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| author | Christophe Leroy <christophe.leroy@c-s.fr> | 2019-03-11 08:30:35 +0000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2019-04-21 23:11:46 +1000 |
| commit | 31ed2b13c48d779efc838ad54e30121e088a62af (patch) | |
| tree | 80890f996c246cd567e2822230b68340919adebf /arch/powerpc/mm/ppc_mmu_32.c | |
| parent | 2679f9bd0abafb3044bcbaac0600b32159ac8bf2 (diff) | |
| download | linux-31ed2b13c48d779efc838ad54e30121e088a62af.tar.gz | |
powerpc/32s: Implement Kernel Userspace Execution Prevention.
To implement Kernel Userspace Execution Prevention, this patch
sets NX bit on all user segments on kernel entry and clears NX bit
on all user segments on kernel exit.
Note that powerpc 601 doesn't have the NX bit, so KUEP will not
work on it. A warning is displayed at startup.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/mm/ppc_mmu_32.c')
| -rw-r--r-- | arch/powerpc/mm/ppc_mmu_32.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/powerpc/mm/ppc_mmu_32.c b/arch/powerpc/mm/ppc_mmu_32.c index f29d2f118b444a..baa75673b1f52e 100644 --- a/arch/powerpc/mm/ppc_mmu_32.c +++ b/arch/powerpc/mm/ppc_mmu_32.c @@ -394,3 +394,16 @@ void setup_initial_memory_limit(phys_addr_t first_memblock_base, else /* Anything else has 256M mapped */ memblock_set_current_limit(min_t(u64, first_memblock_size, 0x10000000)); } + +#ifdef CONFIG_PPC_KUEP +void __init setup_kuep(bool disabled) +{ + pr_info("Activating Kernel Userspace Execution Prevention\n"); + + if (cpu_has_feature(CPU_FTR_601)) + pr_warn("KUEP is not working on powerpc 601 (No NX bit in Seg Regs)\n"); + + if (disabled) + pr_warn("KUEP cannot be disabled yet on 6xx when compiled in\n"); +} +#endif |