int target_munmap(abi_ulong start, abi_ulong len) { abi_ulong end, real_start, real_end, addr; int prot, ret; #ifdef DEBUG_MMAP printf("munmap: start=0x" TARGET_ABI_FMT_lx " len=0x" TARGET_ABI_FMT_lx "\n", start, len); #endif if (start & ~TARGET_PAGE_MASK) return -EINVAL; len = TARGET_PAGE_ALIGN(len); if (len == 0) return -EINVAL; mmap_lock(); end = start + len; real_start = start & qemu_host_page_mask; real_end = HOST_PAGE_ALIGN(end); if (start > real_start) { /* handle host page containing start */ prot = 0; for(addr = real_start; addr < start; addr += TARGET_PAGE_SIZE) { prot |= page_get_flags(addr); } if (real_end == real_start + qemu_host_page_size) { for(addr = end; addr < real_end; addr += TARGET_PAGE_SIZE) { prot |= page_get_flags(addr); } end = real_end; } if (prot != 0) real_start += qemu_host_page_size; } if (end < real_end) { prot = 0; for(addr = end; addr < real_end; addr += TARGET_PAGE_SIZE) { prot |= page_get_flags(addr); } if (prot != 0) real_end -= qemu_host_page_size; } ret = 0; /* unmap what we can */ if (real_start < real_end) { if (RESERVED_VA) { mmap_reserve(real_start, real_end - real_start); } else { ret = munmap(g2h(real_start), real_end - real_start); } } if (ret == 0) page_set_flags(start, start + len, 0); mmap_unlock(); return ret; }
/* Subroutine of mmap_find_vma, used when we have pre-allocated a chunk of guest address space. */ static abi_ulong mmap_find_vma_reserved(abi_ulong start, abi_ulong size) { abi_ulong addr; abi_ulong last_addr; int prot; int looped = 0; if (size > RESERVED_VA) { return (abi_ulong)-1; } last_addr = start; for (addr = start; last_addr + size != addr; addr += qemu_host_page_size) { if (last_addr + size >= RESERVED_VA || (abi_ulong)(last_addr + size) < last_addr) { if (looped) { return (abi_ulong)-1; } last_addr = qemu_host_page_size; addr = 0; looped = 1; continue; } prot = page_get_flags(addr); if (prot) { last_addr = addr + qemu_host_page_size; } } mmap_next_start = addr; return last_addr; }
/* map an incomplete host page */ static int mmap_frag(abi_ulong real_start, abi_ulong start, abi_ulong end, int prot, int flags, int fd, abi_ulong offset) { abi_ulong real_end, addr; void *host_start; int prot1, prot_new; real_end = real_start + qemu_host_page_size; host_start = g2h(real_start); /* get the protection of the target pages outside the mapping */ prot1 = 0; for(addr = real_start; addr < real_end; addr++) { if (addr < start || addr >= end) prot1 |= page_get_flags(addr); } if (prot1 == 0) { /* no page was there, so we allocate one */ void *p = mmap(host_start, qemu_host_page_size, prot, flags | MAP_ANONYMOUS, -1, 0); if (p == MAP_FAILED) return -1; prot1 = prot; } prot1 &= PAGE_BITS; prot_new = prot | prot1; if (!(flags & MAP_ANONYMOUS)) { /* msync() won't work here, so we return an error if write is possible while it is a shared mapping */ if ((flags & MAP_TYPE) == MAP_SHARED && (prot & PROT_WRITE)) return -1; /* adjust protection to be able to read */ if (!(prot1 & PROT_WRITE)) mprotect(host_start, qemu_host_page_size, prot1 | PROT_WRITE); /* read the corresponding file data */ if (pread(fd, g2h(start), end - start, offset) == -1) return -1; /* put final protection */ if (prot_new != (prot1 | PROT_WRITE)) mprotect(host_start, qemu_host_page_size, prot_new); } else { if (prot_new != prot1) { mprotect(host_start, qemu_host_page_size, prot_new); } if (prot_new & PROT_WRITE) { memset(g2h(start), 0, end - start); } } return 0; }
