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qemu/linux-user/i386/signal.c
Richard Henderson 701890bdd0 target/i386: Pass host pointer and size to cpu_x86_{xsave,xrstor} 
We have already validated the memory region in the course of
validating the signal frame.  No need to do it again within
the helper function.

In addition, return failure when the header contains invalid
xstate_bv.  The kernel handles this via exception handling
within XSTATE_OP within xrstor_from_user_sigframe.

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2024-05-26 15:49:58 -07:00

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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"
#include "user/tswap-target.h"
/* from the Linux kernel - /arch/x86/include/uapi/asm/sigcontext.h */
#define TARGET_FP_XSTATE_MAGIC1 0x46505853U /* FPXS */
#define TARGET_FP_XSTATE_MAGIC2 0x46505845U /* FPXE */
#define TARGET_FP_XSTATE_MAGIC2_SIZE 4
struct target_fpreg {
uint16_t significand[4];
uint16_t exponent;
};
/* Legacy x87 fpu state format for FSAVE/FRESTOR. */
struct target_fregs_state {
uint32_t cwd;
uint32_t swd;
uint32_t twd;
uint32_t fip;
uint32_t fcs;
uint32_t foo;
uint32_t fos;
struct target_fpreg st[8];
/* Software status information [not touched by FSAVE]. */
uint16_t status;
uint16_t magic; /* 0xffff: FPU data only, 0x0000: FXSR FPU data */
};
QEMU_BUILD_BUG_ON(sizeof(struct target_fregs_state) != 32 + 80);
struct target_fpx_sw_bytes {
uint32_t magic1;
uint32_t extended_size;
uint64_t xfeatures;
uint32_t xstate_size;
uint32_t reserved[7];
};
QEMU_BUILD_BUG_ON(sizeof(struct target_fpx_sw_bytes) != 12*4);
struct target_fpstate_32 {
struct target_fregs_state fpstate;
X86LegacyXSaveArea fxstate;
};
struct target_sigcontext_32 {
uint16_t gs, __gsh;
uint16_t fs, __fsh;
uint16_t es, __esh;
uint16_t ds, __dsh;
uint32_t edi;
uint32_t esi;
uint32_t ebp;
uint32_t esp;
uint32_t ebx;
uint32_t edx;
uint32_t ecx;
uint32_t eax;
uint32_t trapno;
uint32_t err;
uint32_t eip;
uint16_t cs, __csh;
uint32_t eflags;
uint32_t esp_at_signal;
uint16_t ss, __ssh;
uint32_t fpstate; /* pointer */
uint32_t oldmask;
uint32_t cr2;
};
struct target_sigcontext_64 {
uint64_t r8;
uint64_t r9;
uint64_t r10;
uint64_t r11;
uint64_t r12;
uint64_t r13;
uint64_t r14;
uint64_t r15;
uint64_t rdi;
uint64_t rsi;
uint64_t rbp;
uint64_t rbx;
uint64_t rdx;
uint64_t rax;
uint64_t rcx;
uint64_t rsp;
uint64_t rip;
uint64_t eflags;
uint16_t cs;
uint16_t gs;
uint16_t fs;
uint16_t ss;
uint64_t err;
uint64_t trapno;
uint64_t oldmask;
uint64_t cr2;
uint64_t fpstate; /* pointer */
uint64_t padding[8];
};
#ifndef TARGET_X86_64
# define target_sigcontext target_sigcontext_32
#else
# define target_sigcontext target_sigcontext_64
#endif
/* see Linux/include/uapi/asm-generic/ucontext.h */
struct target_ucontext {
abi_ulong tuc_flags;
abi_ulong tuc_link;
target_stack_t tuc_stack;
struct target_sigcontext tuc_mcontext;
target_sigset_t tuc_sigmask; /* mask last for extensibility */
};
#ifndef TARGET_X86_64
struct sigframe {
abi_ulong pretcode;
int sig;
struct target_sigcontext sc;
/*
* The actual fpstate is placed after retcode[] below, to make room
* for the variable-sized xsave data. The older unused fpstate has
* to be kept to avoid changing the offset of extramask[], which
* is part of the ABI.
