qemu/linux-user/sparc/signal.c

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/*
* Emulation of Linux signals
*
* Copyright (c) 2003 Fabrice Bellard
*
* 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/osdep.h"
#include "qemu.h"
#include "user-internals.h"
#include "signal-common.h"
#include "linux-user/trace.h"
/* A Sparc register window */
struct target_reg_window {
abi_ulong locals[8];
abi_ulong ins[8];
};
/* A Sparc stack frame. */
struct target_stackf {
/*
* Since qemu does not reference fp or callers_pc directly,
* it's simpler to treat fp and callers_pc as elements of ins[],
* and then bundle locals[] and ins[] into reg_window.
*/
struct target_reg_window win;
/*
* Similarly, bundle structptr and xxargs into xargs[].
* This portion of the struct is part of the function call abi,
* and belongs to the callee for spilling argument registers.
*/
abi_ulong xargs[8];
};
struct target_siginfo_fpu {
#ifdef TARGET_SPARC64
uint64_t si_double_regs[32];
uint64_t si_fsr;
uint64_t si_gsr;
uint64_t si_fprs;
#else
/* It is more convenient for qemu to move doubles, not singles. */
uint64_t si_double_regs[16];
uint32_t si_fsr;
uint32_t si_fpqdepth;
struct {
uint32_t insn_addr;
uint32_t insn;
} si_fpqueue [16];
#endif
};
#ifdef TARGET_ARCH_HAS_SETUP_FRAME
struct target_signal_frame {
struct target_stackf ss;
struct target_pt_regs regs;
uint32_t si_mask;
abi_ulong fpu_save;
uint32_t insns[2] QEMU_ALIGNED(8);
abi_ulong extramask[TARGET_NSIG_WORDS - 1];
abi_ulong extra_size; /* Should be 0 */
abi_ulong rwin_save;
};
#endif
struct target_rt_signal_frame {
struct target_stackf ss;
target_siginfo_t info;
struct target_pt_regs regs;
#if defined(TARGET_SPARC64) && !defined(TARGET_ABI32)
abi_ulong fpu_save;
target_stack_t stack;
target_sigset_t mask;
#else
target_sigset_t mask;
abi_ulong fpu_save;
uint32_t insns[2];
target_stack_t stack;
abi_ulong extra_size; /* Should be 0 */
#endif
abi_ulong rwin_save;
};
static abi_ulong get_sigframe(struct target_sigaction *sa,
CPUSPARCState *env,
size_t framesize)
{
abi_ulong sp = get_sp_from_cpustate(env);
/*
* 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 - framesize))) {
return -1;
}
/* This is the X/Open sanctioned signal stack switching. */
sp = target_sigsp(sp, sa) - framesize;
/*
* Always align the stack frame. This handles two cases. First,
* sigaltstack need not be mindful of platform specific stack
* alignment. Second, if we took this signal because the stack
* is not aligned properly, we'd like to take the signal cleanly
* and report that.
*/
sp &= ~15UL;
return sp;
}
static void save_pt_regs(struct target_pt_regs *regs, CPUSPARCState *env)
{
int i;
#if defined(TARGET_SPARC64) && !defined(TARGET_ABI32)
__put_user(sparc64_tstate(env), &regs->tstate);
/* TODO: magic should contain PT_REG_MAGIC + %tt. */
__put_user(0, &regs->magic);
#else
__put_user(cpu_get_psr(env), &regs->psr);
#endif
__put_user(env->pc, &regs->pc);
__put_user(env->npc, &regs->npc);
__put_user(env->y, &regs->y);
for (i = 0; i < 8; i++) {
__put_user(env->gregs[i], &regs->u_regs[i]);
}
for (i = 0; i < 8; i++) {
__put_user(env->regwptr[WREG_O0 + i], &regs->u_regs[i + 8]);
}
}
static void restore_pt_regs(struct target_pt_regs *regs, CPUSPARCState *env)
{
int i;
#if defined(TARGET_SPARC64) && !defined(TARGET_ABI32)
/* User can only change condition codes and %asi in %tstate. */
uint64_t tstate;
__get_user(tstate, &regs->tstate);
cpu_put_ccr(env, tstate >> 32);
env->asi = extract64(tstate, 24, 8);
#else
/*
* User can only change condition codes and FPU enabling in %psr.
* But don't bother with FPU enabling, since a real kernel would
* just re-enable the FPU upon the next fpu trap.
