diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/fork.c | 3 | ||||
| -rw-r--r-- | kernel/gcov/fs.c | 2 | ||||
| -rw-r--r-- | kernel/hung_task.c | 55 | ||||
| -rw-r--r-- | kernel/panic.c | 102 | ||||
| -rw-r--r-- | kernel/resource.c | 16 | ||||
| -rw-r--r-- | kernel/taskstats.c | 50 |
6 files changed, 117 insertions, 111 deletions
diff --git a/kernel/fork.c b/kernel/fork.c index ceedb07a5a00..ea823b28d625 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -858,7 +858,8 @@ void __init fork_init(void) #ifndef ARCH_MIN_TASKALIGN #define ARCH_MIN_TASKALIGN 0 #endif - int align = max_t(int, L1_CACHE_BYTES, ARCH_MIN_TASKALIGN); + int align = max3(L1_CACHE_BYTES, ARCH_MIN_TASKALIGN, + __alignof__(struct task_struct)); unsigned long useroffset, usersize; /* create a slab on which task_structs can be allocated */ diff --git a/kernel/gcov/fs.c b/kernel/gcov/fs.c index 1d19b1be207a..764918570de1 100644 --- a/kernel/gcov/fs.c +++ b/kernel/gcov/fs.c @@ -529,7 +529,7 @@ static void init_node(struct gcov_node *node, struct gcov_info *info, } node->parent = parent; if (name) - strcpy(node->name, name); + strscpy(node->name, name, strlen(name) + 1); } /* diff --git a/kernel/hung_task.c b/kernel/hung_task.c index 6fcc94ce4ca9..b8554aedc589 100644 --- a/kernel/hung_task.c +++ b/kernel/hung_task.c @@ -57,8 +57,20 @@ unsigned long __read_mostly sysctl_hung_task_timeout_secs = CONFIG_DEFAULT_HUNG_ */ static unsigned long __read_mostly sysctl_hung_task_check_interval_secs; +/* + * Limit the number of printed hung tasks to prevent printing + * the same or similar backtraces repeatedly. + */ static int __read_mostly sysctl_hung_task_warnings = 10; +/* + * The number of hung tasks which still can be reported. + * The budget gets restored to the original limit when + * the previous stall is resolved. + */ +static int hung_task_warnings_budget = 10; +static atomic_t reset_hung_task_warnings = ATOMIC_INIT(0); + static int __read_mostly did_panic; static bool hung_task_call_panic; @@ -245,11 +257,11 @@ static void hung_task_info(struct task_struct *t, unsigned long timeout, /* * The given task did not get scheduled for more than * CONFIG_DEFAULT_HUNG_TASK_TIMEOUT. Therefore, complain - * accordingly + * accordingly with full details if the budget is not exhausted. */ - if (sysctl_hung_task_warnings || hung_task_call_panic) { - if (sysctl_hung_task_warnings > 0) - sysctl_hung_task_warnings--; + if (hung_task_warnings_budget || hung_task_call_panic) { + if (hung_task_warnings_budget > 0) + hung_task_warnings_budget--; pr_err("INFO: task %s:%d blocked%s for more than %ld seconds.\n", t->comm, t->pid, t->in_iowait ? " in I/O wait" : "", (jiffies - t->last_switch_time) / HZ); @@ -264,8 +276,8 @@ static void hung_task_info(struct task_struct *t, unsigned long timeout, sched_show_task(t); debug_show_blocker(t, timeout); - if (!sysctl_hung_task_warnings) - pr_info("Future hung task reports are suppressed, see sysctl kernel.hung_task_warnings\n"); + if (!hung_task_warnings_budget && !hung_task_call_panic) + pr_info("hung_task: further per-task details suppressed until warning budget is reset (see sysctl kernel.hung_task_warnings)\n"); } touch_nmi_watchdog(); @@ -304,7 +316,7 @@ static void check_hung_uninterruptible_tasks(unsigned long timeout) unsigned long last_break = jiffies; struct task_struct *g, *t; unsigned long this_round_count; - int need_warning = sysctl_hung_task_warnings; + int need_warning; unsigned long si_mask = hung_task_si_mask; /* @@ -314,6 +326,11 @@ static void check_hung_uninterruptible_tasks(unsigned long timeout) if (test_taint(TAINT_DIE) || did_panic) return; + if (atomic_xchg_acquire(&reset_hung_task_warnings, 0)) + hung_task_warnings_budget = + READ_ONCE(sysctl_hung_task_warnings); + need_warning = hung_task_warnings_budget; + this_round_count = 0; rcu_read_lock(); for_each_process_thread(g, t) { @@ -340,8 +357,15 @@ static void check_hung_uninterruptible_tasks(unsigned long timeout) unlock: rcu_read_unlock(); - if (!this_round_count) + if (!this_round_count) { + hung_task_warnings_budget = + READ_ONCE(sysctl_hung_task_warnings); return; + } + + if (!hung_task_warnings_budget && !hung_task_call_panic) + pr_info("hung_task: %lu hung tasks detected, warning budget exhausted\n", + this_round_count); if (need_warning || hung_task_call_panic) { si_mask |= SYS_INFO_LOCKS; @@ -425,6 +449,19 @@ static int proc_dohung_task_timeout_secs(const struct ctl_table *table, int writ return ret; } +static int proc_dohung_task_warnings(const struct ctl_table *table, int write, + void *buffer, + size_t *lenp, loff_t *ppos) +{ + int ret; + + ret = proc_dointvec_minmax(table, write, buffer, lenp, ppos); + if (!ret && write) + atomic_set_release(&reset_hung_task_warnings, 1); + + return ret; +} + /* * This is needed for proc_doulongvec_minmax of sysctl_hung_task_timeout_secs * and hung_task_check_interval_secs @@ -480,7 +517,7 @@ static const struct ctl_table hung_task_sysctls[] = { .data = &sysctl_hung_task_warnings, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = proc_dointvec_minmax, + .proc_handler = proc_dohung_task_warnings, .extra1 = SYSCTL_NEG_ONE, }, { diff --git a/kernel/panic.c b/kernel/panic.c index 213725b612aa..170744163fc2 100644 --- a/kernel/panic.c +++ b/kernel/panic.c @@ -307,7 +307,7 @@ atomic_t panic_cpu = ATOMIC_INIT(PANIC_CPU_INVALID); atomic_t panic_redirect_cpu = ATOMIC_INIT(PANIC_CPU_INVALID); #if defined(CONFIG_SMP) && defined(CONFIG_CRASH_DUMP) -static char *panic_force_buf; +static char panic_force_buf[PANIC_MSG_BUFSZ]; static int __init panic_force_cpu_setup(char *str) { @@ -326,17 +326,6 @@ static int __init panic_force_cpu_setup(char *str) } early_param("panic_force_cpu", panic_force_cpu_setup); -static int __init panic_force_cpu_late_init(void) -{ - if (panic_force_cpu < 0) - return 0; - - panic_force_buf = kmalloc(PANIC_MSG_BUFSZ, GFP_KERNEL); - - return 0; -} -late_initcall(panic_force_cpu_late_init); - static void do_panic_on_target_cpu(void *info) { panic("%s", (char *)info); @@ -371,15 +360,16 @@ int __weak panic_smp_redirect_cpu(int target_cpu, void *msg) * for the crash kernel to function correctly. This function redirects * panic handling to the CPU specified via the panic_force_cpu= boot parameter. * - * Returns false if panic should proceed on current CPU. - * Returns true if panic was redirected. + * Returns true when this CPU must stop: the panic was redirected or is + * already running on another CPU. + * Returns false when panic() should proceed on this CPU. */ __printf(1, 0) static bool panic_try_force_cpu(const char *fmt, va_list args) { int this_cpu = raw_smp_processor_id(); int old_cpu = PANIC_CPU_INVALID; - const char *msg; + va_list ap; /* Feature not enabled via boot parameter */ if (panic_force_cpu < 0) @@ -396,27 +386,27 @@ static bool panic_try_force_cpu(const char *fmt, va_list args) return false; } - /* Another panic already in progress */ + /* + * Don't redirect when a panic is already in progress. Stop this + * CPU when it's another one, proceed when it's this one. + */ if (panic_in_progress()) - return false; + return panic_on_other_cpu(); /* - * Only one CPU can do the redirect. Use atomic cmpxchg to ensure - * we don't race with another CPU also trying to redirect. + * Only one CPU can do the redirection. Others should go offline. + * Continue with panic() when we already tried the redirection + * from this CPU before, for example via nmi_panic(). */ if (!atomic_try_cmpxchg(&panic_redirect_cpu, &old_cpu, this_cpu)) - return