X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/b0d623f7f2ae71ed96e60569f61f9a9a27016e80..0a7de7458d150b5d4dffc935ba399be265ef0a1a:/bsd/dev/dtrace/dtrace_ptss.c diff --git a/bsd/dev/dtrace/dtrace_ptss.c b/bsd/dev/dtrace/dtrace_ptss.c index 9c75c3f1f..b2cc59819 100644 --- a/bsd/dev/dtrace/dtrace_ptss.c +++ b/bsd/dev/dtrace/dtrace_ptss.c @@ -2,7 +2,7 @@ * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ - * + * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in @@ -11,10 +11,10 @@ * unlawful or unlicensed copies of an Apple operating system, or to * circumvent, violate, or enable the circumvention or violation of, any * terms of an Apple operating system software license agreement. - * + * * Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this file. - * + * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, @@ -22,7 +22,7 @@ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. - * + * * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ @@ -33,6 +33,7 @@ #include #include +#include #include #include @@ -47,8 +48,9 @@ * page of memory, the underlying kernel _MALLOC may block. */ struct dtrace_ptss_page_entry* -dtrace_ptss_claim_entry_locked(struct proc* p) { - lck_mtx_assert(&p->p_dtrace_sprlock, LCK_MTX_ASSERT_OWNED); +dtrace_ptss_claim_entry_locked(struct proc* p) +{ + LCK_MTX_ASSERT(&p->p_dtrace_sprlock, LCK_MTX_ASSERT_OWNED); struct dtrace_ptss_page_entry* entry = NULL; @@ -60,8 +62,9 @@ dtrace_ptss_claim_entry_locked(struct proc* p) { struct dtrace_ptss_page* page = dtrace_ptss_allocate_page(p); // Make sure we actually got a page - if (page == NULL) + if (page == NULL) { return NULL; + } // Add the page to the page list page->next = p->p_dtrace_ptss_pages; @@ -69,18 +72,19 @@ dtrace_ptss_claim_entry_locked(struct proc* p) { // CAS the entries onto the free list. do { - page->entries[DTRACE_PTSS_ENTRIES_PER_PAGE-1].next = p->p_dtrace_ptss_free_list; - } while (!OSCompareAndSwapPtr((void *)page->entries[DTRACE_PTSS_ENTRIES_PER_PAGE-1].next, - (void *)&page->entries[0], - (void * volatile *)&p->p_dtrace_ptss_free_list)); - + page->entries[DTRACE_PTSS_ENTRIES_PER_PAGE - 1].next = p->p_dtrace_ptss_free_list; + } while (!OSCompareAndSwapPtr((void *)page->entries[DTRACE_PTSS_ENTRIES_PER_PAGE - 1].next, + (void *)&page->entries[0], + (void * volatile *)&p->p_dtrace_ptss_free_list)); + // Now that we've added to the free list, try again. continue; } // Claim temp - if (!OSCompareAndSwapPtr((void *)temp, (void *)temp->next, (void * volatile *)&p->p_dtrace_ptss_free_list)) + if (!OSCompareAndSwapPtr((void *)temp, (void *)temp->next, (void * volatile *)&p->p_dtrace_ptss_free_list)) { continue; + } // At this point, we own temp. entry = temp; @@ -95,10 +99,11 @@ dtrace_ptss_claim_entry_locked(struct proc* p) { * This function does not require any locks to be held on entry. */ struct dtrace_ptss_page_entry* -dtrace_ptss_claim_entry(struct proc* p) { +dtrace_ptss_claim_entry(struct proc* p) +{ // Verify no locks held on entry - lck_mtx_assert(&p->p_dtrace_sprlock, LCK_MTX_ASSERT_NOTOWNED); - lck_mtx_assert(&p->p_mlock, LCK_MTX_ASSERT_NOTOWNED); + LCK_MTX_ASSERT(&p->p_dtrace_sprlock, LCK_MTX_ASSERT_NOTOWNED); + LCK_MTX_ASSERT(&p->p_mlock, LCK_MTX_ASSERT_NOTOWNED); struct dtrace_ptss_page_entry* entry = NULL; @@ -113,8 +118,9 @@ dtrace_ptss_claim_entry(struct proc* p) { } // Claim temp - if (!OSCompareAndSwapPtr((void *)temp, (void *)temp->next, (void * volatile *)&p->p_dtrace_ptss_free_list)) + if (!OSCompareAndSwapPtr((void *)temp, (void *)temp->next, (void * volatile *)&p->p_dtrace_ptss_free_list)) { continue; + } // At this point, we own temp. entry = temp; @@ -127,10 +133,15 @@ dtrace_ptss_claim_entry(struct proc* p) { /* * This function does not require any locks