qemu

signal.c (7548B)

---

 /*
  *  arm signal functions
  *
  *  Copyright (c) 2013 Stacey D. Son
  *
  *  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; either version 2 of the License, or
  *  (at your option) any later version.
  *
  *  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.  See the
  *  GNU General Public License for more details.
  *
  *  You should have received a copy of the GNU General Public License
  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
  */
 
 #include "qemu.h"
 
 /*
  * Compare to arm/arm/machdep.c sendsig()
  * Assumes that target stack frame memory is locked.
  */
 abi_long set_sigtramp_args(CPUARMState *env, int sig,
                            struct target_sigframe *frame,
                            abi_ulong frame_addr,
                            struct target_sigaction *ka)
 {
     /*
      * Arguments to signal handler:
      *  r0 = signal number
      *  r1 = siginfo pointer
      *  r2 = ucontext pointer
      *  r5 = ucontext pointer
      *  pc = signal handler pointer
      *  sp = sigframe struct pointer
      *  lr = sigtramp at base of user stack
      */
 
     env->regs[0] = sig;
     env->regs[1] = frame_addr +
         offsetof(struct target_sigframe, sf_si);
     env->regs[2] = frame_addr +
         offsetof(struct target_sigframe, sf_uc);
 
     /* the trampoline uses r5 as the uc address */
     env->regs[5] = frame_addr +
         offsetof(struct target_sigframe, sf_uc);
     env->regs[TARGET_REG_PC] = ka->_sa_handler & ~1;
     env->regs[TARGET_REG_SP] = frame_addr;
     env->regs[TARGET_REG_LR] = TARGET_PS_STRINGS - TARGET_SZSIGCODE;
     /*
      * Low bit indicates whether or not we're entering thumb mode.
      */
     cpsr_write(env, (ka->_sa_handler & 1) * CPSR_T, CPSR_T, CPSRWriteByInstr);
 
     return 0;
 }
 
 static abi_long get_vfpcontext(CPUARMState *env, abi_ulong frame_addr,
                                struct target_sigframe *frame)
 {
     /* see sendsig and get_vfpcontext in sys/arm/arm/exec_machdep.c */
     target_mcontext_vfp_t *vfp = &frame->sf_vfp;
     target_mcontext_t *mcp = &frame->sf_uc.uc_mcontext;
 
     /* Assumes that mcp and vfp are locked */
     for (int i = 0; i < 32; i++) {
         vfp->mcv_reg[i] = tswap64(*aa32_vfp_dreg(env, i));
     }
     vfp->mcv_fpscr = tswap32(vfp_get_fpscr(env));
     mcp->mc_vfp_size = tswap32(sizeof(*vfp));
     mcp->mc_vfp_ptr = tswap32(frame_addr + ((uintptr_t)vfp - (uintptr_t)frame));
     return 0;
 }
 
 /*
  * Compare to arm/arm/exec_machdep.c get_mcontext()
  * Assumes that the memory is locked if mcp points to user memory.
  */
 abi_long get_mcontext(CPUARMState *env, target_mcontext_t *mcp, int flags)
 {
     uint32_t *gr = mcp->__gregs;
 
     gr[TARGET_REG_CPSR] = tswap32(cpsr_read(env));
     if (flags & TARGET_MC_GET_CLEAR_RET) {
         gr[TARGET_REG_R0] = 0;
         gr[TARGET_REG_CPSR] &= ~CPSR_C;
     } else {
         gr[TARGET_REG_R0] = tswap32(env->regs[0]);
     }
 
     gr[TARGET_REG_R1] = tswap32(env->regs[1]);
     gr[TARGET_REG_R2] = tswap32(env->regs[2]);
     gr[TARGET_REG_R3] = tswap32(env->regs[3]);
     gr[TARGET_REG_R4] = tswap32(env->regs[4]);
     gr[TARGET_REG_R5] = tswap32(env->regs[5]);
     gr[TARGET_REG_R6] = tswap32(env->regs[6]);
     gr[TARGET_REG_R7] = tswap32(env->regs[7]);
     gr[TARGET_REG_R8] = tswap32(env->regs[8]);
     gr[TARGET_REG_R9] = tswap32(env->regs[9]);
     gr[TARGET_REG_R10] = tswap32(env->regs[10]);
     gr[TARGET_REG_R11] = tswap32(env->regs[11]);
     gr[TARGET_REG_R12] = tswap32(env->regs[12]);
 
     gr[TARGET_REG_SP] = tswap32(env->regs[13]);
     gr[TARGET_REG_LR] = tswap32(env->regs[14]);
     gr[TARGET_REG_PC] = tswap32(env->regs[15]);
 
