From adbe427b92d18cf3f801e82e9cd664fbe31cea3c Mon Sep 17 00:00:00 2001 From: Vladimir Davydov Date: Wed, 15 Apr 2015 16:13:00 -0700 Subject: memcg: zap mem_cgroup_lookup() mem_cgroup_lookup() is a wrapper around mem_cgroup_from_id(), which checks that id != 0 before issuing the function call. Today, there is no point in this additional check apart from optimization, because there is no css with id <= 0, so that css_from_id, called by mem_cgroup_from_id, will return NULL for any id <= 0. Since mem_cgroup_from_id is only called from mem_cgroup_lookup, let us zap mem_cgroup_lookup, substituting calls to it with mem_cgroup_from_id and moving the check if id > 0 to css_from_id. Signed-off-by: Vladimir Davydov Acked-by: Michal Hocko Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/cgroup.c b/kernel/cgroup.c index a220fdb66568..59aa339a245c 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -5451,7 +5451,7 @@ struct cgroup_subsys_state *css_tryget_online_from_dir(struct dentry *dentry, struct cgroup_subsys_state *css_from_id(int id, struct cgroup_subsys *ss) { WARN_ON_ONCE(!rcu_read_lock_held()); - return idr_find(&ss->css_idr, id); + return id > 0 ? idr_find(&ss->css_idr, id) : NULL; } #ifdef CONFIG_CGROUP_DEBUG -- cgit v1.2.3 From 5bbe3547aa3ba5242366a322a28996872301b703 Mon Sep 17 00:00:00 2001 From: Eric B Munson Date: Wed, 15 Apr 2015 16:13:20 -0700 Subject: mm: allow compaction of unevictable pages Currently, pages which are marked as unevictable are protected from compaction, but not from other types of migration. The POSIX real time extension explicitly states that mlock() will prevent a major page fault, but the spirit of this is that mlock() should give a process the ability to control sources of latency, including minor page faults. However, the mlock manpage only explicitly says that a locked page will not be written to swap and this can cause some confusion. The compaction code today does not give a developer who wants to avoid swap but wants to have large contiguous areas available any method to achieve this state. This patch introduces a sysctl for controlling compaction behavior with respect to the unevictable lru. Users who demand no page faults after a page is present can set compact_unevictable_allowed to 0 and users who need the large contiguous areas can enable compaction on locked memory by leaving the default value of 1. To illustrate this problem I wrote a quick test program that mmaps a large number of 1MB files filled with random data. These maps are created locked and read only. Then every other mmap is unmapped and I attempt to allocate huge pages to the static huge page pool. When the compact_unevictable_allowed sysctl is 0, I cannot allocate hugepages after fragmenting memory. When the value is set to 1, allocations succeed. Signed-off-by: Eric B Munson Acked-by: Michal Hocko Acked-by: Vlastimil Babka Acked-by: Christoph Lameter Acked-by: David Rientjes Acked-by: Rik van Riel Cc: Vlastimil Babka Cc: Thomas Gleixner Cc: Christoph Lameter Cc: Peter Zijlstra Cc: Mel Gorman Cc: David Rientjes Cc: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/sysctl/vm.txt | 11 +++++++++++ include/linux/compaction.h | 1 + kernel/sysctl.c | 9 +++++++++ mm/compaction.c | 7 +++++++ 4 files changed, 28 insertions(+) (limited to 'kernel') diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt index 902b4574acfb..9832ec52f859 100644 --- a/Documentation/sysctl/vm.txt +++ b/Documentation/sysctl/vm.txt @@ -21,6 +21,7 @@ Currently, these files are in /proc/sys/vm: - admin_reserve_kbytes - block_dump - compact_memory +- compact_unevictable_allowed - dirty_background_bytes - dirty_background_ratio - dirty_bytes @@ -106,6 +107,16 @@ huge pages although processes will also directly compact memory as required. ============================================================== +compact_unevictable_allowed + +Available only when CONFIG_COMPACTION is set. When set to 1, compaction is +allowed to examine the unevictable lru (mlocked pages) for pages to compact. +This should be used on systems where stalls for minor page faults are an +acceptable trade for large contiguous free memory. Set to 0 to prevent +compaction from moving pages that are unevictable. Default value is 1. + +============================================================== + dirty_background_bytes Contains the amount of dirty memory at which the background kernel diff --git a/include/linux/compaction.h b/include/linux/compaction.h index a014559e4a49..aa8f61cf3a19 100644 --- a/include/linux/compaction.h +++ b/include/linux/compaction.h @@ -34,6 +34,7 @@ extern int sysctl_compaction_handler(struct ctl_table *table, int write, extern int sysctl_extfrag_threshold; extern int sysctl_extfrag_handler(struct ctl_table *table, int write, void __user *buffer, size_t *length, loff_t *ppos); +extern int sysctl_compact_unevictable_allowed; extern int fragmentation_index(struct zone *zone, unsigned int order); extern unsigned long try_to_compact_pages(gfp_t gfp_mask, unsigned int order, diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 8c0eabd41886..42b7fc2860c1 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -1335,6 +1335,15 @@ static struct ctl_table vm_table[] = { .extra1 = &min_extfrag_threshold, .extra2 = &max_extfrag_threshold, }, + { + .procname = "compact_unevictable_allowed", + .data = &sysctl_compact_unevictable_allowed, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + .extra1 = &zero, + .extra2 = &one, + }, #endif /* CONFIG_COMPACTION */ { diff --git a/mm/compaction.c b/mm/compaction.c index a18201a8124e..570426edcadf 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -1046,6 +1046,12 @@ typedef enum { ISOLATE_SUCCESS, /* Pages isolated, migrate */ } isolate_migrate_t; +/* + * Allow userspace to control policy on scanning the unevictable LRU for + * compactable pages. + */ +int sysctl_compact_unevictable_allowed __read_mostly = 1; + /* * Isolate all pages that can be migrated from the first suitable block, * starting at the block pointed to by the migrate scanner pfn within @@ -1057,6 +1063,7 @@ static isolate_migrate_t isolate_migratepages(struct zone *zone, unsigned long low_pfn, end_pfn; struct page *page; const isolate_mode_t isolate_mode = + (sysctl_compact_unevictable_allowed ? ISOLATE_UNEVICTABLE : 0) | (cc->mode == MIGRATE_ASYNC ? ISOLATE_ASYNC_MIGRATE : 0); /* -- cgit v1.2.3 From 2813893f8b197a14f1e1ddb04d99bce46817c84a Mon Sep 17 00:00:00 2001 From: Iulia Manda Date: Wed, 15 Apr 2015 16:16:41 -0700 Subject: kernel: conditionally support non-root users, groups and capabilities There are a lot of embedded systems that run most or all of their functionality in init, running as root:root. For these systems, supporting multiple users is not necessary. This patch adds a new symbol, CONFIG_MULTIUSER, that makes support for non-root users, non-root groups, and capabilities optional. It is enabled under CONFIG_EXPERT menu. When this symbol is not defined, UID and GID are zero in any possible case and processes always have all capabilities. The following syscalls are compiled out: setuid, setregid, setgid, setreuid, setresuid, getresuid, setresgid, getresgid, setgroups, getgroups, setfsuid, setfsgid, capget, capset. Also, groups.c is compiled out completely. In kernel/capability.c, capable function was moved in order to avoid adding two ifdef blocks. This change saves about 25 KB on a defconfig build. The most minimal kernels have total text sizes in the high hundreds of kB rather than low MB. (The 25k goes down a bit with allnoconfig, but not that much. The kernel was booted in Qemu. All the common functionalities work. Adding users/groups is not