diff options
| author |   Ram Pai <linuxram@us.ibm.com> | 2018-01-18 17:50:40 -0800 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2018-01-20 22:59:04 +1100 |
| commit | e6c2a4797e101a25eced94aa9e1fc42c30247aec (patch) | |
| tree | 97ab4186d328b99f469a0252f419a2f692524139 /arch/powerpc/mm/fault.c | |
| parent | powerpc: implementation for arch_vma_access_permitted() (diff) | |
| download | linux-dev-e6c2a4797e101a25eced94aa9e1fc42c30247aec.tar.xz linux-dev-e6c2a4797e101a25eced94aa9e1fc42c30247aec.zip | |
powerpc: Handle exceptions caused by pkey violation
Handle Data and Instruction exceptions caused by memory
protection-key.
The CPU will detect the key fault if the HPTE is already
programmed with the key.
However if the HPTE is not hashed, a key fault will not
be detected by the hardware. The software will detect
pkey violation in such a case.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/mm/fault.c')
| -rw-r--r-- | arch/powerpc/mm/fault.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index c07896c19517..6417a659b02d 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -427,6 +427,11 @@ static int __do_page_fault(struct pt_regs *regs, unsigned long address, perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, address); + if (error_code & DSISR_KEYFAULT) { + _exception(SIGSEGV, regs, SEGV_PKUERR, address); + return 0; + } + /* * We want to do this outside mmap_sem, because reading code around nip * can result in fault, which will cause a deadlock when called with @@ -498,6 +503,23 @@ good_area: * the fault. */ fault = handle_mm_fault(vma, address, flags); + +#ifdef CONFIG_PPC_MEM_KEYS + /* + * if the HPTE is not hashed, hardware will not detect + * a key fault. Lets check if we failed because of a + * software detected key fault. + */ + if (unlikely(fault & VM_FAULT_SIGSEGV) && + !arch_vma_access_permitted(vma, flags & FAULT_FLAG_WRITE, + is_exec, 0)) { + int pkey = vma_pkey(vma); + + if (likely(pkey)) + return __bad_area(regs, address, SEGV_PKUERR); + } +#endif /* CONFIG_PPC_MEM_KEYS */ + major |= fault & VM_FAULT_MAJOR; /* |