     /*
      * FreeBSD's get_mcontext doesn't save VFP info, but sets the pointer and
      * size to zero.  Applications that need the VFP state use
      * sysarch(ARM_GET_VFPSTATE) and are expected to adjust mcontext after that.
      */
     mcp->mc_vfp_size = 0;
     mcp->mc_vfp_ptr = 0;
     memset(&mcp->mc_spare, 0, sizeof(mcp->mc_spare));
 
     return 0;
 }
 
 /*
  * Compare to arm/arm/exec_machdep.c sendsig()
  * Assumes that the memory is locked if frame points to user memory.
  */
 abi_long setup_sigframe_arch(CPUARMState *env, abi_ulong frame_addr,
                              struct target_sigframe *frame, int flags)
 {
     target_mcontext_t *mcp = &frame->sf_uc.uc_mcontext;
 
     get_mcontext(env, mcp, flags);
     get_vfpcontext(env, frame_addr, frame);
     return 0;
 }
 
 /* Compare to arm/arm/exec_machdep.c set_mcontext() */
 abi_long set_mcontext(CPUARMState *env, target_mcontext_t *mcp, int srflag)
 {
     int err = 0;
     const uint32_t *gr = mcp->__gregs;
     uint32_t cpsr, ccpsr = cpsr_read(env);
     uint32_t fpscr, mask;
 
     cpsr = tswap32(gr[TARGET_REG_CPSR]);
     /*
      * Only allow certain bits to change, reject attempted changes to non-user
      * bits. In addition, make sure we're headed for user mode and none of the
      * interrupt bits are set.
      */
     if ((ccpsr & ~CPSR_USER) != (cpsr & ~CPSR_USER)) {
         return -TARGET_EINVAL;
     }
     if ((cpsr & CPSR_M) != ARM_CPU_MODE_USR ||
         (cpsr & (CPSR_I | CPSR_F)) != 0) {
         return -TARGET_EINVAL;
     }
 
     /*
      * The movs pc,lr instruction that implements the return to userland masks
      * these bits out.
      */
     mask = cpsr & CPSR_T ? 0x1 : 0x3;
 
     /*
      * Make sure that we either have no vfp, or it's the correct size.
      * FreeBSD just ignores it, though, so maybe we'll need to adjust
      * things below instead.
      */
     if (mcp->mc_vfp_size != 0 && mcp->mc_vfp_size != sizeof(target_mcontext_vfp_t)) {
         return -TARGET_EINVAL;
     }
 
     env->regs[0] = tswap32(gr[TARGET_REG_R0]);
     env->regs[1] = tswap32(gr[TARGET_REG_R1]);
     env->regs[2] = tswap32(gr[TARGET_REG_R2]);
     env->regs[3] = tswap32(gr[TARGET_REG_R3]);
     env->regs[4] = tswap32(gr[TARGET_REG_R4]);
     env->regs[5] = tswap32(gr[TARGET_REG_R5]);
     env->regs[6] = tswap32(gr[TARGET_REG_R6]);
     env->regs[7] = tswap32(gr[TARGET_REG_R7]);
     env->regs[8] = tswap32(gr[TARGET_REG_R8]);
     env->regs[9] = tswap32(gr[TARGET_REG_R9]);
     env->regs[10] = tswap32(gr[TARGET_REG_R10]);
     env->regs[11] = tswap32(gr[TARGET_REG_R11]);
     env->regs[12] = tswap32(gr[TARGET_REG_R12]);
 
     env->regs[13] = tswap32(gr[TARGET_REG_SP]);
     env->regs[14] = tswap32(gr[TARGET_REG_LR]);
     env->regs[15] = tswap32(gr[TARGET_REG_PC] & ~mask);
     if (mcp->mc_vfp_size != 0 && mcp->mc_vfp_ptr != 0) {
         /* see set_vfpcontext in sys/arm/arm/exec_machdep.c */
         target_mcontext_vfp_t *vfp;
 
         vfp = lock_user(VERIFY_READ, mcp->mc_vfp_ptr, sizeof(*vfp), 1);
         for (int i = 0; i < 32; i++) {
             __get_user(*aa32_vfp_dreg(env, i), &vfp->mcv_reg[i]);
         }
         __get_user(fpscr, &vfp->mcv_fpscr);
         vfp_set_fpscr(env, fpscr);
         unlock_user(vfp, mcp->mc_vfp_ptr, sizeof(target_ucontext_t));
 
         /*
          * linux-user sets fpexc, fpinst and fpinst2, but these aren't in
          * FreeBSD's mcontext, what to do?
          */
     }
     cpsr_write(env, cpsr, CPSR_USER | CPSR_EXEC, CPSRWriteByInstr);
 
     return err;
 }
 
 /* Compare to arm/arm/machdep.c sys_sigreturn() */
 abi_long get_ucontext_sigreturn(CPUARMState *env, abi_ulong target_sf,
                                 abi_ulong *target_uc)
 {
     *target_uc = target_sf;
 
     return 0;
 }