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2690e61e8e
qemu/user-exec.c
Alexander Graf 732f9e89a1 linux-user: fix segmentation fault passing with h2g(x) != x 
When forwarding a segmentation fault into the guest process, we were passing
the host's address directly into the guest process's signal descriptor.

That obviously confused the guest process, since it didn't know what to make
of the (usually 32-bit truncated) address. Passing in h2g(address) makes the
guest process a lot happier.

To make the code more obvious, introduce a h2g_nocheck() macro that does the
same as h2g(), but allows us to convert addresses that may be outside of guest
mapped range into the guest's view of address space.

This fixes java running in arm-linux-user for me.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
2013-07-23 17:28:28 +03:00

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/*
* User emulator execution
*
* Copyright (c) 2003-2005 Fabrice Bellard
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "config.h"
#include "cpu.h"
#include "disas/disas.h"
#include "tcg.h"
#include "qemu/bitops.h"
#undef EAX
#undef ECX
#undef EDX
#undef EBX
#undef ESP
#undef EBP
#undef ESI
#undef EDI
#undef EIP
#include <signal.h>
#ifdef __linux__
#include <sys/ucontext.h>
#endif
//#define DEBUG_SIGNAL
static void exception_action(CPUArchState *env1)
{
#if defined(TARGET_I386)
raise_exception_err(env1, env1->exception_index, env1->error_code);
#else
cpu_loop_exit(env1);
#endif
}
/* exit the current TB from a signal handler. The host registers are
restored in a state compatible with the CPU emulator
*/
void cpu_resume_from_signal(CPUArchState *env1, void *puc)
{
#ifdef __linux__
struct ucontext *uc = puc;
#elif defined(__OpenBSD__)
struct sigcontext *uc = puc;
#endif
if (puc) {
/* XXX: use siglongjmp ? */
#ifdef __linux__
#ifdef __ia64
sigprocmask(SIG_SETMASK, (sigset_t *)&uc->uc_sigmask, NULL);
#else
sigprocmask(SIG_SETMASK, &uc->uc_sigmask, NULL);
#endif
#elif defined(__OpenBSD__)
sigprocmask(SIG_SETMASK, &uc->sc_mask, NULL);
#endif
}
env1->exception_index = -1;
siglongjmp(env1->jmp_env, 1);
}
/* 'pc' is the host PC at which the exception was raised. 'address' is
the effective address of the memory exception. 'is_write' is 1 if a
write caused the exception and otherwise 0'. 'old_set' is the
signal set which should be restored */
static inline int handle_cpu_signal(uintptr_t pc, unsigned long address,
int is_write, sigset_t *old_set,
void *puc)
{
CPUArchState *env;
int ret;
#if defined(DEBUG_SIGNAL)
qemu_printf("qemu: SIGSEGV pc=0x%08lx address=%08lx w=%d oldset=0x%08lx\n",
pc, address, is_write, *(unsigned long *)old_set);
#endif
/* XXX: locking issue */
if (is_write && h2g_valid(address)
&& page_unprotect(h2g(address), pc, puc)) {
return 1;
}
/* Convert forcefully to guest address space, invalid addresses
are still valid segv ones */
address = h2g_nocheck(address);
env = current_cpu->env_ptr;
/* see if it is an MMU fault */
ret = cpu_handle_mmu_fault(env, address, is_write, MMU_USER_IDX);
if (ret < 0) {
return 0; /* not an MMU fault */
}
if (ret == 0) {
return 1; /* the MMU fault was handled without causing real CPU fault */
}
/* now we have a real cpu fault */
cpu_restore_state(env, pc);
/* we restore the process signal mask as the sigreturn should
do it (XXX: use sigsetjmp) */
sigprocmask(SIG_SETMASK, old_set, NULL);
exception_action(env);
/* never comes here */
return 1;
}
#if defined(__i386__)
#if defined(__APPLE__)
