*/
#include "qemu/osdep.h"
-#include "qemu-common.h"
#include "qemu.h"
+#include "user-internals.h"
#include "elf.h"
#include "cpu_loop-common.h"
+#include "signal-common.h"
+#include "semihosting/common-semi.h"
+#include "target/arm/syndrome.h"
#define get_user_code_u32(x, gaddr, env) \
({ abi_long __r = get_user_u32((x), (gaddr)); \
put_user_u16(__x, (gaddr)); \
})
-/* Commpage handling -- there is no commpage for AArch64 */
+/*
+ * Similar to code in accel/tcg/user-exec.c, but outside the execution loop.
+ * Must be called with mmap_lock.
+ * We get the PC of the entry address - which is as good as anything,
+ * on a real kernel what you get depends on which mode it uses.
+ */
+static void *atomic_mmu_lookup(CPUArchState *env, uint32_t addr, int size)
+{
+ int need_flags = PAGE_READ | PAGE_WRITE_ORG | PAGE_VALID;
+ int page_flags;
+
+ /* Enforce guest required alignment. */
+ if (unlikely(addr & (size - 1))) {
+ force_sig_fault(TARGET_SIGBUS, TARGET_BUS_ADRALN, addr);
+ return NULL;
+ }
+
+ page_flags = page_get_flags(addr);
+ if (unlikely((page_flags & need_flags) != need_flags)) {
+ force_sig_fault(TARGET_SIGSEGV,
+ page_flags & PAGE_VALID ?
+ TARGET_SEGV_ACCERR : TARGET_SEGV_MAPERR, addr);
+ return NULL;
+ }
+
+ return g2h(env_cpu(env), addr);
+}
+
+/*
+ * See the Linux kernel's Documentation/arm/kernel_user_helpers.rst
+ * Input:
+ * r0 = oldval
+ * r1 = newval
+ * r2 = pointer to target value
+ *
+ * Output:
+ * r0 = 0 if *ptr was changed, non-0 if no exchange happened
+ * C set if *ptr was changed, clear if no exchange happened
+ */
+static void arm_kernel_cmpxchg32_helper(CPUARMState *env)
+{
+ uint32_t oldval, newval, val, addr, cpsr, *host_addr;
+
+ oldval = env->regs[0];
+ newval = env->regs[1];
+ addr = env->regs[2];
+
+ mmap_lock();
+ host_addr = atomic_mmu_lookup(env, addr, 4);
+ if (!host_addr) {
+ mmap_unlock();
+ return;
+ }
+
+ val = qatomic_cmpxchg__nocheck(host_addr, oldval, newval);
+ mmap_unlock();
+
+ cpsr = (val == oldval) * CPSR_C;
+ cpsr_write(env, cpsr, CPSR_C, CPSRWriteByInstr);
+ env->regs[0] = cpsr ? 0 : -1;
+}
/*
- * See the Linux kernel's Documentation/arm/kernel_user_helpers.txt
+ * See the Linux kernel's Documentation/arm/kernel_user_helpers.rst
* Input:
* r0 = pointer to oldval
* r1 = pointer to newval
{
uint64_t oldval, newval, val;
uint32_t addr, cpsr;
- target_siginfo_t info;
+ uint64_t *host_addr;
- /* Based on the 32 bit code in do_kernel_trap */
-
- /* XXX: This only works between threads, not between processes.
- It's probably possible to implement this with native host
- operations. However things like ldrex/strex are much harder so
- there's not much point trying. */
- start_exclusive();
- cpsr = cpsr_read(env);
- addr = env->regs[2];
-
- if (get_user_u64(oldval, env->regs[0])) {
- env->exception.vaddress = env->regs[0];
+ addr = env->regs[0];
+ if (get_user_u64(oldval, addr)) {
goto segv;
- };
+ }
- if (get_user_u64(newval, env->regs[1])) {
- env->exception.vaddress = env->regs[1];
+ addr = env->regs[1];
+ if (get_user_u64(newval, addr)) {
goto segv;
- };
+ }
- if (get_user_u64(val, addr)) {
- env->exception.vaddress = addr;
- goto segv;
+ mmap_lock();
+ addr = env->regs[2];
+ host_addr = atomic_mmu_lookup(env, addr, 8);
+ if (!host_addr) {
+ mmap_unlock();
+ return;
}
+#ifdef CONFIG_ATOMIC64
+ val = qatomic_cmpxchg__nocheck(host_addr, oldval, newval);
+ cpsr = (val == oldval) * CPSR_C;
+#else
+ /*
+ * This only works between threads, not between processes, but since
+ * the host has no 64-bit cmpxchg, it is the best that we can do.
