diff options
author | James Bottomley <jejb@mulgrave.il.steeleye.com> | 2007-02-10 13:45:43 -0600 |
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committer | James Bottomley <jejb@mulgrave.il.steeleye.com> | 2007-02-10 13:45:43 -0600 |
commit | 81b7bbd1932a04869d4c8635a75222dfc6089f96 (patch) | |
tree | 285ae868a1e3a41fb0dbfe346c28e380949bcb55 /arch/s390/mm/fault.c | |
parent | 98051995ab44b993f992946055edc6115351f725 (diff) | |
parent | 66efc5a7e3061c3597ac43a8bb1026488d57e66b (diff) |
Merge branch 'linus'
Conflicts:
drivers/scsi/ipr.c
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Diffstat (limited to 'arch/s390/mm/fault.c')
-rw-r--r-- | arch/s390/mm/fault.c | 93 |
1 files changed, 88 insertions, 5 deletions
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index cd85e34d870..9ff143e8774 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -52,7 +52,7 @@ extern int sysctl_userprocess_debug; extern void die(const char *,struct pt_regs *,long); #ifdef CONFIG_KPROBES -ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain); +static ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain); int register_page_fault_notifier(struct notifier_block *nb) { return atomic_notifier_chain_register(¬ify_page_fault_chain, nb); @@ -137,7 +137,9 @@ static int __check_access_register(struct pt_regs *regs, int error_code) /* * Check which address space the address belongs to. - * Returns 1 for user space and 0 for kernel space. + * May return 1 or 2 for user space and 0 for kernel space. + * Returns 2 for user space in primary addressing mode with + * CONFIG_S390_EXEC_PROTECT on and kernel parameter noexec=on. */ static inline int check_user_space(struct pt_regs *regs, int error_code) { @@ -154,7 +156,7 @@ static inline int check_user_space(struct pt_regs *regs, int error_code) return __check_access_register(regs, error_code); if (descriptor == 2) return current->thread.mm_segment.ar4; - return descriptor != 0; + return ((descriptor != 0) ^ (switch_amode)) << s390_noexec; } /* @@ -183,6 +185,77 @@ static void do_sigsegv(struct pt_regs *regs, unsigned long error_code, force_sig_info(SIGSEGV, &si, current); } +#ifdef CONFIG_S390_EXEC_PROTECT +extern long sys_sigreturn(struct pt_regs *regs); +extern long sys_rt_sigreturn(struct pt_regs *regs); +extern long sys32_sigreturn(struct pt_regs *regs); +extern long sys32_rt_sigreturn(struct pt_regs *regs); + +static inline void do_sigreturn(struct mm_struct *mm, struct pt_regs *regs, + int rt) +{ + up_read(&mm->mmap_sem); + clear_tsk_thread_flag(current, TIF_SINGLE_STEP); +#ifdef CONFIG_COMPAT + if (test_tsk_thread_flag(current, TIF_31BIT)) { + if (rt) + sys32_rt_sigreturn(regs); + else + sys32_sigreturn(regs); + return; + } +#endif /* CONFIG_COMPAT */ + if (rt) + sys_rt_sigreturn(regs); + else + sys_sigreturn(regs); + return; +} + +static int signal_return(struct mm_struct *mm, struct pt_regs *regs, + unsigned long address, unsigned long error_code) +{ + pgd_t *pgd; + pmd_t *pmd; + pte_t *pte; + u16 *instruction; + unsigned long pfn, uaddr = regs->psw.addr; + + spin_lock(&mm->page_table_lock); + pgd = pgd_offset(mm, uaddr); + if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd))) + goto out_fault; + pmd = pmd_offset(pgd, uaddr); + if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd))) + goto out_fault; + pte = pte_offset_map(pmd_offset(pgd_offset(mm, uaddr), uaddr), uaddr); + if (!pte || !pte_present(*pte)) + goto out_fault; + pfn = pte_pfn(*pte); + if (!pfn_valid(pfn)) + goto out_fault; + spin_unlock(&mm->page_table_lock); + + instruction = (u16 *) ((pfn << PAGE_SHIFT) + (uaddr & (PAGE_SIZE-1))); + if (*instruction == 0x0a77) + do_sigreturn(mm, regs, 0); + else if (*instruction == 0x0aad) + do_sigreturn(mm, regs, 1); + else { + printk("- XXX - do_exception: task = %s, primary, NO EXEC " + "-> SIGSEGV\n", current->comm); + up_read(&mm->mmap_sem); + current->thread.prot_addr = address; + current->thread.trap_no = error_code; + do_sigsegv(regs, error_code, SEGV_MAPERR, address); + } + return 0; +out_fault: + spin_unlock(&mm->page_table_lock); + return -EFAULT; +} +#endif /* CONFIG_S390_EXEC_PROTECT */ + /* * This routine handles page faults. It determines the address, * and the problem, and then passes it off to one of the appropriate @@ -260,6 +333,17 @@ do_exception(struct pt_regs *regs, unsigned long error_code, int is_protection) vma = find_vma(mm, address); if (!vma) goto bad_area; + +#ifdef CONFIG_S390_EXEC_PROTECT + if (unlikely((user_address == 2) && !(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; +#endif + if (vma->vm_start <= address) goto good_area; if (!(vma->vm_flags & VM_GROWSDOWN)) @@ -452,8 +536,7 @@ void pfault_fini(void) : : "a" (&refbk), "m" (refbk) : "cc"); } -asmlinkage void -pfault_interrupt(__u16 error_code) +static void pfault_interrupt(__u16 error_code) { struct task_struct *tsk; __u16 subcode; |