*/
struct target_fpstate_32 fpstate_unused;
abi_ulong extramask[TARGET_NSIG_WORDS-1];
char retcode[8];
/* fp state follows here */
};
struct rt_sigframe {
abi_ulong pretcode;
int sig;
abi_ulong pinfo;
abi_ulong puc;
struct target_siginfo info;
struct target_ucontext uc;
char retcode[8];
/* fp state follows here */
};
/*
* Verify that vdso-asmoffset.h constants match.
*/
#include "i386/vdso-asmoffset.h"
QEMU_BUILD_BUG_ON(offsetof(struct sigframe, sc.eip)
!= SIGFRAME_SIGCONTEXT_eip);
QEMU_BUILD_BUG_ON(offsetof(struct rt_sigframe, uc.tuc_mcontext.eip)
!= RT_SIGFRAME_SIGCONTEXT_eip);
#else
struct rt_sigframe {
abi_ulong pretcode;
struct target_ucontext uc;
struct target_siginfo info;
/* fp state follows here */
};
#endif
typedef enum {
#ifndef TARGET_X86_64
FPSTATE_FSAVE,
#endif
FPSTATE_FXSAVE,
FPSTATE_XSAVE
} FPStateKind;
static FPStateKind get_fpstate_kind(CPUX86State *env)
{
if (env->features[FEAT_1_ECX] & CPUID_EXT_XSAVE) {
return FPSTATE_XSAVE;
}
#ifdef TARGET_X86_64
return FPSTATE_FXSAVE;
#else
if (env->features[FEAT_1_EDX] & CPUID_FXSR) {
return FPSTATE_FXSAVE;
}
return FPSTATE_FSAVE;
#endif
}
static unsigned get_fpstate_size(CPUX86State *env, FPStateKind fpkind)
{
/*
* Kernel:
* fpu__alloc_mathframe
* xstate_sigframe_size(current->thread.fpu.fpstate);
* size = fpstate->user_size
* use_xsave() ? size + FP_XSTATE_MAGIC2_SIZE : size
* where fpstate->user_size is computed at init in
* fpu__init_system_xstate_size_legacy and
* fpu__init_system_xstate.
*
* Here we have no place to pre-compute, so inline it all.
*/
switch (fpkind) {
case FPSTATE_XSAVE:
return (xsave_area_size(env->xcr0, false)
+ TARGET_FP_XSTATE_MAGIC2_SIZE);
case FPSTATE_FXSAVE:
return sizeof(X86LegacyXSaveArea);
#ifndef TARGET_X86_64
case FPSTATE_FSAVE:
return sizeof(struct target_fregs_state);
#endif
}
g_assert_not_reached();
}
static abi_ptr get_sigframe(struct target_sigaction *ka, CPUX86State *env,
unsigned frame_size, FPStateKind fpkind,
abi_ptr *fpstate, abi_ptr *fxstate, abi_ptr *fpend)
{
abi_ptr sp;
unsigned math_size;
/* Default to using normal stack */
sp = get_sp_from_cpustate(env);
#ifdef TARGET_X86_64
sp -= 128; /* this is the redzone */
#endif
/* This is the X/Open sanctioned signal stack switching. */
if (ka->sa_flags & TARGET_SA_ONSTACK) {
sp = target_sigsp(sp, ka);
} else {
#ifndef TARGET_X86_64
/* This is the legacy signal stack switching. */
if ((env->segs[R_SS].selector & 0xffff) != __USER_DS
&& !(ka->sa_flags & TARGET_SA_RESTORER)
&& ka->sa_restorer) {
sp = ka->sa_restorer;
}
#endif
}
math_size = get_fpstate_size(env, fpkind);
sp = ROUND_DOWN(sp - math_size, 64);
*fpend = sp + math_size;
*fxstate = sp;
#ifndef TARGET_X86_64
if (fpkind != FPSTATE_FSAVE) {
sp -= sizeof(struct target_fregs_state);
}
#endif
*fpstate = sp;
sp -= frame_size;
/*
* Align the stack pointer according to the ABI, i.e. so that on
* function entry ((sp + sizeof(return_addr)) & 15) == 0.
*/
sp += sizeof(target_ulong);
sp = ROUND_DOWN(sp, 16);
sp -= sizeof(target_ulong);
return sp;
}
/*
* Set up a signal frame.
