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qemu/linux-user/arm/signal.c
Richard Henderson 57a0c9384c linux-user: Rename TARGET_QEMU_ESIGRETURN to QEMU_ESIGRETURN 
This value is fully internal to qemu, and so is not a TARGET define.

Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
2021-12-19 20:47:33 -08:00

631 lines
19 KiB
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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"
struct target_sigcontext {
abi_ulong trap_no;
abi_ulong error_code;
abi_ulong oldmask;
abi_ulong arm_r0;
abi_ulong arm_r1;
abi_ulong arm_r2;
abi_ulong arm_r3;
abi_ulong arm_r4;
abi_ulong arm_r5;
abi_ulong arm_r6;
abi_ulong arm_r7;
abi_ulong arm_r8;
abi_ulong arm_r9;
abi_ulong arm_r10;
abi_ulong arm_fp;
abi_ulong arm_ip;
abi_ulong arm_sp;
abi_ulong arm_lr;
abi_ulong arm_pc;
abi_ulong arm_cpsr;
abi_ulong fault_address;
};
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 */
char __unused[128 - sizeof(target_sigset_t)];
abi_ulong tuc_regspace[128] __attribute__((__aligned__(8)));
};
struct target_user_vfp {
uint64_t fpregs[32];
abi_ulong fpscr;
};
struct target_user_vfp_exc {
abi_ulong fpexc;
abi_ulong fpinst;
abi_ulong fpinst2;
};
struct target_vfp_sigframe {
abi_ulong magic;
abi_ulong size;
struct target_user_vfp ufp;
struct target_user_vfp_exc ufp_exc;
} __attribute__((__aligned__(8)));
struct target_iwmmxt_sigframe {
abi_ulong magic;
abi_ulong size;
uint64_t regs[16];
/* Note that not all the coprocessor control registers are stored here */
uint32_t wcssf;
uint32_t wcasf;
uint32_t wcgr0;
uint32_t wcgr1;
uint32_t wcgr2;
uint32_t wcgr3;
} __attribute__((__aligned__(8)));
#define TARGET_VFP_MAGIC 0x56465001
#define TARGET_IWMMXT_MAGIC 0x12ef842a
struct sigframe
{
struct target_ucontext uc;
abi_ulong retcode[4];
};
struct rt_sigframe
{
struct target_siginfo info;
struct sigframe sig;
};
static abi_ptr sigreturn_fdpic_tramp;
/*
* Up to 3 words of 'retcode' in the sigframe are code,
* with retcode[3] being used by fdpic for the function descriptor.
* This code is not actually executed, but is retained for ABI compat.
*
* We will create a table of 8 retcode variants in the sigtramp page.
* Let each table entry use 3 words.
*/
#define RETCODE_WORDS 3
#define RETCODE_BYTES (RETCODE_WORDS * 4)
static inline int valid_user_regs(CPUARMState *regs)
{
return 1;
}
static void
setup_sigcontext(struct target_sigcontext *sc, /*struct _fpstate *fpstate,*/
CPUARMState *env, abi_ulong mask)
{
__put_user(env->regs[0], &sc->arm_r0);
__put_user(env->regs[1], &sc->arm_r1);
__put_user(env->regs[2], &sc->arm_r2);
__put_user(env->regs[3], &sc->arm_r3);
__put_user(env->regs[4], &sc->arm_r4);
__put_user(env->regs[5], &sc->arm_r5);
__put_user(env->regs[6], &sc->arm_r6);
__put_user(env->regs[7], &sc->arm_r7);
__put_user(env->regs[8], &sc->arm_r8);
__put_user(env->regs[9], &sc->arm_r9);
__put_user(env->regs[10], &sc->arm_r10);
__put_user(env->regs[11], &sc->arm_fp);
__put_user(env->regs[12], &sc->arm_ip);
__put_user(env->regs[13], &sc->arm_sp);
__put_user(env->regs[14], &sc->arm_lr);
__put_user(env->regs[15], &sc->arm_pc);
__put_user(cpsr_read(env), &sc->arm_cpsr);
__put_user(/* current->thread.trap_no */ 0, &sc->trap_no);
__put_user(/* current->thread.error_code */ 0, &sc->error_code);
__put_user(/* current->thread.address */ 0, &sc->fault_address);
__put_user(mask, &sc->oldmask);
}