*/
uint32_t psr;
__get_user(psr, &regs->psr);
env->psr = (psr & PSR_ICC) | (env->psr & ~PSR_ICC);
#endif
/* Note that pc and npc are handled in the caller. */
__get_user(env->y, &regs->y);
for (i = 0; i < 8; i++) {
__get_user(env->gregs[i], &regs->u_regs[i]);
}
for (i = 0; i < 8; i++) {
__get_user(env->regwptr[WREG_O0 + i], &regs->u_regs[i + 8]);
}
}
static void save_reg_win(struct target_reg_window *win, CPUSPARCState *env)
{
int i;
for (i = 0; i < 8; i++) {
__put_user(env->regwptr[i + WREG_L0], &win->locals[i]);
}
for (i = 0; i < 8; i++) {
__put_user(env->regwptr[i + WREG_I0], &win->ins[i]);
}
}
static void save_fpu(struct target_siginfo_fpu *fpu, CPUSPARCState *env)
{
int i;
#ifdef TARGET_SPARC64
for (i = 0; i < 32; ++i) {
__put_user(env->fpr[i].ll, &fpu->si_double_regs[i]);
}
__put_user(env->fsr, &fpu->si_fsr);
__put_user(env->gsr, &fpu->si_gsr);
__put_user(env->fprs, &fpu->si_fprs);
#else
for (i = 0; i < 16; ++i) {
__put_user(env->fpr[i].ll, &fpu->si_double_regs[i]);
}
__put_user(env->fsr, &fpu->si_fsr);
__put_user(0, &fpu->si_fpqdepth);
#endif
}
static void restore_fpu(struct target_siginfo_fpu *fpu, CPUSPARCState *env)
{
int i;
#ifdef TARGET_SPARC64
uint64_t fprs;
__get_user(fprs, &fpu->si_fprs);
/* In case the user mucks about with FPRS, restore as directed. */
if (fprs & FPRS_DL) {
for (i = 0; i < 16; ++i) {
__get_user(env->fpr[i].ll, &fpu->si_double_regs[i]);
}
}
if (fprs & FPRS_DU) {
for (i = 16; i < 32; ++i) {
__get_user(env->fpr[i].ll, &fpu->si_double_regs[i]);
}
}
__get_user(env->fsr, &fpu->si_fsr);
__get_user(env->gsr, &fpu->si_gsr);
env->fprs |= fprs;
#else
for (i = 0; i < 16; ++i) {
__get_user(env->fpr[i].ll, &fpu->si_double_regs[i]);
}
__get_user(env->fsr, &fpu->si_fsr);
#endif
}
#ifdef TARGET_ARCH_HAS_SETUP_FRAME
static void install_sigtramp(uint32_t *tramp, int syscall)
{
__put_user(0x82102000u + syscall, &tramp[0]); /* mov syscall, %g1 */
__put_user(0x91d02010u, &tramp[1]); /* t 0x10 */
}
void setup_frame(int sig, struct target_sigaction *ka,
target_sigset_t *set, CPUSPARCState *env)
{
abi_ulong sf_addr;
struct target_signal_frame *sf;
size_t sf_size = sizeof(*sf) + sizeof(struct target_siginfo_fpu);
int i;
sf_addr = get_sigframe(ka, env, sf_size);
trace_user_setup_frame(env, sf_addr);
sf = lock_user(VERIFY_WRITE, sf_addr, sf_size, 0);
if (!sf) {
force_sigsegv(sig);
return;
}
/* 2. Save the current process state */
save_pt_regs(&sf->regs, env);
__put_user(0, &sf->extra_size);
save_fpu((struct target_siginfo_fpu *)(sf + 1), env);
__put_user(sf_addr + sizeof(*sf), &sf->fpu_save);
__put_user(0, &sf->rwin_save); /* TODO: save_rwin_state */
__put_user(set->sig[0], &sf->si_mask);
for (i = 0; i < TARGET_NSIG_WORDS - 1; i++) {
__put_user(set->sig[i + 1], &sf->extramask[i]);
}
save_reg_win(&sf->ss.win, env);
/* 3. signal handler back-trampoline and parameters */
env->regwptr[WREG_SP] = sf_addr;
env->regwptr[WREG_O0] = sig;
env->regwptr[WREG_O1] = sf_addr +
offsetof(struct target_signal_frame, regs);
env->regwptr[WREG_O2] = sf_addr +
offsetof(struct target_signal_frame, regs);
/* 4. signal handler */
env->pc = ka->_sa_handler;
env->npc = env->pc + 4;
/* 5. return to kernel instructions */
if (ka->ka_restorer) {
env->regwptr[WREG_O7] = ka->ka_restorer;
} else {
/* Not used, but retain for ABI compatibility. */
install_sigtramp(sf->insns, TARGET_NR_sigreturn);
env->regwptr[WREG_O7] = default_sigreturn;
}
unlock_user(sf, sf_addr, sf_size);
}
#endif /* TARGET_ARCH_HAS_SETUP_FRAME */
void setup_rt_frame(int sig, struct target_sigaction *ka,
target_siginfo_t *info,
target_sigset_t *set, CPUSPARCState *env)
{
abi_ulong sf_addr;
struct target_rt_signal_frame *sf;
size_t sf_size = sizeof(*sf) + sizeof(struct target_siginfo_fpu);
sf_addr = get_sigframe(ka, env, sf_size);
trace_user_setup_rt_frame(env, sf_addr);
sf = lock_user(VERIFY_WRITE, sf_addr, sf_size, 0);
if (!sf) {