*/
static void fxsave_sigcontext(CPUX86State *env, X86LegacyXSaveArea *fxstate)
{
struct target_fpx_sw_bytes *sw = (void *)&fxstate->sw_reserved;
cpu_x86_fxsave(env, fxstate, sizeof(*fxstate));
__put_user(0, &sw->magic1);
}
static void xsave_sigcontext(CPUX86State *env,
X86LegacyXSaveArea *fxstate,
abi_ptr fpstate_addr,
abi_ptr xstate_addr,
abi_ptr fpend_addr)
{
struct target_fpx_sw_bytes *sw = (void *)&fxstate->sw_reserved;
/*
* extended_size is the offset from fpstate_addr to right after
* the end of the extended save states. On 32-bit that includes
* the legacy FSAVE area.
*/
uint32_t extended_size = fpend_addr - fpstate_addr;
/* Recover xstate_size by removing magic2. */
uint32_t xstate_size = (fpend_addr - xstate_addr
- TARGET_FP_XSTATE_MAGIC2_SIZE);
/* magic2 goes just after xstate. */
uint32_t *magic2 = (void *)fxstate + xstate_size;
/* xstate_addr must be 64 byte aligned for xsave */
assert(!(xstate_addr & 0x3f));
/* Zero the header, XSAVE *adds* features to an existing save state. */
memset(fxstate + 1, 0, sizeof(X86XSaveHeader));
cpu_x86_xsave(env, fxstate, fpend_addr - xstate_addr, env->xcr0);
__put_user(TARGET_FP_XSTATE_MAGIC1, &sw->magic1);
__put_user(extended_size, &sw->extended_size);
__put_user(env->xcr0, &sw->xfeatures);
__put_user(xstate_size, &sw->xstate_size);
__put_user(TARGET_FP_XSTATE_MAGIC2, magic2);
}
static void setup_sigcontext(CPUX86State *env,
struct target_sigcontext *sc,
abi_ulong mask, FPStateKind fpkind,
struct target_fregs_state *fpstate,
abi_ptr fpstate_addr,
X86LegacyXSaveArea *fxstate,
abi_ptr fxstate_addr,
abi_ptr fpend_addr)
{
CPUState *cs = env_cpu(env);
#ifndef TARGET_X86_64
uint16_t magic;
/* already locked in setup_frame() */
__put_user(env->segs[R_GS].selector, (uint32_t *)&sc->gs);
__put_user(env->segs[R_FS].selector, (uint32_t *)&sc->fs);
__put_user(env->segs[R_ES].selector, (uint32_t *)&sc->es);
__put_user(env->segs[R_DS].selector, (uint32_t *)&sc->ds);
__put_user(env->regs[R_EDI], &sc->edi);
__put_user(env->regs[R_ESI], &sc->esi);
__put_user(env->regs[R_EBP], &sc->ebp);
__put_user(env->regs[R_ESP], &sc->esp);
__put_user(env->regs[R_EBX], &sc->ebx);
__put_user(env->regs[R_EDX], &sc->edx);
__put_user(env->regs[R_ECX], &sc->ecx);
__put_user(env->regs[R_EAX], &sc->eax);
__put_user(cs->exception_index, &sc->trapno);
__put_user(env->error_code, &sc->err);
__put_user(env->eip, &sc->eip);
__put_user(env->segs[R_CS].selector, (uint32_t *)&sc->cs);
__put_user(env->eflags, &sc->eflags);
__put_user(env->regs[R_ESP], &sc->esp_at_signal);
__put_user(env->segs[R_SS].selector, (uint32_t *)&sc->ss);
cpu_x86_fsave(env, fpstate, sizeof(*fpstate));
fpstate->status = fpstate->swd;
magic = (fpkind == FPSTATE_FSAVE ? 0 : 0xffff);
__put_user(magic, &fpstate->magic);
#else
