+# Kernel version 4.4 commit ef951599074ba4fad2d0efa0a977129b41e6d203
+# introduced kstrtobool and kstrtobool_from_user.
+#
+AC_DEFUN([LIBCFS_KSTRTOBOOL_FROM_USER], [
+LB_CHECK_COMPILE([if Linux kernel has 'kstrtobool_from_user'],
+kstrtobool_from_user, [
+ #include <linux/kernel.h>
+],[
+ bool result;
+ return kstrtobool_from_user(NULL, 0, &result);
+],[
+ AC_DEFINE(HAVE_KSTRTOBOOL_FROM_USER, 1,
+ [kernel has kstrtobool_from_user])
+])
+]) # LIBCFS_KSTRTOBOOL_FROM_USER
+
+#
+# Kernel version 4.5-rc1 commit d12481bc58fba89427565f8592e88446ec084a24
+# added crypto hash helpers
+#
+AC_DEFUN([LIBCFS_CRYPTO_HASH_HELPERS], [
+LB_CHECK_COMPILE([does crypto hash helper functions exist],
+crypto_hash_helpers, [
+ #include <crypto/hash.h>
+],[
+ crypto_ahash_alg_name(NULL);
+ crypto_ahash_driver_name(NULL);
+],[
+ AC_DEFINE(HAVE_CRYPTO_HASH_HELPERS, 1,
+ [crypto hash helper functions are available])
+])
+]) # LIBCFS_CRYPTO_HASH_HELPERS
+
+#
+# Kernel version 4.5-rc1 commit 3502cad73c4bbf8f6365d539e814159275252c59
+# introduced rhashtable_replace_fast
+#
+AC_DEFUN([LIBCFS_RHASHTABLE_REPLACE], [
+LB_CHECK_COMPILE([if 'rhashtable_replace_fast' exists],
+rhashtable_replace_fast, [
+ #include <linux/rhashtable.h>
+],[
+ const struct rhashtable_params params = { 0 };
+
+ rhashtable_replace_fast(NULL, NULL, NULL, params);
+],[
+ AC_DEFINE(HAVE_RHASHTABLE_REPLACE, 1,
+ [rhashtable_replace_fast() is available])
+])
+]) # LIBCFS_RHASHTABLE_REPLACE
+
+#
+# Kernel version 4.5-rc3 commit 2fe829aca9d7bed5fd6b49c6a1452e5e486b6cc3dd
+# made kset_find_obj() exportable to modules
+#
+AC_DEFUN([LIBCFS_EXPORT_KSET_FIND_OBJ], [
+LB_CHECK_EXPORT([kset_find_obj], [lib/kobject.c],
+ [AC_DEFINE(HAVE_KSET_FIND_OBJ, 1,
+ [kset_find_obj is exported by the kernel])])
+]) # LIBCFS_EXPORT_KSET_FIND_OBJ
+
+#
+# Kernel version 4.6+ commit ef703f49a6c5b909a85149bb6625c4ed0d697186
+# fixed the brokenness of hash_64(). The fix removed GOLDEN_RATIO_PRIME_64
+# since it was a poor prime value.
+#
+AC_DEFUN([LIBCFS_BROKEN_HASH_64], [
+LB_CHECK_COMPILE([kernel has fixed hash_64()],
+broken_hash_64, [
+ #include <linux/hash.h>
+],[
+ int tmp = GOLDEN_RATIO_PRIME_64;
+],[
+ AC_DEFINE(HAVE_BROKEN_HASH_64, 1, [kernel hash_64() is broken])
+])
+]) # LIBCFS_BROKEN_HASH_64
+
+#
+# LIBCFS_STACKTRACE_OPS_ADDRESS_RETURN_INT
+#
+# linux 4.6 kernel changed stacktrace_ops address to return an int
+#
+AC_DEFUN([LIBCFS_STACKTRACE_OPS_ADDRESS_RETURN_INT], [
+LB_CHECK_COMPILE([if 'struct stacktrace_ops' address function returns an int],
+stacktrace_ops_address_return_int, [
+ #include <asm/stacktrace.h>
+],[
+ int rc;
+
+ rc = ((struct stacktrace_ops *)0)->address(NULL, 0, 0);
+],[
+ AC_DEFINE(STACKTRACE_OPS_ADDRESS_RETURN_INT, 1,
+ ['struct stacktrace_ops' address function returns an int])
+])
+]) # LIBCFS_STACKTRACE_OPS_ADDRESS_RETURN_INT
+
+#
+# Kernel version 4.6 removed both struct task_struct and struct mm_struct
+# arguments to get_user_pages
+#
+AC_DEFUN([LIBCFS_GET_USER_PAGES_6ARG], [
+LB_CHECK_COMPILE([if 'get_user_pages()' takes 6 arguments],
+get_user_pages_6arg, [
+ #include <linux/mm.h>
+],[
+ int rc;
+
+ rc = get_user_pages(0, 0, 0, 0, NULL, NULL);
+],[
+ AC_DEFINE(HAVE_GET_USER_PAGES_6ARG, 1,
+ [get_user_pages takes 6 arguments])
+])
+]) # LIBCFS_GET_USER_PAGES_6ARG
+
+#
+# LIBCFS_STRINGHASH
+#
+# 4.6 kernel created stringhash.h which moved stuff out of dcache.h
+# commit f4bcbe792b8f434e32487cff9d9e30ab45a3ce02
+#
+AC_DEFUN([LIBCFS_STRINGHASH], [
+LB_CHECK_LINUX_HEADER([linux/stringhash.h], [
+ AC_DEFINE(HAVE_STRINGHASH, 1,
+ [stringhash.h is present])])
+]) # LIBCFS_STRINGHASH
+
+#
+# LIBCFS_RHASHTABLE_INSERT_FAST
+#
+# 4.7+ kernel commit 5ca8cc5bf11faed257c762018aea9106d529232f
+# changed __rhashtable_insert_fast to support the new function
+# rhashtable_lookup_get_insert_key().