force_sigsegv(sig);
return;
}
/* 2. Save the current process state */
save_reg_win(&sf->ss.win, env);
save_pt_regs(&sf->regs, env);
save_fpu((struct target_siginfo_fpu *)(sf + 1), env);
__put_user(sf_addr + sizeof(*sf), &sf->fpu_save);
__put_user(0, &sf->rwin_save); /* TODO: save_rwin_state */
tswap_siginfo(&sf->info, info);
tswap_sigset(&sf->mask, set);
target_save_altstack(&sf->stack, env);
#ifdef TARGET_ABI32
__put_user(0, &sf->extra_size);
#endif
/* 3. signal handler back-trampoline and parameters */
env->regwptr[WREG_SP] = sf_addr - TARGET_STACK_BIAS;
env->regwptr[WREG_O0] = sig;
env->regwptr[WREG_O1] =
sf_addr + offsetof(struct target_rt_signal_frame, info);
#ifdef TARGET_ABI32
env->regwptr[WREG_O2] =
sf_addr + offsetof(struct target_rt_signal_frame, regs);
#else
env->regwptr[WREG_O2] = env->regwptr[WREG_O1];
#endif
/* 4. signal handler */
env->pc = ka->_sa_handler;
env->npc = env->pc + 4;
/* 5. return to kernel instructions */
#ifdef TARGET_ABI32
if (ka->ka_restorer) {
env->regwptr[WREG_O7] = ka->ka_restorer;
} else {
/* Not used, but retain for ABI compatibility. */
install_sigtramp(sf->insns, TARGET_NR_rt_sigreturn);
env->regwptr[WREG_O7] = default_rt_sigreturn;
}
#else
env->regwptr[WREG_O7] = ka->ka_restorer;
#endif
unlock_user(sf, sf_addr, sf_size);
}
long do_sigreturn(CPUSPARCState *env)
{
#ifdef TARGET_ARCH_HAS_SETUP_FRAME
abi_ulong sf_addr;
struct target_signal_frame *sf = NULL;
abi_ulong pc, npc, ptr;
target_sigset_t set;
sigset_t host_set;
int i;
sf_addr = env->regwptr[WREG_SP];
trace_user_do_sigreturn(env, sf_addr);
/* 1. Make sure we are not getting garbage from the user */
if ((sf_addr & 15) || !lock_user_struct(VERIFY_READ, sf, sf_addr, 1)) {
goto segv_and_exit;
}
/* Make sure stack pointer is aligned. */
__get_user(ptr, &sf->regs.u_regs[14]);
if (ptr & 7) {
goto segv_and_exit;
}
/* Make sure instruction pointers are aligned. */
__get_user(pc, &sf->regs.pc);
__get_user(npc, &sf->regs.npc);
if ((pc | npc) & 3) {
goto segv_and_exit;
}
/* 2. Restore the state */
restore_pt_regs(&sf->regs, env);
env->pc = pc;
env->npc = npc;
__get_user(ptr, &sf->fpu_save);
if (ptr) {
struct target_siginfo_fpu *fpu;
if ((ptr & 3) || !lock_user_struct(VERIFY_READ, fpu, ptr, 1)) {
goto segv_and_exit;
}
restore_fpu(fpu, env);
unlock_user_struct(fpu, ptr, 0);
}
__get_user(ptr, &sf->rwin_save);
if (ptr) {
goto segv_and_exit; /* TODO: restore_rwin */
}
__get_user(set.sig[0], &sf->si_mask);
for (i = 1; i < TARGET_NSIG_WORDS; i++) {
__get_user(set.sig[i], &sf->extramask[i - 1]);
}
target_to_host_sigset_internal(&host_set, &set);
set_sigmask(&host_set);
unlock_user_struct(sf, sf_addr, 0);
return -TARGET_QEMU_ESIGRETURN;
segv_and_exit:
unlock_user_struct(sf, sf_addr, 0);
force_sig(TARGET_SIGSEGV);
return -TARGET_QEMU_ESIGRETURN;
#else
return -TARGET_ENOSYS;
#endif
}
long do_rt_sigreturn(CPUSPARCState *env)
{
abi_ulong sf_addr, tpc, tnpc, ptr;
struct target_rt_signal_frame *sf = NULL;
sigset_t set;
sf_addr = get_sp_from_cpustate(env);
trace_user_do_rt_sigreturn(env, sf_addr);
/* 1. Make sure we are not getting garbage from the user */
if ((sf_addr & 15) || !lock_user_struct(VERIFY_READ, sf, sf_addr, 1)) {
goto segv_and_exit;
}
/* Validate SP alignment. */
__get_user(ptr, &sf->regs.u_regs[8 + WREG_SP]);
if ((ptr + TARGET_STACK_BIAS) & 7) {
goto segv_and_exit;
}
/* Validate PC and NPC alignment. */
__get_user(tpc, &sf->regs.pc);
__get_user(tnpc, &sf->regs.npc);
if ((tpc | tnpc) & 3) {
goto segv_and_exit;
}
/* 2. Restore the state */
restore_pt_regs(&sf->regs, env);
__get_user(ptr, &sf->fpu_save);
if (ptr) {
struct target_siginfo_fpu *fpu;
if ((ptr & 7) || !lock_user_struct(VERIFY_READ, fpu, ptr, 1)) {
goto segv_and_exit;
}
restore_fpu(fpu, env);
unlock_user_struct(fpu, ptr, 0);
}
__get_user(ptr, &sf->rwin_save);
if (ptr) {
goto segv_and_exit; /* TODO: restore_rwin_state */
}