__put_user(env->regs[R_EDI], &sc->rdi);
__put_user(env->regs[R_ESI], &sc->rsi);
__put_user(env->regs[R_EBP], &sc->rbp);
__put_user(env->regs[R_ESP], &sc->rsp);
__put_user(env->regs[R_EBX], &sc->rbx);
__put_user(env->regs[R_EDX], &sc->rdx);
__put_user(env->regs[R_ECX], &sc->rcx);
__put_user(env->regs[R_EAX], &sc->rax);
__put_user(env->regs[8], &sc->r8);
__put_user(env->regs[9], &sc->r9);
__put_user(env->regs[10], &sc->r10);
__put_user(env->regs[11], &sc->r11);
__put_user(env->regs[12], &sc->r12);
__put_user(env->regs[13], &sc->r13);
__put_user(env->regs[14], &sc->r14);
__put_user(env->regs[15], &sc->r15);
__put_user(cs->exception_index, &sc->trapno);
__put_user(env->error_code, &sc->err);
__put_user(env->eip, &sc->rip);
__put_user(env->eflags, &sc->eflags);
__put_user(env->segs[R_CS].selector, &sc->cs);
__put_user((uint16_t)0, &sc->gs);
__put_user((uint16_t)0, &sc->fs);
__put_user(env->segs[R_SS].selector, &sc->ss);
#endif
switch (fpkind) {
case FPSTATE_XSAVE:
xsave_sigcontext(env, fxstate, fpstate_addr, fxstate_addr, fpend_addr);
break;
case FPSTATE_FXSAVE:
fxsave_sigcontext(env, fxstate);
break;
default:
break;
}
__put_user(fpstate_addr, &sc->fpstate);
/* non-iBCS2 extensions.. */
__put_user(mask, &sc->oldmask);
__put_user(env->cr[2], &sc->cr2);
}
#ifndef TARGET_X86_64
static void install_sigtramp(void *tramp)
{
/* This is popl %eax ; movl $syscall,%eax ; int $0x80 */
__put_user(0xb858, (uint16_t *)(tramp + 0));
__put_user(TARGET_NR_sigreturn, (int32_t *)(tramp + 2));
__put_user(0x80cd, (uint16_t *)(tramp + 6));
}
static void install_rt_sigtramp(void *tramp)
{
/* This is movl $syscall,%eax ; int $0x80 */
__put_user(0xb8, (uint8_t *)(tramp + 0));
__put_user(TARGET_NR_rt_sigreturn, (int32_t *)(tramp + 1));
__put_user(0x80cd, (uint16_t *)(tramp + 5));
}
/* compare linux/arch/i386/kernel/signal.c:setup_frame() */
void setup_frame(int sig, struct target_sigaction *ka,
target_sigset_t *set, CPUX86State *env)
{
abi_ptr frame_addr, fpstate_addr, fxstate_addr, fpend_addr;
struct sigframe *frame;
struct target_fregs_state *fpstate;
X86LegacyXSaveArea *fxstate;
unsigned total_size;
FPStateKind fpkind;
fpkind = get_fpstate_kind(env);
frame_addr = get_sigframe(ka, env, sizeof(struct sigframe), fpkind,
&fpstate_addr, &fxstate_addr, &fpend_addr);
trace_user_setup_frame(env, frame_addr);
total_size = fpend_addr - frame_addr;
frame = lock_user(VERIFY_WRITE, frame_addr, total_size, 0);
if (!frame) {
force_sigsegv(sig);
return;
}
fxstate = (void *)frame + (fxstate_addr - frame_addr);
#ifdef TARGET_X86_64
fpstate = NULL;
#else
fpstate = (void *)frame + (fpstate_addr - frame_addr);
#endif
setup_sigcontext(env, &frame->sc, set->sig[0], fpkind,
fpstate, fpstate_addr, fxstate, fxstate_addr, fpend_addr);
for (int i = 1; i < TARGET_NSIG_WORDS; i++) {
__put_user(set->sig[i], &frame->extramask[i - 1]);
}
/* Set up to return from userspace. If provided, use a stub
already in userspace. */
if (ka->sa_flags & TARGET_SA_RESTORER) {
__put_user(ka->sa_restorer, &frame->pretcode);
} else {
/* This is no longer used, but is retained for ABI compatibility. */
install_sigtramp(frame->retcode);
__put_user(default_sigreturn, &frame->pretcode);
}
unlock_user(frame, frame_addr, total_size);
/* Set up registers for signal handler */
env->regs[R_ESP] = frame_addr;
env->eip = ka->_sa_handler;
/* Store argument for both -mregparm=3 and standard. */
env->regs[R_EAX] = sig;