+ */
+ start_exclusive();
+ val = *host_addr;
if (val == oldval) {
- val = newval;
-
- if (put_user_u64(val, addr)) {
- env->exception.vaddress = addr;
- goto segv;
- };
-
- env->regs[0] = 0;
- cpsr |= CPSR_C;
+ *host_addr = newval;
+ cpsr = CPSR_C;
} else {
- env->regs[0] = -1;
- cpsr &= ~CPSR_C;
+ cpsr = 0;
}
- cpsr_write(env, cpsr, CPSR_C, CPSRWriteByInstr);
end_exclusive();
+#endif
+ mmap_unlock();
+
+ cpsr_write(env, cpsr, CPSR_C, CPSRWriteByInstr);
+ env->regs[0] = cpsr ? 0 : -1;
return;
-segv:
- end_exclusive();
- /* We get the PC of the entry address - which is as good as anything,
- on a real kernel what you get depends on which mode it uses. */
- info.si_signo = TARGET_SIGSEGV;
- info.si_errno = 0;
- /* XXX: check env->error_code */
- info.si_code = TARGET_SEGV_MAPERR;
- info._sifields._sigfault._addr = env->exception.vaddress;
- queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
+ segv:
+ force_sig_fault(TARGET_SIGSEGV,
+ page_get_flags(addr) & PAGE_VALID ?
+ TARGET_SEGV_ACCERR : TARGET_SEGV_MAPERR, addr);
}
/* Handle a jump to the kernel code page. */
do_kernel_trap(CPUARMState *env)
{
uint32_t addr;
- uint32_t cpsr;
- uint32_t val;
switch (env->regs[15]) {
case 0xffff0fa0: /* __kernel_memory_barrier */
- /* ??? No-op. Will need to do better for SMP. */
+ smp_mb();
break;
case 0xffff0fc0: /* __kernel_cmpxchg */
- /* XXX: This only works between threads, not between processes.
- It's probably possible to implement this with native host
- operations. However things like ldrex/strex are much harder so
- there's not much point trying. */
- start_exclusive();
- cpsr = cpsr_read(env);
- addr = env->regs[2];
- /* FIXME: This should SEGV if the access fails. */
- if (get_user_u32(val, addr))
- val = ~env->regs[0];
- if (val == env->regs[0]) {
- val = env->regs[1];
- /* FIXME: Check for segfaults. */
- put_user_u32(val, addr);
- env->regs[0] = 0;
- cpsr |= CPSR_C;
- } else {
- env->regs[0] = -1;
- cpsr &= ~CPSR_C;
- }
- cpsr_write(env, cpsr, CPSR_C, CPSRWriteByInstr);
- end_exclusive();
+ arm_kernel_cmpxchg32_helper(env);
break;
case 0xffff0fe0: /* __kernel_get_tls */
env->regs[0] = cpu_get_tls(env);
/* Jump back to the caller. */
addr = env->regs[14];
if (addr & 1) {
- env->thumb = 1;
+ env->thumb = true;
addr &= ~1;
}
env->regs[15] = addr;
return 0;
}
+static bool insn_is_linux_bkpt(uint32_t opcode, bool is_thumb)
+{
+ /*
+ * Return true if this insn is one of the three magic UDF insns
+ * which the kernel treats as breakpoint insns.
+ */
+ if (!is_thumb) {
+ return (opcode & 0x0fffffff) == 0x07f001f0;
+ } else {
+ /*
+ * Note that we get the two halves of the 32-bit T32 insn
+ * in the opposite order to the value the kernel uses in
+ * its undef_hook struct.