static void mmap_reserve(abi_ulong start, abi_ulong size) { abi_ulong real_start; abi_ulong real_end; abi_ulong addr; abi_ulong end; int prot; real_start = start & qemu_host_page_mask; real_end = HOST_PAGE_ALIGN(start + size); end = start + size; if (start > real_start) { /* handle host page containing start */ prot = 0; for (addr = real_start; addr < start; addr += TARGET_PAGE_SIZE) { prot |= page_get_flags(addr); } if (real_end == real_start + qemu_host_page_size) { for (addr = end; addr < real_end; addr += TARGET_PAGE_SIZE) { prot |= page_get_flags(addr); } end = real_end; } if (prot != 0) real_start += qemu_host_page_size; } if (end < real_end) { prot = 0; for (addr = end; addr < real_end; addr += TARGET_PAGE_SIZE) { prot |= page_get_flags(addr); } if (prot != 0) real_end -= qemu_host_page_size; } if (real_start != real_end) { mmap(g2h(real_start), real_end - real_start, PROT_NONE, MAP_FIXED | MAP_ANONYMOUS | MAP_PRIVATE | MAP_NORESERVE, -1, 0); } }
abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size, abi_ulong new_size, unsigned long flags, abi_ulong new_addr) { int prot; void *host_addr; mmap_lock(); if (flags & MREMAP_FIXED) host_addr = (void *) syscall(__NR_mremap, g2h(old_addr), old_size, new_size, flags, new_addr); else if (flags & MREMAP_MAYMOVE) { abi_ulong mmap_start; mmap_start = mmap_find_vma(0, new_size); if (mmap_start == -1) { errno = ENOMEM; host_addr = MAP_FAILED; } else host_addr = (void *) syscall(__NR_mremap, g2h(old_addr), old_size, new_size, flags | MREMAP_FIXED, g2h(mmap_start)); } else { host_addr = mremap(g2h(old_addr), old_size, new_size, flags); /* Check if address fits target address space */ if ((unsigned long)host_addr + new_size > (abi_ulong)-1) { /* Revert mremap() changes */ host_addr = mremap(g2h(old_addr), new_size, old_size, flags); errno = ENOMEM; host_addr = MAP_FAILED; } } if (host_addr == MAP_FAILED) { new_addr = -1; } else { new_addr = h2g(host_addr); prot = page_get_flags(old_addr); page_set_flags(old_addr, old_addr + old_size, 0); page_set_flags(new_addr, new_addr + new_size, prot | PAGE_VALID); } mmap_unlock(); return new_addr; }
/* Subroutine of mmap_find_vma, used when we have pre-allocated a chunk of guest address space. */ static abi_ulong mmap_find_vma_reserved(abi_ulong start, abi_ulong size, abi_ulong align) { abi_ulong addr, end_addr, incr = qemu_host_page_size; int prot; bool looped = false; if (size > reserved_va) { return (abi_ulong)-1; } /* Note that start and size have already been aligned by mmap_find_vma. */ end_addr = start + size; if (start > reserved_va - size) { /* Start at the top of the address space. */ end_addr = ((reserved_va - size) & -align) + size; looped = true; } /* Search downward from END_ADDR, checking to see if a page is in use. */ addr = end_addr; while (1) { addr -= incr; if (addr > end_addr) { if (looped) { /* Failure. The entire address space has been searched. */ return (abi_ulong)-1; } /* Re-start at the top of the address space. */ addr = end_addr = ((reserved_va - size) & -align) + size; looped = true; } else { prot = page_get_flags(addr); if (prot) { /* Page in use. Restart below this page. */ addr = end_addr = ((addr - size) & -align) + size; } else if (addr && addr + size == end_addr) { /* Success! All pages between ADDR and END_ADDR are free. */ if (start == mmap_next_start) { mmap_next_start = addr; } return addr; } } } }
