diff options
Diffstat (limited to 'arch/um/sys-x86_64/signal.c')
| -rw-r--r-- | arch/um/sys-x86_64/signal.c | 56 |
1 files changed, 41 insertions, 15 deletions
diff --git a/arch/um/sys-x86_64/signal.c b/arch/um/sys-x86_64/signal.c index fe1d065332b..e75c4e1838b 100644 --- a/arch/um/sys-x86_64/signal.c +++ b/arch/um/sys-x86_64/signal.c @@ -55,7 +55,8 @@ 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, unsigned long mask) + struct pt_regs *regs, unsigned long mask, + unsigned long sp) { struct faultinfo * fi = ¤t->thread.arch.faultinfo; int err = 0; @@ -70,7 +71,11 @@ int copy_sc_to_user_skas(struct sigcontext *to, struct _fpstate *to_fp, err |= PUTREG(regs, RDI, to, rdi); err |= PUTREG(regs, RSI, to, rsi); err |= PUTREG(regs, RBP, to, rbp); - err |= PUTREG(regs, RSP, to, rsp); + /* Must use orignal RSP, which is passed in, rather than what's in + * the pt_regs, because that's already been updated to point at the + * signal frame. + */ + err |= __put_user(sp, &to->rsp); err |= PUTREG(regs, RBX, to, rbx); err |= PUTREG(regs, RDX, to, rdx); err |= PUTREG(regs, RCX, to, rcx); @@ -102,7 +107,7 @@ int copy_sc_to_user_skas(struct sigcontext *to, struct _fpstate *to_fp, #ifdef CONFIG_MODE_TT int copy_sc_from_user_tt(struct sigcontext *to, struct sigcontext *from, - int fpsize) + int fpsize) { struct _fpstate *to_fp, *from_fp; unsigned long sigs; @@ -120,7 +125,7 @@ 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; @@ -128,11 +133,17 @@ 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 @@ -148,11 +159,12 @@ 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, unsigned long mask) + struct pt_regs *from, unsigned long mask, + 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, mask))); + sizeof(*fp), sp), + copy_sc_to_user_skas(to, fp, from, mask, sp))); } struct rt_sigframe @@ -170,6 +182,7 @@ int setup_signal_stack_si(unsigned long stack_top, int sig, { struct rt_sigframe __user *frame; struct _fpstate __user *fp = NULL; + unsigned long save_sp = PT_REGS_RSP(regs); int err = 0; struct task_struct *me = current; @@ -193,14 +206,25 @@ int setup_signal_stack_si(unsigned long stack_top, int sig, goto out; } + /* 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_RSP(regs) = (unsigned long) frame; + /* Create the ucontext. */ err |= __put_user(0, &frame->uc.uc_flags); err |= __put_user(0, &frame->uc.uc_link); err |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp); - err |= __put_user(sas_ss_flags(PT_REGS_SP(regs)), + err |= __put_user(sas_ss_flags(save_sp), &frame->uc.uc_stack.ss_flags); err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size); - err |= copy_sc_to_user(&frame->uc.uc_mcontext, fp, regs, set->sig[0]); + err |= copy_sc_to_user(&frame->uc.uc_mcontext, fp, regs, set->sig[0], + save_sp); err |= __put_user(fp, &frame->uc.uc_mcontext.fpstate); if (sizeof(*set) == 16) { __put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]); @@ -217,10 +241,10 @@ int setup_signal_stack_si(unsigned long stack_top, int sig, err |= __put_user(ka->sa.sa_restorer, &frame->pretcode); else /* could use a vstub here */ - goto out; + goto restore_sp; if (err) - goto out; + goto restore_sp; /* Set up registers for signal handler */ { @@ -238,10 +262,12 @@ int setup_signal_stack_si(unsigned long stack_top, int sig, PT_REGS_RSI(regs) = (unsigned long) &frame->info; PT_REGS_RDX(regs) = (unsigned long) &frame->uc; PT_REGS_RIP(regs) = (unsigned long) ka->sa.sa_handler; - - PT_REGS_RSP(regs) = (unsigned long) frame; out: - return(err); + return err; + +restore_sp: + PT_REGS_RSP(regs) = save_sp; + return err; } long sys_rt_sigreturn(struct pt_regs *regs) |