From be9b7335e70696bee731c152429b1737e42fe163 Mon Sep 17 00:00:00 2001 From: Nicolas Pitre Date: Thu, 25 Aug 2011 00:24:21 -0400 Subject: mm: add vm_area_add_early() The existing vm_area_register_early() allows for early vmalloc space allocation. However upcoming cleanups in the ARM architecture require that some fixed locations in the vmalloc area be reserved also very early. The name "vm_area_register_early" would have been a good name for the reservation part without the allocation. Since it is already in use with different semantics, let's create vm_area_add_early() instead. Both vm_area_register_early() and vm_area_add_early() can be used together meaning that the former is now implemented using the later where it is ensured that no conflicting areas are added, but no attempt is made to make the allocation scheme in vm_area_register_early() more sophisticated. After all, you must know what you're doing when using those functions. Signed-off-by: Nicolas Pitre Acked-by: Andrew Morton Cc: linux-mm@kvack.org --- mm/vmalloc.c | 29 +++++++++++++++++++++++++++-- 1 file changed, 27 insertions(+), 2 deletions(-) (limited to 'mm/vmalloc.c') diff --git a/mm/vmalloc.c b/mm/vmalloc.c index b669aa6f6caf..3f2b59221b78 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1117,6 +1117,32 @@ void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t pro } EXPORT_SYMBOL(vm_map_ram); +/** + * vm_area_add_early - add vmap area early during boot + * @vm: vm_struct to add + * + * This function is used to add fixed kernel vm area to vmlist before + * vmalloc_init() is called. @vm->addr, @vm->size, and @vm->flags + * should contain proper values and the other fields should be zero. + * + * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING. + */ +void __init vm_area_add_early(struct vm_struct *vm) +{ + struct vm_struct *tmp, **p; + + BUG_ON(vmap_initialized); + for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) { + if (tmp->addr >= vm->addr) { + BUG_ON(tmp->addr < vm->addr + vm->size); + break; + } else + BUG_ON(tmp->addr + tmp->size > vm->addr); + } + vm->next = *p; + *p = vm; +} + /** * vm_area_register_early - register vmap area early during boot * @vm: vm_struct to register @@ -1139,8 +1165,7 @@ void __init vm_area_register_early(struct vm_struct *vm, size_t align) vm->addr = (void *)addr; - vm->next = vmlist; - vmlist = vm; + vm_area_add_early(vm); } void __init vmalloc_init(void) -- cgit From 1368edf0647ac112d8cfa6ce47257dc950c50f5c Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Thu, 8 Dec 2011 14:34:30 -0800 Subject: mm: vmalloc: check for page allocation failure before vmlist insertion Commit f5252e00 ("mm: avoid null pointer access in vm_struct via /proc/vmallocinfo") adds newly allocated vm_structs to the vmlist after it is fully initialised. Unfortunately, it did not check that __vmalloc_area_node() successfully populated the area. In the event of allocation failure, the vmalloc area is freed but the pointer to freed memory is inserted into the vmlist leading to a a crash later in get_vmalloc_info(). This patch adds a check for ____vmalloc_area_node() failure within __vmalloc_node_range. It does not use "goto fail" as in the previous error path as a warning was already displayed by __vmalloc_area_node() before it called vfree in its failure path. Credit goes to Luciano Chavez for doing all the real work of identifying exactly where the problem was. Signed-off-by: Mel Gorman Reported-by: Luciano Chavez Tested-by: Luciano Chavez Reviewed-by: Rik van Riel Acked-by: David Rientjes Cc: [3.1.x+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmalloc.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'mm/vmalloc.c') diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 3231bf332878..1d8b32f07139 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1633,6 +1633,8 @@ void *__vmalloc_node_range(unsigned long size, unsigned long align, goto fail; addr = __vmalloc_area_node(area, gfp_mask, prot, node, caller); + if (!addr) + return NULL; /* * In this function, newly allocated vm_struct is not added -- cgit From 0006526d78e93c3684c806bf7cf3f67dfa49c3c8 Mon Sep 17 00:00:00 2001 From: Kautuk Consul Date: Mon, 19 Dec 2011 17:12:04 -0800 Subject: mm/vmalloc.c: remove static declaration of va from __get_vm_area_node Static storage is not required for the struct vmap_area in __get_vm_area_node. Removing "static" to store this variable on the stack instead. Signed-off-by: Kautuk Consul Acked-by: David Rientjes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/vmalloc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm/vmalloc.c') diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 1d8b32f07139..27be2f0d4cb7 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1290,7 +1290,7 @@ static struct vm_struct *__get_vm_area_node(unsigned long size, unsigned long align, unsigned long flags, unsigned long start, unsigned long end, int node, gfp_t gfp_mask, void *caller) { - static struct vmap_area *va; + struct vmap_area *va; struct vm_struct *area; BUG_ON(in_interrupt()); -- cgit