diff options
Diffstat (limited to 'arch/um/sys-i386')
| -rw-r--r-- | arch/um/sys-i386/signal.c | 59 |
1 files changed, 44 insertions, 15 deletions
diff --git a/arch/um/sys-i386/signal.c b/arch/um/sys-i386/signal.c index 7cd1a82..33a40f5 100644 --- a/arch/um/sys-i386/signal.c +++ b/arch/um/sys-i386/signal.c @@ -58,7 +58,7 @@ static int copy_sc_from_user_skas(struct pt_regs *regs, } int copy_sc_to_user_skas(struct sigcontext *to, struct _fpstate *to_fp, - struct pt_regs *regs) + 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); @@ -132,7 +132,7 @@ int copy_sc_from_user_tt(struct sigcontext *to, struct sigcontext *from, } int copy_sc_to_user_tt(struct sigcontext *to, struct _fpstate *fp, - struct sigcontext *from, int fpsize) + struct sigcontext *from, int fpsize, unsigned long sp) { struct _fpstate *to_fp, *from_fp; int err; @@ -140,11 +140,18 @@ int copy_sc_to_user_tt(struct sigcontext *to, struct _fpstate *fp, to_fp = (fp ? fp : (struct _fpstate *) (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 @@ -159,11 +166,11 @@ static int copy_sc_from_user(struct pt_regs *to, void __user *from) } static int copy_sc_to_user(struct sigcontext *to, struct _fpstate *fp, - struct pt_regs *from) + 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, @@ -174,7 +181,7 @@ 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); } @@ -207,6 +214,7 @@ int setup_signal_stack_sc(unsigned long stack_top, int sig, { struct sigframe __user *frame; void *restorer; + unsigned long save_sp = PT_REGS_SP(regs); int err = 0; stack_top &= -8UL; @@ -218,9 +226,19 @@ int setup_signal_stack_sc(unsigned long stack_top, int sig, 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 +256,7 @@ 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 +266,11 @@ 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, @@ -257,6 +279,7 @@ int setup_signal_stack_si(unsigned long stack_top, int sig, { struct rt_sigframe __user *frame; void *restorer; + unsigned long save_sp = PT_REGS_SP(regs); int err = 0; stack_top &= -8UL; @@ -268,13 +291,16 @@ int setup_signal_stack_si(unsigned long stack_top, int sig, 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 +314,8 @@ 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; @@ -298,7 +323,11 @@ 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) |