target_restore_altstack(&sf->stack, env);
target_to_host_sigset(&set, &sf->mask);
set_sigmask(&set);
env->pc = tpc;
env->npc = tnpc;
unlock_user_struct(sf, sf_addr, 0);
return -TARGET_QEMU_ESIGRETURN;
segv_and_exit:
unlock_user_struct(sf, sf_addr, 0);
force_sig(TARGET_SIGSEGV);
return -TARGET_QEMU_ESIGRETURN;
}
#if defined(TARGET_SPARC64) && !defined(TARGET_ABI32)
#define SPARC_MC_TSTATE 0
#define SPARC_MC_PC 1
#define SPARC_MC_NPC 2
#define SPARC_MC_Y 3
#define SPARC_MC_G1 4
#define SPARC_MC_G2 5
#define SPARC_MC_G3 6
#define SPARC_MC_G4 7
#define SPARC_MC_G5 8
#define SPARC_MC_G6 9
#define SPARC_MC_G7 10
#define SPARC_MC_O0 11
#define SPARC_MC_O1 12
#define SPARC_MC_O2 13
#define SPARC_MC_O3 14
#define SPARC_MC_O4 15
#define SPARC_MC_O5 16
#define SPARC_MC_O6 17
#define SPARC_MC_O7 18
#define SPARC_MC_NGREG 19
typedef abi_ulong target_mc_greg_t;
typedef target_mc_greg_t target_mc_gregset_t[SPARC_MC_NGREG];
struct target_mc_fq {
abi_ulong mcfq_addr;
uint32_t mcfq_insn;
};
/*
* Note the manual 16-alignment; the kernel gets this because it
* includes a "long double qregs[16]" in the mcpu_fregs union,
* which we can't do.
*/
struct target_mc_fpu {
union {
uint32_t sregs[32];
uint64_t dregs[32];
//uint128_t qregs[16];
} mcfpu_fregs;
abi_ulong mcfpu_fsr;
abi_ulong mcfpu_fprs;
abi_ulong mcfpu_gsr;
abi_ulong mcfpu_fq;
unsigned char mcfpu_qcnt;
unsigned char mcfpu_qentsz;
unsigned char mcfpu_enab;
} __attribute__((aligned(16)));
typedef struct target_mc_fpu target_mc_fpu_t;
typedef struct {
target_mc_gregset_t mc_gregs;
target_mc_greg_t mc_fp;
target_mc_greg_t mc_i7;
target_mc_fpu_t mc_fpregs;
} target_mcontext_t;
struct target_ucontext {
abi_ulong tuc_link;
abi_ulong tuc_flags;
target_sigset_t tuc_sigmask;
target_mcontext_t tuc_mcontext;
};
/* {set, get}context() needed for 64-bit SparcLinux userland. */
void sparc64_set_context(CPUSPARCState *env)
{
abi_ulong ucp_addr;
struct target_ucontext *ucp;
target_mc_gregset_t *grp;
linux-user/sparc: Correct sparc64_get/set_context() FPU handling The handling of the FPU state in sparc64_get_context() and sparc64_set_context() is not the same as what the kernel actually does: we unconditionally read and write the FP registers and the FSR, GSR and FPRS, but the kernel logic is more complicated: * in get_context the kernel has code for saving FPU registers, but it is hidden inside an "if (fenab) condition and the fenab flag is always set to 0 (inside an "#if 1" which has been in the kernel for over 15 years). So the effect is that the FPU state part is always written as zeroes. * in set_context the kernel looks at the fenab field in the structure from the guest, and only restores the state if it is set; it also looks at the structure's FPRS to see whether either the upper or lower or both halves of the register file have valid data. Bring our implementations into line with the kernel: * in get_context: - clear the entire target_ucontext at the top of the function (as the kernel does) - then don't write the FPU state, so those fields remain zero - this fixes Coverity issue CID 1432305 by deleting the code it was complaining about * in set_context: - check the fenab and the fpsr to decide which parts of the FPU data to restore, if any - instead of setting the FPU registers by doing two 32-bit loads and filling in the .upper and .lower parts of the CPU_Double union separately, just do a 64-bit load of the whole register at once. This fixes Coverity issue CID 1432303 because we now access the dregs[] part of the mcfpu_fregs union rather than the sregs[] part (which is not large enough to actually cover the whole of the data, so we were accessing off the end of sregs[]) We change both functions in a single commit to avoid potentially breaking bisection. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20201106152738.26026-2-peter.maydell@linaro.org> [lv: fix FPRS_DU loop s/31/32/] Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-11-06 18:27:35 +03:00