+#
+AC_DEFUN([LIBCFS_RHASHTABLE_INSERT_FAST], [
+tmp_flags="$EXTRA_KCFLAGS"
+EXTRA_KCFLAGS="-Werror"
+LB_CHECK_COMPILE([if internal '__rhashtable_insert_fast()' returns int],
+rhashtable_insert_fast, [
+ #include <linux/rhashtable.h>
+],[
+ const struct rhashtable_params params = { 0 };
+ int rc;
+
+ rc = __rhashtable_insert_fast(NULL, NULL, NULL, params);
+],[
+ AC_DEFINE(HAVE_HASHTABLE_INSERT_FAST_RETURN_INT, 1,
+ ['__rhashtable_insert_fast()' returns int])
+])
+EXTRA_KCFLAGS="$tmp_flags"
+]) # LIBCFS_RHASHTABLE_INSERT_FAST
+
+#
+# Kernel version 4.7-rc1 commit 8f6fd83c6c5ec66a4a70c728535ddcdfef4f3697
+# added 3rd arg to rhashtable_walk_init
+#
+AC_DEFUN([LIBCFS_RHASHTABLE_WALK_INIT_3ARG], [
+LB_CHECK_COMPILE([if 'rhashtable_walk_init' has 3 args],
+rhashtable_walk_init, [
+ #include <linux/gfp.h>
+ #include <linux/rhashtable.h>
+],[
+ rhashtable_walk_init(NULL, NULL, GFP_KERNEL);
+],[
+ AC_DEFINE(HAVE_3ARG_RHASHTABLE_WALK_INIT, 1,
+ [rhashtable_walk_init() has 3 args])
+])
+]) # LIBCFS_RHASHTABLE_REPLACE
+
+#
+# Kernel version 4.8-rc6 commit ca26893f05e86497a86732768ec53cd38c0819ca
+# introduced rhashtable_lookup
+#
+AC_DEFUN([LIBCFS_RHASHTABLE_LOOKUP], [
+LB_CHECK_COMPILE([if 'rhashtable_lookup' exist],
+rhashtable_lookup, [
+ #include <linux/rhashtable.h>
+],[
+ const struct rhashtable_params params = { 0 };
+ void *ret;
+
+ ret = rhashtable_lookup(NULL, NULL, params);
+],[
+ AC_DEFINE(HAVE_RHASHTABLE_LOOKUP, 1,
+ [rhashtable_lookup() is available])
+])
+]) # LIBCFS_RHASHTABLE_LOOKUP
+
+#
+# LIBCFS_RHLTABLE
+# Kernel version 4.8-rc6 commit ca26893f05e86497a86732768ec53cd38c0819ca
+# created the rhlist interface to allow inserting duplicate objects
+# into the same table.