false; + return old_cpu != this_cpu; /* - * Use dynamically allocated buffer if available, otherwise - * fall back to static message for early boot panics or allocation failure. + * Do not consume args, the caller reuses them if we fail. */ - if (panic_force_buf) { - vsnprintf(panic_force_buf, PANIC_MSG_BUFSZ, fmt, args); - msg = panic_force_buf; - } else { - msg = "Redirected panic (buffer unavailable)"; - } + va_copy(ap, args); + vsnprintf(panic_force_buf, PANIC_MSG_BUFSZ, fmt, ap); + va_end(ap); console_verbose(); bust_spinlocks(1); @@ -431,7 +421,7 @@ static bool panic_try_force_cpu(const char *fmt, va_list args) dump_stack(); } - if (panic_smp_redirect_cpu(panic_force_cpu, (void *)msg) != 0) { + if (panic_smp_redirect_cpu(panic_force_cpu, panic_force_buf) != 0) { atomic_set(&panic_redirect_cpu, PANIC_CPU_INVALID); pr_warn("panic: failed to redirect to CPU %d, continuing on CPU %d\n", panic_force_cpu, this_cpu); @@ -503,17 +493,35 @@ bool panic_on_other_cpu(void) EXPORT_SYMBOL(panic_on_other_cpu); /* - * A variant of panic() called from NMI context. We return if we've already - * panicked on this CPU. If another CPU already panicked, loop in - * nmi_panic_self_stop() which can provide architecture dependent code such - * as saving register state for crash dump. + * A variant of panic() called from NMI context. The panic is first + * redirected to the CPU requested via panic_force_cpu=, when configured. + * We return if we've already panicked on this CPU. If another CPU already + * panicked, loop in nmi_panic_self_stop() which can provide architecture + * dependent code for saving register state for crash dump. */ -void nmi_panic(struct pt_regs *regs, const char *msg) +void nmi_panic(struct pt_regs *regs, const char *fmt, ...) { + va_list args; + + va_start(args, fmt); + + /* Try to redirect to the requested CPU before claiming panic_cpu. */ + if (panic_try_force_cpu(fmt, args)) { + /* + * Mark ourselves offline so panic_other_cpus_shutdown() won't + * wait for us on architectures that check num_online_cpus(). + */ + set_cpu_online(raw_smp_processor_id(), false); + nmi_panic_self_stop(regs); + } + if (panic_try_start()) - panic("%s", msg); - else if (panic_on_other_cpu()) + vpanic(fmt, args); + + if (panic_on_other_cpu()) nmi_panic_self_stop(regs); + + va_end(args); } EXPORT_SYMBOL(nmi_panic); @@ -567,6 +575,8 @@ static void panic_other_cpus_shutdown(bool crash_kexec) crash_smp_send_stop(); } +void __weak arch_do_panic(void) {} + /** * vpanic - halt the system * @fmt: The text string to print @@ -742,20 +752,9 @@ void vpanic(const char *fmt, va_list args) reboot_mode = panic_reboot_mode; emergency_restart(); } -#ifdef __sparc__ - { - extern int stop_a_enabled; - /* Make sure the user can actually press Stop-A (L1-A) */ - stop_a_enabled = 1; - pr_emerg("Press Stop-A (L1-A) from sun keyboard or send break\n" - "twice on console to return to the boot prom\n"); - } -#endif -#if defined(CONFIG_S390) - disabled_wait(); -#endif pr_emerg("---[ end Kernel panic - not syncing: %s ]---\n", buf); + arch_do_panic(); /* Do not scroll important messages printed above */ suppress_printk = 1; @@ -1225,14 +1224,9 @@ static int panic_print_set(const char *val, const struct kernel_param *kp) return param_set_ulong(val, kp); } -static int panic_print_get(char *val, const struct kernel_param *kp) -{ - return param_get_ulong(val, kp); -} - static const struct kernel_param_ops panic_print_ops = { .set = panic_print_set, - .get = panic_print_get, + .get = param_get_ulong, }; __core_param_cb(panic_print, &panic_print_ops, &panic_print, 0644); diff --git a/kernel/resource.c b/kernel/resource.c index e60539a55541..cfc1a00e86aa 100644 --- a/kernel/resource.c +++ b/kernel/resource.c @@ -1350,8 +1350,8 @@ static