/* Subroutine of mmap_find_vma, used when we have pre-allocated a chunk of guest address space. */ static abi_ulong mmap_find_vma_reserved(abi_ulong start, abi_ulong size) { abi_ulong addr; abi_ulong end_addr; int prot; int looped = 0; if (size > RESERVED_VA) { return (abi_ulong)-1; } size = HOST_PAGE_ALIGN(size); end_addr = start + size; if (end_addr > RESERVED_VA) { end_addr = RESERVED_VA; } addr = end_addr - qemu_host_page_size; while (1) { if (addr > end_addr) { if (looped) { return (abi_ulong)-1; } end_addr = RESERVED_VA; addr = end_addr - qemu_host_page_size; looped = 1; continue; } prot = page_get_flags(addr); if (prot) { end_addr = addr; } if (addr + size == end_addr) { break; } addr -= qemu_host_page_size; } if (start == mmap_next_start) { mmap_next_start = addr; } return addr; }
/* page_init() marks pages used by the host as reserved to be sure not to use them. */ static abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size) { abi_ulong addr, addr1, addr_start; int prot; unsigned long new_brk; new_brk = (unsigned long)sbrk(0); if (last_brk && last_brk < new_brk && last_brk == (target_ulong)last_brk) { /* This is a hack to catch the host allocating memory with brk(). If it uses mmap then we loose. FIXME: We really want to avoid the host allocating memory in the first place, and maybe leave some slack to avoid switching to mmap. */ page_set_flags(last_brk & TARGET_PAGE_MASK, TARGET_PAGE_ALIGN(new_brk), PAGE_RESERVED); } last_brk = new_brk; size = HOST_PAGE_ALIGN(size); start = start & qemu_host_page_mask; addr = start; if (addr == 0) addr = mmap_next_start; addr_start = addr; for(;;) { prot = 0; for(addr1 = addr; addr1 < (addr + size); addr1 += TARGET_PAGE_SIZE) { prot |= page_get_flags(addr1); } if (prot == 0) break; addr += qemu_host_page_size; /* we found nothing */ if (addr == addr_start) return (abi_ulong)-1; } if (start == 0) mmap_next_start = addr + size; return addr; }
/* NOTE: all the constants are the HOST ones */ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot, int flags, int fd, abi_ulong offset) { abi_ulong ret, end, real_start, real_end, retaddr, host_offset, host_len; unsigned long host_start; mmap_lock(); #ifdef DEBUG_MMAP { printf("mmap: start=0x" TARGET_FMT_lx " len=0x" TARGET_FMT_lx " prot=%c%c%c flags=", start, len, prot & PROT_READ ? 'r' : '-', prot & PROT_WRITE ? 'w' : '-', prot & PROT_EXEC ? 'x' : '-'); if (flags & MAP_FIXED) printf("MAP_FIXED "); if (flags & MAP_ANONYMOUS) printf("MAP_ANON "); switch(flags & MAP_TYPE) { case MAP_PRIVATE: printf("MAP_PRIVATE "); break; case MAP_SHARED: printf("MAP_SHARED "); break; default: printf("[MAP_TYPE=0x%x] ", flags & MAP_TYPE); break; } printf("fd=%d offset=" TARGET_FMT_lx "\n", fd, offset); } #endif if (offset & ~TARGET_PAGE_MASK) { errno = EINVAL; goto fail; } len = TARGET_PAGE_ALIGN(len); if (len == 0) goto the_end; real_start = start & qemu_host_page_mask; if (!