+#
+AC_DEFUN([LIBCFS_RHLTABLE], [
+LB_CHECK_COMPILE([does 'struct rhltable' exist],
+rhtable, [
+ #include <linux/rhashtable.h>
+],[
+ struct rhltable *hlt;
+
+ rhltable_destroy(hlt);
+],[
+ AC_DEFINE(HAVE_RHLTABLE, 1,
+ [struct rhltable exist])
+])
+]) # LIBCFS_RHLTABLE
+
+#
+# LIBCFS_STACKTRACE_OPS
+#
+# Kernel version 4.8 commit c8fe4609827aedc9c4b45de80e7cdc8ccfa8541b
+# removed both struct stacktrace_ops and dump_trace() function
+#
+AC_DEFUN([LIBCFS_STACKTRACE_OPS], [
+LB_CHECK_COMPILE([if 'struct stacktrace_ops' exists],
+stacktrace_ops, [
+ struct task_struct;
+ struct pt_regs;
+ #include <asm/stacktrace.h>
+],[
+ struct stacktrace_ops ops;
+ ops.stack = NULL;
+],[
+ AC_DEFINE(HAVE_STACKTRACE_OPS, 1,
+ [struct stacktrace_ops exists])
+])
+]) # LIBCFS_STACKTRACE_OPS
+
+#
+# Kernel version 4.9-rc1 commit 246779dd090bd1b74d2652b3a6ca7759f593b27a
+# introduced rhashtable_walk_enter
+#
+AC_DEFUN([LIBCFS_RHASHTABLE_WALK_ENTER], [
+LB_CHECK_COMPILE([if 'rhashtable_walk_enter' exists],
+rhashtable_walk_enter, [
+ #include <linux/rhashtable.h>
+],[
+ rhashtable_walk_enter(NULL, NULL);
+],[
+ AC_DEFINE(HAVE_RHASHTABLE_WALK_ENTER, 1,
+ [rhashtable_walk_enter() is available])
+])
+]) # LIBCFS_RHASHTABLE_REPLACE
+
+#
+# Kernel version 4.9 commit 768ae309a96103ed02eb1e111e838c87854d8b51
+# mm: replace get_user_pages() write/force parameters with gup_flags
+#
+AC_DEFUN([LIBCFS_GET_USER_PAGES_GUP_FLAGS], [
+LB_CHECK_COMPILE([if 'get_user_pages()' takes gup_flags in arguments],
+get_user_pages_gup_flags, [
+ #include <linux/mm.h>
+],[
+ int rc;
+ rc = get_user_pages(0, 0, FOLL_WRITE, NULL, NULL);
+],[
+ AC_DEFINE(HAVE_GET_USER_PAGES_GUP_FLAGS, 1,
+ [get_user_pages takes gup_flags in arguments])
+])
+]) # LIBCFS_GET_USER_PAGES_GUP_FLAGS
+
+#
+# Kernel version 4.10 commit 7b737965b33188bd3dbb44e938535c4006d97fbb
+# libcfs: Convert to hotplug state machine
+#
+AC_DEFUN([LIBCFS_HOTPLUG_STATE_MACHINE], [
+LB_CHECK_COMPILE([if libcfs supports CPU hotplug state machine],
+cpu_hotplug_state_machine, [
+ #include <linux/cpuhotplug.h>
+],[
+ cpuhp_remove_state(CPUHP_LUSTRE_CFS_DEAD);
+],[
+ AC_DEFINE(HAVE_HOTPLUG_STATE_MACHINE, 1,
+ [hotplug state machine is supported])
+])
+]) # LIBCFS_HOTPLUG_STATE_MACHINE
+
+#
+# Kernel version 4.10-rc3 commit f405df5de3170c00e5c54f8b7cf4766044a032ba
+# introduced refcount_t which is atomic_t plus over flow guards.
+#
+AC_DEFUN([LIBCFS_REFCOUNT_T], [
+tmp_flags="$EXTRA_KCFLAGS"
+EXTRA_KCFLAGS="-Werror"
+LB_CHECK_LINUX_HEADER([linux/refcount.h], [
+ AC_DEFINE(HAVE_REFCOUNT_T, 1,
+ [refcount_t is supported])
+])
+EXTRA_KCFLAGS="$tmp_flags"
+]) # LIBCFS_REFCOUNT_T
+
+#
+# Kernel version 4.12 commit 499118e966f1d2150bd66647c8932343c4e9a0b8
+# introduce memalloc_noreclaim_{save,restore}
+#
+AC_DEFUN([LIBCFS_MEMALLOC_NORECLAIM], [
+LB_CHECK_COMPILE([if memalloc_noreclaim_{save,restore} exist],
+memalloc_noreclaim, [
+ #include <linux/sched/mm.h>
+],[
+ int flag = memalloc_noreclaim_save();
+ memalloc_noreclaim_restore(flag);
+],[
+ AC_DEFINE(HAVE_MEMALLOC_RECLAIM, 1,
+ [memalloc_noreclaim_{save,restore}() is supported])
+])
+]) # LIBCFS_MEMALLOC_NORECLAIM
+
+#
+# LIBCFS_SCHED_HEADERS
+#
+# 4.11 has broken up sched.h into more headers.
