qemu/linux-user/loongarch64/signal.c

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/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
* LoongArch emulation of Linux signals
*
* Copyright (c) 2021 Loongson Technology Corporation Limited
*/
#include "qemu/osdep.h"
#include "qemu.h"
#include "user-internals.h"
#include "signal-common.h"
#include "linux-user/trace.h"
#include "target/loongarch/internals.h"
#include "target/loongarch/vec.h"
#include "vdso-asmoffset.h"
/* FP context was used */
#define SC_USED_FP (1 << 0)
struct target_sigcontext {
abi_ulong sc_pc;
abi_ulong sc_regs[32];
abi_uint sc_flags;
abi_ulong sc_extcontext[0] QEMU_ALIGNED(16);
};
QEMU_BUILD_BUG_ON(sizeof(struct target_sigcontext) != sizeof_sigcontext);
QEMU_BUILD_BUG_ON(offsetof(struct target_sigcontext, sc_pc)
!= offsetof_sigcontext_pc);
QEMU_BUILD_BUG_ON(offsetof(struct target_sigcontext, sc_regs)
!= offsetof_sigcontext_gr);
#define FPU_CTX_MAGIC 0x46505501
#define FPU_CTX_ALIGN 8
struct target_fpu_context {
abi_ulong regs[32];
abi_ulong fcc;
abi_uint fcsr;
} QEMU_ALIGNED(FPU_CTX_ALIGN);
QEMU_BUILD_BUG_ON(offsetof(struct target_fpu_context, regs)
!= offsetof_fpucontext_fr);
#define LSX_CTX_MAGIC 0x53580001
#define LSX_CTX_ALIGN 16
struct target_lsx_context {
abi_ulong regs[2 * 32];
abi_ulong fcc;
abi_uint fcsr;
} QEMU_ALIGNED(LSX_CTX_ALIGN);
#define LASX_CTX_MAGIC 0x41535801
#define LASX_CTX_ALIGN 32
struct target_lasx_context {
abi_ulong regs[4 * 32];
abi_ulong fcc;
abi_uint fcsr;
} QEMU_ALIGNED(LASX_CTX_ALIGN);
#define CONTEXT_INFO_ALIGN 16
struct target_sctx_info {
abi_uint magic;
abi_uint size;
abi_ulong padding;
} QEMU_ALIGNED(CONTEXT_INFO_ALIGN);
QEMU_BUILD_BUG_ON(sizeof(struct target_sctx_info) != sizeof_sctx_info);
struct target_ucontext {
abi_ulong tuc_flags;
abi_ptr tuc_link;
target_stack_t tuc_stack;
target_sigset_t tuc_sigmask;
uint8_t __unused[1024 / 8 - sizeof(target_sigset_t)];
struct target_sigcontext tuc_mcontext;
};
struct target_rt_sigframe {
struct target_siginfo rs_info;
struct target_ucontext rs_uc;
};
QEMU_BUILD_BUG_ON(sizeof(struct target_rt_sigframe)
!= sizeof_rt_sigframe);
QEMU_BUILD_BUG_ON(offsetof(struct target_rt_sigframe, rs_uc.tuc_mcontext)
!= offsetof_sigcontext);
/*
* These two structures are not present in guest memory, are private
* to the signal implementation, but are largely copied from the
* kernel's signal implementation.
