo(ulp, semid); if (un) { - kfree(new); + kvfree(new); goto success; } /* step 5: initialize & link new undo structure */ @@ -2420,7 +2424,7 @@ void exit_sem(struct task_struct *tsk) rcu_read_unlock(); wake_up_q(&wake_q); - kfree_rcu(un, rcu); + kvfree_rcu(un, rcu); } kfree(ulp); } @@ -2435,7 +2439,8 @@ static int sysvipc_sem_proc_show(struct seq_file *s, void *it) /* * The proc interface isn't aware of sem_lock(), it calls - * ipc_lock_object() directly (in sysvipc_find_ipc). + * ipc_lock_object(), i.e. spin_lock(&sma->sem_perm.lock). + * (in sysvipc_find_ipc) * In order to stay compatible with sem_lock(), we must * enter / leave complex_mode. */ diff --git a/ipc/shm.c b/ipc/shm.c index 003234fbbd17..748933e376ca 100644 --- a/ipc/shm.c +++ b/ipc/shm.c @@ -222,7 +222,7 @@ static void shm_rcu_free(struct rcu_head *head) struct shmid_kernel *shp = container_of(ptr, struct shmid_kernel, shm_perm); security_shm_free(&shp->shm_perm); - kvfree(shp); + kfree(shp); } static inline void shm_rmid(struct ipc_namespace *ns, struct shmid_kernel *s) @@ -619,7 +619,7 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params) ns->shm_tot + numpages > ns->shm_ctlall) return -ENOSPC; - shp = kvmalloc(sizeof(*shp), GFP_KERNEL); + shp = kmalloc(sizeof(*shp), GFP_KERNEL); if (unlikely(!shp)) return -ENOMEM; @@ -630,7 +630,7 @@ static int newseg(struct ipc_namespace *ns, struct ipc_params *params) shp->shm_perm.security = NULL; error = security_shm_alloc(&shp->shm_perm); if (error) { - kvfree(shp); + kfree(shp); return error; } diff --git a/ipc/util.c b/ipc/util.c index cfa0045e748d..0027e47626b7 100644 --- a/ipc/util.c +++ b/ipc/util.c @@ -64,6 +64,7 @@ #include <linux/memory.h> #include <linux/ipc_namespace.h> #include <linux/rhashtable.h> +#include <linux/log2.h> #include <asm/unistd.h> @@ -451,6 +452,41 @@ static void ipc_kht_remove(struct ipc_ids *ids, struct kern_ipc_perm *ipcp) } /** + * ipc_search_maxidx - search for the highest assigned index + * @ids: ipc identifier set + * @limit: known upper limit for highest assigned index + * + * The function determines the highest assigned index in @ids. It is intended + * to be called when ids->max_idx needs to be updated. + * Updating ids->max_idx is necessary when the current highest index ipc + * object is deleted. + * If no ipc object is allocated, then -1 is returned. + * + * ipc_ids.rwsem needs to be held by the caller. + */ +static int ipc_search_maxidx(struct ipc_ids *ids, int limit) +{ + int tmpidx; + int i; + int retval; + + i = ilog2(limit+1); + + retval = 0; + for (; i >= 0; i--) { + tmpidx = retval | (1<<i); + /* + * "0" is a possible index value, thus search using + * e.g. 15,7,3,1,0 instead of 16,8,4,2,1. + */ + tmpidx = tmpidx-1; + if (idr_get_next(&ids->ipcs_idr, &tmpidx)) + retval |= (1<<i); + } + return retval - 1; +} + +/** * ipc_rmid - remove an ipc identifier * @ids: ipc identifier set * @ipcp: ipc perm structure containing the identifier to remove @@ -468,11 +504,9 @@ void ipc_rmid(struct ipc_ids *ids, struct kern_ipc_perm *ipcp) ipcp->deleted = true; if (unlikely(idx == ids->max_idx)) { - do { - idx--; - if (idx == -1) - break; - } while (!idr_find(&ids->ipcs_idr, idx)); + idx = ids->max_idx-1; + if (idx >= 0) + idx = ipc_search_maxidx(ids, idx); ids->max_idx = idx; } } diff --git a/ipc/util.h b/ipc/util.h index 5766c61aed0e..2dd7ce0416d8 100644 --- a/ipc/util.h +++ b/ipc/util.h @@ -145,6 +145,9 @@ int ipcperms(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp, short flg); * ipc_get_maxidx - get the highest assigned index * @ids: ipc identifier set * + * The function returns the highest assigned index for @ids. The function + * doesn't scan the idr tree, it uses a cached value. + * * Called with ipc_ids.rwsem held for reading. */ static inline int ipc_get_maxidx(struct ipc_ids *ids) |