#include <sys/ucontext.h>
#define EIP_sig(context) (*((unsigned long *)&(context)->uc_mcontext->ss.eip))
#define TRAP_sig(context) ((context)->uc_mcontext->es.trapno)
#define ERROR_sig(context) ((context)->uc_mcontext->es.err)
#define MASK_sig(context) ((context)->uc_sigmask)
#elif defined(__NetBSD__)
#include <ucontext.h>
#define EIP_sig(context) ((context)->uc_mcontext.__gregs[_REG_EIP])
#define TRAP_sig(context) ((context)->uc_mcontext.__gregs[_REG_TRAPNO])
#define ERROR_sig(context) ((context)->uc_mcontext.__gregs[_REG_ERR])
#define MASK_sig(context) ((context)->uc_sigmask)
#elif defined(__FreeBSD__) || defined(__DragonFly__)
#include <ucontext.h>
#define EIP_sig(context) (*((unsigned long *)&(context)->uc_mcontext.mc_eip))
#define TRAP_sig(context) ((context)->uc_mcontext.mc_trapno)
#define ERROR_sig(context) ((context)->uc_mcontext.mc_err)
#define MASK_sig(context) ((context)->uc_sigmask)
#elif defined(__OpenBSD__)
#define EIP_sig(context) ((context)->sc_eip)
#define TRAP_sig(context) ((context)->sc_trapno)
#define ERROR_sig(context) ((context)->sc_err)
#define MASK_sig(context) ((context)->sc_mask)
#else
#define EIP_sig(context) ((context)->uc_mcontext.gregs[REG_EIP])
#define TRAP_sig(context) ((context)->uc_mcontext.gregs[REG_TRAPNO])
#define ERROR_sig(context) ((context)->uc_mcontext.gregs[REG_ERR])
#define MASK_sig(context) ((context)->uc_sigmask)
#endif
int cpu_signal_handler(int host_signum, void *pinfo,
void *puc)
{
siginfo_t *info = pinfo;
#if defined(__NetBSD__) || defined(__FreeBSD__) || defined(__DragonFly__)
ucontext_t *uc = puc;
#elif defined(__OpenBSD__)
struct sigcontext *uc = puc;
#else
struct ucontext *uc = puc;
#endif
unsigned long pc;
int trapno;
#ifndef REG_EIP
/* for glibc 2.1 */
#define REG_EIP EIP
#define REG_ERR ERR
#define REG_TRAPNO TRAPNO
#endif
pc = EIP_sig(uc);
trapno = TRAP_sig(uc);
return handle_cpu_signal(pc, (unsigned long)info->si_addr,
trapno == 0xe ?
(ERROR_sig(uc) >> 1) & 1 : 0,
&MASK_sig(uc), puc);
}
#elif defined(__x86_64__)
#ifdef __NetBSD__
#define PC_sig(context) _UC_MACHINE_PC(context)
#define TRAP_sig(context) ((context)->uc_mcontext.__gregs[_REG_TRAPNO])
#define ERROR_sig(context) ((context)->uc_mcontext.__gregs[_REG_ERR])
#define MASK_sig(context) ((context)->uc_sigmask)
#elif defined(__OpenBSD__)
#define PC_sig(context) ((context)->sc_rip)
#define TRAP_sig(context) ((context)->sc_trapno)
#define ERROR_sig(context) ((context)->sc_err)
#define MASK_sig(context) ((context)->sc_mask)
#elif defined(__FreeBSD__) || defined(__DragonFly__)
#include <ucontext.h>
#define PC_sig(context) (*((unsigned long *)&(context)->uc_mcontext.mc_rip))
#define TRAP_sig(context) ((context)->uc_mcontext.mc_trapno)
#define ERROR_sig(context) ((context)->uc_mcontext.mc_err)
#define MASK_sig(context) ((context)->uc_sigmask)
#else
#define PC_sig(context) ((context)->uc_mcontext.gregs[REG_RIP])
#define TRAP_sig(context) ((context)->uc_mcontext.gregs[REG_TRAPNO])
#define ERROR_sig(context) ((context)->uc_mcontext.gregs[REG_ERR])
#define MASK_sig(context) ((context)->uc_sigmask)
#endif
int cpu_signal_handler(int host_signum, void *pinfo,
void *puc)
{
siginfo_t *info = pinfo;
unsigned long pc;
#if defined(__NetBSD__) || defined(__FreeBSD__) || defined(__DragonFly__)
ucontext_t *uc = puc;
#elif defined(__OpenBSD__)
struct sigcontext *uc = puc;
#else
struct ucontext *uc = puc;
#endif
pc = PC_sig(uc);
return handle_cpu_signal(pc, (unsigned long)info->si_addr,
TRAP_sig(uc) == 0xe ?
