From 44b4c4450f8d31296ba633d74be753a85fd627bd Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Mon, 14 Dec 2020 13:31:21 +0530 Subject: powerpc/64s: Mark the kuap/kuep functions non __init The kernel calls these functions on CPU online and hence they must not be marked __init. Otherwise if the memory they occupied has been reused the system can crash in various ways. Sachin reported it caused his LPAR to spontaneously restart with no other output. With xmon enabled it may drop into xmon with a dump like: cpu 0x1: Vector: 700 (Program Check) at [c000000003c5fcb0] pc: 00000000011e0a78 lr: 00000000011c51d4 sp: c000000003c5ff50 msr: 8000000000081001 current = 0xc000000002c12b00 paca = 0xc000000003cff280 irqmask: 0x03 irq_happened: 0x01 pid = 0, comm = swapper/1 ... [c000000003c5ff50] 0000000000087c38 (unreliable) [c000000003c5ff70] 000000000003870c [c000000003c5ff90] 000000000000d108 Fixes: 3b47b7549ead ("powerpc/book3s64/kuap: Move KUAP related function outside radix") Reported-by: Sachin Sant Signed-off-by: Aneesh Kumar K.V [mpe: Expand change log with details and xmon output] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20201214080121.358567-1-aneesh.kumar@linux.ibm.com --- arch/powerpc/mm/book3s64/pkeys.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/mm/book3s64/pkeys.c b/arch/powerpc/mm/book3s64/pkeys.c index 2b7ded396db4..f1c6f264ed91 100644 --- a/arch/powerpc/mm/book3s64/pkeys.c +++ b/arch/powerpc/mm/book3s64/pkeys.c @@ -251,7 +251,7 @@ out: } #ifdef CONFIG_PPC_KUEP -void __init setup_kuep(bool disabled) +void setup_kuep(bool disabled) { if (disabled) return; @@ -277,7 +277,7 @@ void __init setup_kuep(bool disabled) #endif #ifdef CONFIG_PPC_KUAP -void __init setup_kuap(bool disabled) +void setup_kuap(bool disabled) { if (disabled) return; -- cgit