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| author | Anton Blanchard <anton@samba.org> | 2017-03-05 10:54:34 +1100 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-03-06 21:44:09 +1100 |
| commit | 6ba422c75facb1b1e0e206c464ee121b8073f7e0 (patch) | |
| tree | 5ab7573657019a678a3607d59a913be3cc86caa3 /arch | |
| parent | 014d02cbf16b3106dc8e93281d2a9c189751ed5e (diff) | |
| download | linux-rpi3-6ba422c75facb1b1e0e206c464ee121b8073f7e0.tar.gz linux-rpi3-6ba422c75facb1b1e0e206c464ee121b8073f7e0.tar.bz2 linux-rpi3-6ba422c75facb1b1e0e206c464ee121b8073f7e0.zip | |
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 <anton@samba.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/kernel/setup_64.c | 5 |
1 files changed, 4 insertions, 1 deletions
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; |