static inline abi_ulong
get_sigframe(struct target_sigaction *ka, CPUARMState *regs, int framesize)
{
unsigned long sp;
sp = target_sigsp(get_sp_from_cpustate(regs), ka);
/*
* ATPCS B01 mandates 8-byte alignment
*/
return (sp - framesize) & ~7;
}
static int
setup_return(CPUARMState *env, struct target_sigaction *ka, int usig,
struct sigframe *frame, abi_ulong sp_addr)
{
abi_ulong handler = 0;
abi_ulong handler_fdpic_GOT = 0;
abi_ulong retcode;
int thumb, retcode_idx;
int is_fdpic = info_is_fdpic(((TaskState *)thread_cpu->opaque)->info);
bool copy_retcode;
if (is_fdpic) {
/* In FDPIC mode, ka->_sa_handler points to a function
* descriptor (FD). The first word contains the address of the
* handler. The second word contains the value of the PIC
* register (r9). */
abi_ulong funcdesc_ptr = ka->_sa_handler;
if (get_user_ual(handler, funcdesc_ptr)
|| get_user_ual(handler_fdpic_GOT, funcdesc_ptr + 4)) {
return 1;
}
} else {
handler = ka->_sa_handler;
}
thumb = handler & 1;
retcode_idx = thumb + (ka->sa_flags & TARGET_SA_SIGINFO ? 2 : 0);
uint32_t cpsr = cpsr_read(env);
cpsr &= ~CPSR_IT;
if (thumb) {
cpsr |= CPSR_T;
} else {
cpsr &= ~CPSR_T;
}
if (env->cp15.sctlr_el[1] & SCTLR_E0E) {
cpsr |= CPSR_E;
} else {
cpsr &= ~CPSR_E;
}
if (ka->sa_flags & TARGET_SA_RESTORER) {
if (is_fdpic) {
__put_user((abi_ulong)ka->sa_restorer, &frame->retcode[3]);
retcode = (sigreturn_fdpic_tramp +
retcode_idx * RETCODE_BYTES + thumb);
copy_retcode = true;
} else {
retcode = ka->sa_restorer;
copy_retcode = false;
}
} else {
retcode = default_sigreturn + retcode_idx * RETCODE_BYTES + thumb;
copy_retcode = true;
}
/* Copy the code to the stack slot for ABI compatibility. */
if (copy_retcode) {
memcpy(frame->retcode, g2h_untagged(retcode & ~1), RETCODE_BYTES);
}
env->regs[0] = usig;
if (is_fdpic) {
env->regs[9] = handler_fdpic_GOT;
}
env->regs[13] = sp_addr;
env->regs[14] = retcode;
env->regs[15] = handler & (thumb ? ~1 : ~3);
cpsr_write(env, cpsr, CPSR_IT | CPSR_T | CPSR_E, CPSRWriteByInstr);
return 0;
}
static abi_ulong *setup_sigframe_vfp(abi_ulong *regspace, CPUARMState *env)
{
int i;
struct target_vfp_sigframe *vfpframe;
vfpframe = (struct target_vfp_sigframe *)regspace;
__put_user(TARGET_VFP_MAGIC, &vfpframe->magic);
__put_user(sizeof(*vfpframe), &vfpframe->size);
for (i = 0; i < 32; i++) {
__put_user(*aa32_vfp_dreg(env, i), &vfpframe->ufp.fpregs[i]);
}
__put_user(vfp_get_fpscr(env), &vfpframe->ufp.fpscr);
__put_user(env->vfp.xregs[ARM_VFP_FPEXC], &vfpframe->ufp_exc.fpexc);
__put_user(env->vfp.xregs[ARM_VFP_FPINST], &vfpframe->ufp_exc.fpinst);
__put_user(env->vfp.xregs[ARM_VFP_FPINST2], &vfpframe->ufp_exc.fpinst2);
return (abi_ulong*)(vfpframe+1);
}
static abi_ulong *setup_sigframe_iwmmxt(abi_ulong *regspace, CPUARMState *env)
{
int i;
struct target_iwmmxt_sigframe *iwmmxtframe;
iwmmxtframe = (struct target_iwmmxt_sigframe *)regspace;
__put_user(TARGET_IWMMXT_MAGIC, &iwmmxtframe->magic);
__put_user(sizeof(*iwmmxtframe), &iwmmxtframe->size);
for (i = 0; i < 16; i++) {
__put_user(env->iwmmxt.regs[i], &iwmmxtframe->regs[i]);
}