(flags & MAP_FIXED)) { abi_ulong mmap_start; void *p; host_offset = offset & qemu_host_page_mask; host_len = len + offset - host_offset; host_len = HOST_PAGE_ALIGN(host_len); mmap_start = mmap_find_vma(real_start, host_len); if (mmap_start == (abi_ulong)-1) { errno = ENOMEM; goto fail; } /* Note: we prefer to control the mapping address. It is especially important if qemu_host_page_size > qemu_real_host_page_size */ p = mmap(g2h(mmap_start), host_len, prot, flags | MAP_FIXED, fd, host_offset); if (p == MAP_FAILED) goto fail; /* update start so that it points to the file position at 'offset' */ host_start = (unsigned long)p; if (!(flags & MAP_ANONYMOUS)) host_start += offset - host_offset; start = h2g(host_start); } else { int flg; target_ulong addr; if (start & ~TARGET_PAGE_MASK) { errno = EINVAL; goto fail; } end = start + len; real_end = HOST_PAGE_ALIGN(end); /* * Test if requested memory area fits target address space * It can fail only on 64-bit host with 32-bit target. * On any other target/host host mmap() handles this error correctly. */ if ((unsigned long)start + len - 1 > (abi_ulong) -1) { errno = EINVAL; goto fail; } for(addr = real_start; addr < real_end; addr += TARGET_PAGE_SIZE) { flg = page_get_flags(addr); if (flg & PAGE_RESERVED) { errno = ENXIO; goto fail; } } /* worst case: we cannot map the file because the offset is not aligned, so we read it */ if (!(flags & MAP_ANONYMOUS) && (offset & ~qemu_host_page_mask) != (start & ~qemu_host_page_mask)) { /* msync() won't work here, so we return an error if write is possible while it is a shared mapping */ if ((flags & MAP_TYPE) == MAP_SHARED && (prot & PROT_WRITE)) { errno = EINVAL; goto fail; } retaddr = target_mmap(start, len, prot | PROT_WRITE, MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (retaddr == -1) goto fail; pread(fd, g2h(start), len, offset); if (!(prot & PROT_WRITE)) { ret = target_mprotect(start, len, prot); if (ret != 0) { start = ret; goto the_end; } } goto the_end; } /* handle the start of the mapping */ if (start > real_start) { if (real_end == real_start + qemu_host_page_size) { /* one single host page */ ret = mmap_frag(real_start, start, end, prot, flags, fd, offset); if (ret == -1) goto fail; goto the_end1; } ret = mmap_frag(real_start, start, real_start + qemu_host_page_size, prot, flags, fd, offset); if (ret == -1) goto fail; real_start += qemu_host_page_size; } /* handle the end of the mapping */ if (end < real_end) { ret = mmap_frag(real_end - qemu_host_page_size, real_end - qemu_host_page_size, real_end, prot, flags, fd, offset + real_end - qemu_host_page_size - start); if (ret == -1) goto fail; real_end -= qemu_host_page_size; } /* map the middle (easier) */ if (real_start < real_end) { void *p; unsigned long offset1; if (flags & MAP_ANONYMOUS) offset1 = 0; else offset1 = offset + real_start - start; p = mmap(g2h(real_start), real_end - real_start, prot, flags, fd, offset1); if (p == MAP_FAILED) goto fail; } } the_end1: page_set_flags(start, start + len, prot | PAGE_VALID); the_end: #ifdef DEBUG_MMAP printf("ret=0x" TARGET_FMT_lx "\n", start); page_dump(stdout); printf("\n"); #endif mmap_unlock(); return start; fail: mmap_unlock(); return -1; }
