From 7f835a59f1c342eb1c170973ad53c493cc38e978 Mon Sep 17 00:00:00 2001 From: Chris Adeniyi-Jones Date: Fri, 24 Jan 2014 15:29:30 -0600 Subject: [PATCH] sim: Add openat/fstatat syscalls and fix mremap This patch adds support for the openat and fstatat syscalls and broadens the support for mremap to make it work on OS X. --- src/kern/linux/linux.hh | 6 ++ src/sim/syscall_emul.hh | 123 ++++++++++++++++++++++++++++++++++------ 2 files changed, 111 insertions(+), 18 deletions(-) diff --git a/src/kern/linux/linux.hh b/src/kern/linux/linux.hh index 1fcd80444..5e929f1c0 100644 --- a/src/kern/linux/linux.hh +++ b/src/kern/linux/linux.hh @@ -227,6 +227,12 @@ class Linux : public OperatingSystem static const unsigned TGT_EWOULDBLOCK = TGT_EAGAIN; static const unsigned TGT_FUTEX_PRIVATE_FLAG = 128; + // for *at syscalls + static const int TGT_AT_FDCWD = -100; + + // for MREMAP + static const unsigned TGT_MREMAP_MAYMOVE = 0x1; + static const unsigned TGT_MREMAP_FIXED = 0x2; }; // class Linux #endif // __LINUX_HH__ diff --git a/src/sim/syscall_emul.hh b/src/sim/syscall_emul.hh index 364b66c0a..ac01ba1e8 100644 --- a/src/sim/syscall_emul.hh +++ b/src/sim/syscall_emul.hh @@ -1,4 +1,16 @@ /* + * Copyright (c) 2012-2013 ARM Limited + * All rights reserved + * + * The license below extends only to copyright in the software and shall + * not be construed as granting a license to any other intellectual + * property including but not limited to intellectual property relating + * to a hardware implementation of the functionality of the software + * licensed hereunder. You may use the software subject to the license + * terms below provided that you ensure that this notice is replicated + * unmodified and in its entirety in all distributions of the software, + * modified or unmodified, in source code or in binary form. + * * Copyright (c) 2003-2005 The Regents of The University of Michigan * All rights reserved. * @@ -600,15 +612,13 @@ ioctlFunc(SyscallDesc *desc, int callnum, LiveProcess *process, return -ENOTTY; } -/// Target open() handler. template -SyscallReturn +static SyscallReturn openFunc(SyscallDesc *desc, int callnum, LiveProcess *process, - ThreadContext *tc) + ThreadContext *tc, int index) { std::string path; - int index = 0; if (!tc->getMemProxy().tryReadString(path, process->getSyscallArg(tc, index))) return -EFAULT; @@ -664,6 +674,28 @@ openFunc(SyscallDesc *desc, int callnum, LiveProcess *process, return process->alloc_fd(fd, path.c_str(), hostFlags, mode, false); } +/// Target open() handler. +template +SyscallReturn +openFunc(SyscallDesc *desc, int callnum, LiveProcess *process, + ThreadContext *tc) +{ + return openFunc(desc, callnum, process, tc, 0); +} + +/// Target openat() handler. +template +SyscallReturn +openatFunc(SyscallDesc *desc, int callnum, LiveProcess *process, + ThreadContext *tc) +{ + int index = 0; + int dirfd = process->getSyscallArg(tc, index); + if (dirfd != OS::TGT_AT_FDCWD) + warn("openat: first argument not AT_FDCWD; unlikely to work"); + return openFunc(desc, callnum, process, tc, 1); +} + /// Target sysinfo() handler. template SyscallReturn @@ -752,40 +784,58 @@ mremapFunc(SyscallDesc *desc, int callnum, LiveProcess *process, ThreadContext * uint64_t old_length = process->getSyscallArg(tc, index); uint64_t new_length = process->getSyscallArg(tc, index); uint64_t flags = process->getSyscallArg(tc, index); + uint64_t provided_address = 0; + bool use_provided_address = flags & OS::TGT_MREMAP_FIXED; + + if (use_provided_address) + provided_address = process->getSyscallArg(tc, index); if ((start % TheISA::VMPageSize != 0) || - (new_length % TheISA::VMPageSize != 0)) { + (new_length % TheISA::VMPageSize != 0) || + (provided_address % TheISA::VMPageSize != 0)) { warn("mremap failing: arguments not page aligned"); return -EINVAL; } if (new_length > old_length) { - if ((start + old_length) == process->mmap_end) { + if ((start + old_length) == process->mmap_end && + (!use_provided_address || provided_address == start)) { uint64_t diff = new_length - old_length; process->allocateMem(process->mmap_end, diff); process->mmap_end += diff; return start; } else { - // sys/mman.h defined MREMAP_MAYMOVE - if (!(flags & 1)) { + if (!use_provided_address && !(flags & OS::TGT_MREMAP_MAYMOVE)) { warn("can't remap here and MREMAP_MAYMOVE flag not set\n"); return -ENOMEM; } else { - process->pTable->remap(start, old_length, process->mmap_end); - warn("mremapping to totally new vaddr %08p-%08p, adding %d\n", - process->mmap_end, process->mmap_end + new_length, new_length); - start = process->mmap_end; + uint64_t new_start = use_provided_address ? + provided_address : process->mmap_end; + process->pTable->remap(start, old_length, new_start); + warn("mremapping to new vaddr %08p-%08p, adding %d\n", + new_start, new_start + new_length, + new_length - old_length); // add on the remaining unallocated pages - process->allocateMem(start + old_length, - new_length - old_length); - process->mmap_end += new_length; - warn("returning %08p as start\n", start); - return start; + process->allocateMem(new_start + old_length, + new_length - old_length, + use_provided_address /* clobber */); + if (!use_provided_address) + process->mmap_end += new_length; + if (use_provided_address && + new_start + new_length > process->mmap_end) { + // something fishy going on here, at least notify the user + // @todo: increase mmap_end? + warn("mmap region limit exceeded with MREMAP_FIXED\n"); + } + warn("returning %08p as start\n", new_start); + return new_start; } } } else { + if (use_provided_address && provided_address != start) + process->pTable->remap(start, new_length, provided_address); process->pTable->unmap(start + new_length, old_length - new_length); - return start; + return use_provided_address ? provided_address : start; } } @@ -853,6 +903,43 @@ stat64Func(SyscallDesc *desc, int callnum, LiveProcess *process, } +/// Target fstatat64() handler. +template +SyscallReturn +fstatat64Func(SyscallDesc *desc, int callnum, LiveProcess *process, + ThreadContext *tc) +{ + int index = 0; + int dirfd = process->getSyscallArg(tc, index); + if (dirfd != OS::TGT_AT_FDCWD) + warn("openat: first argument not AT_FDCWD; unlikely to work"); + + std::string path; + if (!tc->getMemProxy().tryReadString(path, + process->getSyscallArg(tc, index))) + return -EFAULT; + Addr bufPtr = process->getSyscallArg(tc, index); + + // Adjust path for current working directory + path = process->fullPath(path); + +#if NO_STAT64 + struct stat hostBuf; + int result = stat(path.c_str(), &hostBuf); +#else + struct stat64 hostBuf; + int result = stat64(path.c_str(), &hostBuf); +#endif + + if (result < 0) + return -errno; + + copyOutStat64Buf(tc->getMemProxy(), bufPtr, &hostBuf); + + return 0; +} + + /// Target fstat64() handler. template SyscallReturn -- 2.30.2