__put_user(sig, &frame->sig);
/* The kernel clears EDX and ECX even though there is only one arg. */
env->regs[R_EDX] = 0;
env->regs[R_ECX] = 0;
cpu_x86_load_seg(env, R_DS, __USER_DS);
cpu_x86_load_seg(env, R_ES, __USER_DS);
cpu_x86_load_seg(env, R_SS, __USER_DS);
cpu_x86_load_seg(env, R_CS, __USER_CS);
env->eflags &= ~TF_MASK;
}
#endif
/* compare linux/arch/x86/kernel/signal.c:setup_rt_frame() */
void setup_rt_frame(int sig, struct target_sigaction *ka,
target_siginfo_t *info,
target_sigset_t *set, CPUX86State *env)
{
abi_ptr frame_addr, fpstate_addr, fxstate_addr, fpend_addr;
struct rt_sigframe *frame;
X86LegacyXSaveArea *fxstate;
struct target_fregs_state *fpstate;
unsigned total_size;
FPStateKind fpkind;
fpkind = get_fpstate_kind(env);
frame_addr = get_sigframe(ka, env, sizeof(struct rt_sigframe), fpkind,
&fpstate_addr, &fxstate_addr, &fpend_addr);
trace_user_setup_rt_frame(env, frame_addr);
total_size = fpend_addr - frame_addr;
frame = lock_user(VERIFY_WRITE, frame_addr, total_size, 0);
if (!frame) {
goto give_sigsegv;
}
if (ka->sa_flags & TARGET_SA_SIGINFO) {
frame->info = *info;
}
/* Create the ucontext. */
__put_user(fpkind == FPSTATE_XSAVE, &frame->uc.tuc_flags);
__put_user(0, &frame->uc.tuc_link);
target_save_altstack(&frame->uc.tuc_stack, env);
fxstate = (void *)frame + (fxstate_addr - frame_addr);
#ifdef TARGET_X86_64
fpstate = NULL;
#else
fpstate = (void *)frame + (fpstate_addr - frame_addr);
#endif
setup_sigcontext(env, &frame->uc.tuc_mcontext, set->sig[0], fpkind,
fpstate, fpstate_addr, fxstate, fxstate_addr, fpend_addr);
for (int i = 0; i < TARGET_NSIG_WORDS; i++) {
__put_user(set->sig[i], &frame->uc.tuc_sigmask.sig[i]);
}
/*
* Set up to return from userspace. If provided, use a stub
* already in userspace.
*/
if (ka->sa_flags & TARGET_SA_RESTORER) {
__put_user(ka->sa_restorer, &frame->pretcode);
} else {
#ifdef TARGET_X86_64
/* For x86_64, SA_RESTORER is required ABI. */
goto give_sigsegv;
#else
/* This is no longer used, but is retained for ABI compatibility. */
install_rt_sigtramp(frame->retcode);
__put_user(default_rt_sigreturn, &frame->pretcode);
#endif
}
/* Set up registers for signal handler */
env->regs[R_ESP] = frame_addr;
env->eip = ka->_sa_handler;
#ifndef TARGET_X86_64
/* Store arguments for both -mregparm=3 and standard. */
env->regs[R_EAX] = sig;
__put_user(sig, &frame->sig);
env->regs[R_EDX] = frame_addr + offsetof(struct rt_sigframe, info);
__put_user(env->regs[R_EDX], &frame->pinfo);
env->regs[R_ECX] = frame_addr + offsetof(struct rt_sigframe, uc);
__put_user(env->regs[R_ECX], &frame->puc);
#else
env->regs[R_EAX] = 0;
env->regs[R_EDI] = sig;
env->regs[R_ESI] = frame_addr + offsetof(struct rt_sigframe, info);
env->regs[R_EDX] = frame_addr + offsetof(struct rt_sigframe, uc);
#endif
unlock_user(frame, frame_addr, total_size);
cpu_x86_load_seg(env, R_DS, __USER_DS);
cpu_x86_load_seg(env, R_ES, __USER_DS);
cpu_x86_load_seg(env, R_CS, __USER_CS);
cpu_x86_load_seg(env, R_SS, __USER_DS);
env->eflags &= ~TF_MASK;
return;
give_sigsegv:
force_sigsegv(sig);
}
/*
* Restore a signal frame.