/* NOTE: all the constants are the HOST ones, but addresses are target. */ int target_mprotect(abi_ulong start, abi_ulong len, int prot) { abi_ulong end, host_start, host_end, addr; int prot1, ret; #ifdef DEBUG_MMAP printf("mprotect: start=0x" TARGET_FMT_lx "len=0x" TARGET_FMT_lx " prot=%c%c%c\n", start, len, prot & PROT_READ ? 'r' : '-', prot & PROT_WRITE ? 'w' : '-', prot & PROT_EXEC ? 'x' : '-'); #endif if ((start & ~TARGET_PAGE_MASK) != 0) return -EINVAL; len = TARGET_PAGE_ALIGN(len); end = start + len; if (end < start) return -EINVAL; prot &= PROT_READ | PROT_WRITE | PROT_EXEC; if (len == 0) return 0; mmap_lock(); host_start = start & qemu_host_page_mask; host_end = HOST_PAGE_ALIGN(end); if (start > host_start) { /* handle host page containing start */ prot1 = prot; for(addr = host_start; addr < start; addr += TARGET_PAGE_SIZE) { prot1 |= page_get_flags(addr); } if (host_end == host_start + qemu_host_page_size) { for(addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) { prot1 |= page_get_flags(addr); } end = host_end; } ret = mprotect(g2h(host_start), qemu_host_page_size, prot1 & PAGE_BITS); if (ret != 0) goto error; host_start += qemu_host_page_size; } if (end < host_end) { prot1 = prot; for(addr = end; addr < host_end; addr += TARGET_PAGE_SIZE) { prot1 |= page_get_flags(addr); } ret = mprotect(g2h(host_end - qemu_host_page_size), qemu_host_page_size, prot1 & PAGE_BITS); if (ret != 0) goto error; host_end -= qemu_host_page_size; } /* handle the pages in the middle */ if (host_start < host_end) { ret = mprotect(g2h(host_start), host_end - host_start, prot); if (ret != 0) goto error; } page_set_flags(start, start + len, prot | PAGE_VALID); mmap_unlock(); return 0; error: mmap_unlock(); return ret; }
void cpu_loop(CPUAlphaState *env) { CPUState *cs = CPU(alpha_env_get_cpu(env)); int trapnr; target_siginfo_t info; abi_long sysret; while (1) { bool arch_interrupt = true; cpu_exec_start(cs); trapnr = cpu_exec(cs); cpu_exec_end(cs); process_queued_cpu_work(cs); switch (trapnr) { case EXCP_RESET: fprintf(stderr, "Reset requested. Exit\n"); exit(EXIT_FAILURE); break; case EXCP_MCHK: fprintf(stderr, "Machine check exception. Exit\n"); exit(EXIT_FAILURE); break; case EXCP_SMP_INTERRUPT: case EXCP_CLK_INTERRUPT: case EXCP_DEV_INTERRUPT: fprintf(stderr, "External interrupt. Exit\n"); exit(EXIT_FAILURE); break; case EXCP_MMFAULT: info.si_signo = TARGET_SIGSEGV; info.si_errno = 0; info.si_code = (page_get_flags(env->trap_arg0) & PAGE_VALID ? TARGET_SEGV_ACCERR : TARGET_SEGV_MAPERR); info._sifields._sigfault._addr = env->trap_arg0; queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info); break; case EXCP_UNALIGN: info.si_signo = TARGET_SIGBUS; info.si_errno = 0; info.si_code = TARGET_BUS_ADRALN; info._sifields._sigfault._addr = env->trap_arg0; queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info); break; case EXCP_OPCDEC: do_sigill: info.si_signo = TARGET_SIGILL; info.si_errno = 0; info.si_code = TARGET_ILL_ILLOPC; info._sifields._sigfault._addr = env->pc; queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info); break; case EXCP_ARITH: info.si_signo = TARGET_SIGFPE; info.si_errno = 0; info.si_code = TARGET_FPE_FLTINV; info._sifields._sigfault._addr = env->pc; queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info); break; case EXCP_FEN: /* No-op. Linux simply re-enables the FPU. */ break; case EXCP_CALL_PAL: switch (env->error_code) { case 0x80: /* BPT */ info.si_signo = TARGET_SIGTRAP; info.si_errno = 0; info.si_code = TARGET_TRAP_BRKPT; info._sifields._sigfault._addr = env->pc; queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info); break; case 