3.3-stable review patch. If anyone has any objections, please let me know.
------------------ From: Tejun Heo <[email protected]> commit b3dc627cabb33fc95f93da78457770c1b2a364d2 upstream. Commit 24aa07882b ("memblock, x86: Replace memblock_x86_reserve/ free_range() with generic ones") replaced x86 specific memblock operations with the generic ones; unfortunately, it lost zero length operation handling in the process making the kernel panic if somebody tries to reserve zero length area. There isn't much to be gained by being cranky to zero length operations and panicking is almost the worst response. Drop the BUG_ON() in memblock_reserve() and update memblock_add_region/isolate_range() so that all zero length operations are handled as noops. Signed-off-by: Tejun Heo <[email protected]> Reported-by: Valere Monseur <[email protected]> Bisected-by: Joseph Freeman <[email protected]> Tested-by: Joseph Freeman <[email protected]> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=43098 Signed-off-by: Linus Torvalds <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- mm/memblock.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/mm/memblock.c +++ b/mm/memblock.c @@ -330,6 +330,9 @@ static int __init_memblock memblock_add_ phys_addr_t end = base + memblock_cap_size(base, &size); int i, nr_new; + if (!size) + return 0; + /* special case for empty array */ if (type->regions[0].size == 0) { WARN_ON(type->cnt != 1 || type->total_size); @@ -430,6 +433,9 @@ static int __init_memblock memblock_isol *start_rgn = *end_rgn = 0; + if (!size) + return 0; + /* we'll create at most two more regions */ while (type->cnt + 2 > type->max) if (memblock_double_array(type) < 0) @@ -514,7 +520,6 @@ int __init_memblock memblock_reserve(phy (unsigned long long)base, (unsigned long long)base + size, (void *)_RET_IP_); - BUG_ON(0 == size); return memblock_add_region(_rgn, base, size, MAX_NUMNODES); } -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
