429 lines
12 KiB
C
429 lines
12 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright IBM Corp. 2000, 2006
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* Author(s): Denis Joseph Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
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* Gerhard Tonn (ton@de.ibm.com)
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*
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* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
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*/
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#include <linux/compat.h>
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#include <linux/sched.h>
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#include <linux/sched/task_stack.h>
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#include <linux/mm.h>
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#include <linux/smp.h>
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#include <linux/kernel.h>
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#include <linux/signal.h>
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#include <linux/errno.h>
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#include <linux/wait.h>
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#include <linux/ptrace.h>
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#include <linux/unistd.h>
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#include <linux/stddef.h>
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#include <linux/tty.h>
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#include <linux/personality.h>
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#include <linux/binfmts.h>
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#include <asm/ucontext.h>
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#include <linux/uaccess.h>
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#include <asm/lowcore.h>
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#include <asm/switch_to.h>
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#include "compat_linux.h"
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#include "compat_ptrace.h"
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#include "entry.h"
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typedef struct
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{
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__u8 callee_used_stack[__SIGNAL_FRAMESIZE32];
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struct sigcontext32 sc;
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_sigregs32 sregs;
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int signo;
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_sigregs_ext32 sregs_ext;
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__u16 svc_insn; /* Offset of svc_insn is NOT fixed! */
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} sigframe32;
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typedef struct
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{
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__u8 callee_used_stack[__SIGNAL_FRAMESIZE32];
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__u16 svc_insn;
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compat_siginfo_t info;
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struct ucontext32 uc;
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} rt_sigframe32;
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/* Store registers needed to create the signal frame */
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static void store_sigregs(void)
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{
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save_access_regs(current->thread.acrs);
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save_fpu_regs();
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}
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/* Load registers after signal return */
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static void load_sigregs(void)
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{
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restore_access_regs(current->thread.acrs);
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}
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static int save_sigregs32(struct pt_regs *regs, _sigregs32 __user *sregs)
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{
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_sigregs32 user_sregs;
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int i;
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user_sregs.regs.psw.mask = (__u32)(regs->psw.mask >> 32);
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user_sregs.regs.psw.mask &= PSW32_MASK_USER | PSW32_MASK_RI;
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user_sregs.regs.psw.mask |= PSW32_USER_BITS;
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user_sregs.regs.psw.addr = (__u32) regs->psw.addr |
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(__u32)(regs->psw.mask & PSW_MASK_BA);
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for (i = 0; i < NUM_GPRS; i++)
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user_sregs.regs.gprs[i] = (__u32) regs->gprs[i];
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memcpy(&user_sregs.regs.acrs, current->thread.acrs,
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sizeof(user_sregs.regs.acrs));
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fpregs_store((_s390_fp_regs *) &user_sregs.fpregs, ¤t->thread.fpu);
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if (__copy_to_user(sregs, &user_sregs, sizeof(_sigregs32)))
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return -EFAULT;
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return 0;
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}
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static int restore_sigregs32(struct pt_regs *regs,_sigregs32 __user *sregs)
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{
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_sigregs32 user_sregs;
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int i;
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/* Alwys make any pending restarted system call return -EINTR */
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current->restart_block.fn = do_no_restart_syscall;
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if (__copy_from_user(&user_sregs, &sregs->regs, sizeof(user_sregs)))
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return -EFAULT;
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if (!is_ri_task(current) && (user_sregs.regs.psw.mask & PSW32_MASK_RI))
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return -EINVAL;
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/* Test the floating-point-control word. */
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if (test_fp_ctl(user_sregs.fpregs.fpc))
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return -EINVAL;
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/* Use regs->psw.mask instead of PSW_USER_BITS to preserve PER bit. */
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regs->psw.mask = (regs->psw.mask & ~(PSW_MASK_USER | PSW_MASK_RI)) |
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(__u64)(user_sregs.regs.psw.mask & PSW32_MASK_USER) << 32 |
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(__u64)(user_sregs.regs.psw.mask & PSW32_MASK_RI) << 32 |
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(__u64)(user_sregs.regs.psw.addr & PSW32_ADDR_AMODE);
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/* Check for invalid user address space control. */
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if ((regs->psw.mask & PSW_MASK_ASC) == PSW_ASC_HOME)
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regs->psw.mask = PSW_ASC_PRIMARY |
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(regs->psw.mask & ~PSW_MASK_ASC);
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regs->psw.addr = (__u64)(user_sregs.regs.psw.addr & PSW32_ADDR_INSN);