*/
static bool xrstor_sigcontext(CPUX86State *env, FPStateKind fpkind,
X86LegacyXSaveArea *fxstate,
abi_ptr fxstate_addr)
{
struct target_fpx_sw_bytes *sw = (void *)&fxstate->sw_reserved;
uint32_t magic1, magic2;
uint32_t extended_size, xstate_size, min_size, max_size;
uint64_t xfeatures;
void *xstate;
bool ok;
switch (fpkind) {
case FPSTATE_XSAVE:
magic1 = tswap32(sw->magic1);
extended_size = tswap32(sw->extended_size);
xstate_size = tswap32(sw->xstate_size);
min_size = sizeof(X86LegacyXSaveArea) + sizeof(X86XSaveHeader);
max_size = xsave_area_size(env->xcr0, false);
/* Check for the first magic field and other error scenarios. */
if (magic1 != TARGET_FP_XSTATE_MAGIC1 ||
xstate_size < min_size ||
xstate_size > max_size ||
xstate_size > extended_size) {
break;
}
/*
* Restore the features indicated in the frame, masked by
* those currently enabled. Re-check the frame size.
* ??? It is not clear where the kernel does this, but it
* is not in check_xstate_in_sigframe, and so (probably)
* does not fall back to fxrstor.
*/
xfeatures = tswap64(sw->xfeatures) & env->xcr0;
min_size = xsave_area_size(xfeatures, false);
if (xstate_size < min_size) {
return false;
}
/* Re-lock the entire xstate area, with the extensions and magic. */
xstate = lock_user(VERIFY_READ, fxstate_addr,
xstate_size + TARGET_FP_XSTATE_MAGIC2_SIZE, 1);
if (!xstate) {
return false;
}
/*
* Check for the presence of second magic word at the end of memory
* layout. This detects the case where the user just copied the legacy
* fpstate layout with out copying the extended state information
* in the memory layout.
*/
magic2 = tswap32(*(uint32_t *)(xstate + xstate_size));
if (magic2 != TARGET_FP_XSTATE_MAGIC2) {
unlock_user(xstate, fxstate_addr, 0);
break;
}
ok = cpu_x86_xrstor(env, xstate, xstate_size, xfeatures);
unlock_user(xstate, fxstate_addr, 0);
return ok;
default:
break;
}
cpu_x86_fxrstor(env, fxstate, sizeof(*fxstate));
return true;
}
#ifndef TARGET_X86_64
static bool frstor_sigcontext(CPUX86State *env, FPStateKind fpkind,
struct target_fregs_state *fpstate,
abi_ptr fpstate_addr,
X86LegacyXSaveArea *fxstate,
abi_ptr fxstate_addr)
{
switch (fpkind) {
case FPSTATE_XSAVE:
if (!xrstor_sigcontext(env, fpkind, fxstate, fxstate_addr)) {
return false;
}
break;
case FPSTATE_FXSAVE:
cpu_x86_fxrstor(env, fxstate, sizeof(*fxstate));
break;
case FPSTATE_FSAVE:
break;
default:
g_assert_not_reached();
}
/*
* Copy the legacy state because the FP portion of the FX frame has
* to be ignored for histerical raisins. The kernel folds the two
* states together and then performs a single load; here we perform
* the merge within ENV by loading XSTATE/FXSTATE first, then
* overriding with the FSTATE afterward.
*/
cpu_x86_frstor(env, fpstate, sizeof(*fpstate));
return true;
}
#endif
static bool restore_sigcontext(CPUX86State *env, struct target_sigcontext *sc)
{
abi_ptr fpstate_addr;
unsigned tmpflags, math_size;
FPStateKind fpkind;
void *fpstate;
bool ok;
#ifndef TARGET_X86_64
cpu_x86_load_seg(env, R_GS, tswap16(sc->gs));
cpu_x86_load_seg(env, R_FS, tswap16(sc->fs));
cpu_x86_load_seg(env, R_ES, tswap16(sc->es));
cpu_x86_load_seg(env, R_DS, tswap16(sc->ds));
env->regs[R_EDI] = tswapl(sc->edi);
env->regs[R_ESI] = tswapl(sc->esi);
env->regs[R_EBP] = tswapl(sc->ebp);
env->regs[R_ESP] = tswapl(sc->esp);
env->regs[R_EBX] = tswapl(sc->ebx);
env->regs[R_EDX] = tswapl(sc->edx);
env->regs[R_ECX] = tswapl(sc->ecx);