*/
struct ctx_layout {
void *haddr;
abi_ptr gaddr;
unsigned int size;
};
struct extctx_layout {
unsigned long size;
unsigned int flags;
struct ctx_layout fpu;
struct ctx_layout lsx;
struct ctx_layout lasx;
struct ctx_layout end;
};
static abi_ptr extframe_alloc(struct extctx_layout *extctx,
struct ctx_layout *sctx, unsigned size,
unsigned align, abi_ptr orig_sp)
{
abi_ptr sp = orig_sp;
sp -= sizeof(struct target_sctx_info) + size;
align = MAX(align, CONTEXT_INFO_ALIGN);
sp = ROUND_DOWN(sp, align);
sctx->gaddr = sp;
size = orig_sp - sp;
sctx->size = size;
extctx->size += size;
return sp;
}
static abi_ptr setup_extcontext(CPULoongArchState *env,
struct extctx_layout *extctx, abi_ptr sp)
{
memset(extctx, 0, sizeof(struct extctx_layout));
/* Grow down, alloc "end" context info first. */
sp = extframe_alloc(extctx, &extctx->end, 0, CONTEXT_INFO_ALIGN, sp);
/* For qemu, there is no lazy fp context switch, so fp always present. */
extctx->flags = SC_USED_FP;
if (FIELD_EX64(env->CSR_EUEN, CSR_EUEN, ASXE)) {
sp = extframe_alloc(extctx, &extctx->lasx,
sizeof(struct target_lasx_context), LASX_CTX_ALIGN, sp);
} else if (FIELD_EX64(env->CSR_EUEN, CSR_EUEN, SXE)) {
sp = extframe_alloc(extctx, &extctx->lsx,
sizeof(struct target_lsx_context), LSX_CTX_ALIGN, sp);
} else {
sp = extframe_alloc(extctx, &extctx->fpu,
sizeof(struct target_fpu_context), FPU_CTX_ALIGN, sp);
}
return sp;
}
static void setup_sigframe(CPULoongArchState *env,
struct target_sigcontext *sc,
struct extctx_layout *extctx)
{
struct target_sctx_info *info;
int i;
__put_user(extctx->flags, &sc->sc_flags);
__put_user(env->pc, &sc->sc_pc);
__put_user(0, &sc->sc_regs[0]);
for (i = 1; i < 32; ++i) {
__put_user(env->gpr[i], &sc->sc_regs[i]);
}
/*
* Set extension context
*/
if (FIELD_EX64(env->CSR_EUEN, CSR_EUEN, ASXE)) {
struct target_lasx_context *lasx_ctx;
info = extctx->lasx.haddr;
__put_user(LASX_CTX_MAGIC, &info->magic);
__put_user(extctx->lasx.size, &info->size);
lasx_ctx = (struct target_lasx_context *)(info + 1);
for (i = 0; i < 32; ++i) {
__put_user(env->fpr[i].vreg.UD(0), &lasx_ctx->regs[4 * i]);
__put_user(env->fpr[i].vreg.UD(1), &lasx_ctx->regs[4 * i + 1]);
__put_user(env->fpr[i].vreg.UD(2), &lasx_ctx->regs[4 * i + 2]);
__put_user(env->fpr[i].vreg.UD(3), &lasx_ctx->regs[4 * i + 3]);
}
__put_user(read_fcc(env), &lasx_ctx->fcc);
__put_user(env->fcsr0, &lasx_ctx->fcsr);
} else if (FIELD_EX64(env->CSR_EUEN, CSR_EUEN, SXE)) {
struct target_lsx_context *lsx_ctx;
info = extctx->lsx.haddr;
__put_user(LSX_CTX_MAGIC, &info->magic);
__put_user(extctx->lsx.size, &info->size);
lsx_ctx = (struct target_lsx_context *)(info + 1);
for (i = 0; i < 32; ++i) {
__put_user(env->fpr[i].vreg.UD(0), &lsx_ctx->regs[2 * i]);
__put_user(env->fpr[i].vreg.UD(1), &lsx_ctx->regs[2 * i + 1]);
}
__put_user(read_fcc(env), &lsx_ctx->fcc);
__put_user(env->fcsr0, &lsx_ctx->fcsr);
} else {
struct target_fpu_context *fpu_ctx;
info = extctx->fpu.haddr;