possible, failing with -ENOSYS. Bloat-o-meter output: add/remove: 7/87 grow/shrink: 19/397 up/down: 1675/-26325 (-24650) [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Iulia Manda Reviewed-by: Josh Triplett Acked-by: Geert Uytterhoeven Tested-by: Paul E. McKenney Reviewed-by: Paul E. McKenney Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/s390/Kconfig | 1 + drivers/staging/lustre/lustre/Kconfig | 1 + fs/nfs/Kconfig | 2 +- fs/nfsd/Kconfig | 1 + include/linux/capability.h | 29 +++++++++++++++++++++++++++++ include/linux/cred.h | 23 +++++++++++++++++++---- include/linux/uidgid.h | 12 ++++++++++++ init/Kconfig | 19 ++++++++++++++++++- kernel/Makefile | 4 +++- kernel/capability.c | 35 +++++++++++++++++++---------------- kernel/cred.c | 3 +++ kernel/groups.c | 3 --- kernel/sys.c | 2 ++ kernel/sys_ni.c | 14 ++++++++++++++ net/sunrpc/Kconfig | 2 ++ security/Kconfig | 1 + 16 files changed, 126 insertions(+), 26 deletions(-) (limited to 'kernel') diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index a5ced5c3c1e0..de2726a487b0 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -328,6 +328,7 @@ config COMPAT select COMPAT_BINFMT_ELF if BINFMT_ELF select ARCH_WANT_OLD_COMPAT_IPC select COMPAT_OLD_SIGACTION + depends on MULTIUSER help Select this option if you want to enable your system kernel to handle system-calls from ELF binaries for 31 bit ESA. This option diff --git a/drivers/staging/lustre/lustre/Kconfig b/drivers/staging/lustre/lustre/Kconfig index 6725467ef4d0..62c7bba75274 100644 --- a/drivers/staging/lustre/lustre/Kconfig +++ b/drivers/staging/lustre/lustre/Kconfig @@ -10,6 +10,7 @@ config LUSTRE_FS select CRYPTO_SHA1 select CRYPTO_SHA256 select CRYPTO_SHA512 + depends on MULTIUSER help This option enables Lustre file system client support. Choose Y here if you want to access a Lustre file system cluster. To compile diff --git a/fs/nfs/Kconfig b/fs/nfs/Kconfig index c7abc10279af..f31fd0dd92c6 100644 --- a/fs/nfs/Kconfig +++ b/fs/nfs/Kconfig @@ -1,6 +1,6 @@ config NFS_FS tristate "NFS client support" - depends on INET && FILE_LOCKING + depends on INET && FILE_LOCKING && MULTIUSER select LOCKD select SUNRPC select NFS_ACL_SUPPORT if NFS_V3_ACL diff --git a/fs/nfsd/Kconfig b/fs/nfsd/Kconfig index 683bf718aead..fc2d108f5272 100644 --- a/fs/nfsd/Kconfig +++ b/fs/nfsd/Kconfig @@ -6,6 +6,7 @@ config NFSD select SUNRPC select EXPORTFS select NFS_ACL_SUPPORT if NFSD_V2_ACL + depends on MULTIUSER help Choose Y here if you want to allow other computers to access files residing on this system using Sun's Network File System diff --git a/include/linux/capability.h b/include/linux/capability.h index aa93e5ef594c..af9f0b9e80e6 100644 --- a/include/linux/capability.h +++ b/include/linux/capability.h @@ -205,6 +205,7 @@ static inline kernel_cap_t cap_raise_nfsd_set(const kernel_cap_t a, cap_intersect(permitted, __cap_nfsd_set)); } +#ifdef CONFIG_MULTIUSER extern bool has_capability(struct task_struct *t, int cap); extern bool has_ns_capability(struct task_struct *t, struct user_namespace *ns, int cap); @@ -213,6 +214,34 @@ extern bool has_ns_capability_noaudit(struct task_struct *t, struct user_namespace *ns, int cap); extern bool capable(int cap); extern bool ns_capable(struct user_namespace *ns, int cap); +#else +static inline bool has_capability(struct task_struct *t, int cap) +{ + return true; +} +static inline bool has_ns_capability(struct task_struct *t, + struct user_namespace *ns, int cap) +{ + return true; +} +static inline bool has_capability_noaudit(struct task_struct *t, int cap) +{ + return true; +} +static inline bool has_ns_capability_noaudit(struct task_struct *t, + struct user_namespace *ns, int cap) +{ + return true; +} +static inline bool capable(int cap) +{ + return true; +} +static inline bool ns_capable(struct user_namespace *ns, int cap) +{ + return