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authorRob Herring <robh@kernel.org>2018-09-11 17:28:14 +0300
committerRob Herring <robh@kernel.org>2018-09-11 19:28:40 +0300
commite54192b48da75f025ae4b277925eaf6aca1d13bd (patch)
treef31ac5662c779ae66b72c91dcaf3be22087daeca /drivers/of/base.c
parent0413bedabc886c3a56804d1c80a58e99077b1d91 (diff)
downloadlinux-e54192b48da75f025ae4b277925eaf6aca1d13bd.tar.xz
of: fix phandle cache creation for DTs with no phandles
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> Reviewed-by: Frank Rowand <frank.rowand@sony.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Rob Herring <robh@kernel.org>
Diffstat (limited to 'drivers/of/base.c')
-rw-r--r--drivers/of/base.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/of/base.c b/drivers/of/base.c
index 9095b8290150..74eaedd5b860 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;