From 92ff0674f5d8013704cbaeaceb8e3576b36754ee Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Tue, 20 Feb 2018 14:53:22 +0000 Subject: arm64: mm: Rework unhandled user pagefaults to call arm64_force_sig_info Reporting unhandled user pagefaults via arm64_force_sig_info means that __do_user_fault can be drastically simplified, since it no longer has to worry about printing the fault information and can consequently just take the siginfo as a parameter. Signed-off-by: Will Deacon --- arch/arm64/mm/fault.c | 87 +++++++++++++++++++++------------------------------ 1 file changed, 36 insertions(+), 51 deletions(-) (limited to 'arch/arm64/mm') diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index fd5928afd9cd..49dfb08a6c4d 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -43,6 +43,7 @@ #include #include #include +#include #include @@ -289,58 +290,31 @@ static void __do_kernel_fault(unsigned long addr, unsigned int esr, do_exit(SIGKILL); } -static void __do_user_fault(struct task_struct *tsk, unsigned long addr, - unsigned int esr, unsigned int sig, int code, - struct pt_regs *regs, int fault) +static void __do_user_fault(struct siginfo *info, unsigned int esr) { - struct siginfo si; - const struct fault_info *inf; - unsigned int lsb = 0; - - if (unhandled_signal(tsk, sig) && show_unhandled_signals_ratelimited()) { - inf = esr_to_fault_info(esr); - pr_info("%s[%d]: unhandled %s (%d) at 0x%08lx, esr 0x%03x", - tsk->comm, task_pid_nr(tsk), inf->name, sig, - addr, esr); - print_vma_addr(KERN_CONT ", in ", regs->pc); - pr_cont("\n"); - __show_regs(regs); - } - - tsk->thread.fault_address = addr; - tsk->thread.fault_code = esr; - si.si_signo = sig; - si.si_errno = 0; - si.si_code = code; - si.si_addr = (void __user *)addr; - /* - * Either small page or large page may be poisoned. - * In other words, VM_FAULT_HWPOISON_LARGE and - * VM_FAULT_HWPOISON are mutually exclusive. - */ - if (fault & VM_FAULT_HWPOISON_LARGE) - lsb = hstate_index_to_shift(VM_FAULT_GET_HINDEX(fault)); - else if (fault & VM_FAULT_HWPOISON) - lsb = PAGE_SHIFT; - si.si_addr_lsb = lsb; - - force_sig_info(sig, &si, tsk); + current->thread.fault_address = (unsigned long)info->si_addr; + current->thread.fault_code = esr; + arm64_force_sig_info(info, esr_to_fault_info(esr)->name, current); } static void do_bad_area(unsigned long addr, unsigned int esr, struct pt_regs *regs) { - struct task_struct *tsk = current; - const struct fault_info *inf; - /* * If we are in kernel mode at this point, we have no context to * handle this fault with. */ if (user_mode(regs)) { - inf = esr_to_fault_info(esr); - __do_user_fault(tsk, addr, esr, inf->sig, inf->code, regs, 0); - } else + const struct fault_info *inf = esr_to_fault_info(esr); + struct siginfo si = { + .si_signo = inf->sig, + .si_code = inf->code, + .si_addr = (void __user *)addr, + }; + + __do_user_fault(&si, esr); + } else { __do_kernel_fault(addr, esr, regs); + } } #define VM_FAULT_BADMAP 0x010000 @@ -393,7 +367,8 @@ static int __kprobes do_page_fault(unsigned long addr, unsigned int esr, { struct task_struct *tsk; struct mm_struct *mm; - int fault, sig, code, major = 0; + struct siginfo si; + int fault, major = 0; unsigned long vm_flags = VM_READ | VM_WRITE; unsigned int mm_flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE; @@ -525,27 +500,37 @@ retry: return 0; } + clear_siginfo(&si); + si.si_addr = (void __user *)addr; + if (fault & VM_FAULT_SIGBUS) { /* * We had some memory, but were unable to successfully fix up * this page fault. */ - sig = SIGBUS; - code = BUS_ADRERR; - } else if (fault & (VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE)) { - sig = SIGBUS; - code = BUS_MCEERR_AR; + si.si_signo = SIGBUS; + si.si_code = BUS_ADRERR; + } else if (fault & VM_FAULT_HWPOISON_LARGE) { + unsigned int hindex = VM_FAULT_GET_HINDEX(fault); + + si.si_signo = SIGBUS; + si.si_code = BUS_MCEERR_AR; + si.si_addr_lsb = hstate_index_to_shift(hindex); + } else if (fault & VM_FAULT_HWPOISON) { + si.si_signo = SIGBUS; + si.si_code = BUS_MCEERR_AR; + si.si_addr_lsb = PAGE_SHIFT; } else { /* * Something tried to access memory that isn't in our memory * map. */ - sig = SIGSEGV; - code = fault == VM_FAULT_BADACCESS ? - SEGV_ACCERR : SEGV_MAPERR; + si.si_signo = SIGSEGV; + si.si_code = fault == VM_FAULT_BADACCESS ? + SEGV_ACCERR : SEGV_MAPERR; } - __do_user_fault(tsk, addr, esr, sig, code, regs, fault); + __do_user_fault(&si, esr); return 0; no_context: -- cgit v1.2.3-59-g8ed1b