--- /dev/null
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for
+ * more details.
+ */
+
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/kernel.h>
+#include <linux/signal.h>
+#include <linux/errno.h>
+#include <linux/wait.h>
+#include <linux/unistd.h>
+#include <linux/stddef.h>
+#include <linux/personality.h>
+#include <linux/suspend.h>
+#include <linux/ptrace.h>
+#include <linux/elf.h>
+#include <linux/compat.h>
+#include <linux/syscalls.h>
+#include <linux/uaccess.h>
+#include <asm/processor.h>
+#include <asm/ucontext.h>
+#include <asm/sigframe.h>
+#include <asm/syscalls.h>
+#include <asm/vdso.h>
+#include <arch/interrupts.h>
+
+struct compat_ucontext {
+ compat_ulong_t uc_flags;
+ compat_uptr_t uc_link;
+ struct compat_sigaltstack uc_stack;
+ struct sigcontext uc_mcontext;
+ sigset_t uc_sigmask; /* mask last for extensibility */
+};
+
+struct compat_rt_sigframe {
+ unsigned char save_area[C_ABI_SAVE_AREA_SIZE]; /* caller save area */
+ struct compat_siginfo info;
+ struct compat_ucontext uc;
+};
+
+int copy_siginfo_to_user32(struct compat_siginfo __user *to, const siginfo_t *from)
+{
+ int err;
+
+ if (!access_ok(VERIFY_WRITE, to, sizeof(struct compat_siginfo)))
+ return -EFAULT;
+
+ /* If you change siginfo_t structure, please make sure that
+ this code is fixed accordingly.
+ It should never copy any pad contained in the structure
+ to avoid security leaks, but must copy the generic
+ 3 ints plus the relevant union member. */
+ err = __put_user(from->si_signo, &to->si_signo);
+ err |= __put_user(from->si_errno, &to->si_errno);
+ err |= __put_user((short)from->si_code, &to->si_code);
+
+ if (from->si_code < 0) {
+ err |= __put_user(from->si_pid, &to->si_pid);
+ err |= __put_user(from->si_uid, &to->si_uid);
+ err |= __put_user(from->si_int, &to->si_int);
+ } else {
+ /*
+ * First 32bits of unions are always present:
+ * si_pid === si_band === si_tid === si_addr(LS half)
+ */
+ err |= __put_user(from->_sifields._pad[0],
+ &to->_sifields._pad[0]);
+ switch (from->si_code >> 16) {
+ case __SI_FAULT >> 16:
+ break;
+ case __SI_CHLD >> 16:
+ err |= __put_user(from->si_utime, &to->si_utime);
+ err |= __put_user(from->si_stime, &to->si_stime);
+ err |= __put_user(from->si_status, &to->si_status);
+ /* FALL THROUGH */
+ default:
+ case __SI_KILL >> 16:
+ err |= __put_user(from->si_uid, &to->si_uid);
+ break;
+ case __SI_POLL >> 16:
+ err |= __put_user(from->si_fd, &to->si_fd);
+ break;
+ case __SI_TIMER >> 16:
+ err |= __put_user(from->si_overrun, &to->si_overrun);
+ err |= __put_user(from->si_int, &to->si_int);
+ break;
+ /* This is not generated by the kernel as of now. */
+ case __SI_RT >> 16:
+ case __SI_MESGQ >> 16:
+ err |= __put_user(from->si_uid, &to->si_uid);
+ err |= __put_user(from->si_int, &to->si_int);
+ break;
+ }
+ }
+ return err;
+}
+
+int copy_siginfo_from_user32(siginfo_t *to, struct compat_siginfo __user *from)
+{
+ int err;
+
+ if (!access_ok(VERIFY_READ, from, sizeof(struct compat_siginfo)))
+ return -EFAULT;
+
+ memset(to, 0, sizeof(*to));
+
+ err = __get_user(to->si_signo, &from->si_signo);
+ err |= __get_user(to->si_errno, &from->si_errno);
+ err |= __get_user(to->si_code, &from->si_code);
+
+ err |= __get_user(to->si_pid, &from->si_pid);
+ err |= __get_user(to->si_uid, &from->si_uid);
+ err |= __get_user(to->si_int, &from->si_int);
+
+ return err;
+}
+
+/* The assembly shim for this function arranges to ignore the return value. */
+long compat_sys_rt_sigreturn(void)
+{
+ struct pt_regs *regs = current_pt_regs();
+ struct compat_rt_sigframe __user *frame =
+ (struct compat_rt_sigframe __user *) compat_ptr(regs->sp);
+ sigset_t set;
+
+ if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
+ goto badframe;
+ if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
+ goto badframe;
+
+ set_current_blocked(&set);
+
+ if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
+ goto badframe;
+
+ if (compat_restore_altstack(&frame->uc.uc_stack))
+ goto badframe;
+
+ return 0;
+
+badframe:
+ signal_fault("bad sigreturn frame", regs, frame, 0);
+ return 0;
+}
+
+/*
+ * Determine which stack to use..