true; +} +#endif /* CONFIG_MULTIUSER */ extern bool capable_wrt_inode_uidgid(const struct inode *inode, int cap); extern bool file_ns_capable(const struct file *file, struct user_namespace *ns, int cap); diff --git a/include/linux/cred.h b/include/linux/cred.h index 2fb2ca2127ed..8b6c083e68a7 100644 --- a/include/linux/cred.h +++ b/include/linux/cred.h @@ -62,9 +62,27 @@ do { \ groups_free(group_info); \ } while (0) -extern struct group_info *groups_alloc(int); extern struct group_info init_groups; +#ifdef CONFIG_MULTIUSER +extern struct group_info *groups_alloc(int); extern void groups_free(struct group_info *); + +extern int in_group_p(kgid_t); +extern int in_egroup_p(kgid_t); +#else +static inline void groups_free(struct group_info *group_info) +{ +} + +static inline int in_group_p(kgid_t grp) +{ + return 1; +} +static inline int in_egroup_p(kgid_t grp) +{ + return 1; +} +#endif extern int set_current_groups(struct group_info *); extern void set_groups(struct cred *, struct group_info *); extern int groups_search(const struct group_info *, kgid_t); @@ -74,9 +92,6 @@ extern bool may_setgroups(void); #define GROUP_AT(gi, i) \ ((gi)->blocks[(i) / NGROUPS_PER_BLOCK][(i) % NGROUPS_PER_BLOCK]) -extern int in_group_p(kgid_t); -extern int in_egroup_p(kgid_t); - /* * The security context of a task * diff --git a/include/linux/uidgid.h b/include/linux/uidgid.h index 2d1f9b627f91..0ee05da38899 100644 --- a/include/linux/uidgid.h +++ b/include/linux/uidgid.h @@ -29,6 +29,7 @@ typedef struct { #define KUIDT_INIT(value) (kuid_t){ value } #define KGIDT_INIT(value) (kgid_t){ value } +#ifdef CONFIG_MULTIUSER static inline uid_t __kuid_val(kuid_t uid) { return uid.val; @@ -38,6 +39,17 @@ static inline gid_t __kgid_val(kgid_t gid) { return gid.val; } +#else +static inline uid_t __kuid_val(kuid_t uid) +{ + return 0; +} + +static inline gid_t __kgid_val(kgid_t gid) +{ + return 0; +} +#endif #define GLOBAL_ROOT_UID KUIDT_INIT(0) #define GLOBAL_ROOT_GID KGIDT_INIT(0) diff --git a/init/Kconfig b/init/Kconfig index a905b7301e10..3b9df1aa35db 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -394,6 +394,7 @@ endchoice config BSD_PROCESS_ACCT bool "BSD Process Accounting" + depends on MULTIUSER help If you say Y here, a user level program will be able to instruct the kernel (via a special system call) to write process accounting @@ -420,6 +421,7 @@ config BSD_PROCESS_ACCT_V3 config TASKSTATS bool "Export task/process statistics through netlink" depends on NET + depends on MULTIUSER default n help Export selected statistics for tasks/processes through the @@ -1160,6 +1162,7 @@ config CHECKPOINT_RESTORE menuconfig NAMESPACES bool "Namespaces support" if EXPERT + depends on MULTIUSER default !EXPERT help Provides the way to make tasks work with different objects using @@ -1356,11 +1359,25 @@ menuconfig EXPERT config UID16 bool "Enable 16-bit UID system calls" if EXPERT - depends on HAVE_UID16 + depends on HAVE_UID16 && MULTIUSER default y help This enables the legacy 16-bit UID syscall wrappers. +config MULTIUSER + bool "Multiple users, groups and capabilities support" if EXPERT + default y + help + This option enables support for non-root users, groups and + capabilities. + + If you say N here, all processes will run with UID 0, GID 0, and all + possible capabilities. Saying N here also compiles out support for + system calls related to UIDs, GIDs, and capabilities, such as setuid, + setgid, and capset. + + If unsure, say Y here. + config SGETMASK_SYSCALL bool "sgetmask/ssetmask syscalls support" if EXPERT def_bool PARISC || MN10300 || BLACKFIN || M68K || PPC || MIPS || X86 || SPARC || CRIS || MICROBLAZE || SUPERH diff --git a/kernel/Makefile b/kernel/Makefile index 1408b3353a3c..0f8f8b0bc1bf 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -9,7 +9,9 @@ obj-y = fork.o exec_domain.o panic.o \ extable.o params.o \ kthread.o sys_ni.o nsproxy.o \ notifier.o ksysfs.o cred.o reboot.o \ - async.o range.o groups.o smpboot.o + async.o range.o smpboot.o + +obj-$(CONFIG_MULTIUSER) += groups.o ifdef CONFIG_FUNCTION_TRACER # Do not trace debug files and internal ftrace files diff --git a/kernel/capability.c b/kernel/capability.c index 989f5bfc57dc..45432b54d5c6 100644 --- a/kernel/capability.c +++ b/kernel/capability.c @@ -35,6 +35,7 @@ static int __init file_caps_disable(char *str) } __setup("no_file_caps", file_caps_disable); +#ifdef CONFIG_MULTIUSER /* * More recent versions of libcap are available from: * @@ -386,6 +387,24 @@ bool ns_capable(struct user_namespace *ns, int cap) } EXPORT_SYMBOL(ns_capable); + +/** + * capable - Determine if the current task has a superior capability in effect + * @cap: The capability to be tested for + * + * Return true if the current task has the given superior capability currently + * available for use, false if not. + * + * This sets PF_SUPERPRIV on the task if the capability is available on the + * assumption that it's about to be used. + */ +bool capable(int cap) +{ + return ns_capable(&init_user_ns, cap); +} +EXPORT_SYMBOL(capable); +#endif /* CONFIG_MULTIUSER */ + /** * file_ns_capable - Determine if the file's opener had a capability in effect * @file: The file we want to check @@ -411,22 +430,6 @@ bool file_ns_capable(const struct file *file, struct user_namespace *ns, } EXPORT_SYMBOL(file_ns_capable); -/** - * capable - Determine if the current task has a superior capability in effect - * @cap: The capability to be tested for - * - * Return true if the current task has the given superior capability currently - * available for use, false if not. - * - * This sets PF_SUPERPRIV on the task if the capability is available on the - * assumption that it's about to be used. - */ -bool capable(int cap) -{ - return ns_capable(&init_user_ns, cap); -} -EXPORT_SYMBOL(capable); - /** * capable_wrt_inode_uidgid - Check nsown_capable and uid and gid mapped * @inode: The inode in question diff --git a/kernel/cred.c b/kernel/cred.c index e0573a43c7df..ec1c07667ec1 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -29,6 +29,9 @@ static struct kmem_cache *cred_jar; +/* init to 2 - one for init_task, one to ensure it is never freed */ +struct group_info init_groups = { .usage = ATOMIC_INIT(2) }; + /* * The initial credentials for the initial task */ diff --git a/kernel/groups.c b/kernel/groups.c index 664411f171b5..74d431d25251 100644 --- a/kernel/groups.c +++ b/kernel/groups.c @@ -9,9 +9,6 @@ #include #include -/* init to 2 - one for init_task, one to ensure it is never freed */ -struct group_info init_groups = { .usage = ATOMIC_INIT(2) }; - struct group_info *groups_alloc(int gidsetsize) { struct group_info *group_info; diff --git a/kernel/sys.c b/kernel/sys.c index a03d9cd23ed7..3be344902316 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -325,6 +325,7 @@ out_unlock: * SMP: There are not races, the GIDs are checked only by filesystem * operations (as far as semantic preservation is concerned). */ +#ifdef CONFIG_MULTIUSER SYSCALL_DEFINE2(setregid, gid_t, rgid, gid_t, egid) { struct user_namespace *ns = current_user_ns(); @@ -815,6 +816,7 @@ change_okay: commit_creds(new); return old_fsgid; } +#endif /* CONFIG_MULTIUSER */ /** * sys_getpid - return the thread group id of the current process diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index 5adcb0ae3a58..7995ef5868d8 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -159,6 +159,20 @@ cond_syscall(sys_uselib); cond_syscall(sys_fadvise64); cond_syscall(sys_fadvise64_64); cond_syscall(sys_madvise); +cond_syscall(sys_setuid); +cond_syscall(sys_setregid); +cond_syscall(sys_setgid); +cond_syscall(sys_setreuid); +cond_syscall(sys_setresuid); +cond_syscall(sys_getresuid); +cond_syscall(sys_setresgid); +cond_syscall(sys_getresgid); +cond_syscall(sys_setgroups); +cond_syscall(sys_getgroups); +cond_syscall(sys_setfsuid); +cond_syscall(sys_setfsgid); +cond_syscall(sys_capget); +cond_syscall(sys_capset); /* arch-specific