diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/crash_core.c | 1 | ||||
| -rw-r--r-- | kernel/fork.c | 1 | ||||
| -rw-r--r-- | kernel/hung_task.c | 11 | ||||
| -rw-r--r-- | kernel/sys.c | 10 |
4 files changed, 17 insertions, 6 deletions
diff --git a/kernel/crash_core.c b/kernel/crash_core.c index f7674d676889b..b66aced5e8c2e 100644 --- a/kernel/crash_core.c +++ b/kernel/crash_core.c @@ -460,6 +460,7 @@ static int __init crash_save_vmcoreinfo_init(void) VMCOREINFO_NUMBER(PG_hwpoison); #endif VMCOREINFO_NUMBER(PG_head_mask); +#define PAGE_BUDDY_MAPCOUNT_VALUE (~PG_buddy) VMCOREINFO_NUMBER(PAGE_BUDDY_MAPCOUNT_VALUE); #ifdef CONFIG_HUGETLB_PAGE VMCOREINFO_NUMBER(HUGETLB_PAGE_DTOR); diff --git a/kernel/fork.c b/kernel/fork.c index 80b48a8fb47bd..c6d1c1ce9ed70 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -899,6 +899,7 @@ static struct mm_struct *mm_init(struct mm_struct *mm, struct task_struct *p, mm->pinned_vm = 0; memset(&mm->rss_stat, 0, sizeof(mm->rss_stat)); spin_lock_init(&mm->page_table_lock); + spin_lock_init(&mm->arg_lock); mm_init_cpumask(mm); mm_init_aio(mm); mm_init_owner(mm, p); diff --git a/kernel/hung_task.c b/kernel/hung_task.c index 751593ed7c0b0..32b479468e4d5 100644 --- a/kernel/hung_task.c +++ b/kernel/hung_task.c @@ -44,6 +44,7 @@ int __read_mostly sysctl_hung_task_warnings = 10; static int __read_mostly did_panic; static bool hung_task_show_lock; +static bool hung_task_call_panic; static struct task_struct *watchdog_task; @@ -127,10 +128,8 @@ static void check_hung_task(struct task_struct *t, unsigned long timeout) touch_nmi_watchdog(); if (sysctl_hung_task_panic) { - if (hung_task_show_lock) - debug_show_all_locks(); - trigger_all_cpu_backtrace(); - panic("hung_task: blocked tasks"); + hung_task_show_lock = true; + hung_task_call_panic = true; } } @@ -193,6 +192,10 @@ static void check_hung_uninterruptible_tasks(unsigned long timeout) rcu_read_unlock(); if (hung_task_show_lock) debug_show_all_locks(); + if (hung_task_call_panic) { + trigger_all_cpu_backtrace(); + panic("hung_task: blocked tasks"); + } } static long hung_timeout_jiffies(unsigned long last_checked, diff --git a/kernel/sys.c b/kernel/sys.c index d1b2b8d934bb7..38509dc1f77b0 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -2018,7 +2018,11 @@ static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data return error; } - down_write(&mm->mmap_sem); + /* + * arg_lock protects concurent updates but we still need mmap_sem for + * read to exclude races with sys_brk. + */ + down_read(&mm->mmap_sem); /* * We don't validate if these members are pointing to @@ -2032,6 +2036,7 @@ static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data * to any problem in kernel itself */ + spin_lock(&mm->arg_lock); mm->start_code = prctl_map.start_code; mm->end_code = prctl_map.end_code; mm->start_data = prctl_map.start_data; @@ -2043,6 +2048,7 @@ static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data mm->arg_end = prctl_map.arg_end; mm->env_start = prctl_map.env_start; mm->env_end = prctl_map.env_end; + spin_unlock(&mm->arg_lock); /* * Note this update of @saved_auxv is lockless thus @@ -2055,7 +2061,7 @@ static int prctl_set_mm_map(int opt, const void __user *addr, unsigned long data if (prctl_map.auxv_size) memcpy(mm->saved_auxv, user_auxv, sizeof(user_auxv)); - up_write(&mm->mmap_sem); + up_read(&mm->mmap_sem); return 0; } #endif /* CONFIG_CHECKPOINT_RESTORE */ |