+ */
+static inline void __user *compat_get_sigframe(struct k_sigaction *ka,
+ struct pt_regs *regs,
+ size_t frame_size)
+{
+ unsigned long sp;
+
+ /* Default to using normal stack */
+ sp = (unsigned long)compat_ptr(regs->sp);
+
+ /*
+ * 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.
+ */
+ if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size)))
+ return (void __user __force *)-1UL;
+
+ /* 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;
+ }
+
+ sp -= frame_size;
+ /*
+ * Align the stack pointer according to the TILE ABI,
+ * i.e. so that on function entry (sp & 15) == 0.
+ */
+ sp &= -16UL;
+ return (void __user *) sp;
+}
+
+int compat_setup_rt_frame(struct ksignal *ksig, sigset_t *set,
+ struct pt_regs *regs)
+{
+ unsigned long restorer;
+ struct compat_rt_sigframe __user *frame;
+ int err = 0, sig = ksig->sig;
+
+ frame = compat_get_sigframe(&ksig->ka, regs, sizeof(*frame));
+
+ if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
+ goto err;
+
+ /* Always write at least the signal number for the stack backtracer. */
+ if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
+ /* At sigreturn time, restore the callee-save registers too. */
+ err |= copy_siginfo_to_user32(&frame->info, &ksig->info);
+ regs->flags |= PT_FLAGS_RESTORE_REGS;
+ } else {
+ err |= __put_user(ksig->info.si_signo, &frame->info.si_signo);
+ }
+
+ /* Create the ucontext. */
+ err |= __clear_user(&frame->save_area, sizeof(frame->save_area));
+ err |= __put_user(0, &frame->uc.uc_flags);
+ err |= __put_user(0, &frame->uc.uc_link);
+ err |= __compat_save_altstack(&frame->uc.uc_stack, regs->sp);
+ err |= setup_sigcontext(&frame->uc.uc_mcontext, regs);
+ err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
+ if (err)
+ goto err;
+
+ restorer = VDSO_SYM(&__vdso_rt_sigreturn);
+ if (ksig->ka.sa.sa_flags & SA_RESTORER)
+ restorer = ptr_to_compat_reg(ksig->ka.sa.sa_restorer);
+
+ /*
+ * Set up registers for signal handler.
+ * Registers that we don't modify keep the value they had from
+ * user-space at the time we took the signal.
+ * We always pass siginfo and mcontext, regardless of SA_SIGINFO,
+ * since some things rely on this (e.g. glibc's debug/segfault.c).
+ */
+ regs->pc = ptr_to_compat_reg(ksig->ka.sa.sa_handler);
+ regs->ex1 = PL_ICS_EX1(USER_PL, 1); /* set crit sec in handler */
+ regs->sp = ptr_to_compat_reg(frame);
+ regs->lr = restorer;
+ regs->regs[0] = (unsigned long) sig;
+ regs->regs[1] = ptr_to_compat_reg(&frame->info);
+ regs->regs[2] = ptr_to_compat_reg(&frame->uc);
+ regs->flags |= PT_FLAGS_CALLER_SAVES;
+ return 0;
+
+err:
+ trace_unhandled_signal("bad sigreturn frame", regs,
+ (unsigned long)frame, SIGSEGV);
+ return -EFAULT;
+}
Code Review / kvmfornfv.git / blobdiff