+ */
+ return ((opcode & 0xffff) == 0xde01) || (opcode == 0xa000f7f0);
+ }
+}
+
+static bool emulate_arm_fpa11(CPUARMState *env, uint32_t opcode)
+{
+ TaskState *ts = env_cpu(env)->opaque;
+ int rc = EmulateAll(opcode, &ts->fpa, env);
+ int raise, enabled;
+
+ if (rc == 0) {
+ /* Illegal instruction */
+ return false;
+ }
+ if (rc > 0) {
+ /* Everything ok. */
+ env->regs[15] += 4;
+ return true;
+ }
+
+ /* FP exception */
+ rc = -rc;
+ raise = 0;
+
+ /* Translate softfloat flags to FPSR flags */
+ if (rc & float_flag_invalid) {
+ raise |= BIT_IOC;
+ }
+ if (rc & float_flag_divbyzero) {
+ raise |= BIT_DZC;
+ }
+ if (rc & float_flag_overflow) {
+ raise |= BIT_OFC;
+ }
+ if (rc & float_flag_underflow) {
+ raise |= BIT_UFC;
+ }
+ if (rc & float_flag_inexact) {
+ raise |= BIT_IXC;
+ }
+
+ /* Accumulate unenabled exceptions */
+ enabled = ts->fpa.fpsr >> 16;
+ ts->fpa.fpsr |= raise & ~enabled;
+
+ if (raise & enabled) {
+ /*
+ * The kernel's nwfpe emulator does not pass a real si_code.
+ * It merely uses send_sig(SIGFPE, current, 1), which results in
+ * __send_signal() filling out SI_KERNEL with pid and uid 0 (under
+ * the "SEND_SIG_PRIV" case). That's what our force_sig() does.
+ */
+ force_sig(TARGET_SIGFPE);
+ } else {
+ env->regs[15] += 4;
+ }
+ return true;
+}
+
void cpu_loop(CPUARMState *env)
{
CPUState *cs = env_cpu(env);
- int trapnr;
+ int trapnr, si_signo, si_code;
unsigned int n, insn;
- target_siginfo_t info;
- uint32_t addr;
abi_ulong ret;
for(;;) {
case EXCP_NOCP:
case EXCP_INVSTATE:
{
- TaskState *ts = cs->opaque;
uint32_t opcode;
- int rc;
/* we handle the FPU emulation here, as Linux */
/* we get the opcode */
/* FIXME - what to do if get_user() fails? */
get_user_code_u32(opcode, env->regs[15], env);
- rc = EmulateAll(opcode, &ts->fpa, env);
- if (rc == 0) { /* illegal instruction */
- info.si_signo = TARGET_SIGILL;
- info.si_errno = 0;
- info.si_code = TARGET_ILL_ILLOPN;
- info._sifields._sigfault._addr = env->regs[15];
- queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
- } else if (rc < 0) { /* FP exception */
- int arm_fpe=0;
-
- /* translate softfloat flags to FPSR flags */
- if (-rc & float_flag_invalid)
- arm_fpe |= BIT_IOC;
- if (-rc & float_flag_divbyzero)
- arm_fpe |= BIT_DZC;
- if (-rc & float_flag_overflow)
- arm_fpe |= BIT_OFC;
- if (-rc & float_flag_underflow)
- arm_fpe |= BIT_UFC;
- if (-rc & float_flag_inexact)
- arm_fpe |= BIT_IXC;
-
- FPSR fpsr = ts->fpa.fpsr;
- //printf("fpsr 0x%x, arm_fpe 0x%x\n",fpsr,arm_fpe);
-
- if (fpsr & (arm_fpe << 16)) { /* exception enabled? */
- info.si_signo = TARGET_SIGFPE;
- info.si_errno = 0;
-
- /* ordered by priority, least first */
- if (arm_fpe & BIT_IXC) info.si_code = TARGET_FPE_FLTRES;
- if (arm_fpe & BIT_UFC) info.si_code = TARGET_FPE_FLTUND;
- if (arm_fpe & BIT_OFC) info.si_code = TARGET_FPE_FLTOVF;
- if (arm_fpe & BIT_DZC) info.si_code = TARGET_FPE_FLTDIV;
- if (arm_fpe & BIT_IOC) info.si_code = TARGET_FPE_FLTINV;
-
- info._sifields._sigfault._addr = env->regs[15];
- queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
- } else {
- env->regs[15] += 4;
- }
+ /*
+ * The Linux kernel treats some UDF patterns specially
+ * to use as breakpoints (instead of the architectural
+ * bkpt insn). These should trigger a SIGTRAP rather
+ * than SIGILL.
