diff options
Diffstat (limited to 'usr/src/uts/common/os/kmem.c')
| -rw-r--r-- | usr/src/uts/common/os/kmem.c | 40 |
1 files changed, 38 insertions, 2 deletions
diff --git a/usr/src/uts/common/os/kmem.c b/usr/src/uts/common/os/kmem.c index bc0cda418b..ed2c7fc346 100644 --- a/usr/src/uts/common/os/kmem.c +++ b/usr/src/uts/common/os/kmem.c @@ -20,6 +20,7 @@ */ /* * Copyright (c) 1994, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2017, Joyent, Inc. * Copyright (c) 2012, 2017 by Delphix. All rights reserved. * Copyright 2015 Nexenta Systems, Inc. All rights reserved. * Copyright 2018, Joyent, Inc. @@ -1011,6 +1012,7 @@ size_t kmem_transaction_log_size; /* transaction log size [2% of memory] */ size_t kmem_content_log_size; /* content log size [2% of memory] */ size_t kmem_failure_log_size; /* failure log [4 pages per CPU] */ size_t kmem_slab_log_size; /* slab create log [4 pages per CPU] */ +size_t kmem_zerosized_log_size; /* zero-sized log [4 pages per CPU] */ size_t kmem_content_maxsave = 256; /* KMF_CONTENTS max bytes to log */ size_t kmem_lite_minsize = 0; /* minimum buffer size for KMF_LITE */ size_t kmem_lite_maxalign = 1024; /* maximum buffer alignment for KMF_LITE */ @@ -1018,6 +1020,14 @@ int kmem_lite_pcs = 4; /* number of PCs to store in KMF_LITE mode */ size_t kmem_maxverify; /* maximum bytes to inspect in debug routines */ size_t kmem_minfirewall; /* hardware-enforced redzone threshold */ +#ifdef DEBUG +int kmem_warn_zerosized = 1; /* whether to warn on zero-sized KM_SLEEP */ +#else +int kmem_warn_zerosized = 0; /* whether to warn on zero-sized KM_SLEEP */ +#endif + +int kmem_panic_zerosized = 0; /* whether to panic on zero-sized KM_SLEEP */ + #ifdef _LP64 size_t kmem_max_cached = KMEM_BIG_MAXBUF; /* maximum kmem_alloc cache */ #else @@ -1098,6 +1108,7 @@ kmem_log_header_t *kmem_transaction_log; kmem_log_header_t *kmem_content_log; kmem_log_header_t *kmem_failure_log; kmem_log_header_t *kmem_slab_log; +kmem_log_header_t *kmem_zerosized_log; static int kmem_lite_count; /* # of PCs in kmem_buftag_lite_t */ @@ -2853,8 +2864,33 @@ kmem_alloc(size_t size, int kmflag) /* fall through to kmem_cache_alloc() */ } else { - if (size == 0) + if (size == 0) { + if (kmflag != KM_SLEEP && !(kmflag & KM_PANIC)) + return (NULL); + + /* + * If this is a sleeping allocation or one that has + * been specified to panic on allocation failure, we + * consider it to be deprecated behavior to allocate + * 0 bytes. If we have been configured to panic under + * this condition, we panic; if to warn, we warn -- and + * regardless, we log to the kmem_zerosized_log that + * that this condition has occurred (which gives us + * enough information to be able to debug it). + */ + if (kmem_panic && kmem_panic_zerosized) + panic("attempted to kmem_alloc() size of 0"); + + if (kmem_warn_zerosized) { + cmn_err(CE_WARN, "kmem_alloc(): sleeping " + "allocation with size of 0; " + "see kmem_zerosized_log for details"); + } + + kmem_log_event(kmem_zerosized_log, NULL, NULL, NULL); + return (NULL); + } buf = vmem_alloc(kmem_oversize_arena, size, kmflag & KM_VMFLAGS); @@ -4397,8 +4433,8 @@ kmem_init(void) } kmem_failure_log = kmem_log_init(kmem_failure_log_size); - kmem_slab_log = kmem_log_init(kmem_slab_log_size); + kmem_zerosized_log = kmem_log_init(kmem_zerosized_log_size); /* * Initialize STREAMS message caches so allocb() is available. |