diff options
Diffstat (limited to 'arch/um/sys-i386/signal.c')
-rw-r--r-- | arch/um/sys-i386/signal.c | 107 |
1 files changed, 69 insertions, 38 deletions
diff --git a/arch/um/sys-i386/signal.c b/arch/um/sys-i386/signal.c index 7cd1a82dc8c..f5d0e1c37ea 100644 --- a/arch/um/sys-i386/signal.c +++ b/arch/um/sys-i386/signal.c @@ -19,7 +19,7 @@ #include "skas.h" static int copy_sc_from_user_skas(struct pt_regs *regs, - struct sigcontext *from) + struct sigcontext __user *from) { struct sigcontext sc; unsigned long fpregs[HOST_FP_SIZE]; @@ -57,8 +57,8 @@ static int copy_sc_from_user_skas(struct pt_regs *regs, return(0); } -int copy_sc_to_user_skas(struct sigcontext *to, struct _fpstate *to_fp, - struct pt_regs *regs) +int copy_sc_to_user_skas(struct sigcontext *to, struct _fpstate __user *to_fp, + struct pt_regs *regs, unsigned long sp) { struct sigcontext sc; unsigned long fpregs[HOST_FP_SIZE]; @@ -72,7 +72,7 @@ int copy_sc_to_user_skas(struct sigcontext *to, struct _fpstate *to_fp, sc.edi = REGS_EDI(regs->regs.skas.regs); sc.esi = REGS_ESI(regs->regs.skas.regs); sc.ebp = REGS_EBP(regs->regs.skas.regs); - sc.esp = REGS_SP(regs->regs.skas.regs); + sc.esp = sp; sc.ebx = REGS_EBX(regs->regs.skas.regs); sc.edx = REGS_EDX(regs->regs.skas.regs); sc.ecx = REGS_ECX(regs->regs.skas.regs); @@ -92,7 +92,7 @@ int copy_sc_to_user_skas(struct sigcontext *to, struct _fpstate *to_fp, "errno = %d\n", err); return(1); } - to_fp = (to_fp ? to_fp : (struct _fpstate *) (to + 1)); + to_fp = (to_fp ? to_fp : (struct _fpstate __user *) (to + 1)); sc.fpstate = to_fp; if(err) @@ -113,10 +113,11 @@ int copy_sc_to_user_skas(struct sigcontext *to, struct _fpstate *to_fp, * saved pointer is in the kernel, but the sigcontext is in userspace, so we * copy_to_user it. */ -int copy_sc_from_user_tt(struct sigcontext *to, struct sigcontext *from, +int copy_sc_from_user_tt(struct sigcontext *to, struct sigcontext __user *from, int fpsize) { - struct _fpstate *to_fp, *from_fp; + struct _fpstate *to_fp; + struct _fpstate __user *from_fp; unsigned long sigs; int err; @@ -131,20 +132,28 @@ int copy_sc_from_user_tt(struct sigcontext *to, struct sigcontext *from, return(err); } -int copy_sc_to_user_tt(struct sigcontext *to, struct _fpstate *fp, - struct sigcontext *from, int fpsize) +int copy_sc_to_user_tt(struct sigcontext *to, struct _fpstate __user *fp, + struct sigcontext *from, int fpsize, unsigned long sp) { - struct _fpstate *to_fp, *from_fp; + struct _fpstate __user *to_fp; + struct _fpstate *from_fp; int err; - to_fp = (fp ? fp : (struct _fpstate *) (to + 1)); + to_fp = (fp ? fp : (struct _fpstate __user *) (to + 1)); from_fp = from->fpstate; err = copy_to_user(to, from, sizeof(*to)); + + /* The SP in the sigcontext is the updated one for the signal + * delivery. The sp passed in is the original, and this needs + * to be restored, so we stick it in separately. + */ + err |= copy_to_user(&SC_SP(to), sp, sizeof(sp)); + if(from_fp != NULL){ err |= copy_to_user(&to->fpstate, &to_fp, sizeof(to->fpstate)); err |= copy_to_user(to_fp, from_fp, fpsize); } - return(err); + return err; } #endif @@ -158,15 +167,15 @@ static int copy_sc_from_user(struct pt_regs *to, void __user *from) return(ret); } -static int copy_sc_to_user(struct sigcontext *to, struct _fpstate *fp, - struct pt_regs *from) +static int copy_sc_to_user(struct sigcontext *to, struct _fpstate __user *fp, + struct pt_regs *from, unsigned long sp) { return(CHOOSE_MODE(copy_sc_to_user_tt(to, fp, UPT_SC(&from->regs), - sizeof(*fp)), - copy_sc_to_user_skas(to, fp, from))); + sizeof(*fp), sp), + copy_sc_to_user_skas(to, fp, from, sp))); } -static int copy_ucontext_to_user(struct ucontext *uc, struct _fpstate *fp, +static int copy_ucontext_to_user(struct ucontext __user *uc, struct _fpstate __user *fp, sigset_t *set, unsigned long sp) { int err = 0; @@ -174,14 +183,14 @@ static int copy_ucontext_to_user(struct ucontext *uc, struct _fpstate *fp, err |= put_user(current->sas_ss_sp, &uc->uc_stack.ss_sp); err |= put_user(sas_ss_flags(sp), &uc->uc_stack.ss_flags); err |= put_user(current->sas_ss_size, &uc->uc_stack.ss_size); - err |= copy_sc_to_user(&uc->uc_mcontext, fp, ¤t->thread.regs); + err |= copy_sc_to_user(&uc->uc_mcontext, fp, ¤t->thread.regs, sp); err |= copy_to_user(&uc->uc_sigmask, set, sizeof(*set)); return(err); } struct sigframe { - char *pretcode; + char __user *pretcode; int sig; struct sigcontext sc; struct _fpstate fpstate; @@ -191,10 +200,10 @@ struct sigframe struct rt_sigframe { - char *pretcode; + char __user *pretcode; int sig; - struct siginfo *pinfo; - void *puc; + struct siginfo __user *pinfo; + void __user *puc; struct siginfo info; struct ucontext uc; struct _fpstate fpstate; @@ -206,21 +215,32 @@ int setup_signal_stack_sc(unsigned long stack_top, int sig, sigset_t *mask) { struct sigframe __user *frame; - void *restorer; + void __user *restorer; + unsigned long save_sp = PT_REGS_SP(regs); int err = 0; stack_top &= -8UL; - frame = (struct sigframe *) stack_top - 1; + frame = (struct sigframe __user *) stack_top - 1; if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) return 1; - restorer = (void *) frame->retcode; + restorer = frame->retcode; if(ka->sa.sa_flags & SA_RESTORER) restorer = ka->sa.sa_restorer; + /* Update SP now because the page fault handler refuses to extend + * the stack if the faulting address is too far below the current + * SP, which frame now certainly is. If there's an error, the original + * value is restored on the way out. + * When writing the sigcontext to the stack, we have to write the + * original value, so that's passed to copy_sc_to_user, which does + * the right thing with it. + */ + PT_REGS_SP(regs) = (unsigned long) frame; + err |= __put_user(restorer, &frame->pretcode); err |= __put_user(sig, &frame->sig); - err |= copy_sc_to_user(&frame->sc, NULL, regs); + err |= copy_sc_to_user(&frame->sc, NULL, regs, save_sp); err |= __put_user(mask->sig[0], &frame->sc.oldmask); if (_NSIG_WORDS > 1) err |= __copy_to_user(&frame->extramask, &mask->sig[1], @@ -238,7 +258,7 @@ int setup_signal_stack_sc(unsigned long stack_top, int sig, err |= __put_user(0x80cd, (short __user *)(frame->retcode+6)); if(err) - return(err); + goto err; PT_REGS_SP(regs) = (unsigned long) frame; PT_REGS_IP(regs) = (unsigned long) ka->sa.sa_handler; @@ -248,7 +268,11 @@ int setup_signal_stack_sc(unsigned long stack_top, int sig, if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED)) ptrace_notify(SIGTRAP); - return(0); + return 0; + +err: + PT_REGS_SP(regs) = save_sp; + return err; } int setup_signal_stack_si(unsigned long stack_top, int sig, @@ -256,25 +280,29 @@ int setup_signal_stack_si(unsigned long stack_top, int sig, siginfo_t *info, sigset_t *mask) { struct rt_sigframe __user *frame; - void *restorer; + void __user *restorer; + unsigned long save_sp = PT_REGS_SP(regs); int err = 0; stack_top &= -8UL; - frame = (struct rt_sigframe *) stack_top - 1; + frame = (struct rt_sigframe __user *) stack_top - 1; if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) return 1; - restorer = (void *) frame->retcode; + restorer = frame->retcode; if(ka->sa.sa_flags & SA_RESTORER) restorer = ka->sa.sa_restorer; + /* See comment above about why this is here */ + PT_REGS_SP(regs) = (unsigned long) frame; + err |= __put_user(restorer, &frame->pretcode); err |= __put_user(sig, &frame->sig); err |= __put_user(&frame->info, &frame->pinfo); err |= __put_user(&frame->uc, &frame->puc); err |= copy_siginfo_to_user(&frame->info, info); err |= copy_ucontext_to_user(&frame->uc, &frame->fpstate, mask, - PT_REGS_SP(regs)); + save_sp); /* * This is movl $,%eax ; int $0x80 @@ -288,9 +316,8 @@ int setup_signal_stack_si(unsigned long stack_top, int sig, err |= __put_user(0x80cd, (short __user *)(frame->retcode+5)); if(err) - return(err); + goto err; - PT_REGS_SP(regs) = (unsigned long) frame; PT_REGS_IP(regs) = (unsigned long) ka->sa.sa_handler; PT_REGS_EAX(regs) = (unsigned long) sig; PT_REGS_EDX(regs) = (unsigned long) &frame->info; @@ -298,13 +325,17 @@ int setup_signal_stack_si(unsigned long stack_top, int sig, if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED)) ptrace_notify(SIGTRAP); - return(0); + return 0; + +err: + PT_REGS_SP(regs) = save_sp; + return err; } long sys_sigreturn(struct pt_regs regs) { unsigned long sp = PT_REGS_SP(¤t->thread.regs); - struct sigframe __user *frame = (struct sigframe *)(sp - 8); + struct sigframe __user *frame = (struct sigframe __user *)(sp - 8); sigset_t set; struct sigcontext __user *sc = &frame->sc; unsigned long __user *oldmask = &sc->oldmask; @@ -336,8 +367,8 @@ long sys_sigreturn(struct pt_regs regs) long sys_rt_sigreturn(struct pt_regs regs) { - unsigned long __user sp = PT_REGS_SP(¤t->thread.regs); - struct rt_sigframe __user *frame = (struct rt_sigframe *) (sp - 4); + unsigned long sp = PT_REGS_SP(¤t->thread.regs); + struct rt_sigframe __user *frame = (struct rt_sigframe __user *) (sp - 4); sigset_t set; struct ucontext __user *uc = &frame->uc; int sig_size = _NSIG_WORDS * sizeof(unsigned long); |