target_mc_fpu_t *fpup;
abi_ulong pc, npc, tstate;
unsigned int i;
linux-user/sparc: Correct sparc64_get/set_context() FPU handling The handling of the FPU state in sparc64_get_context() and sparc64_set_context() is not the same as what the kernel actually does: we unconditionally read and write the FP registers and the FSR, GSR and FPRS, but the kernel logic is more complicated: * in get_context the kernel has code for saving FPU registers, but it is hidden inside an "if (fenab) condition and the fenab flag is always set to 0 (inside an "#if 1" which has been in the kernel for over 15 years). So the effect is that the FPU state part is always written as zeroes. * in set_context the kernel looks at the fenab field in the structure from the guest, and only restores the state if it is set; it also looks at the structure's FPRS to see whether either the upper or lower or both halves of the register file have valid data. Bring our implementations into line with the kernel: * in get_context: - clear the entire target_ucontext at the top of the function (as the kernel does) - then don't write the FPU state, so those fields remain zero - this fixes Coverity issue CID 1432305 by deleting the code it was complaining about * in set_context: - check the fenab and the fpsr to decide which parts of the FPU data to restore, if any - instead of setting the FPU registers by doing two 32-bit loads and filling in the .upper and .lower parts of the CPU_Double union separately, just do a 64-bit load of the whole register at once. This fixes Coverity issue CID 1432303 because we now access the dregs[] part of the mcfpu_fregs union rather than the sregs[] part (which is not large enough to actually cover the whole of the data, so we were accessing off the end of sregs[]) We change both functions in a single commit to avoid potentially breaking bisection. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20201106152738.26026-2-peter.maydell@linaro.org> [lv: fix FPRS_DU loop s/31/32/] Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-11-06 18:27:35 +03:00
unsigned char fenab;
ucp_addr = env->regwptr[WREG_O0];
if (!lock_user_struct(VERIFY_READ, ucp, ucp_addr, 1)) {
goto do_sigsegv;
}
grp = &ucp->tuc_mcontext.mc_gregs;
__get_user(pc, &((*grp)[SPARC_MC_PC]));
__get_user(npc, &((*grp)[SPARC_MC_NPC]));
if ((pc | npc) & 3) {
goto do_sigsegv;
}
if (env->regwptr[WREG_O1]) {
target_sigset_t target_set;
sigset_t set;
if (TARGET_NSIG_WORDS == 1) {
__get_user(target_set.sig[0], &ucp->tuc_sigmask.sig[0]);
} else {
abi_ulong *src, *dst;
src = ucp->tuc_sigmask.sig;
dst = target_set.sig;
for (i = 0; i < TARGET_NSIG_WORDS; i++, dst++, src++) {
__get_user(*dst, src);
}
}
target_to_host_sigset_internal(&set, &target_set);
set_sigmask(&set);
}
env->pc = pc;
env->npc = npc;
__get_user(env->y, &((*grp)[SPARC_MC_Y]));
__get_user(tstate, &((*grp)[SPARC_MC_TSTATE]));
/* Honour TSTATE_ASI, TSTATE_ICC and TSTATE_XCC only */
env->asi = (tstate >> 24) & 0xff;
cpu_put_ccr(env, (tstate >> 32) & 0xff);
__get_user(env->gregs[1], (&(*grp)[SPARC_MC_G1]));
__get_user(env->gregs[2], (&(*grp)[SPARC_MC_G2]));
__get_user(env->gregs[3], (&(*grp)[SPARC_MC_G3]));
__get_user(env->gregs[4], (&(*grp)[SPARC_MC_G4]));
__get_user(env->gregs[5], (&(*grp)[SPARC_MC_G5]));
__get_user(env->gregs[6], (&(*grp)[SPARC_MC_G6]));
/* Skip g7 as that's the thread register in userspace */
/*
* Note that unlike the kernel, we didn't need to mess with the
* guest register window state to save it into a pt_regs to run
* the kernel. So for us the guest's O regs are still in WREG_O*
* (unlike the kernel which has put them in UREG_I* in a pt_regs)
* and the fp and i7 are still in WREG_I6 and WREG_I7 and don't
* need to be written back to userspace memory.