+ */
+ if (insn_is_linux_bkpt(opcode, env->thumb)) {
+ goto excp_debug;
+ }
- /* accumulate unenabled exceptions */
- if ((!(fpsr & BIT_IXE)) && (arm_fpe & BIT_IXC))
- fpsr |= BIT_IXC;
- if ((!(fpsr & BIT_UFE)) && (arm_fpe & BIT_UFC))
- fpsr |= BIT_UFC;
- if ((!(fpsr & BIT_OFE)) && (arm_fpe & BIT_OFC))
- fpsr |= BIT_OFC;
- if ((!(fpsr & BIT_DZE)) && (arm_fpe & BIT_DZC))
- fpsr |= BIT_DZC;
- if ((!(fpsr & BIT_IOE)) && (arm_fpe & BIT_IOC))
- fpsr |= BIT_IOC;
- ts->fpa.fpsr=fpsr;
- } else { /* everything OK */
- /* increment PC */
- env->regs[15] += 4;
+ if (!env->thumb && emulate_arm_fpa11(env, opcode)) {
+ break;
}
+
+ force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLOPN,
+ env->regs[15]);
}
break;
case EXCP_SWI:
* Otherwise SIGILL. This includes any SWI with
* immediate not originally 0x9fxxxx, because
* of the earlier XOR.
+ * Like the real kernel, we report the addr of the
+ * SWI in the siginfo si_addr but leave the PC
+ * pointing at the insn after the SWI.
*/
- info.si_signo = TARGET_SIGILL;
- info.si_errno = 0;
- info.si_code = TARGET_ILL_ILLTRP;
- info._sifields._sigfault._addr = env->regs[15];
- if (env->thumb) {
- info._sifields._sigfault._addr -= 2;
- } else {
- info._sifields._sigfault._addr -= 4;
- }
- queue_signal(env, info.si_signo,
- QEMU_SI_FAULT, &info);
+ abi_ulong faultaddr = env->regs[15];
+ faultaddr -= env->thumb ? 2 : 4;
+ force_sig_fault(TARGET_SIGILL, TARGET_ILL_ILLTRP,
+ faultaddr);
}
break;
}
env->regs[4],
env->regs[5],
0, 0);
- if (ret == -TARGET_ERESTARTSYS) {
+ if (ret == -QEMU_ERESTARTSYS) {
env->regs[15] -= env->thumb ? 2 : 4;
- } else if (ret != -TARGET_QEMU_ESIGRETURN) {
+ } else if (ret != -QEMU_ESIGRETURN) {
env->regs[0] = ret;
}
}
}
break;
case EXCP_SEMIHOST:
- env->regs[0] = do_arm_semihosting(env);
+ do_common_semihosting(cs);
env->regs[15] += env->thumb ? 2 : 4;
break;
case EXCP_INTERRUPT:
break;
case EXCP_PREFETCH_ABORT:
case EXCP_DATA_ABORT:
- addr = env->exception.vaddress;
- {
- info.si_signo = TARGET_SIGSEGV;
- info.si_errno = 0;
- /* XXX: check env->error_code */
- info.si_code = TARGET_SEGV_MAPERR;
- info._sifields._sigfault._addr = addr;
- queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
+ /* For user-only we don't set TTBCR_EAE, so look at the FSR. */
+ switch (env->exception.fsr & 0x1f) {
+ case 0x1: /* Alignment */
+ si_signo = TARGET_SIGBUS;
+ si_code = TARGET_BUS_ADRALN;
+ break;
+ case 0x3: /* Access flag fault, level 1 */
+ case 0x6: /* Access flag fault, level 2 */
+ case 0x9: /* Domain fault, level 1 */
+ case 0xb: /* Domain fault, level 2 */
+ case 0xd: /* Permission fault, level 1 */
+ case 0xf: /* Permission fault, level 2 */
+ si_signo = TARGET_SIGSEGV;
+ si_code = TARGET_SEGV_ACCERR;
+ break;
+ case 0x5: /* Translation fault, level 1 */
+ case 0x7: /* Translation fault, level 2 */
+ si_signo = TARGET_SIGSEGV;
+ si_code = TARGET_SEGV_MAPERR;
+ break;
+ default:
+ g_assert_not_reached();
}
+ force_sig_fault(si_signo, si_code, env->exception.vaddress);
break;
case EXCP_DEBUG:
case EXCP_BKPT:
excp_debug:
- info.si_signo = TARGET_SIGTRAP;
- info.si_errno = 0;
- info.si_code = TARGET_TRAP_BRKPT;
- queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info);
+ force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, env->regs[15]);
break;
case EXCP_KERNEL_TRAP:
if (do_kernel_trap(env))
for(i = 0; i < 16; i++) {
env->regs[i] = regs->uregs[i];
}
-#ifdef TARGET_WORDS_BIGENDIAN
+#if TARGET_BIG_ENDIAN
/* Enable BE8. */
if (EF_ARM_EABI_VERSION(info->elf_flags) >= EF_ARM_EABI_VER4
&& (info->elf_flags & EF_ARM_BE8)) {