From: Stephen Bates <sbates@xxxxxxxxxxxx> Subject: lib/genalloc.c: make the avail variable an atomic_long_t If the amount of resources allocated to a gen_pool exceeds 2^32 then the avail atomic overflows and this causes problems when clients try and borrow resources from the pool. This is only expected to be an issue on 64 bit systems. Add the <linux/atomic.h> header to pull in atomic_long* operations. So that 32 bit systems continue to use atomic32_t but 64 bit systems can use atomic64_t. Link: http://lkml.kernel.org/r/1509033843-25667-1-git-send-email-sbates@xxxxxxxxxxxx Signed-off-by: Stephen Bates <sbates@xxxxxxxxxxxx> Reviewed-by: Logan Gunthorpe <logang@xxxxxxxxxxxx> Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> Reviewed-by: Daniel Mentz <danielmentz@xxxxxxxxxx> Cc: Jonathan Corbet <corbet@xxxxxxx> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/genalloc.h | 3 ++- lib/genalloc.c | 10 +++++----- 2 files changed, 7 insertions(+), 6 deletions(-) diff -puN include/linux/genalloc.h~genalloc-make-the-avail-variable-an-atomic_long_t include/linux/genalloc.h --- a/include/linux/genalloc.h~genalloc-make-the-avail-variable-an-atomic_long_t +++ a/include/linux/genalloc.h @@ -32,6 +32,7 @@ #include <linux/types.h> #include <linux/spinlock_types.h> +#include <linux/atomic.h> struct device; struct device_node; @@ -71,7 +72,7 @@ struct gen_pool { */ struct gen_pool_chunk { struct list_head next_chunk; /* next chunk in pool */ - atomic_t avail; + atomic_long_t avail; phys_addr_t phys_addr; /* physical starting address of memory chunk */ unsigned long start_addr; /* start address of memory chunk */ unsigned long end_addr; /* end address of memory chunk (inclusive) */ diff -puN lib/genalloc.c~genalloc-make-the-avail-variable-an-atomic_long_t lib/genalloc.c --- a/lib/genalloc.c~genalloc-make-the-avail-variable-an-atomic_long_t +++ a/lib/genalloc.c @@ -194,7 +194,7 @@ int gen_pool_add_virt(struct gen_pool *p chunk->phys_addr = phys; chunk->start_addr = virt; chunk->end_addr = virt + size - 1; - atomic_set(&chunk->avail, size); + atomic_long_set(&chunk->avail, size); spin_lock(&pool->lock); list_add_rcu(&chunk->next_chunk, &pool->chunks); @@ -304,7 +304,7 @@ unsigned long gen_pool_alloc_algo(struct nbits = (size + (1UL << order) - 1) >> order; rcu_read_lock(); list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk) { - if (size > atomic_read(&chunk->avail)) + if (size > atomic_long_read(&chunk->avail)) continue; start_bit = 0; @@ -324,7 +324,7 @@ retry: addr = chunk->start_addr + ((unsigned long)start_bit << order); size = nbits << order; - atomic_sub(size, &chunk->avail); + atomic_long_sub(size, &chunk->avail); break; } rcu_read_unlock(); @@ -390,7 +390,7 @@ void gen_pool_free(struct gen_pool *pool remain = bitmap_clear_ll(chunk->bits, start_bit, nbits); BUG_ON(remain); size = nbits << order; - atomic_add(size, &chunk->avail); + atomic_long_add(size, &chunk->avail); rcu_read_unlock(); return; } @@ -464,7 +464,7 @@ size_t gen_pool_avail(struct gen_pool *p rcu_read_lock(); list_for_each_entry_rcu(chunk, &pool->chunks, next_chunk) - avail += atomic_read(&chunk->avail); + avail += atomic_long_read(&chunk->avail); rcu_read_unlock(); return avail; } _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