*/
__get_user(env->regwptr[WREG_O0], (&(*grp)[SPARC_MC_O0]));
__get_user(env->regwptr[WREG_O1], (&(*grp)[SPARC_MC_O1]));
__get_user(env->regwptr[WREG_O2], (&(*grp)[SPARC_MC_O2]));
__get_user(env->regwptr[WREG_O3], (&(*grp)[SPARC_MC_O3]));
__get_user(env->regwptr[WREG_O4], (&(*grp)[SPARC_MC_O4]));
__get_user(env->regwptr[WREG_O5], (&(*grp)[SPARC_MC_O5]));
__get_user(env->regwptr[WREG_O6], (&(*grp)[SPARC_MC_O6]));
__get_user(env->regwptr[WREG_O7], (&(*grp)[SPARC_MC_O7]));
__get_user(env->regwptr[WREG_FP], &(ucp->tuc_mcontext.mc_fp));
__get_user(env->regwptr[WREG_I7], &(ucp->tuc_mcontext.mc_i7));
linux-user/sparc: Correct sparc64_get/set_context() FPU handling The handling of the FPU state in sparc64_get_context() and sparc64_set_context() is not the same as what the kernel actually does: we unconditionally read and write the FP registers and the FSR, GSR and FPRS, but the kernel logic is more complicated: * in get_context the kernel has code for saving FPU registers, but it is hidden inside an "if (fenab) condition and the fenab flag is always set to 0 (inside an "#if 1" which has been in the kernel for over 15 years). So the effect is that the FPU state part is always written as zeroes. * in set_context the kernel looks at the fenab field in the structure from the guest, and only restores the state if it is set; it also looks at the structure's FPRS to see whether either the upper or lower or both halves of the register file have valid data. Bring our implementations into line with the kernel: * in get_context: - clear the entire target_ucontext at the top of the function (as the kernel does) - then don't write the FPU state, so those fields remain zero - this fixes Coverity issue CID 1432305 by deleting the code it was complaining about * in set_context: - check the fenab and the fpsr to decide which parts of the FPU data to restore, if any - instead of setting the FPU registers by doing two 32-bit loads and filling in the .upper and .lower parts of the CPU_Double union separately, just do a 64-bit load of the whole register at once. This fixes Coverity issue CID 1432303 because we now access the dregs[] part of the mcfpu_fregs union rather than the sregs[] part (which is not large enough to actually cover the whole of the data, so we were accessing off the end of sregs[]) We change both functions in a single commit to avoid potentially breaking bisection. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20201106152738.26026-2-peter.maydell@linaro.org> [lv: fix FPRS_DU loop s/31/32/] Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-11-06 18:27:35 +03:00
fpup = &ucp->tuc_mcontext.mc_fpregs;
__get_user(fenab, &(fpup->mcfpu_enab));
if (fenab) {
abi_ulong fprs;
/*
* We use the FPRS from the guest only in deciding whether
* to restore the upper, lower, or both banks of the FPU regs.
* The kernel here writes the FPU register data into the
* process's current_thread_info state and unconditionally
* clears FPRS and TSTATE_PEF: this disables the FPU so that the
* next FPU-disabled trap will copy the data out of
* current_thread_info and into the real FPU registers.
* QEMU doesn't need to handle lazy-FPU-state-restoring like that,
* so we always load the data directly into the FPU registers
* and leave FPRS and TSTATE_PEF alone (so the FPU stays enabled).
* Note that because we (and the kernel) always write zeroes for
* the fenab and fprs in sparc64_get_context() none of this code
* will execute unless the guest manually constructed or changed
* the context structure.
