return err;
}
+/*
+ * Set up a signal frame.
+ */
#ifdef CONFIG_X86_32
-asmlinkage int sys_sigaltstack(unsigned long bx)
+static const struct {
+ u16 poplmovl;
+ u32 val;
+ u16 int80;
+} __attribute__((packed)) retcode = {
+ 0xb858, /* popl %eax; movl $..., %eax */
+ __NR_sigreturn,
+ 0x80cd, /* int $0x80 */
+};
+
+static const struct {
+ u8 movl;
+ u32 val;
+ u16 int80;
+ u8 pad;
+} __attribute__((packed)) rt_retcode = {
+ 0xb8, /* movl $..., %eax */
+ __NR_rt_sigreturn,
+ 0x80cd, /* int $0x80 */
+ 0
+};
+
+/*
+ * Determine which stack to use..
+ */
+static inline void __user *
+get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
+ void **fpstate)
{
+ unsigned long sp;
+
+ /* Default to using normal stack */
+ sp = regs->sp;
+
/*
- * This is needed to make gcc realize it doesn't own the
- * "struct pt_regs"
+ * If we are on the alternate signal stack and would overflow it, don't.
+ * Return an always-bogus address instead so we will die with SIGSEGV.
*/
- struct pt_regs *regs = (struct pt_regs *)&bx;
- const stack_t __user *uss = (const stack_t __user *)bx;
- stack_t __user *uoss = (stack_t __user *)regs->cx;
+ if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size)))
+ return (void __user *) -1L;
- return do_sigaltstack(uss, uoss, regs->sp);
-}
-#else /* !CONFIG_X86_32 */
-asmlinkage long
-sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
- struct pt_regs *regs)
-{
- return do_sigaltstack(uss, uoss, regs->sp);
+ /* This is the X/Open sanctioned signal stack switching. */
+ if (ka->sa.sa_flags & SA_ONSTACK) {
+ if (sas_ss_flags(sp) == 0)
+ sp = current->sas_ss_sp + current->sas_ss_size;
+ } else {
+ /* This is the legacy signal stack switching. */
+ if ((regs->ss & 0xffff) != __USER_DS &&
+ !(ka->sa.sa_flags & SA_RESTORER) &&
+ ka->sa.sa_restorer)
+ sp = (unsigned long) ka->sa.sa_restorer;
+ }
+
+ if (used_math()) {
+ sp = sp - sig_xstate_size;
+ *fpstate = (struct _fpstate *) sp;
+ if (save_i387_xstate(*fpstate) < 0)
+ return (void __user *)-1L;
+ }
+
+ sp -= frame_size;
+ /*
+ * Align the stack pointer according to the i386 ABI,
+ * i.e. so that on function entry ((sp + 4) & 15) == 0.
+ */
+ sp = ((sp + 4) & -16ul) - 4;
+
+ return (void __user *) sp;
}
-#endif /* CONFIG_X86_32 */
-/*
- * Do a signal return; undo the signal stack.
- */
-static long do_rt_sigreturn(struct pt_regs *regs)
+static int
+__setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
+ struct pt_regs *regs)
{
- struct rt_sigframe __user *frame;
- unsigned long ax;
- sigset_t set;
+ struct sigframe __user *frame;
+ void __user *restorer;
+ int err = 0;
+ void __user *fpstate = NULL;
- frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));
- if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
- goto badframe;
- if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
- goto badframe;
+ frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
- sigdelsetmask(&set, ~_BLOCKABLE);
- spin_lock_irq(¤t->sighand->siglock);
- current->blocked = set;
- recalc_sigpending();
- spin_unlock_irq(¤t->sighand->siglock);
+ if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+ return -EFAULT;
- if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
- goto badframe;
+ if (__put_user(sig, &frame->sig))
+ return -EFAULT;
- if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT)
- goto badframe;
+ if (setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))
+ return -EFAULT;
- return ax;
+ if (_NSIG_WORDS > 1) {
+ if (__copy_to_user(&frame->extramask, &set->sig[1],
+ sizeof(frame->extramask)))
+ return -EFAULT;
+ }
+
+ if (current->mm->context.vdso)
+ restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn);
+ else
+ restorer = &frame->retcode;
+ if (ka->sa.sa_flags & SA_RESTORER)
+ restorer = ka->sa.sa_restorer;
+
+ /* Set up to return from userspace. */
+ err |= __put_user(restorer, &frame->pretcode);
+
+ /*
+ * This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80
+ *
+ * WE DO NOT USE IT ANY MORE! It's only left here for historical
+ * reasons and because gdb uses it as a signature to notice
+ * signal handler stack frames.
