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| author | Christophe Leroy <christophe.leroy@csgroup.eu> | 2021-06-02 08:42:10 +0200 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-06-16 16:09:07 +0200 |
| commit | 10248dcba1205042a3a0ea65eb441030702d97cd (patch) | |
| tree | 47e29ca6d4f4828409d3c64d9a4f5493d13608fa /arch/powerpc/mm | |
| parent | powerpc: Remove CONFIG_PPC_MMU_NOHASH_32 (diff) | |
| download | linux-10248dcba1205042a3a0ea65eb441030702d97cd.tar.xz linux-10248dcba1205042a3a0ea65eb441030702d97cd.zip | |
powerpc/44x: Implement Kernel Userspace Exec Protection (KUEP)
Powerpc 44x has two bits for exec protection in TLBs: one
for user (UX) and one for superviser (SX).
Clear SX on user pages in TLB miss handlers to provide KUEP.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/169310e08152aa1d96c979770291d165ec6896ae.1622616032.git.christophe.leroy@csgroup.eu
Diffstat (limited to 'arch/powerpc/mm')
| -rw-r--r-- | arch/powerpc/mm/nohash/44x.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/powerpc/mm/nohash/44x.c b/arch/powerpc/mm/nohash/44x.c index 3d6ae7c72412..7da6d1e9fc9b 100644 --- a/arch/powerpc/mm/nohash/44x.c +++ b/arch/powerpc/mm/nohash/44x.c @@ -239,3 +239,16 @@ void __init mmu_init_secondary(int cpu) } } #endif /* CONFIG_SMP */ + +#ifdef CONFIG_PPC_KUEP +void __init setup_kuep(bool disabled) +{ + if (disabled) + patch_instruction_site(&patch__tlb_44x_kuep, ppc_inst(PPC_RAW_NOP())); + else + pr_info("Activating Kernel Userspace Execution Prevention\n"); + + if (IS_ENABLED(CONFIG_PPC_47x) && disabled) + patch_instruction_site(&patch__tlb_47x_kuep, ppc_inst(PPC_RAW_NOP())); +} +#endif |