(ERROR_sig(uc) >> 1) & 1 : 0,
&MASK_sig(uc), puc);
}
#elif defined(_ARCH_PPC)
/***********************************************************************
* signal context platform-specific definitions
* From Wine
*/
#ifdef linux
/* All Registers access - only for local access */
#define REG_sig(reg_name, context) \
((context)->uc_mcontext.regs->reg_name)
/* Gpr Registers access */
#define GPR_sig(reg_num, context) REG_sig(gpr[reg_num], context)
/* Program counter */
#define IAR_sig(context) REG_sig(nip, context)
/* Machine State Register (Supervisor) */
#define MSR_sig(context) REG_sig(msr, context)
/* Count register */
#define CTR_sig(context) REG_sig(ctr, context)
/* User's integer exception register */
#define XER_sig(context) REG_sig(xer, context)
/* Link register */
#define LR_sig(context) REG_sig(link, context)
/* Condition register */
#define CR_sig(context) REG_sig(ccr, context)
/* Float Registers access */
#define FLOAT_sig(reg_num, context) \
(((double *)((char *)((context)->uc_mcontext.regs + 48 * 4)))[reg_num])
#define FPSCR_sig(context) \
(*(int *)((char *)((context)->uc_mcontext.regs + (48 + 32 * 2) * 4)))
/* Exception Registers access */
#define DAR_sig(context) REG_sig(dar, context)
#define DSISR_sig(context) REG_sig(dsisr, context)
#define TRAP_sig(context) REG_sig(trap, context)
#endif /* linux */
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
#include <ucontext.h>
#define IAR_sig(context) ((context)->uc_mcontext.mc_srr0)
#define MSR_sig(context) ((context)->uc_mcontext.mc_srr1)
#define CTR_sig(context) ((context)->uc_mcontext.mc_ctr)
#define XER_sig(context) ((context)->uc_mcontext.mc_xer)
#define LR_sig(context) ((context)->uc_mcontext.mc_lr)
#define CR_sig(context) ((context)->uc_mcontext.mc_cr)
/* Exception Registers access */
#define DAR_sig(context) ((context)->uc_mcontext.mc_dar)
#define DSISR_sig(context) ((context)->uc_mcontext.mc_dsisr)
#define TRAP_sig(context) ((context)->uc_mcontext.mc_exc)
#endif /* __FreeBSD__|| __FreeBSD_kernel__ */
#ifdef __APPLE__
#include <sys/ucontext.h>
typedef struct ucontext SIGCONTEXT;
/* All Registers access - only for local access */
#define REG_sig(reg_name, context) \
((context)->uc_mcontext->ss.reg_name)
#define FLOATREG_sig(reg_name, context) \
((context)->uc_mcontext->fs.reg_name)
#define EXCEPREG_sig(reg_name, context) \
((context)->uc_mcontext->es.reg_name)
#define VECREG_sig(reg_name, context) \
((context)->uc_mcontext->vs.reg_name)
/* Gpr Registers access */
#define GPR_sig(reg_num, context) REG_sig(r##reg_num, context)
/* Program counter */
#define IAR_sig(context) REG_sig(srr0, context)
/* Machine State Register (Supervisor) */
#define MSR_sig(context) REG_sig(srr1, context)
#define CTR_sig(context) REG_sig(ctr, context)
/* Link register */
#define XER_sig(context) REG_sig(xer, context)
/* User's integer exception register */
#define LR_sig(context) REG_sig(lr, context)
/* Condition register */
#define CR_sig(context) REG_sig(cr, context)
/* Float Registers access */
#define FLOAT_sig(reg_num, context) \
FLOATREG_sig(fpregs[reg_num], context)
#define FPSCR_sig(context) \
((double)FLOATREG_sig(fpscr, context))
/* Exception Registers access */
/* Fault registers for coredump */