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for (i = 0; i < NUM_GPRS; i++)
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regs->gprs[i] = (__u64) user_sregs.regs.gprs[i];
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memcpy(¤t->thread.acrs, &user_sregs.regs.acrs,
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sizeof(current->thread.acrs));
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fpregs_load((_s390_fp_regs *) &user_sregs.fpregs, ¤t->thread.fpu);
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clear_pt_regs_flag(regs, PIF_SYSCALL); /* No longer in a system call */
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return 0;
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}
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static int save_sigregs_ext32(struct pt_regs *regs,
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_sigregs_ext32 __user *sregs_ext)
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{
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__u32 gprs_high[NUM_GPRS];
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__u64 vxrs[__NUM_VXRS_LOW];
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int i;
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/* Save high gprs to signal stack */
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for (i = 0; i < NUM_GPRS; i++)
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gprs_high[i] = regs->gprs[i] >> 32;
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if (__copy_to_user(&sregs_ext->gprs_high, &gprs_high,
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sizeof(sregs_ext->gprs_high)))
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return -EFAULT;
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/* Save vector registers to signal stack */
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if (MACHINE_HAS_VX) {
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for (i = 0; i < __NUM_VXRS_LOW; i++)
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vxrs[i] = *((__u64 *)(current->thread.fpu.vxrs + i) + 1);
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if (__copy_to_user(&sregs_ext->vxrs_low, vxrs,
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sizeof(sregs_ext->vxrs_low)) ||
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__copy_to_user(&sregs_ext->vxrs_high,
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current->thread.fpu.vxrs + __NUM_VXRS_LOW,
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sizeof(sregs_ext->vxrs_high)))
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return -EFAULT;
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}
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return 0;
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}
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static int restore_sigregs_ext32(struct pt_regs *regs,
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_sigregs_ext32 __user *sregs_ext)
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{
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__u32 gprs_high[NUM_GPRS];
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__u64 vxrs[__NUM_VXRS_LOW];
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int i;
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/* Restore high gprs from signal stack */
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if (__copy_from_user(&gprs_high, &sregs_ext->gprs_high,
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sizeof(sregs_ext->gprs_high)))
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return -EFAULT;
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for (i = 0; i < NUM_GPRS; i++)
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*(__u32 *)®s->gprs[i] = gprs_high[i];
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/* Restore vector registers from signal stack */
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if (MACHINE_HAS_VX) {
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if (__copy_from_user(vxrs, &sregs_ext->vxrs_low,
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sizeof(sregs_ext->vxrs_low)) ||
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__copy_from_user(current->thread.fpu.vxrs + __NUM_VXRS_LOW,
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&sregs_ext->vxrs_high,
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sizeof(sregs_ext->vxrs_high)))
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return -EFAULT;
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for (i = 0; i < __NUM_VXRS_LOW; i++)
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*((__u64 *)(current->thread.fpu.vxrs + i) + 1) = vxrs[i];
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}
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return 0;
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}
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COMPAT_SYSCALL_DEFINE0(sigreturn)
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{
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struct pt_regs *regs = task_pt_regs(current);
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sigframe32 __user *frame = (sigframe32 __user *)regs->gprs[15];
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sigset_t set;
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if (get_compat_sigset(&set, (compat_sigset_t __user *)frame->sc.oldmask))
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goto badframe;
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set_current_blocked(&set);
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save_fpu_regs();
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if (restore_sigregs32(regs, &frame->sregs))
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goto badframe;
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if (restore_sigregs_ext32(regs, &frame->sregs_ext))
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goto badframe;
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load_sigregs();
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return regs->gprs[2];
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badframe:
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force_sig(SIGSEGV, current);
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return 0;
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}
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COMPAT_SYSCALL_DEFINE0(rt_sigreturn)
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{
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struct pt_regs *regs = task_pt_regs(current);
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rt_sigframe32 __user *frame = (rt_sigframe32 __user *)regs->gprs[15];
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sigset_t set;
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if (get_compat_sigset(&set, &frame->uc.uc_sigmask))
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goto badframe;
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set_current_blocked(&set);
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if (compat_restore_altstack(&frame->uc.uc_stack))
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goto badframe;
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save_fpu_regs();
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if (restore_sigregs32(regs, &frame->uc.uc_mcontext))
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goto badframe;
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if (restore_sigregs_ext32(regs, &frame->uc.uc_mcontext_ext))
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goto badframe;
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load_sigregs();
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return regs->gprs[2];
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badframe:
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force_sig(SIGSEGV, current);
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return 0;
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}
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/*
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* Set up a signal frame.
