From 80119ef5c8153e0a6cc5edf00c083dc98a9bd348 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Fri, 23 May 2008 13:04:31 -0700 Subject: mm: fix atomic_t overflow in vm The atomic_t type is 32bit but a 64bit system can have more than 2^32 pages of virtual address space available. Without this we overflow on ludicrously large mappings Signed-off-by: Alan Cox Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/mmap.c | 4 ++-- mm/nommu.c | 4 ++-- mm/swap.c | 4 ++-- 3 files changed, 6 insertions(+), 6 deletions(-) (limited to 'mm') diff --git a/mm/mmap.c b/mm/mmap.c index fac66337da2..669499e7c2f 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -80,7 +80,7 @@ EXPORT_SYMBOL(vm_get_page_prot); int sysctl_overcommit_memory = OVERCOMMIT_GUESS; /* heuristic overcommit */ int sysctl_overcommit_ratio = 50; /* default is 50% */ int sysctl_max_map_count __read_mostly = DEFAULT_MAX_MAP_COUNT; -atomic_t vm_committed_space = ATOMIC_INIT(0); +atomic_long_t vm_committed_space = ATOMIC_LONG_INIT(0); /* * Check that a process has enough memory to allocate a new virtual @@ -177,7 +177,7 @@ int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin) * cast `allowed' as a signed long because vm_committed_space * sometimes has a negative value */ - if (atomic_read(&vm_committed_space) < (long)allowed) + if (atomic_long_read(&vm_committed_space) < (long)allowed) return 0; error: vm_unacct_memory(pages); diff --git a/mm/nommu.c b/mm/nommu.c index ef8c62cec69..dca93fcb8b7 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -39,7 +39,7 @@ struct page *mem_map; unsigned long max_mapnr; unsigned long num_physpages; unsigned long askedalloc, realalloc; -atomic_t vm_committed_space = ATOMIC_INIT(0); +atomic_long_t vm_committed_space = ATOMIC_LONG_INIT(0); int sysctl_overcommit_memory = OVERCOMMIT_GUESS; /* heuristic overcommit */ int sysctl_overcommit_ratio = 50; /* default is 50% */ int sysctl_max_map_count = DEFAULT_MAX_MAP_COUNT; @@ -1410,7 +1410,7 @@ int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin) * cast `allowed' as a signed long because vm_committed_space * sometimes has a negative value */ - if (atomic_read(&vm_committed_space) < (long)allowed) + if (atomic_long_read(&vm_committed_space) < (long)allowed) return 0; error: vm_unacct_memory(pages); diff --git a/mm/swap.c b/mm/swap.c index 91e194445a5..45c9f25a8a3 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -503,7 +503,7 @@ void vm_acct_memory(long pages) local = &__get_cpu_var(committed_space); *local += pages; if (*local > ACCT_THRESHOLD || *local < -ACCT_THRESHOLD) { - atomic_add(*local, &vm_committed_space); + atomic_long_add(*local, &vm_committed_space); *local = 0; } preempt_enable(); @@ -520,7 +520,7 @@ static int cpu_swap_callback(struct notifier_block *nfb, committed = &per_cpu(committed_space, (long)hcpu); if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) { - atomic_add(*committed, &vm_committed_space); + atomic_long_add(*committed, &vm_committed_space); *committed = 0; drain_cpu_pagevecs((long)hcpu); } -- cgit v1.2.3