*/
__get_user(fprs, &(fpup->mcfpu_fprs));
if (fprs & FPRS_DL) {
for (i = 0; i < 16; i++) {
__get_user(env->fpr[i].ll, &(fpup->mcfpu_fregs.dregs[i]));
}
}
if (fprs & FPRS_DU) {
for (i = 16; i < 32; i++) {
__get_user(env->fpr[i].ll, &(fpup->mcfpu_fregs.dregs[i]));
}
}
linux-user/sparc: Correct sparc64_get/set_context() FPU handling The handling of the FPU state in sparc64_get_context() and sparc64_set_context() is not the same as what the kernel actually does: we unconditionally read and write the FP registers and the FSR, GSR and FPRS, but the kernel logic is more complicated: * in get_context the kernel has code for saving FPU registers, but it is hidden inside an "if (fenab) condition and the fenab flag is always set to 0 (inside an "#if 1" which has been in the kernel for over 15 years). So the effect is that the FPU state part is always written as zeroes. * in set_context the kernel looks at the fenab field in the structure from the guest, and only restores the state if it is set; it also looks at the structure's FPRS to see whether either the upper or lower or both halves of the register file have valid data. Bring our implementations into line with the kernel: * in get_context: - clear the entire target_ucontext at the top of the function (as the kernel does) - then don't write the FPU state, so those fields remain zero - this fixes Coverity issue CID 1432305 by deleting the code it was complaining about * in set_context: - check the fenab and the fpsr to decide which parts of the FPU data to restore, if any - instead of setting the FPU registers by doing two 32-bit loads and filling in the .upper and .lower parts of the CPU_Double union separately, just do a 64-bit load of the whole register at once. This fixes Coverity issue CID 1432303 because we now access the dregs[] part of the mcfpu_fregs union rather than the sregs[] part (which is not large enough to actually cover the whole of the data, so we were accessing off the end of sregs[]) We change both functions in a single commit to avoid potentially breaking bisection. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20201106152738.26026-2-peter.maydell@linaro.org> [lv: fix FPRS_DU loop s/31/32/] Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-11-06 18:27:35 +03:00
__get_user(env->fsr, &(fpup->mcfpu_fsr));
__get_user(env->gsr, &(fpup->mcfpu_gsr));
}
unlock_user_struct(ucp, ucp_addr, 0);
return;
do_sigsegv:
unlock_user_struct(ucp, ucp_addr, 0);
force_sig(TARGET_SIGSEGV);
}
void sparc64_get_context(CPUSPARCState *env)
{
abi_ulong ucp_addr;
struct target_ucontext *ucp;
target_mc_gregset_t *grp;
target_mcontext_t *mcp;
int err;
unsigned int i;
target_sigset_t target_set;
sigset_t set;
ucp_addr = env->regwptr[WREG_O0];
if (!lock_user_struct(VERIFY_WRITE, ucp, ucp_addr, 0)) {
goto do_sigsegv;
}
linux-user/sparc: Correct sparc64_get/set_context() FPU handling The handling of the FPU state in sparc64_get_context() and sparc64_set_context() is not the same as what the kernel actually does: we unconditionally read and write the FP registers and the FSR, GSR and FPRS, but the kernel logic is more complicated: * in get_context the kernel has code for saving FPU registers, but it is hidden inside an "if (fenab) condition and the fenab flag is always set to 0 (inside an "#if 1" which has been in the kernel for over 15 years). So the effect is that the FPU state part is always written as zeroes. * in set_context the kernel looks at the fenab field in the structure from the guest, and only restores the state if it is set; it also looks at the structure's FPRS to see whether either the upper or lower or both halves of the register file have valid data. Bring our implementations into line with the kernel: * in get_context: - clear the entire target_ucontext at the top of the function (as the kernel does) - then don't write the FPU state, so those fields remain zero - this fixes Coverity issue CID 1432305 by deleting the code it was complaining about * in set_context: - check the fenab and the fpsr to decide which parts of the FPU data to restore, if any - instead of setting the FPU registers by doing two 32-bit loads and filling in the .upper and .lower parts of the CPU_Double union separately, just do a 64-bit load of the whole register at once. This fixes Coverity issue CID 1432303 because we now access the dregs[] part of the mcfpu_fregs union rather than the sregs[] part (which is not large enough to actually cover the whole of the data, so we were accessing off the end of sregs[]) We change both functions in a single commit to avoid potentially breaking bisection. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20201106152738.26026-2-peter.maydell@linaro.org> [lv: fix FPRS_DU loop s/31/32/] Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-11-06 18:27:35 +03:00
memset(ucp, 0, sizeof(*ucp));
mcp = &ucp->tuc_mcontext;
grp = &mcp->mc_gregs;
/* Skip over the trap instruction, first. */
env->pc = env->npc;
env->npc += 4;
/* If we're only reading the signal mask then do_sigprocmask()
* is guaranteed not to fail, which is important because we don't
* have any way to signal a failure or restart this operation since
* this is not a normal syscall.
