diff options
| -rw-r--r-- | arch/s390/mm/fault.c | 258 |
1 files changed, 129 insertions, 129 deletions
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index fd72c269cdb4..0dcfcfb5b5be 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -34,16 +34,15 @@ #include <asm/pgtable.h> #include <asm/s390_ext.h> #include <asm/mmu_context.h> +#include <asm/compat.h> #include "../kernel/entry.h" #ifndef CONFIG_64BIT #define __FAIL_ADDR_MASK 0x7ffff000 -#define __FIXUP_MASK 0x7fffffff #define __SUBCODE_MASK 0x0200 #define __PF_RES_FIELD 0ULL #else /* CONFIG_64BIT */ #define __FAIL_ADDR_MASK -4096L -#define __FIXUP_MASK ~0L #define __SUBCODE_MASK 0x0600 #define __PF_RES_FIELD 0x8000000000000000ULL #endif /* CONFIG_64BIT */ @@ -52,6 +51,10 @@ extern int sysctl_userprocess_debug; #endif +#define VM_FAULT_BADCONTEXT 0x010000 +#define VM_FAULT_BADMAP 0x020000 +#define VM_FAULT_BADACCESS 0x040000 + static inline int notify_page_fault(struct pt_regs *regs) { int ret = 0; @@ -122,18 +125,22 @@ static inline int user_space_fault(unsigned long trans_exc_code) * Send SIGSEGV to task. This is an external routine * to keep the stack usage of do_page_fault small. */ -static void do_sigsegv(struct pt_regs *regs, unsigned long error_code, - int si_code, unsigned long address) +static noinline void do_sigsegv(struct pt_regs *regs, long int_code, + int si_code, unsigned long trans_exc_code) { struct siginfo si; + unsigned long address; + address = trans_exc_code & __FAIL_ADDR_MASK; + current->thread.prot_addr = address; + current->thread.trap_no = int_code; #if defined(CONFIG_SYSCTL) || defined(CONFIG_PROCESS_DEBUG) #if defined(CONFIG_SYSCTL) if (sysctl_userprocess_debug) #endif { printk("User process fault: interruption code 0x%lX\n", - error_code); + int_code); printk("failing address: %lX\n", address); show_regs(regs); } @@ -144,14 +151,14 @@ static void do_sigsegv(struct pt_regs *regs, unsigned long error_code, force_sig_info(SIGSEGV, &si, current); } -static void do_no_context(struct pt_regs *regs, unsigned long error_code, - unsigned long trans_exc_code) +static noinline void do_no_context(struct pt_regs *regs, long int_code, + unsigned long trans_exc_code) { const struct exception_table_entry *fixup; unsigned long address; /* Are we prepared to handle this kernel fault? */ - fixup = search_exception_tables(regs->psw.addr & __FIXUP_MASK); + fixup = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN); if (fixup) { regs->psw.addr = fixup->fixup | PSW_ADDR_AMODE; return; @@ -169,107 +176,127 @@ static void do_no_context(struct pt_regs *regs, unsigned long error_code, printk(KERN_ALERT "Unable to handle kernel paging request" " at virtual user address %p\n", (void *)address); - die("Oops", regs, error_code); + die("Oops", regs, int_code); do_exit(SIGKILL); } -static void do_low_address(struct pt_regs *regs, unsigned long error_code, - unsigned long trans_exc_code) +static noinline void do_low_address(struct pt_regs *regs, long int_code, + unsigned long trans_exc_code) { /* Low-address protection hit in kernel mode means NULL pointer write access in kernel mode. */ if (regs->psw.mask & PSW_MASK_PSTATE) { /* Low-address protection hit in user mode 'cannot happen'. */ - die ("Low-address protection", regs, error_code); + die ("Low-address protection", regs, int_code); do_exit(SIGKILL); } - do_no_context(regs, error_code, trans_exc_code); + do_no_context(regs, int_code, trans_exc_code); } -static