diff --git a/sys/compat/linux/linux_mmap.c b/sys/compat/linux/linux_mmap.c index a8e790a29..c133c4af7 100644 --- a/sys/compat/linux/linux_mmap.c +++ b/sys/compat/linux/linux_mmap.c @@ -1,425 +1,458 @@ /*- * Copyright (c) 2004 Tim J. Robbins * Copyright (c) 2002 Doug Rabson * Copyright (c) 2000 Marcel Moolenaar * Copyright (c) 1994-1995 Søren Schmidt * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer * in this position and unchanged. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include +#if defined(__amd64__) +#include +#include +#elif defined(__i386__) +#include +#include +#elif defined(__aarch64__) +#include +#include +#endif #define STACK_SIZE (2 * 1024 * 1024) #define GUARD_SIZE (4 * PAGE_SIZE) #if defined(__amd64__) static void linux_fixup_prot(struct thread *td, int *prot); #endif static int linux_mmap_check_fp(struct file *fp, int flags, int prot, int maxprot) { /* Linux mmap() just fails for O_WRONLY files */ if ((fp->f_flag & FREAD) == 0) return (EACCES); return (0); } int linux_mmap_common(struct thread *td, uintptr_t addr, size_t len, int prot, int flags, int fd, off_t pos) { struct mmap_req mr, mr_fixed; struct proc *p = td->td_proc; struct vmspace *vms = td->td_proc->p_vmspace; int bsd_flags, error; LINUX_CTR6(mmap2, "0x%lx, %ld, %ld, 0x%08lx, %ld, 0x%lx", addr, len, prot, flags, fd, pos); error = 0; bsd_flags = 0; /* * Linux mmap(2): * You must specify exactly one of MAP_SHARED and MAP_PRIVATE */ if (!((flags & LINUX_MAP_SHARED) ^ (flags & LINUX_MAP_PRIVATE))) return (EINVAL); if (flags & LINUX_MAP_SHARED) bsd_flags |= MAP_SHARED; if (flags & LINUX_MAP_PRIVATE) bsd_flags |= MAP_PRIVATE; if (flags & LINUX_MAP_FIXED) bsd_flags |= MAP_FIXED; if (flags & LINUX_MAP_ANON) { /* Enforce pos to be on page boundary, then ignore. */ if ((pos & PAGE_MASK) != 0) return (EINVAL); pos = 0; bsd_flags |= MAP_ANON; } else bsd_flags |= MAP_NOSYNC; if (flags & LINUX_MAP_GROWSDOWN) bsd_flags |= MAP_STACK; #if defined(__amd64__) /* * According to the Linux mmap(2) man page, "MAP_32BIT flag * is ignored when MAP_FIXED is set." */ if ((flags & LINUX_MAP_32BIT) && (flags & LINUX_MAP_FIXED) == 0) bsd_flags |= MAP_32BIT; /* * PROT_READ, PROT_WRITE, or PROT_EXEC implies PROT_READ and PROT_EXEC * on Linux/i386 if the binary requires executable stack. * We do this only for IA32 emulation as on native i386 this is does not * make sense without PAE. * * XXX. Linux checks that the file system is not mounted with noexec. */ linux_fixup_prot(td, &prot); #endif /* Linux does not check file descriptor when MAP_ANONYMOUS is set. */ fd = (bsd_flags & MAP_ANON) ? -1 : fd; if (flags & LINUX_MAP_GROWSDOWN) { /* * The Linux MAP_GROWSDOWN option does not limit auto * growth of the region. Linux mmap with this option * takes as addr the initial BOS, and as len, the initial * region size. It can then grow down from addr without * limit. However, Linux threads has an implicit internal * limit to stack size of STACK_SIZE. Its just not * enforced explicitly in Linux. But, here we impose * a limit of (STACK_SIZE - GUARD_SIZE) on the stack * region, since we can do this with our mmap. * * Our mmap with MAP_STACK takes addr as the maximum * downsize limit on BOS, and as len the max size of * the region. It then maps the top SGROWSIZ bytes, * and auto grows the region down, up to the limit * in addr. * * If we don't use the MAP_STACK option, the effect * of this code is to allocate a stack region of a * fixed size of (STACK_SIZE - GUARD_SIZE). */ if ((caddr_t)addr + len > vms->vm_maxsaddr) { /* * Some Linux apps will attempt to mmap * thread stacks near the top of their * address space. If their TOS is greater * than vm_maxsaddr, vm_map_growstack() * will confuse the thread stack with the * process stack and deliver a SEGV if