*/
err = do_sigprocmask(0, NULL, &set);
assert(err == 0);
host_to_target_sigset_internal(&target_set, &set);
if (TARGET_NSIG_WORDS == 1) {
__put_user(target_set.sig[0],
(abi_ulong *)&ucp->tuc_sigmask);
} else {
abi_ulong *src, *dst;
src = target_set.sig;
dst = ucp->tuc_sigmask.sig;
for (i = 0; i < TARGET_NSIG_WORDS; i++, dst++, src++) {
__put_user(*src, dst);
}
}
__put_user(sparc64_tstate(env), &((*grp)[SPARC_MC_TSTATE]));
__put_user(env->pc, &((*grp)[SPARC_MC_PC]));
__put_user(env->npc, &((*grp)[SPARC_MC_NPC]));
__put_user(env->y, &((*grp)[SPARC_MC_Y]));
__put_user(env->gregs[1], &((*grp)[SPARC_MC_G1]));
__put_user(env->gregs[2], &((*grp)[SPARC_MC_G2]));
__put_user(env->gregs[3], &((*grp)[SPARC_MC_G3]));
__put_user(env->gregs[4], &((*grp)[SPARC_MC_G4]));
__put_user(env->gregs[5], &((*grp)[SPARC_MC_G5]));
__put_user(env->gregs[6], &((*grp)[SPARC_MC_G6]));
__put_user(env->gregs[7], &((*grp)[SPARC_MC_G7]));
/*
* Note that unlike the kernel, we didn't need to mess with the
* guest register window state to save it into a pt_regs to run
* the kernel. So for us the guest's O regs are still in WREG_O*
* (unlike the kernel which has put them in UREG_I* in a pt_regs)
* and the fp and i7 are still in WREG_I6 and WREG_I7 and don't
* need to be fished out of userspace memory.
*/
__put_user(env->regwptr[WREG_O0], &((*grp)[SPARC_MC_O0]));
__put_user(env->regwptr[WREG_O1], &((*grp)[SPARC_MC_O1]));
__put_user(env->regwptr[WREG_O2], &((*grp)[SPARC_MC_O2]));
__put_user(env->regwptr[WREG_O3], &((*grp)[SPARC_MC_O3]));
__put_user(env->regwptr[WREG_O4], &((*grp)[SPARC_MC_O4]));
__put_user(env->regwptr[WREG_O5], &((*grp)[SPARC_MC_O5]));
__put_user(env->regwptr[WREG_O6], &((*grp)[SPARC_MC_O6]));
__put_user(env->regwptr[WREG_O7], &((*grp)[SPARC_MC_O7]));
__put_user(env->regwptr[WREG_FP], &(mcp->mc_fp));
__put_user(env->regwptr[WREG_I7], &(mcp->mc_i7));
linux-user/sparc: Correct sparc64_get/set_context() FPU handling The handling of the FPU state in sparc64_get_context() and sparc64_set_context() is not the same as what the kernel actually does: we unconditionally read and write the FP registers and the FSR, GSR and FPRS, but the kernel logic is more complicated: * in get_context the kernel has code for saving FPU registers, but it is hidden inside an "if (fenab) condition and the fenab flag is always set to 0 (inside an "#if 1" which has been in the kernel for over 15 years). So the effect is that the FPU state part is always written as zeroes. * in set_context the kernel looks at the fenab field in the structure from the guest, and only restores the state if it is set; it also looks at the structure's FPRS to see whether either the upper or lower or both halves of the register file have valid data. Bring our implementations into line with the kernel: * in get_context: - clear the entire target_ucontext at the top of the function (as the kernel does) - then don't write the FPU state, so those fields remain zero - this fixes Coverity issue CID 1432305 by deleting the code it was complaining about * in set_context: - check the fenab and the fpsr to decide which parts of the FPU data to restore, if any - instead of setting the FPU registers by doing two 32-bit loads and filling in the .upper and .lower parts of the CPU_Double union separately, just do a 64-bit load of the whole register at once. This fixes Coverity issue CID 1432303 because we now access the dregs[] part of the mcfpu_fregs union rather than the sregs[] part (which is not large enough to actually cover the whole of the data, so we were accessing off the end of sregs[]) We change both functions in a single commit to avoid potentially breaking bisection. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20201106152738.26026-2-peter.maydell@linaro.org> [lv: fix FPRS_DU loop s/31/32/] Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2020-11-06 18:27:35 +03:00
/*
* We don't write out the FPU state. This matches the kernel's
* implementation (which has the code for doing this but
* hidden behind an "if (fenab)" where fenab is always 0).
*/
unlock_user_struct(ucp, ucp_addr, 1);
return;
do_sigsegv:
unlock_user_struct(ucp, ucp_addr, 1);
force_sig(TARGET_SIGSEGV);
}
#else
void setup_sigtramp(abi_ulong sigtramp_page)
{
uint32_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 2 * 8, 0);
assert(tramp != NULL);
default_sigreturn = sigtramp_page;
install_sigtramp(tramp, TARGET_NR_sigreturn);
default_rt_sigreturn = sigtramp_page + 8;
install_sigtramp(tramp + 2, TARGET_NR_rt_sigreturn);
unlock_user(tramp, sigtramp_page, 2 * 8);
}
#endif