+#
+AC_DEFUN([LIBCFS_SCHED_HEADERS], [
+LB_CHECK_LINUX_HEADER([linux/sched/signal.h], [
+ AC_DEFINE(HAVE_SCHED_HEADERS, 1,
+ [linux/sched header directory exist])])
+]) # LIBCFS_SCHED_HEADERS
+
+#
+# Kernel version 4.11-rc1 commit 2c935bc57221cc2edc787c72ea0e2d30cdcd3d5e
+# introduce kref_read
+#
+AC_DEFUN([LIBCFS_KREF_READ], [
+LB_CHECK_COMPILE([if 'kref_read' exists],
+kref_read, [
+ #include <linux/kref.h>
+],[
+ kref_read(NULL);
+],[
+ AC_DEFINE(HAVE_KREF_READ, 1,
+ [kref_read() is available])
+])
+]) LIBCFS_KREF_READ
+
+#
+# Kernel version 4.11-rc1 commit da20420f83ea0fbcf3d03afda08d971ea1d8a356
+# introduced rht_bucket_var
+#
+AC_DEFUN([LIBCFS_RHT_BUCKET_VAR], [
+LB_CHECK_COMPILE([if 'rht_bucket_var' exists],
+rht_bucket_var, [
+ #include <linux/rhashtable.h>
+],[
+
+ rht_bucket_var(NULL, 0);
+],[
+ AC_DEFINE(HAVE_RHT_BUCKET_VAR, 1,
+ [rht_bucket_var() is available])
+])
+]) # LIBCFS_RHT_BUCKET_VAR
+
+#
+# Kernel version 4.11 commit f9fe1c12d126f9887441fa5bb165046f30ddd4b5
+# introduced rhashtable_lookup_get_insert_fast
+#
+AC_DEFUN([LIBCFS_RHASHTABLE_LOOKUP_GET_INSERT_FAST], [
+LB_CHECK_COMPILE([if 'rhashtable_lookup_get_insert_fast' exist],
+rhashtable_lookup_get_insert_fast, [
+ #include <linux/rhashtable.h>
+],[
+ const struct rhashtable_params params = { 0 };
+ void *ret;
+
+ ret = rhashtable_lookup_get_insert_fast(NULL, NULL, params);
+],[
+ AC_DEFINE(HAVE_RHASHTABLE_LOOKUP_GET_INSERT_FAST, 1,
+ [rhashtable_lookup_get_insert_fast() is available])
+])
+]) # LIBCFS_RHASHTABLE_LOOKUP_GET_INSERT_FAST
+
+#
+# Kernel version 4.12-rc2 8f553c498e1772cccb39a114da4a498d22992758
+# provide proper CPU hotplug locking
+#
+AC_DEFUN([LIBCFS_CPUS_READ_LOCK], [
+LB_CHECK_COMPILE([if 'cpus_read_[un]lock' exist],
+cpu_read_lock, [
+ #include <linux/cpu.h>
+],[
+ cpus_read_lock();
+ cpus_read_unlock();
+],[
+ AC_DEFINE(HAVE_CPUS_READ_LOCK, 1, ['cpus_read_lock' exist])
+])
+]) # LIBCFS_CPUS_READ_LOCK
+
+#
+# Kernel version 4.12-rc3 f9727a17db9bab71ddae91f74f11a8a2f9a0ece6
+# renamed uuid_be to uuid_t
+#
+AC_DEFUN([LIBCFS_UUID_T], [
+LB_CHECK_COMPILE([if 'uuid_t' exist],
+uuid_t, [
+ #include <linux/uuid.h>
+],[
+ uuid_t uuid;
+
+ memset(uuid.b, 0, 16);
+],[
+ AC_DEFINE(HAVE_UUID_T, 1, ['uuid_t' exist])
+])
+]) # LIBCFS_UUID_T
+
+#
+# Kernel version 4.12-rc3 commit fd851a3cdc196bfc1d229b5f22369069af532bf8
+# introduce processor.h
+#
+AC_DEFUN([LIBCFS_HAVE_PROCESSOR_HEADER], [
+tmp_flags="$EXTRA_KCFLAGS"
+EXTRA_KCFLAGS="-Werror"
+LB_CHECK_LINUX_HEADER([linux/processor.h], [
+ AC_DEFINE(HAVE_PROCESSOR_H, 1,
+ [processor.h is present])
+])
+EXTRA_KCFLAGS="$tmp_flags"
+]) # LIBCFS_HAVE_PROCESSOR_HEADER
+
+#
+# Kernel verison 4.12-rc6 commit 5dd43ce2f69d42a71dcacdb13d17d8c0ac1fe8f7
+# created wait_bit.h
+#
+AC_DEFUN([LIBCFS_HAVE_WAIT_BIT_HEADER], [
+LB_CHECK_LINUX_HEADER([linux/wait_bit.h], [
+ AC_DEFINE(HAVE_WAIT_BIT_HEADER_H, 1,
+ [wait_bit.h is present])])
+]) # LIBCFS_HAVE_WAIT_BIT_HEADER
+
+#
+# Kernel version 4.12-rc6 commmit 2055da97389a605c8a00d163d40903afbe413921
+# changed:
+# struct wait_queue_head::task_list => ::head
+# struct wait_queue_entry::task_list => ::entry
+#
+AC_DEFUN([LIBCFS_WAIT_QUEUE_TASK_LIST_RENAME], [
+LB_CHECK_COMPILE([if linux wait_queue_head list_head is named head],
