diff options
| author |   Ram Pai <linuxram@us.ibm.com> | 2018-01-18 17:50:42 -0800 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2018-01-20 22:59:05 +1100 |
| commit | 99cd1302327a2ccaedf905e9f6a8d8fd234bd485 (patch) | |
| tree | fe969743ada5b66e4bfe93eb960d3eb3265ea8d8 /arch/powerpc/mm/fault.c | |
| parent | powerpc: introduce get_mm_addr_key() helper (diff) | |
| download | linux-dev-99cd1302327a2ccaedf905e9f6a8d8fd234bd485.tar.xz linux-dev-99cd1302327a2ccaedf905e9f6a8d8fd234bd485.zip | |
powerpc: Deliver SEGV signal on pkey violation
The value of the pkey, whose protection got violated,
is made available in si_pkey field of the siginfo structure.
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 | 39 |
1 files changed, 27 insertions, 12 deletions
diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index 6417a659b02d..d3a6e0395eaa 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -107,7 +107,8 @@ static bool store_updates_sp(struct pt_regs *regs) */ static int -__bad_area_nosemaphore(struct pt_regs *regs, unsigned long address, int si_code) +__bad_area_nosemaphore(struct pt_regs *regs, unsigned long address, int si_code, + int pkey) { /* * If we are in kernel mode, bail out with a SEGV, this will @@ -117,17 +118,18 @@ __bad_area_nosemaphore(struct pt_regs *regs, unsigned long address, int si_code) if (!user_mode(regs)) return SIGSEGV; - _exception(SIGSEGV, regs, si_code, address); + _exception_pkey(SIGSEGV, regs, si_code, address, pkey); return 0; } static noinline int bad_area_nosemaphore(struct pt_regs *regs, unsigned long address) { - return __bad_area_nosemaphore(regs, address, SEGV_MAPERR); + return __bad_area_nosemaphore(regs, address, SEGV_MAPERR, 0); } -static int __bad_area(struct pt_regs *regs, unsigned long address, int si_code) +static int __bad_area(struct pt_regs *regs, unsigned long address, int si_code, + int pkey) { struct mm_struct *mm = current->mm; @@ -137,12 +139,18 @@ static int __bad_area(struct pt_regs *regs, unsigned long address, int si_code) */ up_read(&mm->mmap_sem); - return __bad_area_nosemaphore(regs, address, si_code); + return __bad_area_nosemaphore(regs, address, si_code, pkey); } static noinline int bad_area(struct pt_regs *regs, unsigned long address) { - return __bad_area(regs, address, SEGV_MAPERR); + return __bad_area(regs, address, SEGV_MAPERR, 0); +} + +static int bad_key_fault_exception(struct pt_regs *regs, unsigned long address, + int pkey) +{ + return __bad_area_nosemaphore(regs, address, SEGV_PKUERR, pkey); } static int do_sigbus(struct pt_regs *regs, unsigned long address, @@ -427,10 +435,9 @@ 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; - } + if (error_code & DSISR_KEYFAULT) + return bad_key_fault_exception(regs, address, + get_mm_addr_key(mm, address)); /* * We want to do this outside mmap_sem, because reading code around nip @@ -513,10 +520,18 @@ good_area: if (unlikely(fault & VM_FAULT_SIGSEGV) && !arch_vma_access_permitted(vma, flags & FAULT_FLAG_WRITE, is_exec, 0)) { + /* + * The PGD-PDT...PMD-PTE tree may not have been fully setup. + * Hence we cannot walk the tree to locate the PTE, to locate + * the key. Hence let's use vma_pkey() to get the key; instead + * of get_mm_addr_key(). + */ int pkey = vma_pkey(vma); - if (likely(pkey)) - return __bad_area(regs, address, SEGV_PKUERR); + if (likely(pkey)) { + up_read(&mm->mmap_sem); + return bad_key_fault_exception(regs, address, pkey); + } } #endif /* CONFIG_PPC_MEM_KEYS */ |