+ */
+ err |= __put_user(*((u64 *)&retcode), (u64 *)frame->retcode);
+
+ if (err)
+ return -EFAULT;
+
+ /* Set up registers for signal handler */
+ regs->sp = (unsigned long)frame;
+ regs->ip = (unsigned long)ka->sa.sa_handler;
+ regs->ax = (unsigned long)sig;
+ regs->dx = 0;
+ regs->cx = 0;
+
+ regs->ds = __USER_DS;
+ regs->es = __USER_DS;
+ regs->ss = __USER_DS;
+ regs->cs = __USER_CS;
-badframe:
- signal_fault(regs, frame, "rt_sigreturn");
return 0;
}
-#ifdef CONFIG_X86_32
-asmlinkage int sys_rt_sigreturn(unsigned long __unused)
+static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
+ sigset_t *set, struct pt_regs *regs)
{
- struct pt_regs *regs = (struct pt_regs *)&__unused;
+ struct rt_sigframe __user *frame;
+ void __user *restorer;
+ int err = 0;
+ void __user *fpstate = NULL;
- return do_rt_sigreturn(regs);
-}
-#else /* !CONFIG_X86_32 */
-asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
-{
- return do_rt_sigreturn(regs);
-}
-#endif /* CONFIG_X86_32 */
+ frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
-/*
- * Set up a signal frame.
- */
+ if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+ return -EFAULT;
+
+ 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);
+ if (err)
+ return -EFAULT;
+
+ /* Create the ucontext. */
+ if (cpu_has_xsave)
+ err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags);
+ else
+ err |= __put_user(0, &frame->uc.uc_flags);
+ err |= __put_user(0, &frame->uc.uc_link);
+ err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
+ err |= __put_user(sas_ss_flags(regs->sp),
+ &frame->uc.uc_stack.ss_flags);
+ err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
+ err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
+ regs, set->sig[0]);
+ err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+ if (err)
+ return -EFAULT;
+
+ /* Set up to return from userspace. */
+ restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn);
+ if (ka->sa.sa_flags & SA_RESTORER)
+ restorer = ka->sa.sa_restorer;
+ err |= __put_user(restorer, &frame->pretcode);
+
+ /*
+ * This is movl $__NR_rt_sigreturn, %ax ; int $0x80
+ *
+ * WE DO NOT USE IT ANY MORE! It's only left here for historical
+ * reasons and because gdb uses it as a signature to notice
+ * signal handler stack frames.
+ */
+ err |= __put_user(*((u64 *)&rt_retcode), (u64 *)frame->retcode);
+ if (err)
+ return -EFAULT;
+
+ /* Set up registers for signal handler */
+ regs->sp = (unsigned long)frame;
+ regs->ip = (unsigned long)ka->sa.sa_handler;
+ regs->ax = (unsigned long)sig;
+ regs->dx = (unsigned long)&frame->info;
+ regs->cx = (unsigned long)&frame->uc;
+
+ regs->ds = __USER_DS;
+ regs->es = __USER_DS;
+ regs->ss = __USER_DS;
+ regs->cs = __USER_CS;
+
+ return 0;
+}
+#else /* !CONFIG_X86_32 */
/*
* Determine which stack to use..
*/
return 0;
}
+#endif /* CONFIG_X86_32 */
+
+#ifdef CONFIG_X86_32
+asmlinkage int sys_sigaltstack(unsigned long bx)
+{
+ /*
+ * This is needed to make gcc realize it doesn't own the
+ * "struct pt_regs"
+ */
+ struct pt_regs *regs = (struct pt_regs *)&bx;
+ const stack_t __user *uss = (const stack_t __user *)bx;
+ stack_t __user *uoss = (stack_t __user *)regs->cx;
+
+ return do_sigaltstack(uss, uoss, regs->sp);
+}
+#else /* !CONFIG_X86_32 */
+asmlinkage long
+sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
+ struct pt_regs *regs)
+{
+ return do_sigaltstack(uss, uoss, regs->sp);
+}
+#endif /* CONFIG_X86_32 */
+
+/*
+ * Do a signal return; undo the signal stack.
+ */
+static long do_rt_sigreturn(struct pt_regs *regs)
+{
+ struct rt_sigframe __user *frame;
+ unsigned long ax;
+ sigset_t set;
+
+ frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));
+ if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+ goto badframe;
+ if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
+ goto badframe;
+
+ sigdelsetmask(&set, ~_BLOCKABLE);
+ spin_lock_irq(¤t->sighand->siglock);
+ current->blocked = set;
+ recalc_sigpending();
+ spin_unlock_irq(¤t->sighand->siglock);
+
+ if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
+ goto badframe;
+
+ if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT)
+ goto badframe;
+
+ return ax;
+
+badframe:
+ signal_fault(regs, frame, "rt_sigreturn");
+ return 0;
+}
+
+#ifdef CONFIG_X86_32
+asmlinkage int sys_rt_sigreturn(unsigned long __unused)
+{
+ struct pt_regs *regs = (struct pt_regs *)&__unused;
+
+ return do_rt_sigreturn(regs);
+}
+#else /* !CONFIG_X86_32 */
+asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
+{
+ return do_rt_sigreturn(regs);
+}
+#endif /* CONFIG_X86_32 */
/*
* OK, we're invoking a handler
git.samba.org / sfrench / cifs-2.6.git / blobdiff