weak syscall entries */ cond_syscall(sys_pciconfig_read); diff --git a/net/sunrpc/Kconfig b/net/sunrpc/Kconfig index fb78117b896c..9068e72aa73c 100644 --- a/net/sunrpc/Kconfig +++ b/net/sunrpc/Kconfig @@ -1,9 +1,11 @@ config SUNRPC tristate + depends on MULTIUSER config SUNRPC_GSS tristate select OID_REGISTRY + depends on MULTIUSER config SUNRPC_BACKCHANNEL bool diff --git a/security/Kconfig b/security/Kconfig index beb86b500adf..bf4ec46474b6 100644 --- a/security/Kconfig +++ b/security/Kconfig @@ -21,6 +21,7 @@ config SECURITY_DMESG_RESTRICT config SECURITY bool "Enable different security models" depends on SYSFS + depends on MULTIUSER help This allows you to choose different security modules to be configured into your kernel. -- cgit v1.2.3 From 96831c0a6738f88f89e7012f4df0a747514af0a0 Mon Sep 17 00:00:00 2001 From: Jakub Sitnicki Date: Wed, 15 Apr 2015 16:16:44 -0700 Subject: kernel/resource.c: remove deprecated __check_region() and friends All users of __check_region(), check_region(), and check_mem_region() are gone. We got rid of the last user in v4.0-rc1. Remove them. bloat-o-meter on x86_64 shows: add/remove: 0/3 grow/shrink: 0/0 up/down: 0/-102 (-102) function old new delta __kstrtab___check_region 15 - -15 __ksymtab___check_region 16 - -16 __check_region 71 - -71 Signed-off-by: Jakub Sitnicki Cc: Bjorn Helgaas Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/ioport.h | 8 -------- kernel/resource.c | 32 -------------------------------- 2 files changed, 40 deletions(-) (limited to 'kernel') diff --git a/include/linux/ioport.h b/include/linux/ioport.h index 2c5250222278..388e3ae94f7a 100644 --- a/include/linux/ioport.h +++ b/include/linux/ioport.h @@ -196,10 +196,8 @@ extern struct resource * __request_region(struct resource *, /* Compatibility cruft */ #define release_region(start,n) __release_region(&ioport_resource, (start), (n)) -#define check_mem_region(start,n) __check_region(&iomem_resource, (start), (n)) #define release_mem_region(start,n) __release_region(&iomem_resource, (start), (n)) -extern int __check_region(struct resource *, resource_size_t, resource_size_t); extern void __release_region(struct resource *, resource_size_t, resource_size_t); #ifdef CONFIG_MEMORY_HOTREMOVE @@ -207,12 +205,6 @@ extern int release_mem_region_adjustable(struct resource *, resource_size_t, resource_size_t); #endif -static inline int __deprecated check_region(resource_size_t s, - resource_size_t n) -{ - return __check_region(&ioport_resource, s, n); -} - /* Wrappers for managed devices */ struct device; diff --git a/kernel/resource.c b/kernel/resource.c index 19f2357dfda3..90552aab5f2d 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -1034,8 +1034,6 @@ resource_size_t resource_alignment(struct resource *res) * * request_region creates a new busy region. * - * check_region returns non-zero if the area is already busy. - * * release_region releases a matching busy region. */ @@ -1097,36 +1095,6 @@ struct resource * __request_region(struct resource *parent, } EXPORT_SYMBOL(__request_region); -/** - * __check_region - check if a resource region is busy or free - * @parent: parent resource descriptor - * @start: resource start address - * @n: resource region size - * - * Returns 0 if the region is free at the moment it is checked, - * returns %-EBUSY if the region is busy. - * - * NOTE: - * This function is deprecated because its use is racy. - * Even if it returns 0, a subsequent call to request_region() - * may fail because another driver etc. just allocated the region. - * Do NOT use it. It will be removed from the kernel. - */ -int __check_region(struct resource *parent, resource_size_t start, - resource_size_t n) -{ - struct resource * res; - - res = __request_region(parent, start, n, "check-region", 0); - if (!res) - return -EBUSY; - - release_resource(res); - free_resource(res); - return 0; -} -EXPORT_SYMBOL(__check_region); - /** * __release_region - release a previously reserved resource region * @parent: parent resource descriptor -- cgit v1.2.3 From 972fae6993cbbb934345011664dc703c0891dda3 Mon Sep 17 00:00:00 2001 From: Aaron Tomlin Date: Wed, 15 Apr 2015 16:16:47 -0700 Subject: kernel/hung_task.c: change hung_task.c to use for_each_process_thread() In check_hung_uninterruptible_tasks() avoid the use of deprecated while_each_thread(). The "max_count" logic will prevent a livelock - see commit 0c740d0a ("introduce for_each_thread() to replace the buggy while_each_thread()"). Having said this let's use for_each_process_thread(). Signed-off-by: Aaron Tomlin Acked-by: Oleg Nesterov Cc: David Rientjes Cc: Dave Wysochanski Cc: Aaron Tomlin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/hung_task.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/hung_task.c b/kernel/hung_task.c index 06db12434d72..e0f90c2b57aa 100644 --- a/kernel/hung_task.c +++ b/kernel/hung_task.c @@ -169,7 +169,7 @@ static void check_hung_uninterruptible_tasks(unsigned long timeout) return; rcu_read_lock(); - do_each_thread(g, t) { + for_each_process_thread(g, t) { if (!max_count--) goto unlock; if (!--batch_count) { @@ -180,7 +180,7 @@ static void check_hung_uninterruptible_tasks(unsigned long timeout) /* use "==" to skip the TASK_KILLABLE tasks waiting on NFS */ if (t->state == TASK_UNINTERRUPTIBLE) check_hung_task(t, timeout); - } while_each_thread(g, t); + } unlock: rcu_read_unlock(); } -- cgit v1.2.3 From 7a54f46b301cfab8a0d7365aa186545f8b98f22e Mon Sep 17 00:00:00 2001 From: Joel Stanley Date: Wed, 15 Apr 2015 16:16:53 -0700 Subject: kernel/reboot.c: add orderly_reboot for graceful reboot The kernel has orderly_poweroff which allows the kernel to initiate a graceful shutdown of userspace, by running /sbin/poweroff. This adds orderly_reboot that will cause userspace to shut itself down by calling /sbin/reboot. This will be used for shutdown initiated by a system controller on platforms that do not use ACPI. orderly_reboot() should be used when the system wants to allow userspace to gracefully shut itself down. For cases where the system may imminently catch on fire, the existing emergency_restart() provides an immediate reboot without involving userspace. Signed-off-by: Joel Stanley Cc: Fabian Frederick Cc: Benjamin Herrenschmidt Cc: Michael Ellerman Cc: Rusty Russell Cc: Jeremy Kerr Cc: David S. Miller Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/reboot.h | 3 ++- kernel/reboot.c | 53 +++++++++++++++++++++++++++++++++++++++++++++----- 2 files changed, 50 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/include/linux/reboot.h b/include/linux/reboot.h index 67fc8fcdc4b0..a7ff409f386d 100644 --- a/include/linux/reboot.h +++ b/include/linux/reboot.h @@ -70,7 +70,8 @@ void ctrl_alt_del(void); #define POWEROFF_CMD_PATH_LEN 256 extern char poweroff_cmd[POWEROFF_CMD_PATH_LEN]; -extern int orderly_poweroff(bool force); +extern void orderly_poweroff(bool force); +extern void orderly_reboot(void); /* * Emergency restart, callable from an interrupt handler. diff --git a/kernel/reboot.c b/kernel/reboot.c index 5925f5ae8dff..d20c85d9f8c0 100644 --- a/kernel/reboot.c +++ b/kernel/reboot.c @@ -387,8 +387,9 @@ void ctrl_alt_del(void) } char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff"; +static const char reboot_cmd[] = "/sbin/reboot"; -static int __orderly_poweroff(bool force) +static int run_cmd(const char *cmd) { char **argv; static char *envp[] = { @@ -397,8 +398,7 @@ static int __orderly_poweroff(bool force) NULL }; int ret; - - argv = argv_split(GFP_KERNEL, poweroff_cmd, NULL); + argv = argv_split(GFP_KERNEL, cmd, NULL); if (argv) { ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC); argv_free(argv); @@ -406,8 +406,33 @@ static int __orderly_poweroff(bool force) ret = -ENOMEM; } + return ret; +} + +static int __orderly_reboot(void) +{ + int ret; + + ret = run_cmd(reboot_cmd); + + if (ret) { + pr_warn("Failed to start orderly reboot: forcing the issue\n"); + emergency_sync(); + kernel_restart(NULL); + } + + return ret; +} + +static int __orderly_poweroff(bool force) +{ + int ret; + + ret = run_cmd(poweroff_cmd); + if (ret && force) { pr_warn("Failed to start orderly shutdown: forcing the issue\n"); + /* * I guess this should try to kick off some daemon to sync and * poweroff asap. Or not even bother syncing if we're doing an @@ -436,15 +461,33 @@ static DECLARE_WORK(poweroff_work, poweroff_work_func); * This may be called from any context to trigger a system shutdown. * If the orderly shutdown fails, it will force an immediate shutdown. */ -int orderly_poweroff(bool force) +void orderly_poweroff(bool force) { if (force) /* do not override the pending "true" */ poweroff_force = true; schedule_work(&poweroff_work); - return 0; } EXPORT_SYMBOL_GPL(orderly_poweroff); +static void reboot_work_func(struct work_struct *work) +{ + __orderly_reboot(); +} + +static DECLARE_WORK(reboot_work, reboot_work_func); + +/** + * orderly_reboot - Trigger an orderly system reboot + * + * This may be called from any context to trigger a system reboot. + * If the orderly reboot fails, it will force an immediate reboot. + */ +void orderly_reboot(void) +{ + schedule_work(&reboot_work); +} +EXPORT_SYMBOL_GPL(orderly_reboot); + static int __init reboot_setup(char *str) { for (;;) { -- cgit v1.2.3 From 94ff212d096d96afea29e41585b0d8ce41087c0f Mon Sep 17 00:00:00 2001 From: Joe Perches Date: Wed, 15 Apr 2015 16:18:20 -0700 Subject: cgroup: remove use of seq_printf return value The seq_printf return value, because it's frequently misused, will eventually be converted to void. See: commit 1f33c41c03da ("seq_file: Rename seq_overflow() to seq_has_overflowed() and make public") Signed-off-by: Joe Perches Acked-by: Tejun Heo Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 59aa339a245c..469dd547770c 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -4196,7 +4196,9 @@ static void *cgroup_pidlist_next(struct seq_file *s, void *v, loff_t *pos) static int cgroup_pidlist_show(struct seq_file *s, void *v) { - return seq_printf(s, "%d\n", *(int *)v); + seq_printf(s, "%d\n", *(int *)v); + + return 0; } static u64 cgroup_read_notify_on_release(struct cgroup_subsys_state *css, -- cgit v1.2.3 From 962e3707d9fb16bcf66ec5e5ebcea5248b9c2ab3 Mon Sep 17 00:00:00 2001 From: Joe Perches Date: Wed, 15 Apr 2015 16:18:22 -0700 Subject: tracing: remove use of seq_printf return value The seq_printf return value, because it's frequently misused, will eventually be converted to void. See: commit 1f33c41c03da ("seq_file: Rename seq_overflow() to seq_has_overflowed() and make public") Miscellanea: o Remove unused return value from trace_lookup_stack Signed-off-by: Joe Perches Acked-by: Steven Rostedt Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/trace/trace_stack.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index c3e4fcfddd45..3f34496244e9 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -327,11 +327,11 @@ static void t_stop(struct seq_file *m, void *p) local_irq_enable(); } -static int trace_lookup_stack(struct seq_file *m, long i) +static void trace_lookup_stack(struct seq_file *m, long i) { unsigned long addr = stack_dump_trace[i]; - return seq_printf(m, "%pS\n", (void *)addr); + seq_printf(m, "%pS\n", (void *)addr); } static void print_disabled(struct seq_file *m) -- cgit v1.2.3