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*/
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/*
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* Determine which stack to use..
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*/
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static inline void __user *
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get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size)
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{
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unsigned long sp;
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/* Default to using normal stack */
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sp = (unsigned long) A(regs->gprs[15]);
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/* Overflow on alternate signal stack gives SIGSEGV. */
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if (on_sig_stack(sp) && !on_sig_stack((sp - frame_size) & -8UL))
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return (void __user *) -1UL;
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/* This is the X/Open sanctioned signal stack switching. */
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if (ka->sa.sa_flags & SA_ONSTACK) {
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if (! sas_ss_flags(sp))
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sp = current->sas_ss_sp + current->sas_ss_size;
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}
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return (void __user *)((sp - frame_size) & -8ul);
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}
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static int setup_frame32(struct ksignal *ksig, sigset_t *set,
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struct pt_regs *regs)
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{
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int sig = ksig->sig;
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sigframe32 __user *frame;
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unsigned long restorer;
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size_t frame_size;
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/*
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* gprs_high are always present for 31-bit compat tasks.
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* The space for vector registers is only allocated if
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* the machine supports it
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*/
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frame_size = sizeof(*frame) - sizeof(frame->sregs_ext.__reserved);
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if (!MACHINE_HAS_VX)
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frame_size -= sizeof(frame->sregs_ext.vxrs_low) +
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sizeof(frame->sregs_ext.vxrs_high);
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frame = get_sigframe(&ksig->ka, regs, frame_size);
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if (frame == (void __user *) -1UL)
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return -EFAULT;
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/* Set up backchain. */
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if (__put_user(regs->gprs[15], (unsigned int __user *) frame))
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return -EFAULT;
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/* Create struct sigcontext32 on the signal stack */
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if (put_compat_sigset((compat_sigset_t __user *)frame->sc.oldmask,
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set, sizeof(compat_sigset_t)))
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return -EFAULT;
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if (__put_user(ptr_to_compat(&frame->sregs), &frame->sc.sregs))
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return -EFAULT;
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/* Store registers needed to create the signal frame */
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store_sigregs();
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/* Create _sigregs32 on the signal stack */
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if (save_sigregs32(regs, &frame->sregs))
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return -EFAULT;
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/* Place signal number on stack to allow backtrace from handler. */
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if (__put_user(regs->gprs[2], (int __force __user *) &frame->signo))
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return -EFAULT;
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/* Create _sigregs_ext32 on the signal stack */
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if (save_sigregs_ext32(regs, &frame->sregs_ext))
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return -EFAULT;
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/* Set up to return from userspace. If provided, use a stub
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already in userspace. */
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if (ksig->ka.sa.sa_flags & SA_RESTORER) {
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restorer = (unsigned long __force)
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ksig->ka.sa.sa_restorer | PSW32_ADDR_AMODE;
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} else {
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/* Signal frames without vectors registers are short ! */
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__u16 __user *svc = (void __user *) frame + frame_size - 2;
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if (__put_user(S390_SYSCALL_OPCODE | __NR_sigreturn, svc))
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return -EFAULT;
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restorer = (unsigned long __force) svc | PSW32_ADDR_AMODE;
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}
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/* Set up registers for signal handler */
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regs->gprs[14] = restorer;
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regs->gprs[15] = (__force __u64) frame;
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/* Force 31 bit amode and default user address space control. */
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regs->psw.mask = PSW_MASK_BA |
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(PSW_USER_BITS & PSW_MASK_ASC) |
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(regs->psw.mask & ~PSW_MASK_ASC);
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regs->psw.addr = (__force __u64) ksig->ka.sa.sa_handler;
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regs->gprs[2] = sig;
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regs->gprs[3] = (__force __u64) &frame->sc;
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/* We forgot to include these in the sigcontext.
