From 6ba422c75facb1b1e0e206c464ee121b8073f7e0 Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Sun, 5 Mar 2017 10:54:34 +1100 Subject: [PATCH] powerpc/64: Avoid panic during boot due to divide by zero in init_cache_info() I see a panic in early boot when building with a recent gcc toolchain. The issue is a divide by zero, which is undefined. Older toolchains let us get away with it: int foo(int a) { return a / 0; } foo: li 9,0 divw 3,3,9 extsw 3,3 blr But newer ones catch it: foo: trap Add a check to avoid the divide by zero. Fixes: e2827fe5c156 ("powerpc/64: Clean up ppc64_caches using a struct per cache") Signed-off-by: Anton Blanchard Acked-by: Benjamin Herrenschmidt Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/setup_64.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c index adf2084f214b..9cfaa8b69b5f 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -408,7 +408,10 @@ static void init_cache_info(struct ppc_cache_info *info, u32 size, u32 lsize, info->line_size = lsize; info->block_size = bsize; info->log_block_size = __ilog2(bsize); - info->blocks_per_page = PAGE_SIZE / bsize; + if (bsize) + info->blocks_per_page = PAGE_SIZE / bsize; + else + info->blocks_per_page = 0; if (sets == 0) info->assoc = 0xffff;