env->regs[R_EAX] = tswapl(sc->eax);
env->eip = tswapl(sc->eip);
#else
env->regs[8] = tswapl(sc->r8);
env->regs[9] = tswapl(sc->r9);
env->regs[10] = tswapl(sc->r10);
env->regs[11] = tswapl(sc->r11);
env->regs[12] = tswapl(sc->r12);
env->regs[13] = tswapl(sc->r13);
env->regs[14] = tswapl(sc->r14);
env->regs[15] = tswapl(sc->r15);
env->regs[R_EDI] = tswapl(sc->rdi);
env->regs[R_ESI] = tswapl(sc->rsi);
env->regs[R_EBP] = tswapl(sc->rbp);
env->regs[R_EBX] = tswapl(sc->rbx);
env->regs[R_EDX] = tswapl(sc->rdx);
env->regs[R_EAX] = tswapl(sc->rax);
env->regs[R_ECX] = tswapl(sc->rcx);
env->regs[R_ESP] = tswapl(sc->rsp);
env->eip = tswapl(sc->rip);
#endif
cpu_x86_load_seg(env, R_CS, lduw_p(&sc->cs) | 3);
cpu_x86_load_seg(env, R_SS, lduw_p(&sc->ss) | 3);
tmpflags = tswapl(sc->eflags);
env->eflags = (env->eflags & ~0x40DD5) | (tmpflags & 0x40DD5);
fpstate_addr = tswapl(sc->fpstate);
if (fpstate_addr == 0) {
return true;
}
fpkind = get_fpstate_kind(env);
math_size = get_fpstate_size(env, fpkind);
#ifndef TARGET_X86_64
if (fpkind != FPSTATE_FSAVE) {
math_size += sizeof(struct target_fregs_state);
}
#endif
fpstate = lock_user(VERIFY_READ, fpstate_addr, math_size, 1);
if (!fpstate) {
return false;
}
#ifdef TARGET_X86_64
ok = xrstor_sigcontext(env, fpkind, fpstate, fpstate_addr);
#else
ok = frstor_sigcontext(env, fpkind, fpstate, fpstate_addr,
fpstate + sizeof(struct target_fregs_state),
fpstate_addr + sizeof(struct target_fregs_state));
#endif
unlock_user(fpstate, fpstate_addr, 0);
return ok;
}
/* Note: there is no sigreturn on x86_64, there is only rt_sigreturn */
#ifndef TARGET_X86_64
long do_sigreturn(CPUX86State *env)
{
struct sigframe *frame;
abi_ulong frame_addr = env->regs[R_ESP] - 8;
target_sigset_t target_set;
sigset_t set;
trace_user_do_sigreturn(env, frame_addr);
if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
force_sig(TARGET_SIGSEGV);
return -QEMU_ESIGRETURN;
}
/* Set blocked signals. */
__get_user(target_set.sig[0], &frame->sc.oldmask);
for (int i = 1; i < TARGET_NSIG_WORDS; i++) {
__get_user(target_set.sig[i], &frame->extramask[i - 1]);
}
target_to_host_sigset_internal(&set, &target_set);
set_sigmask(&set);
/* Restore registers */
if (!restore_sigcontext(env, &frame->sc)) {
force_sig(TARGET_SIGSEGV);
}
unlock_user_struct(frame, frame_addr, 0);
return -QEMU_ESIGRETURN;
}
#endif
long do_rt_sigreturn(CPUX86State *env)
{
abi_ulong frame_addr;
struct rt_sigframe *frame;
sigset_t set;
frame_addr = env->regs[R_ESP] - sizeof(abi_ulong);
trace_user_do_rt_sigreturn(env, frame_addr);
if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1))
goto badframe;
target_to_host_sigset(&set, &frame->uc.tuc_sigmask);
set_sigmask(&set);
if (!restore_sigcontext(env, &frame->uc.tuc_mcontext)) {
goto badframe;
}
target_restore_altstack(&frame->uc.tuc_stack, env);
unlock_user_struct(frame, frame_addr, 0);
return -QEMU_ESIGRETURN;
badframe:
unlock_user_struct(frame, frame_addr, 0);
force_sig(TARGET_SIGSEGV);
return -QEMU_ESIGRETURN;
}
#ifndef TARGET_X86_64
void setup_sigtramp(abi_ulong sigtramp_page)
{
uint16_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, 2 * 8, 0);
assert(tramp != NULL);
default_sigreturn = sigtramp_page;
install_sigtramp(tramp);
default_rt_sigreturn = sigtramp_page + 8;
install_rt_sigtramp(tramp + 8);
unlock_user(tramp, sigtramp_page, 2 * 8);
}
#endif
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