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To avoid breaking binary compatibility, they are passed as args. */
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if (sig == SIGSEGV || sig == SIGBUS || sig == SIGILL ||
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sig == SIGTRAP || sig == SIGFPE) {
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/* set extra registers only for synchronous signals */
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regs->gprs[4] = regs->int_code & 127;
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regs->gprs[5] = regs->int_parm_long;
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regs->gprs[6] = current->thread.last_break;
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}
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return 0;
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}
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static int setup_rt_frame32(struct ksignal *ksig, sigset_t *set,
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struct pt_regs *regs)
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{
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rt_sigframe32 __user *frame;
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unsigned long restorer;
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size_t frame_size;
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u32 uc_flags;
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frame_size = sizeof(*frame) -
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sizeof(frame->uc.uc_mcontext_ext.__reserved);
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/*
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* gprs_high are always present for 31-bit compat tasks.
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* The space for vector registers is only allocated if
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* the machine supports it
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*/
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uc_flags = UC_GPRS_HIGH;
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if (MACHINE_HAS_VX) {
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uc_flags |= UC_VXRS;
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} else
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frame_size -= sizeof(frame->uc.uc_mcontext_ext.vxrs_low) +
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sizeof(frame->uc.uc_mcontext_ext.vxrs_high);
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frame = get_sigframe(&ksig->ka, regs, frame_size);
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if (frame == (void __user *) -1UL)
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return -EFAULT;
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/* Set up backchain. */
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if (__put_user(regs->gprs[15], (unsigned int __force __user *) frame))
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return -EFAULT;
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/* Set up to return from userspace. If provided, use a stub
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already in userspace. */
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if (ksig->ka.sa.sa_flags & SA_RESTORER) {
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restorer = (unsigned long __force)
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ksig->ka.sa.sa_restorer | PSW32_ADDR_AMODE;
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} else {
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__u16 __user *svc = &frame->svc_insn;
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if (__put_user(S390_SYSCALL_OPCODE | __NR_rt_sigreturn, svc))
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return -EFAULT;
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restorer = (unsigned long __force) svc | PSW32_ADDR_AMODE;
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}
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/* Create siginfo on the signal stack */
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if (copy_siginfo_to_user32(&frame->info, &ksig->info))
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return -EFAULT;
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/* Store registers needed to create the signal frame */
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store_sigregs();
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/* Create ucontext on the signal stack. */
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if (__put_user(uc_flags, &frame->uc.uc_flags) ||
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__put_user(0, &frame->uc.uc_link) ||
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__compat_save_altstack(&frame->uc.uc_stack, regs->gprs[15]) ||
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save_sigregs32(regs, &frame->uc.uc_mcontext) ||
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put_compat_sigset(&frame->uc.uc_sigmask, set, sizeof(compat_sigset_t)) ||
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save_sigregs_ext32(regs, &frame->uc.uc_mcontext_ext))
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return -EFAULT;
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/* Set up registers for signal handler */
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regs->gprs[14] = restorer;
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regs->gprs[15] = (__force __u64) frame;
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/* Force 31 bit amode and default user address space control. */
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regs->psw.mask = PSW_MASK_BA |
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(PSW_USER_BITS & PSW_MASK_ASC) |
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(regs->psw.mask & ~PSW_MASK_ASC);
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regs->psw.addr = (__u64 __force) ksig->ka.sa.sa_handler;
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regs->gprs[2] = ksig->sig;
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regs->gprs[3] = (__force __u64) &frame->info;
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regs->gprs[4] = (__force __u64) &frame->uc;
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regs->gprs[5] = current->thread.last_break;
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return 0;
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}
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/*
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* OK, we're invoking a handler
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*/
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void handle_signal32(struct ksignal *ksig, sigset_t *oldset,
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struct pt_regs *regs)
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{
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int ret;
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/* Set up the stack frame */
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if (ksig->ka.sa.sa_flags & SA_SIGINFO)
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ret = setup_rt_frame32(ksig, oldset, regs);
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else
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ret = setup_frame32(ksig, oldset, regs);
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signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLE_STEP));
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}
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