+wait_queue_task_list, [
+ #include <linux/wait.h>
+],[
+ wait_queue_head_t e;
+
+ INIT_LIST_HEAD(&e.head);
+],[
+ AC_DEFINE(HAVE_WAIT_QUEUE_ENTRY_LIST, 1,
+ [linux wait_queue_head_t list_head is name head])
+])
+]) # LIBCFS_WAIT_QUEUE_TASK_LIST_RENAME
+
+#
+# LIBCFS_WAIT_QUEUE_ENTRY
+#
+# Kernel version 4.13 ac6424b981bce1c4bc55675c6ce11bfe1bbfa64f
+# Rename wait_queue_t => wait_queue_entry_t
+#
+AC_DEFUN([LIBCFS_WAIT_QUEUE_ENTRY], [
+LB_CHECK_COMPILE([if 'wait_queue_entry_t' exists],
+wait_queue_entry, [
+ #include <linux/wait.h>
+],[
+ wait_queue_entry_t e;
+
+ e.flags = 0;
+],[
+ AC_DEFINE(HAVE_WAIT_QUEUE_ENTRY, 1,
+ ['wait_queue_entry_t' is available])
+])
+]) # LIBCFS_WAIT_QUEUE_ENTRY
+
+#
+# LIBCFS_NEW_KERNEL_WRITE
+#
+# Kernel version 4.14 e13ec939e96b13e664bb6cee361cc976a0ee621a
+# changed kernel_write prototype to make is plug compatible
+# with the unexported vfs_write()
+#
+AC_DEFUN([LIBCFS_NEW_KERNEL_WRITE], [
+tmp_flags="$EXTRA_KCFLAGS"
+EXTRA_KCFLAGS="-Werror"
+LB_CHECK_COMPILE([if 'kernel_write' matches other read/write helpers],
+kernel_write_match, [
+ #include <linux/fs.h>
+],[
+ const void *buf = NULL;
+ loff_t pos = 0;
+ return kernel_write(NULL, buf, 0, &pos);
+],[
+ AC_DEFINE(HAVE_NEW_KERNEL_WRITE, 1,
+ ['kernel_write' aligns with read/write helpers])
+])
+EXTRA_KCFLAGS="$tmp_flags"
+]) # LIBCFS_NEW_KERNEL_WRITE
+
+#
+# LIBCFS_MM_TOTALRAM_PAGES_FUNC
+#
+# kernel 5.0 commit ca79b0c211af63fa3276f0e3fd7dd9ada2439839
+# mm: convert totalram_pages and totalhigh_pages variables to atomic
+#
+AC_DEFUN([LIBCFS_MM_TOTALRAM_PAGES_FUNC], [
+tmp_flags="$EXTRA_KCFLAGS"
+EXTRA_KCFLAGS="-Werror"
+LB_CHECK_COMPILE([if totalram_pages is a function],
+totalram_pages, [
+ #include <linux/mm.h>
+],[
+ totalram_pages_inc();
+],[
+ AC_DEFINE(HAVE_TOTALRAM_PAGES_AS_FUNC, 1,
+ [if totalram_pages is a function])
+])
+EXTRA_KCFLAGS="$tmp_flags"
+]) # LIBCFS_MM_TOTALRAM_PAGES_FUNC
+
+#
+# LIBCFS_NEW_KERNEL_WRITE
+#
+# 4.14 commit bdd1d2d3d251c65b74ac4493e08db18971c09240 changed
+# the signature of kernel_read to match other read/write helpers
+# and place offset last.
+#
+AC_DEFUN([LIBCFS_NEW_KERNEL_READ], [
+tmp_flags="$EXTRA_KCFLAGS"
+EXTRA_KCFLAGS="-Werror"
+LB_CHECK_COMPILE([if 'kernel_read()' has loff_t *pos as last parameter],
+kernel_read, [
+ #include <linux/fs.h>
+ ],[
+ loff_t pos = 0;
+ kernel_read(NULL, NULL, 0, &pos);
+],[
+ AC_DEFINE(HAVE_KERNEL_READ_LAST_POSP, 1,
+ [kernel_read() signature ends with loff_t *pos])
+])
+EXTRA_KCFLAGS="$tmp_flags"
+]) # LIBCFS_NEW_KERNEL_READ
+
+#
+# LIBCFS_DEFINE_TIMER
+#
+# Kernel version 4.14 commit 1d27e3e2252ba9d949ca82fbdb73cde102cb2067
+# remove expires and data arguments from DEFINE_TIMER. Also the callback
+# when from using unsigned long argument to using struct timer_list pointer.
+#
+AC_DEFUN([LIBCFS_DEFINE_TIMER], [
+LB_CHECK_COMPILE([if DEFINE_TIMER takes only 2 arguments],
+define_timer, [
+ #include <linux/timer.h>
+],[
+ static DEFINE_TIMER(my_timer, NULL);
+],[
+ AC_DEFINE(HAVE_NEW_DEFINE_TIMER, 1,
+ [DEFINE_TIMER uses only 2 arguements])
+])
+]) # LIBCFS_DEFINE_TIMER
+
+#
+# LIBCFS_EXPORT_SAVE_STACK_TRACE_TSK
+#
+# Kernel 2.6.27 commit 8594698ebddeef5443b7da8258ae33b3eaca61d5
+# exported save_stack_trace_tsk for x86.