void do_sigbus(struct pt_regs *regs, unsigned long error_code, - unsigned long trans_exc_code) +static noinline void do_sigbus(struct pt_regs *regs, long int_code, + unsigned long trans_exc_code) { struct task_struct *tsk = current; - struct mm_struct *mm = tsk->mm; - up_read(&mm->mmap_sem); /* * Send a sigbus, regardless of whether we were in kernel * or user mode. */ tsk->thread.prot_addr = trans_exc_code & __FAIL_ADDR_MASK; - tsk->thread.trap_no = error_code; + tsk->thread.trap_no = int_code; force_sig(SIGBUS, tsk); - - /* Kernel mode? Handle exceptions or die */ - if (!(regs->psw.mask & PSW_MASK_PSTATE)) - do_no_context(regs, error_code, trans_exc_code); } #ifdef CONFIG_S390_EXEC_PROTECT -static int signal_return(struct mm_struct *mm, struct pt_regs *regs, - unsigned long address, unsigned long error_code) +static noinline int signal_return(struct pt_regs *regs, long int_code, + unsigned long trans_exc_code) { u16 instruction; int rc; -#ifdef CONFIG_COMPAT - int compat; -#endif - pagefault_disable(); rc = __get_user(instruction, (u16 __user *) regs->psw.addr); - pagefault_enable(); - if (rc) - return -EFAULT; - up_read(&mm->mmap_sem); - clear_tsk_thread_flag(current, TIF_SINGLE_STEP); -#ifdef CONFIG_COMPAT - compat = is_compat_task(); - if (compat && instruction == 0x0a77) - sys32_sigreturn(); - else if (compat && instruction == 0x0aad) - sys32_rt_sigreturn(); - else -#endif - if (instruction == 0x0a77) - sys_sigreturn(); - else if (instruction == 0x0aad) - sys_rt_sigreturn(); - else { - current->thread.prot_addr = address; - current->thread.trap_no = error_code; - do_sigsegv(regs, error_code, SEGV_MAPERR, address); - } + if (!rc && instruction == 0x0a77) { + clear_tsk_thread_flag(current, TIF_SINGLE_STEP); + if (is_compat_task()) + sys32_sigreturn(); + else + sys_sigreturn(); + } else if (!rc && instruction == 0x0aad) { + clear_tsk_thread_flag(current, TIF_SINGLE_STEP); + if (is_compat_task()) + sys32_rt_sigreturn(); + else + sys_rt_sigreturn(); + } else + do_sigsegv(regs, int_code, SEGV_MAPERR, trans_exc_code); return 0; } #endif /* CONFIG_S390_EXEC_PROTECT */ +static noinline void do_fault_error(struct pt_regs *regs, long int_code, + unsigned long trans_exc_code, int fault) +{ + int si_code; + + switch (fault) { + case VM_FAULT_BADACCESS: +#ifdef CONFIG_S390_EXEC_PROTECT + if ((regs->psw.mask & PSW_MASK_ASC) == PSW_ASC_SECONDARY && + (trans_exc_code & 3) == 0) { + signal_return(regs, int_code, trans_exc_code); + break; + } +#endif /* CONFIG_S390_EXEC_PROTECT */ + case VM_FAULT_BADMAP: + /* Bad memory access. Check if it is kernel or user space. */ + if (regs->psw.mask & PSW_MASK_PSTATE) { + /* User mode accesses just cause a SIGSEGV */ + si_code = (fault == VM_FAULT_BADMAP) ? + SEGV_MAPERR : SEGV_ACCERR; + do_sigsegv(regs, int_code, si_code, trans_exc_code); + return; + } + case VM_FAULT_BADCONTEXT: + do_no_context(regs, int_code, trans_exc_code); + break; + default: /* fault & VM_FAULT_ERROR */ + if (fault & VM_FAULT_OOM) + pagefault_out_of_memory(); + else if (fault & VM_FAULT_SIGBUS) { + do_sigbus(regs, int_code, trans_exc_code); + /* Kernel mode? Handle exceptions or die */ + if (!