| Message ID | 20180911145607.6009-1-robh@kernel.org |
|---|---|
| State | Accepted |
| Commit | e54192b48da75f025ae4b277925eaf6aca1d13bd |
| Headers | show |
| Series | of: fix phandle cache creation for DTs with no phandles | expand |
diff --git a/drivers/of/base.c b/drivers/of/base.c index a055cd1ef96d..17ae594b7014 100644 --- a/drivers/of/base.c +++ b/drivers/of/base.c @@ -140,6 +140,9 @@ void of_populate_phandle_cache(void) if (np->phandle && np->phandle != OF_PHANDLE_ILLEGAL) phandles++; + if (!phandles) + goto out; + cache_entries = roundup_pow_of_two(phandles); phandle_cache_mask = cache_entries - 1;
With commit 0b3ce78e90fc ("of: cache phandle nodes to reduce cost of of_find_node_by_phandle()"), a G3 PowerMac fails to boot. The root cause is the DT for this system has no phandle properties when booted with BootX. of_populate_phandle_cache() does not handle the case of no phandles correctly. The problem is roundup_pow_of_two() for 0 is undefined. The implementation subtracts 1 underflowing and then things are in the weeds. Fixes: 0b3ce78e90fc ("of: cache phandle nodes to reduce cost of of_find_node_by_phandle()") Cc: stable@vger.kernel.org # 4.17+ Reported-by: Finn Thain <fthain@telegraphics.com.au> Tested-by: Stan Johnson <userm57@yahoo.com> Cc: Frank Rowand <frowand.list@gmail.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Rob Herring <robh@kernel.org> --- Here's a formal patch of what Stan tested. Will send to Linus this week. Rob drivers/of/base.c | 3 +++ 1 file changed, 3 insertions(+) -- 2.17.1