0x81: /* BUGCHK */ info.si_signo = TARGET_SIGTRAP; info.si_errno = 0; info.si_code = 0; info._sifields._sigfault._addr = env->pc; queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info); break; case 0x83: /* CALLSYS */ trapnr = env->ir[IR_V0]; sysret = do_syscall(env, trapnr, env->ir[IR_A0], env->ir[IR_A1], env->ir[IR_A2], env->ir[IR_A3], env->ir[IR_A4], env->ir[IR_A5], 0, 0); if (sysret == -TARGET_ERESTARTSYS) { env->pc -= 4; break; } if (sysret == -TARGET_QEMU_ESIGRETURN) { break; } /* Syscall writes 0 to V0 to bypass error check, similar to how this is handled internal to Linux kernel. (Ab)use trapnr temporarily as boolean indicating error. */ trapnr = (env->ir[IR_V0] != 0 && sysret < 0); env->ir[IR_V0] = (trapnr ? -sysret : sysret); env->ir[IR_A3] = trapnr; break; case 0x86: /* IMB */ /* ??? We can probably elide the code using page_unprotect that is checking for self-modifying code. Instead we could simply call tb_flush here. Until we work out the changes required to turn off the extra write protection, this can be a no-op. */ break; case 0x9E: /* RDUNIQUE */ /* Handled in the translator for usermode. */ abort(); case 0x9F: /* WRUNIQUE */ /* Handled in the translator for usermode. */ abort(); case 0xAA: /* GENTRAP */ info.si_signo = TARGET_SIGFPE; switch (env->ir[IR_A0]) { case TARGET_GEN_INTOVF: info.si_code = TARGET_FPE_INTOVF; break; case TARGET_GEN_INTDIV: info.si_code = TARGET_FPE_INTDIV; break; case TARGET_GEN_FLTOVF: info.si_code = TARGET_FPE_FLTOVF; break; case TARGET_GEN_FLTUND: info.si_code = TARGET_FPE_FLTUND; break; case TARGET_GEN_FLTINV: info.si_code = TARGET_FPE_FLTINV; break; case TARGET_GEN_FLTINE: info.si_code = TARGET_FPE_FLTRES; break; case TARGET_GEN_ROPRAND: info.si_code = 0; break; default: info.si_signo = TARGET_SIGTRAP; info.si_code = 0; break; } info.si_errno = 0; info._sifields._sigfault._addr = env->pc; queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info); break; default: goto do_sigill; } break; case EXCP_DEBUG: info.si_signo = gdb_handlesig(cs, TARGET_SIGTRAP); if (info.si_signo) { info.si_errno = 0; info.si_code = TARGET_TRAP_BRKPT; queue_signal(env, info.si_signo, QEMU_SI_FAULT, &info); } else { arch_interrupt = false; } break; case EXCP_INTERRUPT: /* Just indicate that signals should be handled asap. */ break; case EXCP_ATOMIC: cpu_exec_step_atomic(cs); arch_interrupt = false; break; default: fprintf(stderr, "Unhandled trap: 0x%x\n", trapnr); cpu_dump_state(cs, stderr, fprintf, 0); exit(EXIT_FAILURE); } process_pending_signals (env); /* Most of the traps imply a transition through PALcode, which implies an REI instruction has been executed. Which means that RX and LOCK_ADDR should be cleared. But there are a few exceptions for traps internal to QEMU. */ if (arch_interrupt) { env->flags &= ~ENV_FLAG_RX_FLAG; env->lock_addr = -1; } } }
abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size, abi_ulong new_size, unsigned long flags, abi_ulong new_addr) { int prot; void *host_addr; mmap_lock(); if (flags & MREMAP_FIXED) { host_addr = (void *) syscall(__NR_mremap, g2h(old_addr), old_size, new_size, flags, g2h(new_addr)); if (RESERVED_VA && host_addr != MAP_FAILED) { /* If new and old addresses overlap then the above mremap will already have failed with EINVAL. */ mmap_reserve(old_addr, old_size); } } else if (flags & MREMAP_MAYMOVE) { abi_ulong mmap_start; mmap_start = mmap_find_vma(0, new_size); if (mmap_start == -1) { errno = ENOMEM; host_addr = MAP_FAILED; } else { host_addr = (void *) syscall(__NR_mremap, g2h(old_addr), old_size, new_size, flags | MREMAP_FIXED, g2h(mmap_start)); if ( RESERVED_VA ) { mmap_reserve(old_addr, old_size); } } } else { int prot = 0; if (RESERVED_VA && old_size < new_size) { abi_ulong addr; for (addr = old_addr + old_size; addr < old_addr + new_size; addr++) { prot |= page_get_flags(addr); } } if (prot == 0) { host_addr = mremap(g2h(old_addr), old_size, new_size, flags); if (host_addr != MAP_FAILED && RESERVED_VA && old_size > new_size) { mmap_reserve(old_addr + old_size, new_size - old_size); } } else { errno = ENOMEM; host_addr = MAP_FAILED; } /* Check if address fits target address space */ if ((unsigned long)host_addr + new_size > (abi_ulong)-1) { /* Revert mremap() changes */ host_addr = mremap(g2h(old_addr), new_size, old_size, flags); errno = ENOMEM; host_addr = MAP_FAILED; } } if (host_addr == MAP_FAILED) { new_addr = -1; } else { new_addr = h2g(host_addr); prot = page_get_flags(old_addr); page_set_flags(old_addr, old_addr + old_size, 0); page_set_flags(new_addr, new_addr + new_size, prot | PAGE_VALID); } tb_invalidate_phys_range(new_addr, new_addr + new_size); mmap_unlock(); return new_addr; }
/* NOTE: all the constants are the HOST ones */ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot, int flags, int fd, abi_ulong offset) { abi_ulong ret, end, real_start, real_end, retaddr, host_offset, host_len; unsigned long host_start; mmap_lock(); #ifdef DEBUG_MMAP { printf("mmap: start=0x" TARGET_ABI_FMT_lx " len=0x" TARGET_ABI_FMT_lx " prot=%c%c%c flags=", start, len, prot & PROT_READ ? 'r' : '-', prot & PROT_WRITE ? 'w' : '-', prot & PROT_EXEC ? 'x' : '-'); if (flags & MAP_FIXED) printf("MAP_FIXED "); if (flags & MAP_ANONYMOUS) printf("MAP_ANON "); switch(flags & MAP_TYPE) { case MAP_PRIVATE: printf("MAP_PRIVATE "); break; case MAP_SHARED: printf("MAP_SHARED "); break; default: printf("[MAP_TYPE=0x%x] ", flags & MAP_TYPE); break; } printf("fd=%d offset=" TARGET_ABI_FMT_lx "\n", fd, offset); } #endif if (offset & ~TARGET_PAGE_MASK) { errno = EINVAL; goto fail; } len = TARGET_PAGE_ALIGN(len); if (len == 0) goto the_end; real_start = start & qemu_host_page_mask; /* When mapping files into a memory area larger than the file, accesses to pages beyond the file size will cause a SIGBUS. For example, if mmaping a file of 100 bytes on a host with 4K pages emulating a target with 8K pages, the target expects to be able to access the first 8K. But the host will trap us on any access beyond 4K. When emulating a target with a larger page-size than the hosts, we may need to truncate file maps at EOF and add extra anonymous pages up to the targets page boundary. */ if ((qemu_real_host_page_size < TARGET_PAGE_SIZE) && !(flags & MAP_ANONYMOUS)) { struct stat sb; if (fstat (fd, &sb) == -1) goto fail; /* Are we trying to create a map beyond EOF?. */ if (offset + len > sb.st_size) { /* If so, truncate the file map at eof aligned with the hosts real pagesize. Additional anonymous maps will be created beyond EOF. */ len = (sb.st_size - offset); len += qemu_real_host_page_size - 1; len &= ~(qemu_real_host_page_size - 1); } } if (!