__put_user(FPU_CTX_MAGIC, &info->magic);
__put_user(extctx->fpu.size, &info->size);
fpu_ctx = (struct target_fpu_context *)(info + 1);
for (i = 0; i < 32; ++i) {
__put_user(env->fpr[i].vreg.UD(0), &fpu_ctx->regs[i]);
}
__put_user(read_fcc(env), &fpu_ctx->fcc);
__put_user(env->fcsr0, &fpu_ctx->fcsr);
}
/*
* Set end context
*/
info = extctx->end.haddr;
__put_user(0, &info->magic);
__put_user(0, &info->size);
}
static bool parse_extcontext(struct extctx_layout *extctx, abi_ptr frame)
{
memset(extctx, 0, sizeof(*extctx));
while (1) {
abi_uint magic, size;
if (get_user_u32(magic, frame) || get_user_u32(size, frame + 4)) {
return false;
}
switch (magic) {
case 0: /* END */
extctx->end.gaddr = frame;
extctx->end.size = size;
extctx->size += size;
return true;
case FPU_CTX_MAGIC:
if (size < (sizeof(struct target_sctx_info) +
sizeof(struct target_fpu_context))) {
return false;
}
extctx->fpu.gaddr = frame;
extctx->fpu.size = size;
extctx->size += size;
break;
case LSX_CTX_MAGIC:
if (size < (sizeof(struct target_sctx_info) +
sizeof(struct target_lsx_context))) {
return false;
}
extctx->lsx.gaddr = frame;
extctx->lsx.size = size;
extctx->size += size;
break;
case LASX_CTX_MAGIC:
if (size < (sizeof(struct target_sctx_info) +
sizeof(struct target_lasx_context))) {
return false;
}
extctx->lasx.gaddr = frame;
extctx->lasx.size = size;
extctx->size += size;
break;
default:
return false;
}
frame += size;
}
}
static void restore_sigframe(CPULoongArchState *env,
struct target_sigcontext *sc,
struct extctx_layout *extctx)
{
int i;
abi_ulong fcc;
__get_user(env->pc, &sc->sc_pc);
for (i = 1; i < 32; ++i) {
__get_user(env->gpr[i], &sc->sc_regs[i]);
}
if (extctx->lasx.haddr) {
struct target_lasx_context *lasx_ctx =
extctx->lasx.haddr + sizeof(struct target_sctx_info);
for (i = 0; i < 32; ++i) {
__get_user(env->fpr[i].vreg.UD(0), &lasx_ctx->regs[4 * i]);
__get_user(env->fpr[i].vreg.UD(1), &lasx_ctx->regs[4 * i + 1]);
__get_user(env->fpr[i].vreg.UD(2), &lasx_ctx->regs[4 * i + 2]);
__get_user(env->fpr[i].vreg.UD(3), &lasx_ctx->regs[4 * i + 3]);
}
__get_user(fcc, &lasx_ctx->fcc);
write_fcc(env, fcc);
__get_user(env->fcsr0, &lasx_ctx->fcsr);
restore_fp_status(env);
} else if (extctx->lsx.haddr) {
struct target_lsx_context *lsx_ctx =
extctx->lsx.haddr + sizeof(struct target_sctx_info);
for (i = 0; i < 32; ++i) {
__get_user(env->fpr[i].vreg.UD(0), &lsx_ctx->regs[2 * i]);
__get_user(env->fpr[i].vreg.UD(1), &lsx_ctx->regs[2 * i + 1]);
}
__get_user(fcc, &lsx_ctx->fcc);
write_fcc(env, fcc);
__get_user(env->fcsr0, &lsx_ctx->fcsr);
restore_fp_status(env);
} else if (extctx->fpu.haddr) {
struct target_fpu_context *fpu_ctx =
extctx->fpu.haddr + sizeof(struct target_sctx_info);
for (i = 0; i < 32; ++i) {
__get_user(env->fpr[i].vreg.UD(0), &fpu_ctx->regs[i]);
}
__get_user(fcc, &fpu_ctx->fcc);
write_fcc(env, fcc);
__get_user(env->fcsr0, &fpu_ctx->fcsr);
restore_fp_status(env);
}
}
/*
* Determine which stack to use.