they * attempt to grow the thread stack past their * current stacksize rlimit. To avoid this, * adjust vm_maxsaddr upwards to reflect * the current stacksize rlimit rather * than the maximum possible stacksize. * It would be better to adjust the * mmap'ed region, but some apps do not check * mmap's return value. */ PROC_LOCK(p); vms->vm_maxsaddr = (char *)round_page(vms->vm_stacktop) - lim_cur_proc(p, RLIMIT_STACK); PROC_UNLOCK(p); } /* * This gives us our maximum stack size and a new BOS. * If we're using VM_STACK, then mmap will just map * the top SGROWSIZ bytes, and let the stack grow down * to the limit at BOS. If we're not using VM_STACK * we map the full stack, since we don't have a way * to autogrow it. */ if (len <= STACK_SIZE - GUARD_SIZE) { addr = addr - (STACK_SIZE - GUARD_SIZE - len); len = STACK_SIZE - GUARD_SIZE; } } /* * FreeBSD is free to ignore the address hint if MAP_FIXED wasn't * passed. However, some Linux applications, like the ART runtime, * depend on the hint. If the MAP_FIXED wasn't passed, but the * address is not zero, try with MAP_FIXED and MAP_EXCL first, * and fall back to the normal behaviour if that fails. */ mr = (struct mmap_req) { .mr_hint = addr, .mr_len = len, .mr_prot = prot, .mr_flags = bsd_flags, .mr_fd = fd, .mr_pos = pos, .mr_check_fp_fn = linux_mmap_check_fp, }; if (addr != 0 && (bsd_flags & MAP_FIXED) == 0 && (bsd_flags & MAP_EXCL) == 0) { mr_fixed = mr; mr_fixed.mr_flags |= MAP_FIXED | MAP_EXCL; error = kern_mmap(td, &mr_fixed); if (error == 0) goto out; } error = kern_mmap(td, &mr); out: LINUX_CTR2(mmap2, "return: %d (%p)", error, td->td_retval[0]); return (error); } int linux_mprotect_common(struct thread *td, uintptr_t addr, size_t len, int prot) { int flags = 0; /* XXX Ignore PROT_GROWSUP for now. */ prot &= ~LINUX_PROT_GROWSUP; if ((prot & ~(LINUX_PROT_GROWSDOWN | PROT_READ | PROT_WRITE | PROT_EXEC)) != 0) return (EINVAL); if ((prot & LINUX_PROT_GROWSDOWN) != 0) { prot &= ~LINUX_PROT_GROWSDOWN; flags |= VM_MAP_PROTECT_GROWSDOWN; } #if defined(__amd64__) linux_fixup_prot(td, &prot); #endif return (kern_mprotect(td, addr, len, prot, flags)); } /* * Implement Linux madvise(MADV_DONTNEED), which has unusual semantics: for * anonymous memory, pages in the range are immediately discarded. */ static int linux_madvise_dontneed(struct thread *td, vm_offset_t start, vm_offset_t end) { vm_map_t map; vm_map_entry_t entry; vm_object_t backing_object, object; vm_offset_t estart, eend; vm_pindex_t pstart, pend; int error; map = &td->td_proc->p_vmspace->vm_map; if (!vm_map_range_valid(map, start, end)) return (EINVAL); start = trunc_page(start); end = round_page(end); error = 0; vm_map_lock_read(map); if (!vm_map_lookup_entry(map, start, &entry)) entry = vm_map_entry_succ(entry); for (; entry->start < end; entry = vm_map_entry_succ(entry)) { if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) continue; if (entry->wired_count != 0) { error = EINVAL; break; } object = entry->object.vm_object; if (object == NULL) continue; if ((object->flags & (OBJ_UNMANAGED | OBJ_FICTITIOUS)) != 0) continue; pstart = OFF_TO_IDX(entry->offset); if (start > entry->start) { pstart += atop(start - entry->start); estart = start; } else { estart = entry->start; } pend = OFF_TO_IDX(entry->offset) + atop(entry->end - entry->start); if (entry->end > end) { pend -= atop(entry->end - end); eend = end; } else { eend = entry->end; } if ((object->flags & (OBJ_ANON | OBJ_ONEMAPPING)) == (OBJ_ANON | OBJ_ONEMAPPING)) { /* * Singly-mapped anonymous memory is discarded. This * does not match Linux's semantics when the object * belongs to a shadow chain of length > 1, since * subsequent faults may retrieve pages from an * intermediate anonymous object. However, handling * this case correctly introduces