int __request_region_locked(struct resource *res, struct resource *parent } if (conflict->flags & flags & IORESOURCE_MUXED) { add_wait_queue(&muxed_resource_wait, &wait); - write_unlock(&resource_lock); set_current_state(TASK_UNINTERRUPTIBLE); + write_unlock(&resource_lock); schedule(); remove_wait_queue(&muxed_resource_wait, &wait); write_lock(&resource_lock); @@ -1833,7 +1833,7 @@ __setup("reserve=", reserve_setup); */ int iomem_map_sanity_check(resource_size_t addr, unsigned long size) { - resource_size_t end = addr + size - 1; + struct resource mem = DEFINE_RES_MEM(addr, size); struct resource *p; int err = 0; @@ -1843,12 +1843,10 @@ int iomem_map_sanity_check(resource_size_t addr, unsigned long size) * We can probably skip the resources without * IORESOURCE_IO attribute? */ - if (p->start > end) - continue; - if (p->end < addr) + if (!resource_overlaps(p, &mem)) continue; - if (PFN_DOWN(p->start) <= PFN_DOWN(addr) && - PFN_DOWN(p->end) >= PFN_DOWN(end)) + if (PFN_DOWN(p->start) <= PFN_DOWN(mem.start) && + PFN_DOWN(p->end) >= PFN_DOWN(mem.end)) continue; /* * if a resource is "BUSY", it's not a hardware resource @@ -1859,8 +1857,8 @@ int iomem_map_sanity_check(resource_size_t addr, unsigned long size) if (p->flags & IORESOURCE_BUSY) continue; - pr_debug("resource sanity check: requesting [mem %pa-%pa], which spans more than %s %pR\n", - &addr, &end, p->name, p); + pr_debug("resource sanity check: requesting %pR, which spans more than %s %pR\n", + &mem, p->name, p); err = -1; break; } diff --git a/kernel/taskstats.c b/kernel/taskstats.c index f31df72f0e9d..bf517788b840 100644 --- a/kernel/taskstats.c +++ b/kernel/taskstats.c @@ -59,8 +59,7 @@ static DEFINE_PER_CPU(struct listener_list, listener_array); enum actions { REGISTER, - DEREGISTER, - CPU_DONT_CARE + DEREGISTER }; static int prepare_reply(struct genl_info *info, u8 cmd, struct sk_buff **skbp, @@ -473,7 +472,8 @@ static size_t taskstats_packet_size(void) return size; } -static int cmd_attr_pid(struct genl_info *info) +static int cmd_attr_pid_tgid(struct genl_info *info, int attr, + int (*fill)(pid_t, struct taskstats *)) { struct taskstats *stats; struct sk_buff *rep_skb; @@ -488,41 +488,15 @@ static int cmd_attr_pid(struct genl_info *info) return rc; rc = -EINVAL; - pid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_PID]); - stats = mk_reply(rep_skb, TASKSTATS_TYPE_PID, pid); + pid = nla_get_u32(info->attrs[attr]); + stats = mk_reply(rep_skb, + attr == TASKSTATS_CMD_ATTR_PID + ? TASKSTATS_TYPE_PID : TASKSTATS_TYPE_TGID, + pid); if (!stats) goto err; - rc = fill_stats_for_pid(pid, stats); - if (rc < 0) - goto err; - return send_reply(rep_skb, info); -err: - nlmsg_free(rep_skb); - return rc; -} - -static int cmd_attr_tgid(struct genl_info *info) -{ - struct taskstats *stats; - struct sk_buff *rep_skb; - size_t size; - u32 tgid; - int rc; - - size = taskstats_packet_size(); - - rc = prepare_reply(info, TASKSTATS_CMD_NEW, &rep_skb, size); - if (rc < 0) - return rc; - - rc = -EINVAL; - tgid = nla_get_u32(info->attrs[TASKSTATS_CMD_ATTR_TGID]); - stats = mk_reply(rep_skb, TASKSTATS_TYPE_TGID, tgid); - if (!stats) - goto err; - - rc = fill_stats_for_tgid(tgid, stats); + rc = fill(pid, stats); if (rc < 0) goto err; return send_reply(rep_skb, info); @@ -542,9 +516,11 @@ static int taskstats_user_cmd(struct sk_buff *skb, struct genl_info *info) TASKSTATS_CMD_ATTR_DEREGISTER_CPUMASK, DEREGISTER); else if (info->attrs[TASKSTATS_CMD_ATTR_PID]) - return cmd_attr_pid(info); + return cmd_attr_pid_tgid(info, TASKSTATS_CMD_ATTR_PID, + fill_stats_for_pid); else if (info->attrs[TASKSTATS_CMD_ATTR_TGID]) - return cmd_attr_tgid(info); + return cmd_attr_pid_tgid(info, TASKSTATS_CMD_ATTR_TGID, + fill_stats_for_tgid); else return -EINVAL; } |