__put_user(env->vfp.xregs[ARM_IWMMXT_wCSSF], &iwmmxtframe->wcssf);
__put_user(env->vfp.xregs[ARM_IWMMXT_wCASF], &iwmmxtframe->wcssf);
__put_user(env->vfp.xregs[ARM_IWMMXT_wCGR0], &iwmmxtframe->wcgr0);
__put_user(env->vfp.xregs[ARM_IWMMXT_wCGR1], &iwmmxtframe->wcgr1);
__put_user(env->vfp.xregs[ARM_IWMMXT_wCGR2], &iwmmxtframe->wcgr2);
__put_user(env->vfp.xregs[ARM_IWMMXT_wCGR3], &iwmmxtframe->wcgr3);
return (abi_ulong*)(iwmmxtframe+1);
}
static void setup_sigframe(struct target_ucontext *uc,
target_sigset_t *set, CPUARMState *env)
{
struct target_sigaltstack stack;
int i;
abi_ulong *regspace;
/* Clear all the bits of the ucontext we don't use. */
memset(uc, 0, offsetof(struct target_ucontext, tuc_mcontext));
memset(&stack, 0, sizeof(stack));
target_save_altstack(&stack, env);
memcpy(&uc->tuc_stack, &stack, sizeof(stack));
setup_sigcontext(&uc->tuc_mcontext, env, set->sig[0]);
/* Save coprocessor signal frame. */
regspace = uc->tuc_regspace;
if (cpu_isar_feature(aa32_vfp_simd, env_archcpu(env))) {
regspace = setup_sigframe_vfp(regspace, env);
}
if (arm_feature(env, ARM_FEATURE_IWMMXT)) {
regspace = setup_sigframe_iwmmxt(regspace, env);
}
/* Write terminating magic word */
__put_user(0, regspace);
for(i = 0; i < TARGET_NSIG_WORDS; i++) {
__put_user(set->sig[i], &uc->tuc_sigmask.sig[i]);
}
}
void setup_frame(int usig, struct target_sigaction *ka,
target_sigset_t *set, CPUARMState *regs)
{
struct sigframe *frame;
abi_ulong frame_addr = get_sigframe(ka, regs, sizeof(*frame));
trace_user_setup_frame(regs, frame_addr);
if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
goto sigsegv;
}
setup_sigframe(&frame->uc, set, regs);
if (setup_return(regs, ka, usig, frame, frame_addr)) {
goto sigsegv;
}
unlock_user_struct(frame, frame_addr, 1);
return;
sigsegv:
unlock_user_struct(frame, frame_addr, 1);
force_sigsegv(usig);
}
void setup_rt_frame(int usig, struct target_sigaction *ka,
target_siginfo_t *info,
target_sigset_t *set, CPUARMState *env)
{
struct rt_sigframe *frame;
abi_ulong frame_addr = get_sigframe(ka, env, sizeof(*frame));
abi_ulong info_addr, uc_addr;
trace_user_setup_rt_frame(env, frame_addr);
if (!lock_user_struct(VERIFY_WRITE, frame, frame_addr, 0)) {
goto sigsegv;
}
info_addr = frame_addr + offsetof(struct rt_sigframe, info);
uc_addr = frame_addr + offsetof(struct rt_sigframe, sig.uc);
tswap_siginfo(&frame->info, info);
setup_sigframe(&frame->sig.uc, set, env);
if (setup_return(env, ka, usig, &frame->sig, frame_addr)) {
goto sigsegv;
}
env->regs[1] = info_addr;
env->regs[2] = uc_addr;
unlock_user_struct(frame, frame_addr, 1);
return;
sigsegv:
unlock_user_struct(frame, frame_addr, 1);
force_sigsegv(usig);
}
static int
restore_sigcontext(CPUARMState *env, struct target_sigcontext *sc)
{
int err = 0;
uint32_t cpsr;
__get_user(env->regs[0], &sc->arm_r0);
__get_user(env->regs[1], &sc->arm_r1);
__get_user(env->regs[2], &sc->arm_r2);
__get_user(env->regs[3], &sc->arm_r3);
__get_user(env->regs[4], &sc->arm_r4);
__get_user(env->regs[5], &sc->arm_r5);
__get_user(env->regs[6], &sc->arm_r6);
__get_user(env->regs[7], &sc->arm_r7);
__get_user(env->regs[8], &sc->arm_r8);
__get_user(env->regs[9], &sc->arm_r9);
__get_user(env->regs[10], &sc->arm_r10);
__get_user(env->regs[11], &sc->arm_fp);
__get_user(env->regs[12], &sc->arm_ip);
__get_user(env->regs[13], &sc->arm_sp);
__get_user(env->regs[14], &sc->arm_lr);
__get_user(env->regs[15], &sc->arm_pc);
__get_user(cpsr, &sc->arm_cpsr);
cpsr_write(env, cpsr, CPSR_USER | CPSR_EXEC, CPSRWriteByInstr);
