qemu/bsd-user/arm/signal.c

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/*
* 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;
}