(flags & MAP_FIXED)) { abi_ulong mmap_start; void *p; host_offset = offset & qemu_host_page_mask; host_len = len + offset - host_offset; host_len = HOST_PAGE_ALIGN(host_len); mmap_start = mmap_find_vma(real_start, host_len); if (mmap_start == (abi_ulong)-1) { errno = ENOMEM; goto fail; } /* Note: we prefer to control the mapping address. It is especially important if qemu_host_page_size > qemu_real_host_page_size */ p = mmap(g2h(mmap_start), host_len, prot, flags | MAP_FIXED | MAP_ANONYMOUS, -1, 0); if (p == MAP_FAILED) goto fail; /* update start so that it points to the file position at 'offset' */ host_start = (unsigned long)p; if (!(flags & MAP_ANONYMOUS)) { p = mmap(g2h(mmap_start), len, prot, flags | MAP_FIXED, fd, host_offset); host_start += offset - host_offset; } start = h2g(host_start); } else { int flg; target_ulong addr; if (start & ~TARGET_PAGE_MASK) { errno = EINVAL; goto fail; } end = start + len; real_end = HOST_PAGE_ALIGN(end); /* * Test if requested memory area fits target address space * It can fail only on 64-bit host with 32-bit target. * On any other target/host host mmap() handles this error correctly. */ if ((unsigned long)start + len - 1 > (abi_ulong) -1) { errno = EINVAL; goto fail; } for(addr = real_start; addr < real_end; addr += TARGET_PAGE_SIZE) { flg = page_get_flags(addr); if (flg & PAGE_RESERVED) { errno = ENXIO; goto fail; } } /* worst case: we cannot map the file because the offset is not aligned, so we read it */ if (!(flags & MAP_ANONYMOUS) && (offset & ~qemu_host_page_mask) != (start & ~qemu_host_page_mask)) { /* msync() won't work here, so we return an error if write is possible while it is a shared mapping */ if ((flags & MAP_TYPE) == MAP_SHARED && (prot & PROT_WRITE)) { errno = EINVAL; goto fail; } retaddr = target_mmap(start, len, prot | PROT_WRITE, MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (retaddr == -1) goto fail; if (pread(fd, g2h(start), len, offset) == -1) goto fail; if (!(prot & PROT_WRITE)) { ret = target_mprotect(start, len, prot); if (ret != 0) { start = ret; goto the_end; } } goto the_end; } /* handle the start of the mapping */ if (start > real_start) { if (real_end == real_start + qemu_host_page_size) { /* one single host page */ ret = mmap_frag(real_start, start, end, prot, flags, fd, offset); if (ret == -1) goto fail; goto the_end1; } ret = mmap_frag(real_start, start, real_start + qemu_host_page_size, prot, flags, fd, offset); if (ret == -1) goto fail; real_start += qemu_host_page_size; } /* handle the end of the mapping */ if (end < real_end) { ret = mmap_frag(real_end - qemu_host_page_size, real_end - qemu_host_page_size, real_end, prot, flags, fd, offset + real_end - qemu_host_page_size - start); if (ret == -1) goto fail; real_end -= qemu_host_page_size; } /* map the middle (easier) */ if (real_start < real_end) { void *p; unsigned long offset1; if (flags & MAP_ANONYMOUS) offset1 = 0; else offset1 = offset + real_start - start; p = mmap(g2h(real_start), real_end - real_start, prot, flags, fd, offset1); if (p == MAP_FAILED) goto fail; } } the_end1: page_set_flags(start, start + len, prot | PAGE_VALID); the_end: #ifdef DEBUG_MMAP printf("ret=0x" TARGET_ABI_FMT_lx "\n", start); page_dump(stdout); printf("\n"); #endif mmap_unlock(); return start; fail: mmap_unlock(); return -1; }