diff options
| author | Ram Pai <linuxram@us.ibm.com> | 2018-12-20 12:03:30 -0800 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2018-12-21 14:46:50 +1100 |
| commit | 2cd4bd192ee94848695c1c052d87913260e10f36 (patch) | |
| tree | 196e1d7a1fb878dae550092bc739c5ac5e4318db /arch/powerpc/include | |
| parent | 2f07229f02d4c55affccd11a61af4fd4b94dc436 (diff) | |
powerpc/pkeys: Fix handling of pkey state across fork()
Protection key tracking information is not copied over to the
mm_struct of the child during fork(). This can cause the child to
erroneously allocate keys that were already allocated. Any allocated
execute-only key is lost aswell.
Add code; called by dup_mmap(), to copy the pkey state from parent to
child explicitly.
This problem was originally found by Dave Hansen on x86, which turns
out to be a problem on powerpc aswell.
Fixes: cf43d3b26452 ("powerpc: Enable pkey subsystem")
Cc: stable@vger.kernel.org # v4.16+
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/include')
| -rw-r--r-- | arch/powerpc/include/asm/mmu_context.h | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h index c05efd2e8736..e687ed31d85a 100644 --- a/arch/powerpc/include/asm/mmu_context.h +++ b/arch/powerpc/include/asm/mmu_context.h @@ -217,12 +217,6 @@ static inline void enter_lazy_tlb(struct mm_struct *mm, #endif } -static inline int arch_dup_mmap(struct mm_struct *oldmm, - struct mm_struct *mm) -{ - return 0; -} - #ifdef CONFIG_PPC_BOOK3E_64 static inline void arch_exit_mmap(struct mm_struct *mm) { @@ -247,6 +241,7 @@ static inline void arch_bprm_mm_init(struct mm_struct *mm, #ifdef CONFIG_PPC_MEM_KEYS bool arch_vma_access_permitted(struct vm_area_struct *vma, bool write, bool execute, bool foreign); +void arch_dup_pkeys(struct mm_struct *oldmm, struct mm_struct *mm); #else /* CONFIG_PPC_MEM_KEYS */ static inline bool arch_vma_access_permitted(struct vm_area_struct *vma, bool write, bool execute, bool foreign) @@ -259,6 +254,7 @@ static inline bool arch_vma_access_permitted(struct vm_area_struct *vma, #define thread_pkey_regs_save(thread) #define thread_pkey_regs_restore(new_thread, old_thread) #define thread_pkey_regs_init(thread) +#define arch_dup_pkeys(oldmm, mm) static inline u64 pte_to_hpte_pkey_bits(u64 pteflags) { @@ -267,5 +263,12 @@ static inline u64 pte_to_hpte_pkey_bits(u64 pteflags) #endif /* CONFIG_PPC_MEM_KEYS */ +static inline int arch_dup_mmap(struct mm_struct *oldmm, + struct mm_struct *mm) +{ + arch_dup_pkeys(oldmm, mm); + return 0; +} + #endif /* __KERNEL__ */ #endif /* __ASM_POWERPC_MMU_CONTEXT_H */ |