+# Kernel 2.6.27 commit 01f4b8b8b8db09b88be7df7e51192e4e678b69d3
+# exported save_stack_trace_tsk for powerpc
+# Kernel 4.13 commit e27c7fa015d61c8be6a2c32b2144aad2ae6ec975
+# exported save_stack_trace_tsk for arm64
+# Kernel 4.14 commit 9a3dc3186fc3795e076a4122da9e0258651a9631
+# exported save_stack_trace_tsk for arm
+#
+AC_DEFUN([LIBCFS_EXPORT_SAVE_STACK_TRACE_TSK], [
+LB_CHECK_EXPORT([save_stack_trace_tsk], [arch/$SUBARCH/kernel/stacktrace.c],
+ [AC_DEFINE(HAVE_SAVE_STACK_TRACE_TSK, 1,
+ [save_stack_trace_tsk is exported])])
+]) # LIBCFS_EXPORT_SAVE_STACK_TRACE_TSK
+
+#
+# LIBCFS_LOCKDEP_IS_HELD
+#
+# Kernel v4.15-rc8-106-g08f36ff64234
+# lockdep: Make lockdep checking constant
+#
+AC_DEFUN([LIBCFS_LOCKDEP_IS_HELD], [
+tmp_flags="$EXTRA_KCFLAGS"
+EXTRA_KCFLAGS="-Werror"
+LB_CHECK_COMPILE([if 'lockdep_is_held()' uses const argument],
+lockdep_is_held, [
+ #include <linux/lockdep.h>
+],[
+#ifdef CONFIG_LOCKDEP
+ const struct spinlock *lock = NULL;
+
+ lockdep_is_held(lock);
+#endif
+],[],[
+ AC_DEFINE(NEED_LOCKDEP_IS_HELD_DISCARD_CONST, 1,
+ [lockdep_is_held() argument is const])
+])
+EXTRA_KCFLAGS="$tmp_flags"
+]) # LIBCFS_LOCKDEP_IS_HELD
+
+#
+# LIBCFS_TIMER_SETUP
+#
+# Kernel version 4.15 commit e99e88a9d2b067465adaa9c111ada99a041bef9a
+# setup_timer() was replaced by timer_setup(), where the callback
+# argument is the structure already holding the struct timer_list.
+#
+AC_DEFUN([LIBCFS_TIMER_SETUP], [
+LB_CHECK_COMPILE([if setup_timer has been replaced with timer_setup],
+timer_setup, [
+ #include <linux/timer.h>
+],[
+ timer_setup(NULL, NULL, 0);
+],[
+ AC_DEFINE(HAVE_TIMER_SETUP, 1,
+ [timer_setup has replaced setup_timer])
+])
+]) # LIBCFS_TIMER_SETUP
+
+#
+# LIBCFS_WAIT_VAR_EVENT
+#
+# Kernel version 4.16-rc4 commit 6b2bb7265f0b62605e8caee3613449ed0db270b9
+# added wait_var_event()
+#
+AC_DEFUN([LIBCFS_WAIT_VAR_EVENT], [
+LB_CHECK_COMPILE([if 'wait_var_event' exist],
+wait_var_event, [
+ #ifdef HAVE_WAIT_BIT_HEADER_H
+ #include <linux/wait_bit.h>
+ #endif
+ #include <linux/wait.h>
+],[
+ wake_up_var(NULL);
+],[
+ AC_DEFINE(HAVE_WAIT_VAR_EVENT, 1,
+ ['wait_var_event' is available])
+])
+]) # LIBCFS_WAIT_VAR_EVENT
+
+#
+# LIBCFS_BITMAP_ALLOC
+#
+# Kernel version 4.17 commit c42b65e363ce97a828f81b59033c3558f8fa7f70
+# added bitmap memory allocation handling.