#define DAR_sig(context) EXCEPREG_sig(dar, context)
#define DSISR_sig(context) EXCEPREG_sig(dsisr, context)
/* number of powerpc exception taken */
#define TRAP_sig(context) EXCEPREG_sig(exception, context)
#endif /* __APPLE__ */
int cpu_signal_handler(int host_signum, void *pinfo,
void *puc)
{
siginfo_t *info = pinfo;
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
ucontext_t *uc = puc;
#else
struct ucontext *uc = puc;
#endif
unsigned long pc;
int is_write;
pc = IAR_sig(uc);
is_write = 0;
#if 0
/* ppc 4xx case */
if (DSISR_sig(uc) & 0x00800000) {
is_write = 1;
}
#else
if (TRAP_sig(uc) != 0x400 && (DSISR_sig(uc) & 0x02000000)) {
is_write = 1;
}
#endif
return handle_cpu_signal(pc, (unsigned long)info->si_addr,
is_write, &uc->uc_sigmask, puc);
}
#elif defined(__alpha__)
int cpu_signal_handler(int host_signum, void *pinfo,
void *puc)
{
siginfo_t *info = pinfo;
struct ucontext *uc = puc;
uint32_t *pc = uc->uc_mcontext.sc_pc;
uint32_t insn = *pc;
int is_write = 0;
/* XXX: need kernel patch to get write flag faster */
switch (insn >> 26) {
case 0x0d: /* stw */
case 0x0e: /* stb */
case 0x0f: /* stq_u */
case 0x24: /* stf */
case 0x25: /* stg */
case 0x26: /* sts */
case 0x27: /* stt */
case 0x2c: /* stl */
case 0x2d: /* stq */
case 0x2e: /* stl_c */
case 0x2f: /* stq_c */
is_write = 1;
}
return handle_cpu_signal(pc, (unsigned long)info->si_addr,
is_write, &uc->uc_sigmask, puc);
}
#elif defined(__sparc__)
int cpu_signal_handler(int host_signum, void *pinfo,
void *puc)
{
siginfo_t *info = pinfo;
int is_write;
uint32_t insn;
#if !defined(__arch64__) || defined(CONFIG_SOLARIS)
uint32_t *regs = (uint32_t *)(info + 1);
void *sigmask = (regs + 20);
/* XXX: is there a standard glibc define ? */
unsigned long pc = regs[1];
#else
#ifdef __linux__
struct sigcontext *sc = puc;
unsigned long pc = sc->sigc_regs.tpc;
void *sigmask = (void *)sc->sigc_mask;
#elif defined(__OpenBSD__)
struct sigcontext *uc = puc;
unsigned long pc = uc->sc_pc;
void *sigmask = (void *)(long)uc->sc_mask;
#endif
#endif
/* XXX: need kernel patch to get write flag faster */
is_write = 0;
insn = *(uint32_t *)pc;
if ((insn >> 30) == 3) {
switch ((insn >> 19) & 0x3f) {
case 0x05: /* stb */
case 0x15: /* stba */
case 0x06: /* sth */
case 0x16: /* stha */
case 0x04: /* st */
case 0x14: /* sta */
case 0x07: /* std */
case 0x17: /* stda */
case 0x0e: /* stx */
case 0x1e: /* stxa */
case 0x24: /* stf */
case 0x34: /* stfa */
case 0x27: /* stdf */
case 0x37: /* stdfa */
case 0x26: /* stqf */
case 0x36: /* stqfa */
case 0x25: /* stfsr */
case 0x3c: /* casa */
case 0x3e: /* casxa */
is_write = 1;
break;
}
}
return handle_cpu_signal(pc, (unsigned long)info->si_addr,
is_write, sigmask, NULL);
}
#elif defined(__arm__)
int cpu_signal_handler(int host_signum, void *pinfo,
void *puc)
{
siginfo_t *info = pinfo;
struct ucontext *uc = puc;
unsigned long pc;
int is_write;
#if defined(__GLIBC__) && (__GLIBC__ < 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ <= 3))
pc = uc->uc_mcontext.gregs[R15];
#else
pc = uc->uc_mcontext.arm_pc;
#endif
/* error_code is the FSR value, in which bit 11 is WnR (assuming a v6 or
* later processor; on v5 we will always report this as a read).
