From e59464c735db19619cde2aa331609adb02005f5b Mon Sep 17 00:00:00 2001 From: Changli Gao Date: Fri, 23 Apr 2010 13:17:45 -0400 Subject: flex_array: fix the panic when calling flex_array_alloc() without __GFP_ZERO memset() is called with the wrong address and the kernel panics. Signed-off-by: Changli Gao Cc: Patrick McHardy Acked-by: David Rientjes Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/flex_array.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib/flex_array.c') diff --git a/lib/flex_array.c b/lib/flex_array.c index 66eef2e4483..41b1804fa72 100644 --- a/lib/flex_array.c +++ b/lib/flex_array.c @@ -99,7 +99,7 @@ struct flex_array *flex_array_alloc(int element_size, unsigned int total, ret->element_size = element_size; ret->total_nr_elements = total; if (elements_fit_in_base(ret) && !(flags & __GFP_ZERO)) - memset(ret->parts[0], FLEX_ARRAY_FREE, + memset(&ret->parts[0], FLEX_ARRAY_FREE, FLEX_ARRAY_BASE_BYTES_LEFT); return ret; } -- cgit v1.2.3-70-g09d2 From ea98eed9bcb62d1319db8b1210712c6a110a886c Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Mon, 9 Aug 2010 17:20:56 -0700 Subject: flex_array: add helpers to get and put to make pointers easy to use Getting and putting arrays of pointers with flex arrays is a PITA. You have to remember to pass &ptr to the _put and you have to do weird and wacky casting to get the ptr back from the _get. Add two functions flex_array_get_ptr() and flex_array_put_ptr() to handle all of the magic. [akpm@linux-foundation.org: simplification suggested by Joe] Signed-off-by: Eric Paris Cc: David Rientjes Cc: Dave Hansen Cc: Joe Perches Cc: James Morris Cc: Joe Perches Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/flex_array.h | 5 +++++ lib/flex_array.c | 25 ++++++++++++++++++++++++- 2 files changed, 29 insertions(+), 1 deletion(-) (limited to 'lib/flex_array.c') diff --git a/include/linux/flex_array.h b/include/linux/flex_array.h index 1d747f72298..631b77f2ac7 100644 --- a/include/linux/flex_array.h +++ b/include/linux/flex_array.h @@ -70,4 +70,9 @@ int flex_array_clear(struct flex_array *fa, unsigned int element_nr); void *flex_array_get(struct flex_array *fa, unsigned int element_nr); int flex_array_shrink(struct flex_array *fa); +#define flex_array_put_ptr(fa, nr, src, gfp) \ + flex_array_put(fa, nr, &(void *)(src), gfp) + +void *flex_array_get_ptr(struct flex_array *fa, unsigned int element_nr); + #endif /* _FLEX_ARRAY_H */ diff --git a/lib/flex_array.c b/lib/flex_array.c index 41b1804fa72..77a6fea7481 100644 --- a/lib/flex_array.c +++ b/lib/flex_array.c @@ -171,6 +171,8 @@ __fa_get_part(struct flex_array *fa, int part_nr, gfp_t flags) * Note that this *copies* the contents of @src into * the array. If you are trying to store an array of * pointers, make sure to pass in &ptr instead of ptr. + * You may instead wish to use the flex_array_put_ptr() + * helper function. * * Locking must be provided by the caller. */ @@ -265,7 +267,8 @@ int flex_array_prealloc(struct flex_array *fa, unsigned int start, * * Returns a pointer to the data at index @element_nr. Note * that this is a copy of the data that was passed in. If you - * are using this to store pointers, you'll get back &ptr. + * are using this to store pointers, you'll get back &ptr. You + * may instead wish to use the flex_array_get_ptr helper. * * Locking must be provided by the caller. */ @@ -286,6 +289,26 @@ void *flex_array_get(struct flex_array *fa, unsigned int element_nr) return &part->elements[index_inside_part(fa, element_nr)]; } +/** + * flex_array_get_ptr - pull a ptr back out of the array + * @fa: the flex array from which to extract data + * @element_nr: index of the element to fetch from the array + * + * Returns the pointer placed in the flex array at element_nr using + * flex_array_put_ptr(). This function should not be called if the + * element in question was not set using the _put_ptr() helper. + */ +void *flex_array_get_ptr(struct flex_array *fa, unsigned int element_nr) +{ + void **tmp; + + tmp = flex_array_get(fa, element_nr); + if (!tmp) + return NULL; + + return *tmp; +} + static int part_is_free(struct flex_array_part *part) { int i; -- cgit v1.2.3-70-g09d2 From 78c377d1b5e7ef15c8c307c2aa2511602a0829c3 Mon Sep 17 00:00:00 2001 From: David Rientjes Date: Wed, 12 Jan 2011 16:59:55 -0800 Subject: flex_array: export symbols to modules Alex said: I want to use flex_array to store a sparse array of ATM cell re-assembly buffers for my ATM over Ethernet driver. Using the per-vcc user_back structure causes problems when stacked with things like br2684. Add EXPORT_SYMBOL() for all publically accessible flex array functions and move to obj-y so that modules may use this library. Signed-off-by: David Rientjes Cc: Dave Hansen Cc: Paul Mundt Reported-by: Alex Bennee Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/Makefile | 4 ++-- lib/flex_array.c | 10 ++++++++++ 2 files changed, 12 insertions(+), 2 deletions(-) (limited to 'lib/flex_array.c') diff --git a/lib/Makefile b/lib/Makefile index d7b6e30a3a1..2f59e0a1dd8 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -12,7 +12,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \ idr.o int_sqrt.o extable.o prio_tree.o \ sha1.o irq_regs.o reciprocal_div.o argv_split.o \ proportions.o prio_heap.o ratelimit.o show_mem.o \ - is_single_threaded.o plist.o decompress.o flex_array.o + is_single_threaded.o plist.o decompress.o lib-$(CONFIG_MMU) += ioremap.o lib-$(CONFIG_SMP) += cpumask.o @@ -21,7 +21,7 @@ lib-y += kobject.o kref.o klist.o obj-y += bcd.o div64.o sort.o parser.o halfmd4.o debug_locks.o random32.o \ bust_spinlocks.o hexdump.o kasprintf.o bitmap.o scatterlist.o \ - string_helpers.o gcd.o lcm.o list_sort.o uuid.o + string_helpers.o gcd.o lcm.o list_sort.o uuid.o flex_array.o ifeq ($(CONFIG_DEBUG_KOBJECT),y) CFLAGS_kobject.o += -DDEBUG diff --git a/lib/flex_array.c b/lib/flex_array.c index 77a6fea7481..c0ea40ba208 100644 --- a/lib/flex_array.c +++ b/lib/flex_array.c @@ -23,6 +23,7 @@ #include #include #include +#include struct flex_array_part { char elements[FLEX_ARRAY_PART_SIZE]; @@ -103,6 +104,7 @@ struct flex_array *flex_array_alloc(int element_size, unsigned int total, FLEX_ARRAY_BASE_BYTES_LEFT); return ret; } +EXPORT_SYMBOL(flex_array_alloc); static int fa_element_to_part_nr(struct flex_array *fa, unsigned int element_nr) @@ -126,12 +128,14 @@ void flex_array_free_parts(struct flex_array *fa) for (part_nr = 0; part_nr < FLEX_ARRAY_NR_BASE_PTRS; part_nr++) kfree(fa->parts[part_nr]); } +EXPORT_SYMBOL(flex_array_free_parts); void flex_array_free(struct flex_array *fa) { flex_array_free_parts(fa); kfree(fa); } +EXPORT_SYMBOL(flex_array_free); static unsigned int index_inside_part(struct flex_array *fa, unsigned int element_nr) @@ -196,6 +200,7 @@ int flex_array_put(struct flex_array *fa, unsigned int element_nr, void *src, memcpy(dst, src, fa->element_size); return 0; } +EXPORT_SYMBOL(flex_array_put); /** * flex_array_clear - clear element in array at @element_nr @@ -223,6 +228,7 @@ int flex_array_clear(struct flex_array *fa, unsigned int element_nr) memset(dst, FLEX_ARRAY_FREE, fa->element_size); return 0; } +EXPORT_SYMBOL(flex_array_clear); /** * flex_array_prealloc - guarantee that array space exists @@ -259,6 +265,7 @@ int flex_array_prealloc(struct flex_array *fa, unsigned int start, } return 0; } +EXPORT_SYMBOL(flex_array_prealloc); /** * flex_array_get - pull data back out of the array @@ -288,6 +295,7 @@ void *flex_array_get(struct flex_array *fa, unsigned int element_nr) } return &part->elements[index_inside_part(fa, element_nr)]; } +EXPORT_SYMBOL(flex_array_get); /** * flex_array_get_ptr - pull a ptr back out of the array @@ -308,6 +316,7 @@ void *flex_array_get_ptr(struct flex_array *fa, unsigned int element_nr) return *tmp; } +EXPORT_SYMBOL(flex_array_get_ptr); static int part_is_free(struct flex_array_part *part) { @@ -348,3 +357,4 @@ int flex_array_shrink(struct flex_array *fa) } return ret; } +EXPORT_SYMBOL(flex_array_shrink); -- cgit v1.2.3-70-g09d2