+#
+AC_DEFUN([LIBCFS_BITMAP_ALLOC], [
+LB_CHECK_COMPILE([if Linux bitmap memory management exist],
+bitmap_alloc, [
+ #include <linux/bitmap.h>
+],[
+ unsigned long *map = bitmap_alloc(1, GFP_KERNEL);
+],[
+ AC_DEFINE(HAVE_BITMAP_ALLOC, 1,
+ [Linux bitmap can be allocated])
+])
+]) # LIBCFS_BITMAP_ALLOC
+
+#
+# LIBCFS_CLEAR_AND_WAKE_UP_BIT
+#
+# Kernel version 4.17-rc2 commit 8236b0ae31c837d2b3a2565c5f8d77f637e824cc
+# added clear_and_wake_up_bit()
+#
+AC_DEFUN([LIBCFS_CLEAR_AND_WAKE_UP_BIT], [
+LB_CHECK_COMPILE([if 'clear_and_wake_up_bit' exist],
+clear_and_wake_up_bit, [
+ #ifdef HAVE_WAIT_BIT_HEADER_H
+ #include <linux/wait_bit.h>
+ #endif
+ #include <linux/wait.h>
+],[
+ clear_and_wake_up_bit(0, NULL);
+],[
+ AC_DEFINE(HAVE_CLEAR_AND_WAKE_UP_BIT, 1,
+ ['clear_and_wake_up_bit' is available])
+])
+]) # LIBCFS_CLEAR_AND_WAKE_UP_BIT
+
+#
+# LIBCFS_XARRAY_SUPPORT
+#
+# 4.19-rc5 kernel commit 3159f943aafdbacb2f94c38fdaadabf2bbde2a14
+# replaced the radix tree implementation with Xarrays. This change
+# introduced functionaly needed for general Xarray support
+#
+AC_DEFUN([LIBCFS_XARRAY_SUPPORT], [
+tmp_flags="$EXTRA_KCFLAGS"
+EXTRA_KCFLAGS="-Werror"
+LB_CHECK_COMPILE([if page cache uses Xarray],
+xarray_support, [
+ #include <linux/xarray.h>
+],[
+ xa_is_value(NULL);
+],[
+ AC_DEFINE(HAVE_XARRAY_SUPPORT, 1,
+ [kernel Xarray implementation lacks 'xa_is_value'])
+])
+EXTRA_KCFLAGS="$tmp_flags"
+]) # LIBCFS_XARRAY_SUPPORT
+
+#
+# LIBCFS_HAVE_IOV_ITER_TYPE
+#
+# kernel 4.20 commit 00e23707442a75b404392cef1405ab4fd498de6b
+# iov_iter: Use accessor functions to access an iterator's type and direction.
+#
+AC_DEFUN([LIBCFS_HAVE_IOV_ITER_TYPE], [
+tmp_flags="$EXTRA_KCFLAGS"
+EXTRA_KCFLAGS="-Werror"
+LB_CHECK_COMPILE([if iov_iter_type exists],
+macro_iov_iter_type_exists, [
+ #include <linux/uio.h>
+],[
+ struct iov_iter iter = { .type = ITER_KVEC };
+ enum iter_type type = iov_iter_type(&iter);
+ (void)type;
+],[
+ AC_DEFINE(HAVE_IOV_ITER_TYPE, 1,
+ [if iov_iter_type exists])
+])
+EXTRA_KCFLAGS="$tmp_flags"
+]) # LIBCFS_HAVE_IOV_ITER_TYPE
+
+#
+# LIBCFS_GET_REQUEST_KEY_AUTH
+#
+# kernel 5.0 commit 822ad64d7e46a8e2c8b8a796738d7b657cbb146d
+# keys: Fix dependency loop between construction record and auth key
+#
+# Added <keys/request_key_auth-type.h> and get_request_key_auth()
+# which was propagated to stable
+#
+AC_DEFUN([LIBCFS_GET_REQUEST_KEY_AUTH], [
+tmp_flags="$EXTRA_KCFLAGS"
+EXTRA_KCFLAGS="-Werror"
+LB_CHECK_COMPILE([if get_request_key_auth() is available],
+get_request_key_auth_exported, [
+ #include <linux/key.h>
+ #include <linux/keyctl.h>
+ #include <keys/request_key_auth-type.h>
+],[
+ struct key *ring;
+ const struct key *key = NULL;
+ struct request_key_auth *rka = get_request_key_auth(key);
+
+ ring = key_get(rka->dest_keyring);
+],[
+ AC_DEFINE(HAVE_GET_REQUEST_KEY_AUTH, 1,
+ [get_request_key_auth() is available])
+])
+EXTRA_KCFLAGS="$tmp_flags"
+]) # LIBCFS_GET_REQUEST_KEY_AUTH
+
+#
+# LIBCFS_LOOKUP_USER_KEY
+#
+# kernel 5.3 commit 3cf5d076fb4d48979f382bc9452765bf8b79e740
+# signal: Remove task parameter from force_sig
+#
+AC_DEFUN([LIBCFS_LOOKUP_USER_KEY], [
+tmp_flags="$EXTRA_KCFLAGS"
+EXTRA_KCFLAGS="-Werror"
+LB_CHECK_COMPILE([if lookup_user_key() is available],
+lookup_user_key_exported, [