(regs->psw.mask & PSW_MASK_PSTATE)) + do_no_context(regs, int_code, trans_exc_code); + } else + BUG(); + break; + } +} + /* * This routine handles page faults. It determines the address, * and the problem, and then passes it off to one of the appropriate * routines. * - * error_code: + * interruption code (int_code): * 04 Protection -> Write-Protection (suprression) * 10 Segment translation -> Not present (nullification) * 11 Page translation -> Not present (nullification) * 3b Region third trans. -> Not present (nullification) */ -static inline void -do_exception(struct pt_regs *regs, unsigned long error_code, int write, - unsigned long trans_exc_code) +static inline int do_exception(struct pt_regs *regs, int write, + unsigned long trans_exc_code) { struct task_struct *tsk; struct mm_struct *mm; struct vm_area_struct *vma; unsigned long address; - int si_code; int fault; if (notify_page_fault(regs)) - return; + return 0; tsk = current; mm = tsk->mm; @@ -279,8 +306,9 @@ do_exception(struct pt_regs *regs, unsigned long error_code, int write, * we are not in an interrupt and that there is a * user context. */ + fault = VM_FAULT_BADCONTEXT; if (unlikely(!user_space_fault(trans_exc_code) || in_atomic() || !mm)) - goto no_context; + goto out; address = trans_exc_code & __FAIL_ADDR_MASK; /* @@ -292,41 +320,35 @@ do_exception(struct pt_regs *regs, unsigned long error_code, int write, perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, 0, regs, address); down_read(&mm->mmap_sem); - si_code = SEGV_MAPERR; + fault = VM_FAULT_BADMAP; vma = find_vma(mm, address); if (!vma) - goto bad_area; + goto out_up; + if (unlikely(vma->vm_start > address)) { + if (!(vma->vm_flags & VM_GROWSDOWN)) + goto out_up; + if (expand_stack(vma, address)) + goto out_up; + } + + /* + * Ok, we have a good vm_area for this memory access, so + * we can handle it.. + */ + fault = VM_FAULT_BADACCESS; #ifdef CONFIG_S390_EXEC_PROTECT if (unlikely((regs->psw.mask & PSW_MASK_ASC) == PSW_ASC_SECONDARY && (trans_exc_code & 3) == 0 && !(vma->vm_flags & VM_EXEC))) - if (!signal_return(mm, regs, address, error_code)) - /* - * signal_return() has done an up_read(&mm->mmap_sem) - * if it returns 0. - */ - return; + goto out_up; #endif - - if (vma->vm_start <= address) - goto good_area; - if (!(vma->vm_flags & VM_GROWSDOWN)) - goto bad_area; - if (expand_stack(vma, address)) - goto bad_area; -/* - * Ok, we have a good vm_area for this memory access, so - * we can handle it.. - */ -good_area: - si_code = SEGV_ACCERR; if (!write) { /* page not present, check vm flags */ if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE))) - goto bad_area; + goto out_up; } else { if (!(vma->vm_flags & VM_WRITE)) - goto bad_area; + goto out_up; } if (is_vm_hugetlb_page(vma)) @@ -337,17 +359,9 @@ good_area: * the fault. */ fault = handle_mm_fault(mm, vma, address, write ? FAULT_FLAG_WRITE : 0); - if (unlikely(fault & VM_FAULT_ERROR)) { - if (fault & VM_FAULT_OOM) { - up_read(&mm->mmap_sem); - pagefault_out_of_memory(); - return; - } else if (fault & VM_FAULT_SIGBUS) { - do_sigbus(regs, error_code, address); - return; - } - BUG(); - } + if (unlikely(fault & VM_FAULT_ERROR)) + goto out_up; + if (fault & VM_FAULT_MAJOR) { tsk->maj_flt++; perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ, 1, 0, @@ -357,67 +371,55 @@ good_area: perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN, 1, 0, regs, address); } - up_read(&mm->mmap_sem); /* * The instruction that caused the program check will * be repeated. Don't signal single step via SIGTRAP. */ clear_tsk_thread_flag(tsk, TIF_SINGLE_STEP); - return; - -/* - * Something tried to access memory that isn't in our memory map.. - * Fix it, but check if it's kernel or user first.. - */ -bad_area: + fault = 0; +out_up: up_read(&mm->mmap_sem); - - /* User mode accesses just cause a SIGSEGV */ - if (regs->psw.mask & PSW_MASK_PSTATE) { - tsk->thread.prot_addr = address; - tsk->thread.trap_no = error_code; - do_sigsegv(regs, error_code, si_code, address); - return; - } - -no_context: - do_no_context(regs, error_code, trans_exc_code); +out: + return fault; } -void __kprobes do_protection_exception(struct pt_regs *regs, - long error_code) +void __kprobes do_protection_exception(struct pt_regs *regs, long int_code) { unsigned long trans_exc_code = S390_lowcore.trans_exc_code; + int fault; /* Protection exception is supressing, decrement psw address. */ - regs->psw.addr -= (error_code >> 16); + regs->psw.addr -= (int_code >> 16); /* * Check for low-address protection. This needs to be treated * as a special case because the translation exception code * field is not guaranteed to contain valid data in this case. */ if (unlikely(!(trans_exc_code & 4))) { - do_low_address(regs, error_code, trans_exc_code); + do_low_address(regs, int_code, trans_exc_code); return; } - do_exception(regs, 4, 1, trans_exc_code); + fault = do_exception(regs, 1, trans_exc_code); + if (unlikely(fault)) + do_fault_error(regs, 4, trans_exc_code, fault); } -void __kprobes do_dat_exception(struct pt_regs *regs, long error_code) +void __kprobes do_dat_exception(struct pt_regs *regs, long int_code) { - do_exception(regs, error_code & 0xff, 0, S390_lowcore.trans_exc_code); + unsigned long trans_exc_code = S390_lowcore.trans_exc_code; + int fault; + + fault = do_exception(regs, 0, trans_exc_code); + if (unlikely(fault)) + do_fault_error(regs, int_code & 255, trans_exc_code, fault); } #ifdef CONFIG_64BIT -void __kprobes do_asce_exception(struct pt_regs *regs, unsigned long error_code) +void __kprobes do_asce_exception(struct pt_regs *regs, long int_code) { unsigned long trans_exc_code = S390_lowcore.trans_exc_code; - struct mm_struct *mm; + struct mm_struct *mm = current->mm; struct vm_area_struct *vma; - unsigned long address; - - mm = current->mm; - address = trans_exc_code & __FAIL_ADDR_MASK; if (unlikely(!user_space_fault(trans_exc_code) || in_atomic() || !mm)) goto no_context; @@ -425,7 +427,7 @@ void __kprobes do_asce_exception(struct pt_regs *regs, unsigned long error_code) local_irq_enable(); down_read(&mm->mmap_sem); - vma = find_vma(mm, address); + vma = find_vma(mm, trans_exc_code & __FAIL_ADDR_MASK); up_read(&mm->mmap_sem); if (vma) { @@ -435,14 +437,12 @@ void __kprobes do_asce_exception(struct pt_regs *regs, unsigned long error_code) /* User mode accesses just cause a SIGSEGV */ if (regs->psw.mask & PSW_MASK_PSTATE) { - current->thread.prot_addr = address; - current->thread.trap_no = error_code; - do_sigsegv(regs, error_code, SEGV_MAPERR, address); + do_sigsegv(regs, int_code, SEGV_MAPERR, trans_exc_code); return; } no_context: - do_no_context(regs, error_code, trans_exc_code); + do_no_context(regs, int_code, trans_exc_code); } #endif @@ -507,7 +507,7 @@ void pfault_fini(void) : : "a" (&refbk), "m" (refbk) : "cc"); } -static void pfault_interrupt(__u16 error_code) +static void pfault_interrupt(__u16 int_code) { struct task_struct *tsk; __u16 subcode; |