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author | Darren Stevens <darren@stevens-zone.net> | 2017-01-23 19:42:54 +0000 |
---|---|---|
committer | Sasha Levin <alexander.levin@verizon.com> | 2017-03-06 17:29:30 -0500 |
commit | 078d15b1f19330048c89fd258e3870b73148776c (patch) | |
tree | 2d838799d9a246f97911eefce0525caf3b4b9a52 | |
parent | 574c2c0bdd8a3cdd91cc2bef476f53273c522c04 (diff) |
powerpc: Add missing error check to prom_find_boot_cpu()
[ Upstream commit af2b7fa17eb92e52b65f96604448ff7a2a89ee99 ]
prom_init.c calls 'instance-to-package' twice, but the return
is not checked during prom_find_boot_cpu(). The result is then
passed to prom_getprop(), which could be PROM_ERROR. Add a return check
to prevent this.
This was found on a pasemi system, where CFE doesn't have a working
'instance-to package' prom call.
Before Commit 5c0484e25ec0 ('powerpc: Endian safe trampoline') the area
around addr 0 was mostly 0's and this doesn't cause a problem. Once the
macro 'FIXUP_ENDIAN' has been added to head_64.S, the low memory area
now has non-zero values, which cause the prom_getprop() call
to hang.
mpe: Also confirmed that under SLOF if 'instance-to-package' did fail
with PROM_ERROR we would crash in SLOF. So the bug is not specific to
CFE, it's just that other open firmwares don't trigger it because they
have a working 'instance-to-package'.
Fixes: 5c0484e25ec0 ("powerpc: Endian safe trampoline")
Cc: stable@vger.kernel.org # v3.13+
Signed-off-by: Darren Stevens <darren@stevens-zone.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
-rw-r--r-- | arch/powerpc/kernel/prom_init.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c index ae97ba211d8e..f409bfc0ae42 100644 --- a/arch/powerpc/kernel/prom_init.c +++ b/arch/powerpc/kernel/prom_init.c @@ -2633,6 +2633,9 @@ static void __init prom_find_boot_cpu(void) cpu_pkg = call_prom("instance-to-package", 1, 1, prom_cpu); + if (!PHANDLE_VALID(cpu_pkg)) + return; + prom_getprop(cpu_pkg, "reg", &rval, sizeof(rval)); prom.cpu = be32_to_cpu(rval); |