*/
static abi_ptr get_sigframe(struct target_sigaction *ka,
CPULoongArchState *env,
struct extctx_layout *extctx)
{
abi_ulong sp;
sp = target_sigsp(get_sp_from_cpustate(env), ka);
sp = ROUND_DOWN(sp, 16);
sp = setup_extcontext(env, extctx, sp);
sp -= sizeof(struct target_rt_sigframe);
assert(QEMU_IS_ALIGNED(sp, 16));
return sp;
}
void setup_rt_frame(int sig, struct target_sigaction *ka,
target_siginfo_t *info,
target_sigset_t *set, CPULoongArchState *env)
{
struct target_rt_sigframe *frame;
struct extctx_layout extctx;
abi_ptr frame_addr;
int i;
frame_addr = get_sigframe(ka, env, &extctx);
trace_user_setup_rt_frame(env, frame_addr);
frame = lock_user(VERIFY_WRITE, frame_addr,
sizeof(*frame) + extctx.size, 0);
if (!frame) {
force_sigsegv(sig);
return;
}
if (FIELD_EX64(env->CSR_EUEN, CSR_EUEN, ASXE)) {
extctx.lasx.haddr = (void *)frame + (extctx.lasx.gaddr - frame_addr);
extctx.end.haddr = (void *)frame + (extctx.end.gaddr - frame_addr);
} else if (FIELD_EX64(env->CSR_EUEN, CSR_EUEN, SXE)) {
extctx.lsx.haddr = (void *)frame + (extctx.lsx.gaddr - frame_addr);
extctx.end.haddr = (void *)frame + (extctx.end.gaddr - frame_addr);
} else {
extctx.fpu.haddr = (void *)frame + (extctx.fpu.gaddr - frame_addr);
extctx.end.haddr = (void *)frame + (extctx.end.gaddr - frame_addr);
}
tswap_siginfo(&frame->rs_info, info);
__put_user(0, &frame->rs_uc.tuc_flags);
__put_user(0, &frame->rs_uc.tuc_link);
target_save_altstack(&frame->rs_uc.tuc_stack, env);
setup_sigframe(env, &frame->rs_uc.tuc_mcontext, &extctx);
for (i = 0; i < TARGET_NSIG_WORDS; i++) {
__put_user(set->sig[i], &frame->rs_uc.tuc_sigmask.sig[i]);
}
env->gpr[4] = sig;
env->gpr[5] = frame_addr + offsetof(struct target_rt_sigframe, rs_info);
env->gpr[6] = frame_addr + offsetof(struct target_rt_sigframe, rs_uc);
env->gpr[3] = frame_addr;
env->gpr[1] = default_rt_sigreturn;
env->pc = ka->_sa_handler;
unlock_user(frame, frame_addr, sizeof(*frame) + extctx.size);
}
long do_rt_sigreturn(CPULoongArchState *env)
{
struct target_rt_sigframe *frame;
struct extctx_layout extctx;
abi_ulong frame_addr;
sigset_t blocked;
frame_addr = env->gpr[3];
trace_user_do_rt_sigreturn(env, frame_addr);
if (!parse_extcontext(&extctx, frame_addr + sizeof(*frame))) {
goto badframe;
}
frame = lock_user(VERIFY_READ, frame_addr,
sizeof(*frame) + extctx.size, 1);
if (!frame) {
goto badframe;
}
if (extctx.lasx.gaddr) {
extctx.lasx.haddr = (void *)frame + (extctx.lasx.gaddr - frame_addr);
} else if (extctx.lsx.gaddr) {
extctx.lsx.haddr = (void *)frame + (extctx.lsx.gaddr - frame_addr);
} else if (extctx.fpu.gaddr) {
extctx.fpu.haddr = (void *)frame + (extctx.fpu.gaddr - frame_addr);
}
target_to_host_sigset(&blocked, &frame->rs_uc.tuc_sigmask);
set_sigmask(&blocked);
restore_sigframe(env, &frame->rs_uc.tuc_mcontext, &extctx);
target_restore_altstack(&frame->rs_uc.tuc_stack, env);
unlock_user(frame, frame_addr, 0);
return -QEMU_ESIGRETURN;
badframe:
force_sig(TARGET_SIGSEGV);
return -QEMU_ESIGRETURN;
}
void setup_sigtramp(abi_ulong sigtramp_page)
{
uint32_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 8, 0);
assert(tramp != NULL);
__put_user(0x03822c0b, tramp + 0); /* ori a7, zero, 0x8b */
__put_user(0x002b0000, tramp + 1); /* syscall 0 */
default_rt_sigreturn = sigtramp_page;
unlock_user(tramp, sigtramp_page, 8);
}