From 36a3d1dd4e16bcd0d2ddfb4a2ec7092f0ae0d931 Mon Sep 17 00:00:00 2001 From: Stephen Bates Date: Fri, 17 Nov 2017 15:28:16 -0800 Subject: [PATCH] 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 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@raithlin.com Signed-off-by: Stephen Bates Reviewed-by: Logan Gunthorpe Reviewed-by: Mathieu Desnoyers Reviewed-by: Daniel Mentz Cc: Jonathan Corbet Cc: Andrew Morton Cc: Will Deacon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/genalloc.h | 3 ++- lib/genalloc.c | 10 +++++----- 2 files changed, 7 insertions(+), 6 deletions(-) diff --git a/include/linux/genalloc.h b/include/linux/genalloc.h index 6dfec4d638df..872f930f1b06 100644 --- a/include/linux/genalloc.h +++ b/include/linux/genalloc.h @@ -32,6 +32,7 @@ #include #include +#include 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 --git a/lib/genalloc.c b/lib/genalloc.c index 144fe6b1a03e..ca06adc4f445 100644 --- a/lib/genalloc.c +++ b/lib/genalloc.c @@ -194,7 +194,7 @@ int gen_pool_add_virt(struct gen_pool *pool, unsigned long virt, phys_addr_t phy 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 gen_pool *pool, size_t size, 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 @@ unsigned long gen_pool_alloc_algo(struct gen_pool *pool, size_t size, 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, unsigned long addr, size_t size) 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 *pool) 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; }