a fair bit of * complexity. */ VM_OBJECT_WLOCK(object); if ((object->flags & OBJ_ONEMAPPING) != 0) { vm_object_collapse(object); vm_object_page_remove(object, pstart, pend, 0); backing_object = object->backing_object; if (backing_object != NULL && (backing_object->flags & OBJ_ANON) != 0) linux_msg(td, "possibly incorrect MADV_DONTNEED"); VM_OBJECT_WUNLOCK(object); continue; } VM_OBJECT_WUNLOCK(object); } /* * Handle shared mappings. Remove them outright instead of * calling pmap_advise(), for consistency with Linux. */ pmap_remove(map->pmap, estart, eend); vm_object_madvise(object, pstart, pend, MADV_DONTNEED); } vm_map_unlock_read(map); return (error); } int linux_madvise_common(struct thread *td, uintptr_t addr, size_t len, int behav) { switch (behav) { case LINUX_MADV_NORMAL: return (kern_madvise(td, addr, len, MADV_NORMAL)); case LINUX_MADV_RANDOM: return (kern_madvise(td, addr, len, MADV_RANDOM)); case LINUX_MADV_SEQUENTIAL: return (kern_madvise(td, addr, len, MADV_SEQUENTIAL)); case LINUX_MADV_WILLNEED: return (kern_madvise(td, addr, len, MADV_WILLNEED)); case LINUX_MADV_DONTNEED: return (linux_madvise_dontneed(td, addr, addr + len)); case LINUX_MADV_FREE: return (kern_madvise(td, addr, len, MADV_FREE)); case LINUX_MADV_REMOVE: linux_msg(curthread, "unsupported madvise MADV_REMOVE"); return (EINVAL); case LINUX_MADV_DONTFORK: return (kern_minherit(td, addr, len, INHERIT_NONE)); case LINUX_MADV_DOFORK: return (kern_minherit(td, addr, len, INHERIT_COPY)); case LINUX_MADV_MERGEABLE: linux_msg(curthread, "unsupported madvise MADV_MERGEABLE"); return (EINVAL); case LINUX_MADV_UNMERGEABLE: /* We don't merge anyway. */ return (0); case LINUX_MADV_HUGEPAGE: /* Ignored; on FreeBSD huge pages are always on. */ return (0); case LINUX_MADV_NOHUGEPAGE: #if 0 /* * Don't warn - Firefox uses it a lot, and in real Linux it's * an optional feature. */ linux_msg(curthread, "unsupported madvise MADV_NOHUGEPAGE"); #endif return (EINVAL); case LINUX_MADV_DONTDUMP: return (kern_madvise(td, addr, len, MADV_NOCORE)); case LINUX_MADV_DODUMP: return (kern_madvise(td, addr, len, MADV_CORE)); case LINUX_MADV_WIPEONFORK: return (kern_minherit(td, addr, len, INHERIT_ZERO)); case LINUX_MADV_KEEPONFORK: return (kern_minherit(td, addr, len, INHERIT_COPY)); case LINUX_MADV_HWPOISON: linux_msg(curthread, "unsupported madvise MADV_HWPOISON"); return (EINVAL); case LINUX_MADV_SOFT_OFFLINE: linux_msg(curthread, "unsupported madvise MADV_SOFT_OFFLINE"); return (EINVAL); case -1: /* * -1 is sometimes used as a dummy value to detect simplistic * madvise(2) stub implementations. This safeguard is used by * BoringSSL, for example, before assuming MADV_WIPEONFORK is * safe to use. Don't produce an "unsupported" error message * for this special dummy value, which is unlikely to be used * by any new advisory behavior feature. */ return (EINVAL); default: linux_msg(curthread, "unsupported madvise behav %d", behav); return (EINVAL); } } #if defined(__amd64__) static void linux_fixup_prot(struct thread *td, int *prot) { struct linux_pemuldata *pem; if (SV_PROC_FLAG(td->td_proc, SV_ILP32) && *prot & PROT_READ) { pem = pem_find(td->td_proc); if (pem->persona & LINUX_READ_IMPLIES_EXEC) *prot |= PROT_EXEC; } } #endif + +int +linux_munmap(struct thread *td, struct linux_munmap_args *args) +{ + size_t length; + + /* Linux requires addresses to be page aligned */ + if ((uintptr_t)args->addr & PAGE_MASK) + return (EINVAL); + + /* Check to see if len is 0, this is the EXACT + * same operation linux does to check to see + * if len is 0. + * Citing linux/mm/vma.c + */ + if(args->len == 0) + return (EINVAL); + + /* round up to next page boundary */ + length = roundup2(args->len, PAGE_SIZE); + + return (kern_munmap(td, (uintptr_t) args->addr, length)); +}