err |= !valid_user_regs(env);
return err;
}
static abi_ulong *restore_sigframe_vfp(CPUARMState *env, abi_ulong *regspace)
{
int i;
abi_ulong magic, sz;
uint32_t fpscr, fpexc;
struct target_vfp_sigframe *vfpframe;
vfpframe = (struct target_vfp_sigframe *)regspace;
__get_user(magic, &vfpframe->magic);
__get_user(sz, &vfpframe->size);
if (magic != TARGET_VFP_MAGIC || sz != sizeof(*vfpframe)) {
return 0;
}
for (i = 0; i < 32; i++) {
__get_user(*aa32_vfp_dreg(env, i), &vfpframe->ufp.fpregs[i]);
}
__get_user(fpscr, &vfpframe->ufp.fpscr);
vfp_set_fpscr(env, fpscr);
__get_user(fpexc, &vfpframe->ufp_exc.fpexc);
/* Sanitise FPEXC: ensure VFP is enabled, FPINST2 is invalid
* and the exception flag is cleared
*/
fpexc |= (1 << 30);
fpexc &= ~((1 << 31) | (1 << 28));
env->vfp.xregs[ARM_VFP_FPEXC] = fpexc;
__get_user(env->vfp.xregs[ARM_VFP_FPINST], &vfpframe->ufp_exc.fpinst);
__get_user(env->vfp.xregs[ARM_VFP_FPINST2], &vfpframe->ufp_exc.fpinst2);
return (abi_ulong*)(vfpframe + 1);
}
static abi_ulong *restore_sigframe_iwmmxt(CPUARMState *env,
abi_ulong *regspace)
{
int i;
abi_ulong magic, sz;
struct target_iwmmxt_sigframe *iwmmxtframe;
iwmmxtframe = (struct target_iwmmxt_sigframe *)regspace;
__get_user(magic, &iwmmxtframe->magic);
__get_user(sz, &iwmmxtframe->size);
if (magic != TARGET_IWMMXT_MAGIC || sz != sizeof(*iwmmxtframe)) {
return 0;
}
for (i = 0; i < 16; i++) {
__get_user(env->iwmmxt.regs[i], &iwmmxtframe->regs[i]);
}
__get_user(env->vfp.xregs[ARM_IWMMXT_wCSSF], &iwmmxtframe->wcssf);
__get_user(env->vfp.xregs[ARM_IWMMXT_wCASF], &iwmmxtframe->wcssf);
__get_user(env->vfp.xregs[ARM_IWMMXT_wCGR0], &iwmmxtframe->wcgr0);
__get_user(env->vfp.xregs[ARM_IWMMXT_wCGR1], &iwmmxtframe->wcgr1);
__get_user(env->vfp.xregs[ARM_IWMMXT_wCGR2], &iwmmxtframe->wcgr2);
__get_user(env->vfp.xregs[ARM_IWMMXT_wCGR3], &iwmmxtframe->wcgr3);
return (abi_ulong*)(iwmmxtframe + 1);
}
static int do_sigframe_return(CPUARMState *env,
target_ulong context_addr,
struct target_ucontext *uc)
{
sigset_t host_set;
abi_ulong *regspace;
target_to_host_sigset(&host_set, &uc->tuc_sigmask);
set_sigmask(&host_set);
if (restore_sigcontext(env, &uc->tuc_mcontext)) {
return 1;
}
/* Restore coprocessor signal frame */
regspace = uc->tuc_regspace;
if (cpu_isar_feature(aa32_vfp_simd, env_archcpu(env))) {
regspace = restore_sigframe_vfp(env, regspace);
if (!regspace) {
return 1;
}
}
if (arm_feature(env, ARM_FEATURE_IWMMXT)) {
regspace = restore_sigframe_iwmmxt(env, regspace);
if (!regspace) {
return 1;
}
}
target_restore_altstack(&uc->tuc_stack, env);
#if 0
/* Send SIGTRAP if we're single-stepping */
if (ptrace_cancel_bpt(current))
send_sig(SIGTRAP, current, 1);
#endif
return 0;
}
long do_sigreturn(CPUARMState *env)
{
abi_ulong frame_addr;
struct sigframe *frame = NULL;
/*
* Since we stacked the signal on a 64-bit boundary,
* then 'sp' should be word aligned here. If it's
* not, then the user is trying to mess with us.