+ #include <linux/key.h>
+ #include <linux/keyctl.h>
+],[
+ lookup_user_key(KEY_SPEC_USER_KEYRING, 0, 0);
+],[
+ AC_DEFINE(HAVE_LOOKUP_USER_KEY, 1,
+ [lookup_user_key() is available])
+])
+EXTRA_KCFLAGS="$tmp_flags"
+]) # LIBCFS_LOOKUP_USER_KEY
+
+#
+# LIBCFS_FORCE_SIG_WITH_TASK
+#
+# kernel 5.3 commit 3cf5d076fb4d48979f382bc9452765bf8b79e740
+# signal: Remove task parameter from force_sig
+#
+AC_DEFUN([LIBCFS_FORCE_SIG_WITH_TASK], [
+tmp_flags="$EXTRA_KCFLAGS"
+EXTRA_KCFLAGS="-Werror"
+LB_CHECK_COMPILE([if force_sig has task parameter],
+force_sig_with_task, [
+ #include <linux/sched/signal.h>
+],[
+ force_sig(SIGINT, NULL);
+],[
+ AC_DEFINE(HAVE_FORCE_SIG_WITH_TASK, 1,
+ [force_sig() has task parameter])
+])
+EXTRA_KCFLAGS="$tmp_flags"
+]) # LIBCFS_FORCE_SIG_WITH_TASK
+
+#
+# LIBCFS_CACHE_DETAIL_WRITERS
+#
+# kernel v5.3-rc2-1-g64a38e840ce5
+# SUNRPC: Track writers of the 'channel' file to improve cache_listeners_exist
+#
+AC_DEFUN([LIBCFS_CACHE_DETAIL_WRITERS], [
+tmp_flags="$EXTRA_KCFLAGS"
+EXTRA_KCFLAGS="-Werror"
+LB_CHECK_COMPILE([if struct cache_detail has writers],
+cache_detail_writers_atomic, [
+ #include <linux/sunrpc/cache.h>
+
+ static struct cache_detail rsi_cache;
+],[
+ atomic_set(&rsi_cache.writers, 0);
+],[
+ AC_DEFINE(HAVE_CACHE_DETAIL_WRITERS, 1,
+ [struct cache_detail has writers])
+])
+EXTRA_KCFLAGS="$tmp_flags"
+]) # LIBCFS_CACHE_DETAIL_WRITERS
+
+#
+# LIBCFS_VMALLOC_2ARGS
+#
+# kernel v5.8-rc1~201^2~19
+# mm: remove the pgprot argument to __vmalloc
+AC_DEFUN([LIBCFS_VMALLOC_2ARGS], [
+LB_CHECK_COMPILE([if __vmalloc has 2 args],
+vmalloc_2args, [
+ #include <linux/vmalloc.h>
+],[
+ __vmalloc(0, 0);
+],[
+ AC_DEFINE(HAVE_VMALLOC_2ARGS, 1,
+ [__vmalloc only takes 2 args.])
+])
+]) # LIBCFS_VMALLOC_2ARGS
+
+#
+# LIBCFS_HAVE_NR_UNSTABLE_NFS
+#
+# kernel v5.8-rc1~201^2~75
+# mm/writeback: discard NR_UNSTABLE_NFS, use NR_WRITEBACK instead
+#
+AC_DEFUN([LIBCFS_HAVE_NR_UNSTABLE_NFS], [
+tmp_flags="$EXTRA_KCFLAGS"
+EXTRA_KCFLAGS="-Werror"
+LB_CHECK_COMPILE([if NR_UNSTABLE_NFS still in use],
+nr_unstable_nfs_exists, [
+ #include <linux/mm.h>
+
+ int i;
+],[
+ i = NR_UNSTABLE_NFS;
+],[
+ AC_DEFINE(HAVE_NR_UNSTABLE_NFS, 1,
+ [NR_UNSTABLE_NFS is still in use.])
+])
+EXTRA_KCFLAGS="$tmp_flags"
+]) # LIBCFS_HAVE_NR_UNSTABLE_NFS
+
+#
+# LIBCFS_HAVE_MMAP_LOCK
+#
+# kernel v5.8-rc1~83^2~24
+# mmap locking API: rename mmap_sem to mmap_lock
+#
+AC_DEFUN([LIBCFS_HAVE_MMAP_LOCK], [
+LB_CHECK_COMPILE([if mmap_lock API is available],
+mmap_write_lock, [
+ #include <linux/mm.h>
+],[
+ mmap_write_lock(NULL);
+],[
+ AC_DEFINE(HAVE_MMAP_LOCK, 1,
+ [mmap_lock API is available.])
+])
+]) # LIBCFS_HAVE_MMAP_LOCK
+
+#
+# LIBCFS_KERNEL_SETSOCKOPT
+#
+# kernel v5.8-rc1~165^2~59^2
+# net: remove kernel_setsockopt
+AC_DEFUN([LIBCFS_KERNEL_SETSOCKOPT], [
+tmp_flags="$EXTRA_KCFLAGS"
+EXTRA_KCFLAGS="-Werror"
+LB_CHECK_COMPILE([if kernel_setsockopt still in use],
+kernel_setsockopt_exists, [
+ #include <linux/net.h>
+],[
+ kernel_setsockopt(NULL, 0, 0, NULL, 0);
+],[
+ AC_DEFINE(HAVE_KERNEL_SETSOCKOPT, 1,
+ [kernel_setsockopt still in use])
+])
+EXTRA_KCFLAGS="$tmp_flags"
+]) # LIBCFS_KERNEL_SETSOCKOPT
+
+AC_DEFUN([LIBCFS_PROG_LINUX_SRC], [] )
+AC_DEFUN([LIBCFS_PROG_LINUX_RESULTS], [])
+
+#