to be held on entry. + * + * (PR-11138709) A NULL p->p_dtrace_ptss_pages means the entry can + * no longer be referenced safely. When found in this state, the chore + * of releasing an entry to the free list is ignored. */ void -dtrace_ptss_release_entry(struct proc* p, struct dtrace_ptss_page_entry* e) { - if (p && e) { +dtrace_ptss_release_entry(struct proc* p, struct dtrace_ptss_page_entry* e) +{ + if (p && p->p_dtrace_ptss_pages && e) { do { e->next = p->p_dtrace_ptss_free_list; } while (!OSCompareAndSwapPtr((void *)e->next, (void *)e, (void * volatile *)&p->p_dtrace_ptss_free_list)); @@ -139,7 +150,7 @@ dtrace_ptss_release_entry(struct proc* p, struct dtrace_ptss_page_entry* e) { /* * This function allocates a new page in the target process's address space. - * + * * It returns a dtrace_ptss_page that has its entries chained, with the last * entries next field set to NULL. It does not add the page or the entries to * the process's page/entry lists. @@ -151,47 +162,55 @@ dtrace_ptss_allocate_page(struct proc* p) { // Allocate the kernel side data struct dtrace_ptss_page* ptss_page = _MALLOC(sizeof(struct dtrace_ptss_page), M_TEMP, M_ZERO | M_WAITOK); - if (ptss_page == NULL) + if (ptss_page == NULL) { return NULL; + } // Now allocate a page in user space and set its protections to allow execute. task_t task = p->task; vm_map_t map = get_task_map_reference(task); + if (map == NULL) { + goto err; + } - mach_vm_address_t addr = 0LL; - mach_vm_size_t size = PAGE_SIZE; // We need some way to assert that this matches vm_map_round_page() !!! + mach_vm_size_t size = PAGE_MAX_SIZE; + mach_vm_offset_t addr = 0; + mach_vm_offset_t write_addr = 0; + /* + * The embedded OS has extra permissions for writable and executable pages. + * To ensure correct permissions, we must set the page protections separately. + */ + vm_prot_t cur_protection = VM_PROT_READ | VM_PROT_EXECUTE; + vm_prot_t max_protection = VM_PROT_READ | VM_PROT_EXECUTE | VM_PROT_WRITE; -#if CONFIG_EMBEDDED - /* The embedded OS has extra permissions for writable and executable pages. We can't pass in the flags - * we need for the correct permissions from mach_vm_allocate, so need to call mach_vm_map directly. */ - vm_map_offset_t map_addr = 0; - kern_return_t kr = mach_vm_map(map, &map_addr, size, 0, VM_FLAGS_ANYWHERE, IPC_PORT_NULL, 0, FALSE, VM_PROT_READ|VM_PROT_EXECUTE, VM_PROT_READ|VM_PROT_EXECUTE, VM_INHERIT_DEFAULT); + kern_return_t kr = mach_vm_map_kernel(map, &addr, size, 0, VM_FLAGS_ANYWHERE, VM_MAP_KERNEL_FLAGS_NONE, VM_KERN_MEMORY_NONE, IPC_PORT_NULL, 0, FALSE, cur_protection, max_protection, VM_INHERIT_DEFAULT); if (kr != KERN_SUCCESS) { goto err; } - addr = map_addr; -#else - kern_return_t kr = mach_vm_allocate(map, &addr, size, VM_FLAGS_ANYWHERE); - if (kr != KERN_SUCCESS) { + /* + * If on embedded, remap the scratch space as writable at another + * virtual address + */ + kr = mach_vm_remap_kernel(map, &write_addr, size, 0, VM_FLAGS_ANYWHERE, VM_KERN_MEMORY_NONE, map, addr, FALSE, &cur_protection, &max_protection, VM_INHERIT_DEFAULT); + if (kr != KERN_SUCCESS || !(max_protection & VM_PROT_WRITE)) { goto err; } - kr = mach_vm_protect(map, addr, size, 0, VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE); + kr = mach_vm_protect(map, (mach_vm_offset_t)write_addr, (mach_vm_size_t)size, 0, VM_PROT_READ | VM_PROT_WRITE); if (kr != KERN_SUCCESS) { - mach_vm_deallocate(map, addr, size); goto err; - } -#endif + } // Chain the page entries. int i; - for (i=0; ientries[i].addr = addr + (i * DTRACE_PTSS_SCRATCH_SPACE_PER_THREAD); - ptss_page->entries[i].next = &ptss_page->entries[i+1]; + ptss_page->entries[i].write_addr = write_addr + (i * DTRACE_PTSS_SCRATCH_SPACE_PER_THREAD); + ptss_page->entries[i].next = &ptss_page->entries[i + 1]; } // The last entry should point to NULL - ptss_page->entries[DTRACE_PTSS_ENTRIES_PER_PAGE-1].next = NULL; + ptss_page->entries[DTRACE_PTSS_ENTRIES_PER_PAGE - 1].next = NULL; vm_map_deallocate(map); @@ -200,14 +219,16 @@ dtrace_ptss_allocate_page(struct proc* p) err: _FREE(ptss_page, M_TEMP); - vm_map_deallocate(map); + if (map) { + vm_map_deallocate(map); + } return NULL; } /* * This function frees an existing page in the target process's address space. - * + * * It does not alter any of the process's page/entry lists. * * TODO: Inline in dtrace_ptrace_exec_exit? @@ -225,17 +246,21 @@ dtrace_ptss_free_page(struct proc* p, struct dtrace_ptss_page* ptss_page) // Silent failures, no point in checking return code. mach_vm_deallocate(map, addr, size); + mach_vm_address_t write_addr = ptss_page->entries[0].write_addr; + mach_vm_deallocate(map, write_addr, size); + vm_map_deallocate(map); } /* * This function assumes that the target process has been - * suspended, and the proc_lock & sprlock is held + * suspended, and the proc_lock & sprlock is held */ void -dtrace_ptss_enable(struct proc* p) { - lck_mtx_assert(&p->p_dtrace_sprlock, LCK_MTX_ASSERT_OWNED); - lck_mtx_assert(&p->p_mlock, LCK_MTX_ASSERT_OWNED); +dtrace_ptss_enable(struct proc* p) +{ + LCK_MTX_ASSERT(&p->p_dtrace_sprlock, LCK_MTX_ASSERT_OWNED); + LCK_MTX_ASSERT(&p->p_mlock, LCK_MTX_ASSERT_OWNED); struct uthread* uth; /* @@ -254,13 +279,14 @@ dtrace_ptss_enable(struct proc* p) { * It assumes the sprlock is held, and the proc_lock is not. */ void -dtrace_ptss_exec_exit(struct proc* p) { +dtrace_ptss_exec_exit(struct proc* p) +{ /* * Should hold sprlock to touch the pages list. Must not * hold the proc lock to avoid deadlock. */ - lck_mtx_assert(&p->p_dtrace_sprlock, LCK_MTX_ASSERT_OWNED); - lck_mtx_assert(&p->p_mlock, LCK_MTX_ASSERT_NOTOWNED); + LCK_MTX_ASSERT(&p->p_dtrace_sprlock, LCK_MTX_ASSERT_OWNED); + LCK_MTX_ASSERT(&p->p_mlock, LCK_MTX_ASSERT_NOTOWNED); p->p_dtrace_ptss_free_list = NULL; @@ -269,11 +295,11 @@ dtrace_ptss_exec_exit(struct proc* p) { while (temp != NULL) { struct dtrace_ptss_page* next = temp->next; - + // Do we need to specifically mach_vm_deallocate the user pages? // This can be called when the process is exiting, I believe the proc's // vm_map_t may already be toast. - + // Must be certain to free the kernel memory! _FREE(temp, M_TEMP); temp = next; @@ -290,7 +316,8 @@ dtrace_ptss_exec_exit(struct proc* p) { * Parent and child sprlock should be held, and proc_lock must NOT be held. */ void -dtrace_ptss_fork(struct proc* parent, struct proc* child) { +dtrace_ptss_fork(struct proc* parent, struct proc* child) +{ // The child should not have any pages/entries allocated at this point. // ASSERT(child->p_dtrace_ptss_pages == NULL); // ASSERT(child->p_dtrace_ptss_free_list == NULL); @@ -302,15 +329,15 @@ dtrace_ptss_fork(struct proc* parent, struct proc* child) { * Finally, to prevent a deadlock with the fasttrap cleanup code, * neither the parent or child proc_lock should be held. */ - lck_mtx_assert(&parent->p_dtrace_sprlock, LCK_MTX_ASSERT_OWNED); - lck_mtx_assert(&parent->p_mlock, LCK_MTX_ASSERT_NOTOWNED); - lck_mtx_assert(&child->p_dtrace_sprlock, LCK_MTX_ASSERT_OWNED); - lck_mtx_assert(&child->p_mlock, LCK_MTX_ASSERT_NOTOWNED); + LCK_MTX_ASSERT(&parent->p_dtrace_sprlock, LCK_MTX_ASSERT_OWNED); + LCK_MTX_ASSERT(&parent->p_mlock, LCK_MTX_ASSERT_NOTOWNED); + LCK_MTX_ASSERT(&child->p_dtrace_sprlock, LCK_MTX_ASSERT_OWNED); + LCK_MTX_ASSERT(&child->p_mlock, LCK_MTX_ASSERT_NOTOWNED); // Get page list from *PARENT* struct dtrace_ptss_page* temp = parent->p_dtrace_ptss_pages; - while (temp != NULL) { + while (temp != NULL) { // Freeing the page in the *CHILD* dtrace_ptss_free_page(child, temp);