*/
is_write = extract32(uc->uc_mcontext.error_code, 11, 1);
return handle_cpu_signal(pc, (unsigned long)info->si_addr,
is_write,
&uc->uc_sigmask, puc);
}
#elif defined(__aarch64__)
int cpu_signal_handler(int host_signum, void *pinfo,
void *puc)
{
siginfo_t *info = pinfo;
struct ucontext *uc = puc;
uint64_t pc;
int is_write = 0; /* XXX how to determine? */
pc = uc->uc_mcontext.pc;
return handle_cpu_signal(pc, (uint64_t)info->si_addr,
is_write, &uc->uc_sigmask, puc);
}
#elif defined(__mc68000)
int cpu_signal_handler(int host_signum, void *pinfo,
void *puc)
{
siginfo_t *info = pinfo;
struct ucontext *uc = puc;
unsigned long pc;
int is_write;
pc = uc->uc_mcontext.gregs[16];
/* XXX: compute is_write */
is_write = 0;
return handle_cpu_signal(pc, (unsigned long)info->si_addr,
is_write,
&uc->uc_sigmask, puc);
}
#elif defined(__ia64)
#ifndef __ISR_VALID
/* This ought to be in <bits/siginfo.h>... */
# define __ISR_VALID 1
#endif
int cpu_signal_handler(int host_signum, void *pinfo, void *puc)
{
siginfo_t *info = pinfo;
struct ucontext *uc = puc;
unsigned long ip;
int is_write = 0;
ip = uc->uc_mcontext.sc_ip;
switch (host_signum) {
case SIGILL:
case SIGFPE:
case SIGSEGV:
case SIGBUS:
case SIGTRAP:
if (info->si_code && (info->si_segvflags & __ISR_VALID)) {
/* ISR.W (write-access) is bit 33: */
is_write = (info->si_isr >> 33) & 1;
}
break;
default:
break;
}
return handle_cpu_signal(ip, (unsigned long)info->si_addr,
is_write,
(sigset_t *)&uc->uc_sigmask, puc);
}
#elif defined(__s390__)
int cpu_signal_handler(int host_signum, void *pinfo,
void *puc)
{
siginfo_t *info = pinfo;
struct ucontext *uc = puc;
unsigned long pc;
uint16_t *pinsn;
int is_write = 0;
pc = uc->uc_mcontext.psw.addr;
/* ??? On linux, the non-rt signal handler has 4 (!) arguments instead
of the normal 2 arguments. The 3rd argument contains the "int_code"
from the hardware which does in fact contain the is_write value.
The rt signal handler, as far as I can tell, does not give this value
at all. Not that we could get to it from here even if it were. */
/* ??? This is not even close to complete, since it ignores all
of the read-modify-write instructions. */
pinsn = (uint16_t *)pc;
switch (pinsn[0] >> 8) {
case 0x50: /* ST */
case 0x42: /* STC */
case 0x40: /* STH */
is_write = 1;
break;
case 0xc4: /* RIL format insns */
switch (pinsn[0] & 0xf) {
case 0xf: /* STRL */
case 0xb: /* STGRL */
case 0x7: /* STHRL */
is_write = 1;
}
break;
case 0xe3: /* RXY format insns */
switch (pinsn[2] & 0xff) {
case 0x50: /* STY */
case 0x24: /* STG */
case 0x72: /* STCY */
case 0x70: /* STHY */
case 0x8e: /* STPQ */
case 0x3f: /* STRVH */
case 0x3e: /* STRV */
case 0x2f: /* STRVG */
is_write = 1;
}
break;
}
return handle_cpu_signal(pc, (unsigned long)info->si_addr,
is_write, &uc->uc_sigmask, puc);
}
#elif defined(__mips__)
int cpu_signal_handler(int host_signum, void *pinfo,
void *puc)
{
siginfo_t *info = pinfo;
struct ucontext *uc = puc;
greg_t pc = uc->uc_mcontext.pc;
int is_write;
/* XXX: compute is_write */
is_write = 0;
return handle_cpu_signal(pc, (unsigned long)info->si_addr,
is_write, &uc->uc_sigmask, puc);
}
#elif defined(__hppa__)
int cpu_signal_handler(int host_signum, void *pinfo,
void *puc)
{
siginfo_t *info = pinfo;
struct ucontext *uc = puc;
unsigned long pc = uc->uc_mcontext.sc_iaoq[0];
uint32_t insn = *(uint32_t *)pc;
int is_write = 0;
/* XXX: need kernel patch to get write flag faster. */
switch (insn >> 26) {
case 0x1a: /* STW */
case 0x19: /* STH */
case 0x18: /* STB */
case 0x1b: /* STWM */
is_write = 1;
break;
case 0x09: /* CSTWX, FSTWX, FSTWS */
case 0x0b: /* CSTDX, FSTDX, FSTDS */
/* Distinguish from coprocessor load ... */
is_write = (insn >> 9) & 1;
break;
case 0x03:
switch ((insn >> 6) & 15) {
case 0xa: /* STWS */
case 0x9: /* STHS */
case 0x8: /* STBS */
case 0xe: /* STWAS */
case 0xc: /* STBYS */
is_write = 1;
}
break;
}
return handle_cpu_signal(pc, (unsigned long)info->si_addr,
is_write, &uc->uc_sigmask, puc);
}
#else
#error host CPU specific signal handler needed
#endif
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