*/
frame_addr = env->regs[13];
trace_user_do_sigreturn(env, frame_addr);
if (frame_addr & 7) {
goto badframe;
}
if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
goto badframe;
}
if (do_sigframe_return(env,
frame_addr + offsetof(struct sigframe, uc),
&frame->uc)) {
goto badframe;
}
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;
}
long do_rt_sigreturn(CPUARMState *env)
{
abi_ulong frame_addr;
struct rt_sigframe *frame = NULL;
/*
* Since we stacked the signal on a 64-bit boundary,
* then 'sp' should be word aligned here. If it's
* not, then the user is trying to mess with us.
*/
frame_addr = env->regs[13];
trace_user_do_rt_sigreturn(env, frame_addr);
if (frame_addr & 7) {
goto badframe;
}
if (!lock_user_struct(VERIFY_READ, frame, frame_addr, 1)) {
goto badframe;
}
if (do_sigframe_return(env,
frame_addr + offsetof(struct rt_sigframe, sig.uc),
&frame->sig.uc)) {
goto badframe;
}
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;
}
/*
* EABI syscalls pass the number via r7.
* Note that the kernel still adds the OABI syscall number to the trap,
* presumably for backward ABI compatibility with unwinders.
*/
#define ARM_MOV_R7_IMM(X) (0xe3a07000 | (X))
#define ARM_SWI_SYS(X) (0xef000000 | (X) | ARM_SYSCALL_BASE)
#define THUMB_MOVS_R7_IMM(X) (0x2700 | (X))
#define THUMB_SWI_SYS 0xdf00
static void write_arm_sigreturn(uint32_t *rc, int syscall)
{
__put_user(ARM_MOV_R7_IMM(syscall), rc);
__put_user(ARM_SWI_SYS(syscall), rc + 1);
/* Wrote 8 of 12 bytes */
}
static void write_thm_sigreturn(uint32_t *rc, int syscall)
{
__put_user(THUMB_SWI_SYS << 16 | THUMB_MOVS_R7_IMM(syscall), rc);
/* Wrote 4 of 12 bytes */
}
/*
* Stub needed to make sure the FD register (r9) contains the right value.
* Use the same instruction sequence as the kernel.
*/
static void write_arm_fdpic_sigreturn(uint32_t *rc, int ofs)
{
assert(ofs <= 0xfff);
__put_user(0xe59d3000 | ofs, rc + 0); /* ldr r3, [sp, #ofs] */
__put_user(0xe8930908, rc + 1); /* ldm r3, { r3, r9 } */
__put_user(0xe12fff13, rc + 2); /* bx r3 */
/* Wrote 12 of 12 bytes */
}
static void write_thm_fdpic_sigreturn(void *vrc, int ofs)
{
uint16_t *rc = vrc;
assert((ofs & ~0x3fc) == 0);
__put_user(0x9b00 | (ofs >> 2), rc + 0); /* ldr r3, [sp, #ofs] */
__put_user(0xcb0c, rc + 1); /* ldm r3, { r2, r3 } */
__put_user(0x4699, rc + 2); /* mov r9, r3 */
__put_user(0x4710, rc + 3); /* bx r2 */
/* Wrote 8 of 12 bytes */
}
void setup_sigtramp(abi_ulong sigtramp_page)
{
uint32_t total_size = 8 * RETCODE_BYTES;
uint32_t *tramp = lock_user(VERIFY_WRITE, sigtramp_page, total_size, 0);
assert(tramp != NULL);
default_sigreturn = sigtramp_page;
write_arm_sigreturn(&tramp[0 * RETCODE_WORDS], TARGET_NR_sigreturn);
write_thm_sigreturn(&tramp[1 * RETCODE_WORDS], TARGET_NR_sigreturn);
write_arm_sigreturn(&tramp[2 * RETCODE_WORDS], TARGET_NR_rt_sigreturn);
write_thm_sigreturn(&tramp[3 * RETCODE_WORDS], TARGET_NR_rt_sigreturn);
sigreturn_fdpic_tramp = sigtramp_page + 4 * RETCODE_BYTES;
write_arm_fdpic_sigreturn(tramp + 4 * RETCODE_WORDS,
offsetof(struct sigframe, retcode[3]));
write_thm_fdpic_sigreturn(tramp + 5 * RETCODE_WORDS,
offsetof(struct sigframe, retcode[3]));
write_arm_fdpic_sigreturn(tramp + 6 * RETCODE_WORDS,
offsetof(struct rt_sigframe, sig.retcode[3]));
write_thm_fdpic_sigreturn(tramp + 7 * RETCODE_WORDS,
offsetof(struct rt_sigframe, sig.retcode[3]));
unlock_user(tramp, sigtramp_page, total_size);
}
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